[Federal Register Volume 77, Number 243 (Tuesday, December 18, 2012)]
[Proposed Rules]
[Pages 74923-74985]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-30117]



[[Page 74923]]

Vol. 77

Tuesday,

No. 243

December 18, 2012

Part II





Environmental Protection Agency





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40 CFR Part 131





Water Quality Standards for the State of Florida's Estuaries, Coastal 
Waters, and South Florida Inland Flowing Waters; Water Quality 
Standards for the State of Florida's Streams and Downstream Protection 
Values for Lakes: Remanded Provisions; Proposed Rules

Federal Register / Vol. 77, No. 243 / Tuesday, December 18, 2012 / 
Proposed Rules

[[Page 74924]]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 131

[EPA-HQ-OW-2010-0222; FRL-9759-3]
RIN 2040-AF21


Water Quality Standards for the State of Florida's Estuaries, 
Coastal Waters, and South Florida Inland Flowing Waters

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The U.S. Environmental Protection Agency (EPA or Agency) is 
proposing numeric water quality criteria to protect ecological systems, 
aquatic life, and human health from nitrogen and phosphorus pollution 
in estuaries and coastal waters within the State of Florida not covered 
by EPA-approved State rulemaking, and south Florida inland flowing 
waters. These proposed criteria apply to Florida waters that are 
designated as Class I, Class II, or Class III waters and they are 
intended to protect these designated uses as well as implement for the 
purposes of the Clean Water Act the State's narrative nutrient 
provision at Subsection 62-302.530(47)(b), Florida Administrative Code 
(F.A.C.), which provides that ``[i]n no case shall nutrient 
concentrations of a body of water be altered so as to cause an 
imbalance in natural populations of aquatic flora or fauna.''

DATES: Comments must be received on or before February 19, 2013. 
Because of EPA's obligation to sign a notice of final rulemaking on or 
before September 30, 2013 under Consent Decree, the Agency regrets that 
it will be unable to grant any requests to extend this deadline.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-OW-
2010-0222, by one of the following methods:
    1. www.regulations.gov: Follow the on-line instructions for 
submitting comments.
    2. Email: ow-docket@epa.gov.
    3. Mail to: Water Docket, U.S. Environmental Protection Agency, 
Mail code: 2822T, 1200 Pennsylvania Avenue NW, Washington, DC 20460, 
Attention: Docket ID No. EPA-HQ-OW-2010-0222.
    4. Hand Delivery: EPA Docket Center, EPA West Room 3334, 1301 
Constitution Avenue NW, Washington, DC 20004, Attention Docket ID No. 
EPA-HQ-OW-2010-0222. Such deliveries are only accepted during the 
Docket's normal hours of operation, and special arrangements should be 
made for deliveries of boxed information.
    Instructions: Direct your comments to Docket ID No. EPA-HQ-OW-2010-
0222. EPA's policy is that all comments received will be included in 
the public docket without change and may be made available online at 
www.regulations.gov, including any personal information provided, 
unless the comment includes information claimed to be Confidential 
Business Information (CBI) or other information whose disclosure is 
restricted by statute. Do not submit information that you consider to 
be CBI or otherwise protected through www.regulations.gov or email. The 
www.regulations.gov Web site is an ``anonymous access'' system, which 
means EPA will not know your identity or contact information unless you 
provide it in the body of your comment. If you submit an electronic 
comment, EPA recommends that you include your name and other contact 
information in the body of your comment and with any disk or CD-ROM you 
submit. If EPA cannot read your comment due to technical difficulties 
and cannot contact you for clarification, EPA may not be able to 
consider your comment. Electronic files should avoid the use of special 
characters, any form of encryption, and be free of any defects or 
viruses. For additional information about EPA's public docket visit the 
EPA Docket Center homepage at http://www.epa.gov/epahome/dockets.htm.
    Docket: All documents in the docket are listed in the 
www.regulations.gov index. Although listed in the index, some 
information is not publicly available, e.g., CBI or other information 
whose disclosure is restricted by statute. Certain other material, such 
as copyrighted material, will be publicly available only in hard copy. 
Publicly available docket materials are available either electronically 
in www.regulations.gov or in hard copy at a docket facility. The Office 
of Water (OW) Docket Center is open from 8:30 a.m. until 4:30 p.m., 
Monday through Friday, excluding legal holidays. The OW Docket Center 
telephone number is (202) 566-2426, and the Docket address is OW 
Docket, EPA West, Room 3334, 1301 Constitution Avenue NW., Washington, 
DC 20004. The Public Reading Room is open from 8:30 a.m. to 4:30 p.m., 
Monday through Friday, excluding legal holidays. The telephone number 
for the Public Reading Room is (202) 566-1744.

FOR FURTHER INFORMATION CONTACT: Erica Fleisig, U.S. EPA Headquarters, 
Office of Water, Mailcode: 4305T, 1200 Pennsylvania Avenue NW, 
Washington, DC 20460; telephone number: (202) 566-1057; email address: 
fleisig.erica@epa.gov.

SUPPLEMENTARY INFORMATION: This supplementary information section is 
organized as follows:

Table of Contents

I. General Information
    A. Executive Summary
    B. Which water bodies are affected by this rule?
    C. What entities may be affected by this rule?
    D. What should I consider as I prepare my comments for EPA?
    E. How can I get copies of this document and other related 
information?
II. Background
    A. Nitrogen and Phosphorus Pollution
    B. Statutory and Regulatory Background
    C. Water Quality Criteria
    D. EPA Determination Regarding Florida and Consent Decree
    E. EPA's Rulemaking and Subsequent Litigation
    F. Florida Adoption of Numeric Nutrient Criteria and EPA 
Approval
III. Proposed Numeric Criteria for Florida's Estuaries, Coastal 
Waters, and South Florida Inland Flowing Waters
    A. General Information and Approaches
    B. Proposed Numeric Criteria for Estuaries
    C. Proposed Numeric Criteria for Coastal Waters
    D. Proposed Numeric Criteria for South Florida Inland Flowing 
Waters
    E. Applicability of Criteria When Final
IV. Under what conditions will EPA either not finalize or withdraw 
these Federal standards?
V. Alternative Regulatory Approaches and Implementation Mechanisms
    A. Designating Uses
    B. Variances
    C. Site-Specific Alternative Criteria
    D. Compliance Schedules
VI. Economic Analysis
    A. Incrementally Impaired Waters
    B. Point Source Costs
    C. Non-Point Source Costs
    D. Governmental Costs
    E. Summary of Costs
    F. Benefits
VII. Statutory and Executive Order Reviews
    A. Executive Orders 12866 (Regulatory Planning and Review) and 
13563 (Improving Regulation and Regulatory Review)
    B. Paperwork Reduction Act
    C. Regulatory Flexibility Act
    D. Unfunded Mandates Reform Act
    E. Executive Order 13132 (Federalism)
    F. Executive Order 13175 (Consultation and Coordination With 
Indian Tribal Governments)
    G. Executive Order 13045 (Protection of Children From 
Environmental Health and Safety Risks)
    H. Executive Order 13211 (Actions That Significantly Affect 
Energy Supply, Distribution, or Use)
    I. National Technology Transfer Advancement Act of 1995
    J. Executive Order 12898 (Federal Actions To Address 
Environmental Justice in

[[Page 74925]]

Minority Populations and Low-Income Populations)

I. General Information

A. Executive Summary

1. Purpose of the Regulatory Action
    The primary purpose of this rule is to propose numeric water 
quality criteria to protect ecological systems, aquatic life, and human 
health within the State of Florida from nitrogen and phosphorus 
pollution. The criteria proposed in this rule apply to certain 
estuaries and coastal waters within the State of Florida and south 
Florida inland flowing waters (e.g., rivers, streams, canals),\1\ with 
the exception of waters within the lands of the Miccosukee and Seminole 
Tribes, the Everglades Agricultural Area (EAA), and the Everglades 
Protection Area (EvPA).\2\
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    \1\ EPA has distinguished south Florida inland flowing waters as 
waters in the South Florida Nutrient Watershed Region (SFNWR). The 
SFNWR was defined previously in EPA's final rule for lakes and 
flowing waters as the area south of Lake Okeechobee, the 
Caloosahatchee River watershed (including Estero Bay) to the west of 
Lake Okeechobee, and the St. Lucie watershed to the east of Lake 
Okeechobee.
    \2\ FL Statute Section 373.4592 (1994) subsection (2) 
Definitions: (e) ``Everglades Agricultural Area'' or ``EAA'' means 
the Everglades Agricultural Area, which are those lands described in 
FL Statute Section 373.4592 (1994) subsection (15). FL Statute 
Section 373.4592 (1994) subsection (2) Definitions: (h) ``Everglades 
Protection Area'' means Water Conservation Areas 1 (which includes 
the Arthur R. Marshall Loxahatchee National Wildlife Refuge), 2A, 
2B, 3A, and 3B, and the Everglades National Park.
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    The criteria support implementation of pollution control programs 
authorized under the Clean Water Act (CWA). As part of a comprehensive 
program to restore and protect the Nation's waters, Section 303(c) of 
the CWA directs states to adopt water quality standards for their 
navigable waters. CWA Section 303(c)(2)(A) and EPA's implementing 
regulations at 40 CFR 131 require that state water quality standards 
include the designated use (e.g. public water supply, propagation of 
fish and wildlife, recreational purposes) and criteria that protect 
those uses. Criteria may be numeric or narrative in form, but 
consistent with EPA regulations at 40 CFR 131.11(a)(1), such criteria 
``must be based on sound scientific rationale and must contain 
sufficient parameters or constituents to protect the designated use.'' 
EPA regulations at 40 CFR 131.10(b) also provide that ``[i]n 
designating uses of a water body and the appropriate criteria for those 
uses, the state shall take into consideration the water quality 
standards of downstream waters and ensure that its water quality 
standards provide for the attainment and maintenance of the water 
quality standards of downstream waters.'' The CWA requires that any new 
or revised water quality standards developed by states be submitted to 
EPA for review and approval or disapproval, and authorizes the EPA 
Administrator to determine, even in the absence of a state submission, 
that a new or revised standard is needed to meet CWA requirements.
    Florida is known for its abundant and aesthetically beautiful 
natural resources, particularly its aquatic resources, which are very 
important to Florida's economy. Florida's coastal and estuarine waters 
play an especially important part in sustaining the environment and the 
economy in the State. For example, Florida's saltwater sport fishing 
industry contributes over $5 billion to the State's economy and more 
than 54,000 jobs annually; the State's commercial saltwater fishing 
industry contributes over $1 billion and more than 10,000 jobs 
annually.\3\ In 2007, nearly 11.3 million residents and 46.3 million 
visitors participated in recreational saltwater beach activities in 
Florida. Nearly 3.5 million residents and approximately 1.4 million 
visitors used saltwater boat ramps, over 4.2 million residents and 
about 3 million visitors participated in saltwater non-boat fishing, 
and over 2.6 million residents and almost 1 million visitors 
participated in canoeing and kayaking.\4\
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    \3\ FFWCC. 2011. The economic impact of saltwater fishing in 
Florida. Florida Fish and Wildlife Conservation Commission. http://myfwc.com/conservation/value/saltwater-fishing. Accessed December 
2011.
    \4\ FDEP. 2008. Chapter 5--Outdoor Recreation Demand and Need. 
In Outdoor Recreation in Florida, 2008: Florida's Comprehensive 
Outdoor Recreation Plan, Final Draft. Florida Department of 
Environmental Protection, Division of Recreation and Parks, 
Tallahassee, FL. http://www.dep.state.fl.us/parks/planning/forms/SCORP5.pdf. Accessed December 2011.
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    However, nitrogen and phosphorus pollution has contributed to 
serious water quality degradation affecting these coastal and estuarine 
resources in the State of Florida, as well as other Florida waters. In 
the most recent Florida Department of Environmental Protection (FDEP) 
water quality assessment report, the Integrated Water Quality 
Assessment for Florida: 2012 305(b) Report and 303(d) List Update, FDEP 
describes widespread water quality impairment in Florida due to 
nitrogen and phosphorus pollution. FDEP's 2012 report identifies 
approximately 754 square miles (482,560 acres) of estuaries (about 14 
percent of assessed estuarine area) and 102 square miles (65,280 acres) 
of coastal waters (about 1.6 percent of assessed coastal waters) as 
impaired by nutrients. In addition, the same report indicates that 
1,108 miles of rivers and streams (about 8 percent of assessed river 
and stream miles) and 107 square miles (68,480 acres) of lakes (about 5 
percent of assessed lake square miles) are impaired due to nutrient 
pollution.\5\
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    \5\ FDEP. 2012. Integrated Water Quality Assessment for Florida: 
2012 305(b) Report and 303(d) List Update. (May 2012). Florida 
Department of Environmental Protection, Division of Environmental 
Assessment and Restoration, Tallahassee, FL. http://www.dep.state.fl.us/water/docs/2012_integrated_report.pdf. 
Accessed August 2012.
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    On January 14, 2009, EPA determined under CWA section 303(c)(4)(B) 
that new or revised water quality standards (WQS) in the form of 
numeric nutrient water quality criteria are necessary to protect the 
designated uses that Florida has set for its Class I, Class II, and 
Class III waters. Subsequently, EPA entered into a Consent Decree with 
Florida Wildlife Federation, Sierra Club, Conservancy of Southwest 
Florida, Environmental Confederation of Southwest Florida, and St. 
Johns Riverkeeper, effective on December 30, 2009, which established a 
schedule for EPA to propose and promulgate numeric nutrient criteria 
for Florida's lakes, flowing waters, estuaries, and coastal waters. The 
Consent Decree also provided that if Florida submitted and EPA approved 
numeric nutrient criteria for any relevant waterbodies before the dates 
outlined in the schedule, EPA would no longer be obligated to propose 
or promulgate criteria for those waterbodies.
    On June 13, 2012, FDEP submitted new and revised WQS for review by 
the EPA pursuant to section 303(c) of the CWA. These new and revised 
WQS are set out primarily in Rule 62-302 of the F.A.C. [Surface Water 
Quality Standards]. FDEP also submitted amendments to Rule 62-303, 
F.A.C. [Identification of Impaired Surface Waters], which sets out 
Florida's methodology for assessing whether waters are attaining State 
WQS. On November 30, 2012, EPA approved the provisions of these rules 
submitted for review that constitute new or revised WQS (hereafter 
referred to as the ``newly-approved State WQS'').
    Among the newly-approved State WQS are numeric criteria for 
nutrients that apply to a set of estuaries and coastal marine waters in 
Florida. Specifically, these newly-approved State WQS apply to 
Clearwater Harbor/St. Joseph Sound, Tampa Bay, Sarasota Bay, Charlotte 
Harbor/Estero Bay, Clam Bay, Tidal Cocohatchee River/Ten Thousand 
Islands, Florida Bay, Florida

[[Page 74926]]

Keys, and Biscayne Bay.\6\ Under the Consent Decree, EPA is relieved of 
its obligation to propose numeric criteria for these waters.
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    \6\ Clam Bay, Tidal Cocohatchee River/Ten Thousand Islands, 
Florida Bay, Florida Keys, and Biscayne Bay are collectively 
referred to in this proposed rule as ``south Florida marine 
waters,'' as these are the predominantly marine waters downstream of 
the South Florida Nutrient Watershed Region.
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    Finally, as described in EPA's November 30, 2012 approval of 
Florida's new or revised WQS, while EPA believes that the provisions 
addressing downstream protection will provide for quantitative 
approaches to ensure the attainment and maintenance of downstream 
waters consistent with 40 CFR 131.10(b), the provisions themselves do 
not consist of numeric values. Because EPA is currently subject to a 
Consent Decree deadline to sign a rule proposing numeric downstream 
protection values (DPVs) for Florida by November 30, 2012, EPA is 
proposing numeric DPVs to comply with the Consent Decree. However, EPA 
has amended its January 2009 determination to specify that numeric 
criteria for downstream protection are not necessary and that 
quantitative approaches designed to ensure the attainment and 
maintenance of downstream water quality standards, such as those 
established by Florida, are sufficient to meet CWA requirements. As 
such, EPA will ask the court to modify the Consent Decree consistent 
with the Agency's amended determination, i.e., to not require EPA to 
promulgate numeric DPVs for Florida. Accordingly, EPA approved the 
State's downstream protection provisions subject to the district court 
modifying the Consent Decree to not require EPA to promulgate numeric 
DPVs for Florida. If the district court agrees to so modify the Consent 
Decree, EPA will not promulgate numeric DPVs for Florida. However, if 
the district court declines to so modify the Consent Decree, EPA would 
intend to promulgate numeric DPVs for Florida and would also expect to 
revisit its November 30, 2012 approval of the State Rule's downstream 
protection provisions to modify or withdraw its approval. Therefore, 
EPA has also reserved its authority to do so in its approval document.
    A full description of all of EPA's recent actions on Florida 
numeric nutrient criteria and related implications for EPA's own rules 
can be found at http://water.epa.gov/lawsregs/rulesregs/florida_index.cfm.
    EPA is proposing these numeric criteria in accordance with the 
terms of the January 14, 2009 determination, December 2009 Consent 
Decree, and subsequent revisions to that Consent Decree that require 
the EPA Administrator to sign this proposal by November 30, 2012 
(discussed in more detail in Section II.D). EPA believes that the 
proposed criteria in this rule will assure protection of Florida's 
existing designated uses and are based on sound and substantial 
scientific data and analyses.
2. Summary of the Major Provisions of the Regulatory Action
    To develop these proposed numeric nutrient criteria for Florida's 
estuaries, coastal waters, and south Florida inland flowing waters, the 
Agency conducted a detailed scientific analysis of the substantial 
amount of water quality data available from Florida's extensive 
monitoring data set.
    EPA concluded that an approach using relevant biological endpoints 
and multiple lines of evidence including stressor-response analyses and 
mechanistic modeling was a strong and scientifically sound approach for 
deriving numeric nutrient criteria for estuaries, in the form of total 
nitrogen (TN), total phosphorus (TP) and chlorophyll a concentrations. 
EPA's methodology and the resulting proposed estuarine numeric nutrient 
criteria are presented in more detail in Section III.B of this notice 
of proposed rulemaking.
    For coastal waters on the Atlantic and Gulf coasts of Florida, EPA 
is proposing to use a reference condition-based approach. EPA chose to 
use satellite remote sensing in all coastal areas of Florida except the 
Big Bend Coastal region. Using this approach, EPA developed chlorophyll 
a criteria from satellite remote sensing imagery and field data to 
calibrate the satellite remote sensing imagery. In the Big Bend Coastal 
region of Florida,\7\ where satellite remote sensing predictions of 
chlorophyll a were not possible due to reflectance that interferes with 
the remote sensing imagery in that area, EPA used mechanistic and 
statistical models to determine TN, TP, and chlorophyll a criteria for 
these coastal waters.\8\ EPA's methodology and results for its proposed 
coastal criteria are presented in more detail in Sections III.B and 
III.C.
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    \7\ This area includes waters offshore of Apalachicola Bay, 
Alligator Harbor, Ochlockonee Bay, Big Bend/Apalachee Bay, Suwannee 
River, and Springs Coast.
    \8\ EPA derived TN and TP criteria for coastal waters in the Big 
Bend Coastal region because mechanistic models were used in these 
areas.
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    EPA is proposing numeric nutrient criteria to ensure the attainment 
and maintenance of the water quality standards in downstream estuaries 
and south Florida marine waters pursuant to the provisions of 40 CFR 
131.10(b). EPA examined a variety of modeling techniques and data to 
assess whether waters entering an estuary protect the water quality 
standards within the estuary. Accordingly, EPA is proposing an approach 
to derive TN and TP criteria expressed as downstream protection values 
(DPVs) at the points where inland flowing waters flow into estuaries, 
or marine waters in south Florida (referred to as `pour points'). These 
proposed DPVs apply to all flowing waters, including south Florida 
inland flowing waters (with the exception of waters within the lands of 
the Miccosukee and Seminole Tribes, EAA, and EvPA), that flow directly 
into estuaries or south Florida marine waters. EPA's proposed approach 
for deriving DPVs at the pour points involves an evaluation of water 
quality in the downstream estuary, water quality conditions at the pour 
point, and selecting a method to derive the DPV values based on 
available data. The proposed approaches for deriving DPVs in flowing 
waters are presented in more detail in Sections III.B and III.D.
    Finally, EPA is proposing to extend the approach finalized in 40 
CFR 131.43(e) \9\ to allow development of Site-Specific Alternative 
Criteria (SSAC) for estuaries, coastal waters, and south Florida inland 
flowing waters. EPA's rationale for extending these SSAC provisions is 
discussed in more detail in Section V.C.
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    \9\ 40 CFR 131.43(e) authorizes the derivation of Federal Site-
Specific Alternative Criteria (SSAC) after EPA review and approval 
of applicant submissions of scientifically defensible criteria that 
meet the requirements of CWA section 303(c) and EPA's implementing 
regulations at 40 CFR 131.
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    EPA has incorporated sound science, local expertise, and 
substantial Florida-specific data throughout the development of these 
proposed numeric TN, TP, and chlorophyll a criteria. EPA relied upon 
peer-reviewed criteria development methodologies,\10\ relevant 
biological endpoints, and a substantial

[[Page 74927]]

body of scientific analysis provided to EPA by FDEP, as well as other 
federal, State, and local partners such as the National Park Service; 
National Oceanic and Atmospheric Administration (NOAA); U.S. Geological 
Survey (USGS); Tampa Bay, Indian River Lagoon, Sarasota Bay and 
Charlotte Harbor National Estuary Programs; St. Johns River and South 
Florida Water Management Districts; and Florida International 
University.
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    \10\ USEPA. 2000a. Nutrient Criteria Technical Guidance Manual: 
Lakes and Reservoirs. EPA-822-B-00-001. U.S. Environmental 
Protection Agency, Office of Water, Washington, DC.
     USEPA. 2000b. Nutrient Criteria Technical Guidance Manual: 
Rivers and Streams. EPA-822-B-00-002. U.S. Environmental Protection 
Agency, Office of Water, Washington, DC.
    USEPA. 2001. Nutrient Criteria Technical Guidance Manual: 
Estuarine and Coastal Marine Waters. EPA-822-B-01-003. U.S. 
Environmental Protection Agency, Office of Water, Washington, DC.
    USEPA. 2010. Using Stressor-Response Relationships to Derive 
Numeric Nutrient Criteria. EPA-820-S-10-001. U.S. Environmental 
Protection Agency, Office of Water, Washington, DC.
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    EPA sought feedback on the scientific defensibility of the 
approaches outlined in this proposed rule through a Science Advisory 
Board (SAB) review.\11\ The SAB assembled a group of eighteen expert 
panelists to review EPA's Methods and Approaches for Deriving Numeric 
Criteria for Nitrogen/Phosphorus Pollution in Florida's Estuaries, 
Coastal Waters, and Southern Inland Flowing Waters.\12\ The SAB 
recommendations \13\ strengthened the scientific basis of these 
proposed numeric nutrient criteria. A number of key interest groups 
presented their comments and views on the underlying science as part of 
the SAB review process. In addition, EPA met with several groups of 
stakeholders with local technical expertise to discuss potential 
approaches for deriving scientifically defensible numeric nutrient 
criteria.
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    \11\ USEPA-SAB. 2011. Review of EPA's draft Approaches for 
Deriving Numeric Nutrient Criteria for Florida's Estuaries, Coastal 
Waters, and Southern Inland Flowing Waters. EPA-SAB-11-010. U.S. 
Environmental Protection Agency, Science Advisory Board, Washington, 
DC.
    \12\ USEPA. 2010. Methods and Approaches for Deriving Numeric 
Criteria for Nitrogen/Phosphorus Pollution in Florida's Estuaries, 
Coastal Waters, and Southern Inland Flowing Waters. U.S. 
Environmental Protection Agency, Office of Water, Washington, DC.
    \13\ USEPA-SAB. 2011. Review of EPA's draft Approaches for 
Deriving Numeric Nutrient Criteria for Florida's Estuaries, Coastal 
Waters, and Southern Inland Flowing Waters. EPA-SAB-11-010. U.S. 
Environmental Protection Agency, Science Advisory Board, Washington, 
DC.
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3. Costs and Benefits
    For the reasons presented in this notice, this is not an 
economically significant regulatory action under Executive Order 12866. 
Under the CWA, EPA's promulgation of WQS establishes standards that the 
State of Florida implements through the National Pollutant Discharge 
Elimination System (NPDES) permit process for point source dischargers 
and may also result in new or revised requirements for nitrogen and 
phosphorus pollution treatment controls on other sources (e.g., 
agriculture, urban runoff, and septic systems) through the development 
of Total Maximum Daily Loads (TMDLs) and Basin Management Action Plans 
(BMAPs). As a result of this action, the State of Florida will need to 
ensure that permits it issues and Waste Load Allocations (WLAs) issued 
under TMDLs and BMAPs include any limitations on discharges and other 
sources necessary to comply with the standards established in the final 
rule. In doing so, the State will have considerable discretion and a 
number of choices associated with permit writing (e.g., relating to 
compliance schedules, variances, etc.) and flexibilities built into the 
TMDL and BMAP process for WLA assignment. While Florida's 
implementation of the rule may ultimately result in new or revised 
permit conditions for some dischargers and WLA requirements for control 
on other sources, EPA's action, by itself, does not establish any 
requirements directly applicable to regulated entities or other sources 
of nitrogen and phosphorus pollution. Additionally, Florida already has 
an existing narrative water quality criterion \14\ which requires that 
nutrients not be present in estuaries and coastal waters in Florida or 
in south Florida inland flowing waters in concentrations that cause an 
imbalance in natural populations of flora and fauna. The proposed 
criteria in this rule are consistent with and serve to implement the 
State's existing narrative nutrient provision.
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    \14\ Subsection 62-302.530(47)(b), Florida Administrative Code 
(F.A.C.), provides that ``[i]n no case shall nutrient concentrations 
of a body of water be altered so as to cause an imbalance in natural 
populations of aquatic flora or fauna.''
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    Although the proposed rule does not establish any requirements 
directly applicable to regulated entities or other sources of nutrient 
pollution, EPA developed an economic analysis to provide information on 
potential costs and benefits that may be associated with the State 
implementation requirements that may be necessary to ensure attainment 
of WQS. EPA conducted an analysis to estimate both the increase in the 
number of impaired waters that may be identified as a result of the 
proposed rule and the annual cost of CWA pollution control actions 
likely to be implemented by the State of Florida to assure attainment 
of applicable State water quality designated uses for these waters. It 
is important to note that the costs and benefits of pollution controls 
needed to attain water quality standards for nutrients for waters 
already identified as impaired by the State (including waters with 
TMDLs in place and without TMDLs in place) are not included in EPA 
estimates of the cost of the rule. EPA believes that these costs and 
benefits would be incurred in the absence of the current proposed rule 
and are therefore part of the baseline against which the costs and 
benefits of this rule are measured. EPA's analysis is fully described 
in the document entitled Economic Analysis of Proposed Water Quality 
Standards for the State of Florida's Estuaries, Coastal Waters, and 
South Florida Inland Flowing Waters (hereinafter referred to as the 
Economic Analysis), which can be found in the docket and record for 
this proposed rule. The final conclusion of this assessment is that the 
incremental costs associated with the proposed rule range between 
$239.0 million and $632.4 million per year (2010 dollars) and total 
monetized benefits may be in the range from $39.0 to $53.4 million 
annually. EPA's analysis describes additional benefits that could not 
be monetized. EPA has provided estimates of the annual costs and 
benefits; these exceed the $100 million threshold that defines an 
economically significant rule under section 3(f) of Executive Order 
12866. However, EPA cautions that these estimates cannot be used to 
determine that this rule is economically significant. The direct effect 
of this rule is to provide Florida with a numeric articulation of its 
current narrative articulation of nutrients criteria, without affecting 
the resulting level of protection offered by the criteria. The 
estimates of costs and benefits here are indirect estimates (costs and 
benefits associated with controls for waters that would immediately be 
judged to be impaired due to numeric criteria) of the direct effects of 
this proposed rule (decreasing the time to implement TMDLs on impaired 
waters), and the relationship these indirect estimates bear to the true 
costs and benefits cannot be determined.

B. Which water bodies are affected by this rule?

    EPA's proposed rule applies to estuaries and coastal marine waters 
that have been classified by Florida as Class II (Shellfish Propagation 
or Harvesting) or Class III (Recreation, Propagation and Maintenance of 
a Healthy, Well-Balanced Population of Fish and Wildlife), including 
tidal creeks and marine lakes, but excluding the estuarine and marine 
waters contained in Florida's newly-approved State WQS. This proposed 
rule also applies to south Florida inland flowing waters that have been 
classified by Florida as Class I (Potable Water Supplies) or Class III 
water bodies pursuant to Section 62-302.400, F.A.C., excluding wetlands 
(e.g. sloughs in south Florida) and flowing waters within the lands of 
the Miccosukee and Seminole Tribes, EvPA,

[[Page 74928]]

or EAA.\15\ Pursuant to Subsection 62-302.400(4), F.A.C., ``Class I, 
II, and III surface waters share water quality criteria established to 
protect fish consumption, recreation and the propagation and 
maintenance of a healthy, well-balanced population of fish and 
wildlife.'' \16\ Florida currently has a narrative nutrient criterion 
at Subsection 62-302.530(47)(b), F.A.C.\17\ established to protect 
these three uses and EPA is numerically interpreting Florida's 
narrative criterion for the purpose of protecting the Class I, II, and 
III surface waters for the purposes of the CWA in this proposed 
rulemaking.
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    \15\ In this rule, EPA is interpreting the existing State 
narrative criterion under Subsection 62-302.530(47)(b), F.A.C. That 
criterion applies to Florida waters classified as Class I (Potable 
Water Supplies), Class II (Shellfish Propagation or Harvesting), and 
Class III Marine and Fresh (Recreation, Propagation and Maintenance 
of a Healthy, Well-Balanced Population of Fish and Wildlife). EPA is 
not aware of any marine waters that Florida has classified as Class 
I potable water supply. Therefore, for purposes of this rule, EPA is 
interpreting Subsection 62-302.530(47)(b), F.A.C. to protect fish 
consumption, recreation, and the propagation and maintenance of a 
healthy, well-balanced population of fish and wildlife in Florida's 
Class II and III estuarine and coastal waters.
    \16\ Class I waters also include an applicable nitrate limit of 
10 mg/L and nitrite limit of 1 mg/L for the protection of human 
health in drinking water supplies. The nitrate limit applies at the 
entry point to the distribution system (i.e., after any treatment); 
see Section 62-550, F.A.C., for additional details.
    \17\ ``[i]n no case shall nutrient concentrations of a body of 
water be altered so as to cause an imbalance in natural populations 
of aquatic flora or fauna''
---------------------------------------------------------------------------

    EPA is not proposing to change any of Florida's water body 
classifications with this regulation. The proposed criteria in this 
regulation would only apply to water bodies that are currently 
classified by Florida as Class I, II, or III and not to water bodies 
with other classifications such as Class III limited waters \18\ for 
which use attainability analyses (UAAs) and SSACs for nutrients have 
been established, or Class IV canals in Florida's agricultural areas.
---------------------------------------------------------------------------

    \18\ Class III limited waters include waters that support fish 
consumption; recreation or limited recreation; and/or propagation 
and maintenance of a limited population of fish and wildlife; see 
Chapter 62-302.400(1) F.A.C. for more details.
---------------------------------------------------------------------------

    EPA is defining estuary to be consistent with Florida's definition 
of estuary in Section 62-303.200, F.A.C., where ``estuary'' shall mean 
``predominantly marine regions of interaction between rivers and 
nearshore ocean waters, where tidal action and river flow mix fresh and 
salt water.'' Such areas include bays, mouths of rivers, and lagoons 
that have been classified as Class II (Shellfish Propagation or 
Harvesting) or Class III (Recreation, Propagation and Maintenance of a 
Healthy, Well-Balanced Population of Fish and Wildlife) water bodies 
pursuant to Section 62-302.400, F.A.C., excluding wetlands.
    EPA is defining coastal waters based on Florida's definitions of 
open coastal waters and open ocean waters, taking into account that CWA 
jurisdiction extends to three nautical miles from shore.\19\ EPA's 
definition of ``coastal waters'' is all marine waters that have been 
classified as Class II (Shellfish Propagation or Harvesting) or Class 
III (Recreation, Propagation and Maintenance of a Healthy, Well-
Balanced Population of Fish and Wildlife) water bodies pursuant to 
Section 62-302.400, F.A.C., extending to three nautical miles from 
shore that are not classified as estuaries. EPA's proposed rule defines 
``marine waters'' to mean surface waters in which the chloride 
concentration at the surface is greater than or equal to 1,500 
milligrams per liter (mg/L).
---------------------------------------------------------------------------

    \19\ While CWA jurisdiction, and therefore EPA's proposed 
criteria, extend only to three nautical miles from shore (CWA 
section 502(8)), Florida State jurisdiction extends beyond three 
nautical miles. Florida's seaward boundary in Gulf of Mexico waters 
is 3 marine leagues (9 nautical miles) and in Atlantic waters is 3 
nautical miles (Submerged Lands Act of 1953. http://www.boem.gov/uploadedFiles/submergedLA.pdf; United States v. Florida, 363 U.S. 
121 (1960)). Florida defines open coastal waters as ``all gulf or 
ocean waters that are not classified as estuaries or open ocean 
waters.'' Open ocean waters consist of ``all surface waters 
extending seaward from the most seaward natural 90-foot (15-fathom) 
isobath'' (Subsection 62-303.200, F.A.C.).
---------------------------------------------------------------------------

    EPA is defining tidal creeks as relatively small coastal 
tributaries with variable salinity that lie at the transition zone 
between terrestrial uplands and the open estuary. For another subset of 
marine waters, marine lakes, EPA is proposing to use the definition of 
``marine waters'' and the definition of lakes included previously in 
Water Quality Standards for the State of Florida's Lakes and Flowing 
Waters (40 CFR 131.43) to define a marine lake as a slow-moving or 
standing body of marine water that occupies an inland basin that is not 
a stream, spring, or wetland.
    EPA previously defined ``flowing waters'' in Water Quality 
Standards for the State of Florida's Lakes and Flowing Waters (40 CFR 
131.43). A flowing water is defined as ``a free-flowing, predominantly 
fresh surface water in a defined channel, and includes rivers, creeks, 
branches, canals, freshwater sloughs, and other similar water bodies.'' 
Consistent with EPA's definition in 40 CFR 131.43, EPA defines 
``canal'' for this proposed rule to mean a trench, the bottom of which 
is normally covered by water with the upper edges of its two sides 
normally above water. Also as defined in 40 CFR 131.43, ``predominantly 
fresh waters'' means surface waters in which the chloride concentration 
at the surface is less than 1,500 mg/L. EPA is not proposing criteria 
for areas currently managed by the State as wetlands (such as sloughs 
in south Florida), which are outside the scope of this rulemaking.\20\
---------------------------------------------------------------------------

    \20\ FDEP. 2001. Chapter 2: Ecological Description. In: 
Everglades Phosphorus Criterion Technical Support Document. Part 
III: WCA-3/ENP. Florida Department of Environmental Protection, 
Everglades Technical Support Section. http://www.dep.state.fl.us/water/wqssp/.everglades/docs/pctsd/IIIChapter.2.pdf. Accessed 
January, 10, 2011.
    Doherty, S.J., C.R. Lane, and M.T. Brown. 2000. Proposed 
Classification for Biological Assessment of Florida Inland 
Freshwater Wetlands. Report to the Florida Department of 
Environmental Protection. Contract No. WM68 (Development of a 
Biological Approach for Assessing Wetland Function and Integrity). 
Center for Wetlands, University of Florida, Gainesville, FL.
    Ogden, J.C. 2005. Everglades ridge and slough conceptual 
ecological model. Wetlands 25(4):810-820.
---------------------------------------------------------------------------

C. What entities may be affected by this rule?

    Citizens concerned with water quality in Florida may be interested 
in this rulemaking. Entities discharging nitrogen or phosphorus to 
estuaries, coastal waters, and flowing waters in Florida could be 
indirectly affected by this rulemaking because water quality standards 
are used in determining National Pollutant Discharge Elimination System 
(NPDES) permit limits. Examples of categories and entities that may 
ultimately be affected are listed in the following table:

------------------------------------------------------------------------
                                             Examples of potentially
                Category                        affected entities
------------------------------------------------------------------------
Industry...............................  Industries discharging
                                          pollutants to estuaries,
                                          coastal waters and flowing
                                          waters in the State of
                                          Florida.
Municipalities.........................  Publicly-owned treatment works
                                          discharging pollutants to
                                          estuaries, coastal waters and
                                          flowing waters in the State of
                                          Florida.
Stormwater Management Districts........  Entities responsible for
                                          managing stormwater runoff in
                                          the State of Florida.
------------------------------------------------------------------------

    This table is not intended to be exhaustive, but rather provides a 
guide for entities that may be indirectly affected by this action. 
Other types of entities not listed in the table, such as non-point 
source contributors to nitrogen and phosphorus pollution in Florida's 
waters, may be affected through implementation of Florida's water 
quality standards program (e.g., through Basin Management Action Plans 
(BMAPs)). Any parties or entities

[[Page 74929]]

conducting activities within Florida watersheds covered by this 
proposed rule, or who depend upon or contribute to the water quality of 
the estuaries, coastal waters, and flowing waters of Florida, may be 
affected by this rule. To determine whether your facility or activities 
may be affected by this action, you should examine this proposed rule. 
If you have questions regarding the applicability of this action to a 
particular entity, consult the person listed in the preceding FOR 
FURTHER INFORMATION CONTACT section.

D. What should I consider as I prepare my comments for EPA?

    1. Submitting CBI. Do not submit confidential business information 
(CBI) to EPA through http://www.regulations.gov or email. Clearly mark 
the part or all of the information that you claim to be CBI. For CBI 
information in a disk or CD-ROM that you mail to EPA, mark the outside 
of the disk or CD-ROM as CBI and then identify electronically within 
the disk or CD-ROM the specific information that is claimed as CBI. In 
addition to one complete version of the comment that includes 
information claimed as CBI, a copy of the comment that does not contain 
the information claimed as CBI must be submitted for inclusion in the 
public docket. Information so marked will not be disclosed except in 
accordance with procedures set forth in 40 CFR part 2.
    2. Tips for Preparing Your Comments. When submitting comments, 
remember to:
     Identify the rulemaking by docket number and other 
identifying information (subject heading, Federal Register date, and 
page number).
     Follow directions--The agency may ask you to respond to 
specific questions or organize comments by referencing a Code of 
Federal Regulations (CFR) part or section number.
     Explain why you agree or disagree; suggest alternatives 
and substitute language for your requested changes.
     Describe any assumptions and provide any technical 
information and/or data that you used.
     If you estimate potential costs or burdens, explain how 
you arrived at your estimate in sufficient detail to allow for it to be 
reproduced.
     Provide specific examples to illustrate your concerns, and 
suggest alternatives.
     Make sure to submit your comments by the comment period 
deadline identified.
    Commenters who submitted public comments or scientific information 
on the portions of EPA's January 26, 2010 proposed Water Quality 
Standards for the State of Florida's Lakes and Flowing Waters (75 FR 
4173) that are addressed in this proposal should reconsider their 
previous comments in light of the new information presented in this 
proposal and must re-submit their comments during the public comment 
period for this rulemaking to receive EPA response.

E. How can I get copies of this document and other related information?

    1. Docket. EPA has established an official public docket for this 
action under Docket Id. No. EPA-HQ-OW-2010-0222. The official public 
docket consists of the document specifically referenced in this action, 
any public comments received, and other information related to this 
action. Although a part of the official docket, the public docket does 
not include CBI or other information whose disclosure is restricted by 
statute. The official public docket is the collection of materials that 
is available for public viewing at the OW Docket, EPA West, Room 3334, 
1301 Constitution Ave. NW., Washington, DC 20004. This Docket Facility 
is open from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding 
legal holidays. The Docket telephone number is 202-566-2426. A 
reasonable fee will be charged for copies.
    2. Electronic Access. You may access this Federal Register document 
electronically through the EPA Internet under the ``Federal Register'' 
listings at http://www.epa.gov/fedrgstr/. An electronic version of the 
public docket is available through EPA's electronic public docket and 
comment system, EPA Dockets. You may use EPA Dockets at http://www.regulations.gov to view public comments, access the index listing 
of the contents of the official public docket, and to access those 
documents in the public docket that are available electronically. For 
additional information about EPA's public docket, visit the EPA Docket 
Center homepage at http://www.epa.gov/epahome/dockets.htm. Although not 
all docket materials may be available electronically, you may still 
access any of the publicly available docket materials through the 
Docket Facility identified in Section I.E(1).

II. Background

A. Nitrogen and Phosphorus Pollution

1. What is nitrogen and phosphorus pollution?
a. Overview of Nitrogen and Phosphorus Pollution
    Excess loading of nitrogen and phosphorus to surface water bodies 
and groundwater is one of the leading causes of water quality 
impairments in the United States.\21\ The problem extends to both fresh 
and marine waters,\22\ leading to over 15,000 nutrient pollution-
related impairments in 49 states across the country--a figure that may 
substantially understate the problem as many waters have yet to be 
assessed.\23\ Estuaries and coastal waters are especially vulnerable to 
nitrogen and phosphorus pollution because they are the ultimate 
receiving waters for most major watersheds transporting nitrogen and 
phosphorus loadings from multiple upstream sources.\24\
---------------------------------------------------------------------------

    \21\ Dubrovsky, N.M., K.R. Burow, G.M. Clark, J.M. Gronberg, 
P.A. Hamilton, K.J. Hitt, D.K. Mueller, M.D. Munn, B.T. Nolan, L.J. 
Puckett, M.G. Rupert, T.M. Short, NE. Spahr, L.A. Sprague, and W.G. 
Wilber. 2010. The Quality of our Nation's waters--Nutrients in the 
Nation's Streams and Groundwater, 1992-2004. Circular 1350. U.S. 
Geological Survey, National Water Quality Assessment Program, 
Reston, VA. http://water.usgs.gov/nawqa/nutrients/pubs/circ1350. 
Accessed December 2011.
    \22\ Smith, V.H., S.B. Joye, and R.W. Howarth. 2006. 
Eutrophication of freshwater and coastal marine ecosystems. 
Limnology and Oceanography 51(1, part 2):351-355.
    Schindler, D.W. 2006. Recent advances in the understanding and 
management of eutrophication. Limnology and Oceanography 51(1, 
part2):356-363.
    \23\ Nationally, only 27% of rivers and streams and less than 
50% of lakes, reservoirs, and ponds have been assessed for 
impairment (USEPA. 2011. National Summary of State Information. U.S. 
Environmental Protection Agency, Watershed Assessment, Tracking & 
Environmental Results. http://iaspub.epa.gov/waters10/attains_nation_cy.control. Accessed January 2012).
    \24\ Bricker, S., B. Longstaff, W. Dennison, A. Jones, K. 
Boicourt, C. Wicks, and J. Woerner. 2007. Effects of Nutrient 
Enrichment in the Nation's Estuaries: A Decade of Change. NOAA 
Coastal Ocean Program Decision Analysis Series No. 26. National 
Centers for Coastal Ocean Science, Silver Spring, MD. http://ccma.nos.noaa.gov/publications/eutroupdate/Accessed January 2012.
    National Research Council. 2000. Clean Coastal Waters: 
Understanding and Reducing the Effects of Nutrient Pollution. Report 
prepared by the Ocean Study Board and Water Science and Technology 
Board, Commission on Geosciences, Environment and Resources, 
National Resource Council, Washington, DC.
---------------------------------------------------------------------------

    The problem of nitrogen and phosphorus pollution is not new. Over 
forty years ago, a 1969 report by the National Academy of Sciences \25\ 
noted that ``[m]an's activities, which introduce excess nutrients, 
along with other

[[Page 74930]]

pollutants, into lakes, streams, and estuaries, are causing significant 
changes in aquatic environments. The excess nutrients greatly 
accelerate the process of eutrophication. The pollution problem is 
critical because of increased population, industrial growth, 
intensification of agricultural production, river-basin development, 
recreational use of waters, and domestic and industrial exploitation of 
shore properties. Accelerated eutrophication causes changes in plant 
and animal life--changes that often interfere with use of water, 
detract from natural beauty, and reduce property values.'' A 2000 
report by the National Research Council \26\ concluded that ``* * * 
scientists, coastal managers, and public decision-makers have come to 
recognize that coastal ecosystems suffer a number of environmental 
problems that can, at times, be attributed to the introduction of 
excess nutrients from upstream watersheds. The problems are caused by a 
complex chain of events and vary from site to site, but the fundamental 
driving force is the accumulation of nitrogen and phosphorus in fresh 
water on its way to the sea.''
---------------------------------------------------------------------------

    \25\ National Academy of Sciences. 1969. Eutrophication: Causes, 
Consequences, Correctives. National Academy of Sciences, Washington, 
DC.
    \26\ National Research Council. 2000. Clean Coastal Waters: 
Understanding and Reducing the Effects of Nutrient Pollution. Report 
prepared by the Ocean Study Board and Water Science and Technology 
Board, Commission on Geosciences, Environment and Resources, 
National Resource Council, Washington, DC.
---------------------------------------------------------------------------

    Florida has long struggled with nutrient pollution impacts to its 
surface and ground waters. Florida's flat topography makes Florida 
particularly susceptible to nitrogen and phosphorus pollution because 
water moves more slowly over the landscape, allowing time for nitrogen 
and phosphorus pollution to accumulate in water bodies and cause 
eutrophication. Florida's high rainfall levels contribute to increased 
run-off, and higher temperatures and sunlight contribute to 
eutrophication when excess nutrients are available.\27\
---------------------------------------------------------------------------

    \27\ Perry, W.B. 2008. Everglades restoration and water quality 
challenges in south Florida. Ecotoxicology 17:569-578.
---------------------------------------------------------------------------

    In FDEP's 2012 Integrated Water Quality Assessment for Florida: 
2012 305(b) Report and 303(d) List Update, nutrient pollution is ranked 
as the fifth major cause of estuary impairments by impaired square 
miles \28\ and the fifth major cause of impairments in coastal 
waters.\29\ FDEP documents nutrient pollution impairments in 754 square 
miles (482,560 acres) of estuaries (about 14 percent of the estuarine 
area assessed by Florida) and 102 square miles (65,280 acres) of 
coastal waters (about 1.6 percent of the assessed coastal waters).\30\
---------------------------------------------------------------------------

    \28\ First, second, third, and fourth major causes of estuary 
impairments by impaired square miles are mercury in fish, DO, 
bacteria in shellfish, and fecal coliform, respectively.
    \29\ FDEP. 2012. Integrated Water Quality Assessment for 
Florida: 2012 305(b) Report and 303(d) List Update. (May 2012). 
Florida Department of Environmental Protection, Division of 
Environmental Assessment and Restoration, Tallahassee, FL. http://www.dep.state.fl.us/water/docs/2012_integrated_report.pdf. 
Accessed August 2012.
    \30\ FDEP. 2012. Integrated Water Quality Assessment for 
Florida: 2012 305(b) Report and 303(d) List Update. (May 2012). 
Florida Department of Environmental Protection, Division of 
Environmental Assessment and Restoration, Tallahassee, FL. http://www.dep.state.fl.us/water/docs/2012_integrated_report.pdf. 
Accessed August 2012.
---------------------------------------------------------------------------

    FDEP noted in its 2008 Integrated Water Quality Assessment for 
Florida: 2008 305(b) Report and 303(d) List Update that nitrogen and 
phosphorus pollution poses several challenges in Florida. FDEP stated, 
``The close connection between surface and groundwater, in combination 
with the pressures of continued population growth, accompanying 
development, and extensive agricultural operations, present Florida 
with a unique set of challenges for managing both water quality and 
quantity in the future. After trending downward for 20 years, beginning 
in 2000 phosphorus levels again began moving upward, likely due to the 
cumulative impacts of non-point source pollution associated with 
increased population and development. Increasing pollution from urban 
stormwater and agricultural activities is having other significant 
effects.'' \31\
---------------------------------------------------------------------------

    \31\ FDEP. 2008. Integrated Water Quality Assessment for 
Florida: 2008 305(b) Report and 303(d) List Update. Florida 
Department of Environmental Protection, Division of Environmental 
Assessment and Restoration, Tallahassee, FL. http://www.dep.state.fl.us/water/docs/2008_Integrated_Report.pdf. 
Accessed July 2011.
---------------------------------------------------------------------------

    To better understand the nitrogen and phosphorus pollution problem 
in Florida, EPA looked at trends in the data Florida uses to create its 
Integrated Water Quality Reports,\32\ and found increasing 
concentrations of nitrogen and phosphorus compounds in Florida waters 
over the 12 year period from 1996-2008. Florida's Impaired Waters Rule 
(IWR) data indicate that levels of total nitrogen have increased 
approximately 20 percent from a state-wide average of 1.06 mg/L in 1996 
to 1.27 mg/L in 2008 and average state-wide total phosphorus levels 
have increased approximately 40 percent from an average of 0.108 mg/L 
in 1996 to 0.151 mg/L in 2008.
---------------------------------------------------------------------------

    \32\ IWR Run 40. Updated through February 2010.
---------------------------------------------------------------------------

    On a national scale, the primary sources of nitrogen and phosphorus 
pollution can be grouped into five major categories: (1) Urban and 
suburban stormwater runoff--sources associated with residential and 
commercial land use and development; (2) municipal and industrial 
wastewater discharges; (3) row crop agriculture and fertilizer use; (4) 
livestock production and manure management practices; and (5) 
atmospheric deposition resulting from nitrogen oxide emissions from 
fossil fuel combustion and ammonia emissions from row crop agriculture 
and livestock production. These sources contribute loadings of 
anthropogenic nitrogen and phosphorus to surface and groundwaters, and 
may cause harmful impacts to aquatic ecosystems and imbalances in the 
natural populations of aquatic flora and fauna.\33\
---------------------------------------------------------------------------

    \33\ State-EPA Nutrient Innovations Task Group. 2009. An Urgent 
Call to Action: Report of the State-EPA Nutrient Innovations Task 
Group. http://water.epa.gov/scitech/swguidance/standards/criteria/nutrients/upload/2009_08_27_criteria_nutrient_nitgreport.pdf 
Accessed May 2012.
---------------------------------------------------------------------------

    In general, the major sources of nitrogen and phosphorus pollution 
in Florida estuarine and coastal waters are the same as those found at 
the national scale: urban and suburban stormwater runoff, wastewater 
discharges, row crop agriculture, livestock production, and atmospheric 
deposition. As is the case with much of the southern United States, 
Florida's population continues to grow, with Florida among the top ten 
fastest growing states.\34\ Florida's population growth is concentrated 
in major cities and along the coast. As of 2005, Florida's highest 
population density was along its eastern coast; there has also been 
significant population expansion along the western coast from Tampa to 
the south. As populations grow, the increased nitrogen and phosphorus 
pollution resulting from increased urban stormwater runoff, municipal 
wastewater discharges, air deposition, and agricultural livestock 
activities and row-crop runoff can place increased stress on all 
ecosystems.
---------------------------------------------------------------------------

    \34\ U.S. Census Bureau. 2011. Population Distribution and 
Change: 2000 to 2010. http://www.census.gov/prod/cen2010/briefs/c2010br-01.pdf. Accessed July 2011.
---------------------------------------------------------------------------

    In nearly half of the estuaries examined for this rulemaking, urban 
or stormwater runoff is a major contributor of nitrogen and phosphorus 
pollution. For example, a report issued in 2010 by the Sarasota Bay 
Estuary Program indicates that in Sarasota Bay, nutrients are primarily 
transported to the estuary by stormwater runoff, which is the 
predominant source in all segments of the estuary (42-60 percent of the 
total nitrogen load).\35\ Similarly, according to

[[Page 74931]]

the Tampa Bay Estuary Program, the largest source of nitrogen to Tampa 
Bay is also runoff (63 percent of total nitrogen loadings to Tampa Bay 
from 1999-2003).\36\ Impervious land cover is a large driver of 
stormwater volume. In 2005, one study estimated that 7 percent of 
Florida's area had total impervious area greater than 20 percent, and 
of that, a quarter of that land had total impervious area greater than 
40 percent. As Florida's population grows, it is likely that the 
resulting expansion of impervious cover will cause increased harmful 
impacts on water quality in coastal areas, wetlands, and other aquatic 
ecosystems.\37\
---------------------------------------------------------------------------

    \35\ SBEP. 2010. Numeric Nutrient Criteria for Sarasota Bay. 
Prepared for the Sarasota Bay Estuary Program by Janicki 
Environmental, Inc. http://www.sarasotabay.org/documents/SBEP-NNC-Final-Report.pdf. Accessed August 2011.
    \36\ TBEP. No date. About the Tampa Bay Estuary Program, State 
of the Bay: Water and Sediment Quality. Tampa Bay Estuary Program. 
http://www.tbep.org/tbep/stateofthebay/waterquality.html. Accessed 
January 2012.
    \37\ Exum, L.R., S.L. Bird, J. Harrison, and C.A. Perkins. 2005. 
Estimating and Projecting Impervious Cover in the Southeastern 
United States. EPA/600/R-05/061. U.S. Environmental Protection 
Agency, Office of Research and Development, Washington, DC.
---------------------------------------------------------------------------

    Wastewater is also a significant contributor of nitrogen and 
phosphorus pollution. In Florida, there are 443 domestic (not including 
septic systems) and industrial wastewater dischargers with individual 
NPDES permits.\38\ Of those facilities, 198 are classified as domestic 
(municipal) wastewater facilities, which treat sanitary wastewater or 
sewage from homes, businesses, and institutions. The other 245 
facilities are classified as industrial wastewater facilities. About 
one third of Florida's population uses on-site sewage treatment and 
disposal (septic tanks) to treat wastewater.\39\
---------------------------------------------------------------------------

    \38\ Facilities with NPDES permits either discharge to surface 
waters or ground waters, using methods that include land 
application, beneficial reuse of reclaimed water, and deep well 
injection. USEPA. 2011. Permit Compliance System Database. U.S. 
Environmental Protection Agency. http://www.epa.gov/enviro/facts/pcs/customized.html. Accessed June 2011.
    There are also 34,508 dischargers covered under generic or 
general permits, which FDEP regulates based on categories of 
wastewater facilities or activities that involve the same or similar 
types of operations or wastes.
    \39\ FDEP. 2011. General Facts and Statistics about Wastewater 
in Florida. Florida Department of Environmental Protection. http://www.dep.state.fl.us/water/wastewater/facts.htm. Accessed January 
2012.
---------------------------------------------------------------------------

    In Florida, fewer than a quarter of individually permitted domestic 
and industrial facilities are authorized to discharge to surface 
waters. The remaining permittees are authorized to discharge solely to 
groundwater through land-application, beneficial reuse of reclaimed 
water, or deep well injection. Domestic wastewater treatment facilities 
permitted by FDEP produce over 1.5 billion gallons of treated effluent 
and reclaimed water per day, with a total treatment capacity of over 
2.5 billion gallons per day. Eighteen percent of domestic wastewater 
treatment facilities have treatment capacities greater than 500,000 
gallons per day, whereas 73 percent of domestic wastewater treatment 
facilities have capacities less than 100,000 gallons per day.\40\
---------------------------------------------------------------------------

    \40\ FDEP. 2011. Wastewater Program. Florida Department of 
Environmental Protection. http://www.dep.state.fl.us/water/wastewater/index.htm Accessed January 2012.
---------------------------------------------------------------------------

    Wastewater has been cited as contributing to negative impacts on 
water quality in some areas. On the east coast of Florida, septic 
systems contribute an estimated 1.5 million pounds of nitrogen per year 
to Florida's Indian River Lagoon.\41\ There have been some successes in 
reducing the impact of wastewater on marine waters. In Tampa Bay, 
wastewater treatment plants were one of the major sources of nitrogen 
prior to the institution of tertiary nitrogen removal. This treatment 
has contributed to an improvement in Tampa Bay's water quality.\42\
---------------------------------------------------------------------------

    \41\ USEPA. 2003. EPA Voluntary National Guidelines for 
Management of Onsite and Clustered (Decentralized) Wastewater 
Treatment Systems. EPA-832-B-03-001. U.S. Environmental Protection 
Agency, Office of Water, Washington, DC. http://www.epa.gov/owm/septic/pubs/septic_guidelines.pdf. Accessed August 2011.
    \42\ Johansson, J.O.R., and H.S. Greening. 2000. Seagrass 
Restoration in Tampa Bay: A Resource-based Approach to Estuarine 
Management. Chapter 20 In: Seagrasses: Monitoring, Ecology, 
Physiology, and Management, ed. S.A. Bortone, pp. 279-293. CRC 
Press, Boca Raton, FL.
---------------------------------------------------------------------------

    There have been a number of studies examining the sources of 
nitrogen and phosphorus pollution in waters across Florida. One area of 
study is Biscayne Bay, located on the southeast coast of Florida, 
adjacent to Miami. Nutrient pollution in the Bay comes from a number of 
key sources that vary geographically: stormwater runoff from urban 
areas, discharges from the Black Point Landfill and Sewage Treatment 
Plant, agricultural runoff from canals in the South Dade agricultural 
basin, and contaminated ground water.\43\ In the northern section of 
the Bay, there are inputs from five canals, a landfill, and urban 
runoff. The southern section of the Bay has a greater contribution from 
agricultural sources.\44\ In one study, researchers found that canals 
conveying waters from agricultural and urban areas contributed 88 
percent and 66 percent of the Bay's total dissolved inorganic nitrogen 
and total phosphorus loads, respectively.\45\
---------------------------------------------------------------------------

    \43\ Caccia, V.G., and J.N. Boyer. 2007. A nutrient loading 
budget for Biscayne Bay, Florida. Marine Pollution Bulletin 
54(7):994-1008.
    Caccia, V.G., and J.N. Boyer. 2005. Spatial patterning of water 
quality in Biscayne Bay, Florida as a function of land use and water 
management. Marine Pollution Bulletin 50(11):1416-1429.
    \44\ Caccia, V.G., and J.N. Boyer. 2005. Spatial patterning of 
water quality in Biscayne Bay, Florida as a function of land use and 
water management. Marine Pollution Bulletin 50(11):1416-1429.
    \45\ Caccia, V.G., and J.N. Boyer. 2007. A nutrient loading 
budget for Biscayne Bay, Florida. Marine Pollution Bulletin 
54(7):994-1008.
---------------------------------------------------------------------------

b. Adverse Impacts of Nitrogen and Phosphorus Pollution on Aquatic Life
    Nitrogen and phosphorus pollution in surface and ground waters 
degrade water quality and negatively impact aquatic life through 
processes associated with eutrophication.\46\ Eutrophication is a 
predictable, well-understood, and widely-documented biological process 
by which anthropogenic nitrogen and phosphorus pollution results in 
increased growth of algae (plankton and periphyton).\47\
---------------------------------------------------------------------------

    \46\ Eutrophication is the process by which a water body becomes 
enriched with organic material, which is formed by primary 
productivity (i.e., photosynthetic activity) and can be stimulated 
to harmful levels by the anthropogenic introduction of high 
concentrations of nutrients--particularly nitrogen and phosphorus 
(National Research Council. 2000. Clean Coastal Waters: 
Understanding and Reducing the Effects of Nutrient Pollution. Report 
prepared by the Ocean Study Board and Water Science and Technology 
Board, Commission on Geosciences, Environment and Resources, 
National Resource Council, Washington, DC. See also Nixon. SW. 1995. 
Coastal marine eutrophication: A definition, social causes, and 
future concerns. Ophelia 41:199-219.)
    \47\ Cambridge, M.L., J.R. How, P.S. Lavery, and M.A. 
Vanderklift. 2007. Retrospective analysis of epiphyte assemblages in 
relation to seagrass loss in a eutrophic coastal embayment. Marine 
Ecology Progress Series 346:97-107.
    Frankovich, T.A., and J.W. Fourqurean. 1997. Seagrass epiphyte 
loads along a nutrient availability gradient, Florida Bay, USA. 
Marine Ecology Progress Series 159:37-50.
    Peterson, B.J., T.A. Frankovich, and J.C. Zieman. 2007. Response 
of seagrass epiphyte loading to field manipulations of 
fertilization, gastropod grazing and leaf turnover rates. Journal of 
Experimental Marine Biology and Ecology 349(1):61-72.
    Howarth, R., D. Anderson, J. Cloern, C. Elfring, C. Hopkinson, 
B. Lapointe, T. Malone, N. Marcus, K.J. McGlathery, A. Sharpley, and 
D. Walker. 2000. Nutrient pollution of coastal rivers, bays, and 
seas. Issues in Ecology 7:1-15.
    Cloern, J.E. 2001. Our evolving conceptual model of the coastal 
eutrophication problem. Marine Ecology Progress Series 210:223-253.
    Elser, J.J., M.E.S. Bracken, E.E. Cleland, D.S. Gruner, W.S. 
Harpole, H. Hillebrand, J.T. Ngai, E.W. Seabloom, J.B. Shurin, and 
J.E. Smith. 2007. Global analysis of nitrogen and phosphorus 
limitation of primary production in freshwater, marine, and 
terrestrial ecosystems. Ecology Letters 10:1135-1142.
    Smith, V.H. 2006. Responses of estuarine and coastal marine 
phytoplankton to nitrogen and phosphorus enrichment. Limnology and 
Oceanography 51(1, part 2): 377-384.
    Vitousek, P.M., J.D. Aber, R.W. Howarth, G.E. Likens, P.A. 
Matson, D.W. Schindler, W.H. Schlesinger, and D.G. Tilman. 1997. 
Human alteration of the global nitrogen cycle: Sources and 
consequences. Ecological Applications 7(3):737-750.
    Bricker, S.B., J.G. Ferreira, and T. Simas. 2003. An integrated 
methodology for assessment of estuarine trophic status. Ecological 
Modelling 169(1):39-60.
    Bricker, S.B., B. Longstaff, W. Dennison, A. Jones, K. Boicourt, 
C. Wicks, and J. Woerner. 2008. Effects of nutrient enrichment in 
the nation's estuaries: A decade of change. Harmful Algae 8(1):21-
32.
    Boyer, J.N., C.R. Kelble, P.B. Ortner, and D.T. Rudnick. 2009. 
Phytoplankton bloom status: Chlorophyll a biomass as an indicator of 
water quality condition in the southern estuaries of Florida, USA. 
Ecological Indicators 9(6, Supplement 1):S56-S67.
    Hutchinson, G.E. 1961. The paradox of plankton. American 
Naturalist 95:137-145.
    Piehler, M.F., L.J. Twomey, N.S. Hall, and H.W. Paerl. 2004. 
Impacts of inorganic nutrient enrichment on phytoplankton community 
structure and function in Pamlico Sound, NC, USA. Estuarine Coastal 
and Shelf Science 61(2):197-209.
    Sanders, J.G., S.J. Cibik, C.F. D'Elia, and W.R. Boynton. 1987. 
Nutrient enrichment studies in a coastal plain estuary: changes in 
phytoplankton species composition. Canadian Journal of Fisheries & 
Aquatic Sciences 44:83-90.
    Parsons, T.R., P.J. Harrison, and R. Waters. 1978. An 
experimental simulation of changes in diatom and flagellate blooms. 
Journal of Experimental Marine Biology and Ecology 32:285-294.
    Paerl, H.W. 1988. Nuisance phytoplankton blooms in coastal, 
estuarine, and inland waters. Limnology and Oceanography 33(4):823-
847.
    Harding, Jr., L.W. 1994. Long-term trends in the distribution of 
phytoplankton in Chesapeake Bay: roles of light, nutrients, and 
streamflow. Marine Ecology Progress Series 104:267-291.
    Richardson, K. 1997. Harmful or Exceptional Phytoplankton Blooms 
in the Marine Ecosystem. Advances in Marine Biology. 31:301-385.
    Hagy, J.D., J.C. Kurtz, and R.M. Greene. 2008. An Approach for 
Developing Numeric Nutrient Criteria for a Gulf Coast Estuary. U.S. 
Environmental Protection Agency, Office of Research and Development, 
National Health and Environmental Effects Research Laboratory, 
Research Triangle Park, NC., EPA 600R-08/004, 44 pp.

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[[Page 74932]]

    Nitrogen and phosphorus pollution increases algal growth that 
negatively impacts many aspects of ecological communities. As algae 
growth accelerates in response to nutrient pollution, there may be 
negative changes in algal species composition and competition among 
species, leading to harmful, adverse effects, such as the increased 
growth or dominance of toxic or otherwise harmful algal species.\48\ 
These harmful algal blooms (HABs) can contain undesirable species of 
diatoms, cyanobacteria, and dinoflagellates, which are known to 
generate toxins that are a threat to both aquatic life and recreational 
activities.\49\ Many nuisance taxa of algae are also less palatable to 
aquatic organisms that consume phytoplankton, so prolonged HABs can 
impact the food supply of the overall aquatic community. More than 100 
HAB species have been identified in the United States.\50\
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    \48\ Paerl, H.W. 1988. Nuisance phytoplankton blooms in coastal, 
estuarine, and inland waters. Limnology and Oceanography 33(4):823-
847.
    Anderson, D.M., P.M. Glibert, and J.M. Burkholder. 2002. Harmful 
algal blooms and eutrophication: Nutrient sources, composition, and 
consequences. Estuaries 25(4):704-726.
    Anderson, D.M., J.M. Burkholder, W.P. Cochlan, P.M. Glibert, 
C.J. Gobler, C.A. Heil, R.M. Kudela, M.L. Parsons, J.E.J. Rensel, 
D.W. Townsend, V.L. Trainer, and G.A. Vargo. 2008. Harmful algal 
blooms and eutrophication: Examining linkages from selected coastal 
regions of the United States. Harmful Algae 8(1):39-53.
    \49\ Anderson, D.M., P.M. Glibert, and J.M. Burkholder. 2002. 
Harmful algal blooms and eutrophication: Nutrient sources, 
composition, and consequences. Estuaries 25(4):704-726.
    Paerl, H.W. 2002. Connecting atmospheric nitrogen deposition to 
coastal eutrophication. Environmental Science & Technology 
36(15):323A-326A.
    Anderson, D.M., J.M. Burkholder, W.P. Cochlan, P.M. Glibert, 
C.J. Gobler, C.A. Heil, R.M. Kudela, M.L. Parsons, J.E.J. Rensel, 
D.W. Townsend, V.L. Trainer, and G.A. Vargo. 2008. Harmful algal 
blooms and eutrophication: Examining linkages from selected coastal 
regions of the United States. Harmful Algae 8(1):39-53.
    \50\ Abbott, G.M., J.H. Landsberg, A.R. Reich, K.A. Steidinger, 
S. Ketchen, and C. Blackmore. 2009. Resource Guide for Public Health 
Response to Harmful Algal Blooms in Florida. FWRI Technical Report 
TR-14. Florida Fish and Wildlife Conservation Commission, Fish and 
Wildlife Research Institute, St. Petersburg, FL. http://myfwc.com/research/redtide/task-force/reports-presentations/resource-guide-for-public-health-response-to-harmful-algal-blooms-in-florida/Accessed June 2011.
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    Marine and fresh waters of the United States are increasingly being 
negatively impacted by HABs.\51\ HAB toxins have been linked to 
illnesses and deaths of marine animals, including sea lions, turtles, 
fish, seabirds, dolphins, and manatees.\52\ Diatoms in HABs, such as 
Pseudo-nitzschia, produce domoic acid.\53\ Domoic acid has been shown 
to accumulate in the tissue of mussels, crabs, and fish, causing their 
predators to become ill or die.\54\ Domoic acid poisoning has been 
reported as the cause of death of humpback whales in the Gulf of Maine 
in 2003 and sea lions in California's Monterey Bay during May and June 
of 1998.\55\ Other toxin-producing algal species that have been linked 
to harmful, adverse aquatic life impacts include Pfisteria piscicida, 
which produces several toxins that impact fish and humans \56\ and the 
flagellate Heterosigma akashiwo which produces an ichthyotoxin that 
kills fish.\57\
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    \51\ Dortch, Q., P. Glibert, E. Jewett, and C. Lopez. 2008. 
Introduction. Chapter 1 In: HAB RDDTT 2 National Workshop Report, A 
plan for Reducing HABs and HAB Impacts. eds. Q. Dortch, D.M. 
Anderson, D.L. Ayres, and P.M. Glibert, pp. 5-12. Woods Hole, MA.
    \52\ WHOI. 2008. Marine Mammals. Woods Hole Oceanographic 
Institution. http://www.whoi.edu/redtide/page.do?pid=14215. Accessed 
June 2011.
    WHOI. 2008. HAB Impacts on Wildlife. Woods Hole Oceanographic 
Institution. http://www.whoi.edu/redtide/page.do?pid=9682. Accessed 
June 2011.
    NOAA. 2011. Overview of Harmful Algal Blooms. National Oceanic 
and Atmospheric Administration, Center for Sponsored Coastal Ocean 
Research.
    http://www.cop.noaa.gov/stressors/extremeevents/hab/default.aspx. Accessed June 2011.
    \53\ Thessen, A.E., and D.K. Stoecker. 2008. Distribution, 
abundance and domoic acid analysis of the toxic diatom genus Pseudo-
nitzschia from the Chesapeake Bay. Estuaries and Coasts 31:664-672.
    \54\ Bushaw-Newton, K.L., and K.G. Sellner. 1999. Harmful Algal 
Blooms. In: NOAA's State of the Coast Report. National Oceanic and 
Atmospheric Administration, Silver Spring, MD. http://oceanservice.noaa.gov/Web sites/retiredsites/sotc--pdf/hab.pdf. 
Accessed June 2011.
    \55\ MBARI. 2000, January 5. Molecular Probes Link Sea Lion 
Deaths to Toxic Algal Bloom. MBARI News and Information. Monterey 
Bay Aquarium Research Institute. http://www.mbari.org/news/news_releases/2000/jan06_scholin.html. Accessed June 2011.
    \56\ Waring G.T., E. Josephson, K. Maze-Foley, and P.E. Rosel, 
eds. 2010. Humpback Whale (Megaptera novaeangliae): Gulf of Maine 
Stock (December 2009). In: U.S. Atlantic and Gulf of Mexico Marine 
Mammal Stock Assessments--2010, NOAA Technical Memorandum NMFS-NE-
219. National Oceanic and Atmospheric Administration, National 
Marine Fisheries Service, Northeast Fisheries Science Center, Woods 
Hole, MA. http://www.nefsc.noaa.gov/publications/tm/tm219/. Accessed 
January 2012.
    \57\ Rensel, J.E.J. 2007. Fish kills from the harmful alga 
Heterosigma akashiwo in Puget Sound: Recent blooms and review. 
Prepared for National Oceanic and Atmospheric Administration, Center 
for Sponsored Coastal Ocean Research, by Rensel Associates Aquatic 
Sciences, Arlington, Washington, in cooperation with American Gold 
Seafoods, LLC. http://www.whoi.edu/fileserver.do?id=39383&pt=2&p=29109. Accessed January 2012.
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    Secondly, excessive algal growth as a result of nitrogen and 
phosphorus pollution reduces water clarity, resulting in reduced light 
availability for macrophytes and seagrasses.\58\ Seagrasses cover 
approximately 2.7 million acres throughout the State and are a central 
ecological feature of Florida's dynamic, highly productive marine 
ecosystems.\59\ A substantial body of scientific research has linked 
nitrogen and phosphorus pollution, and

[[Page 74933]]

subsequent reduced light availability, to seagrass decline. Excessive 
nutrient inputs increase phytoplankton biomass and thereby increase 
water column light attenuation, which limits the light available for 
seagrass photosynthesis. This results in reduced growth and increased 
mortality of seagrasses. In addition, nitrogen and phosphorus pollution 
can lead to excess growth of epiphytic algae on seagrasses that blocks 
the light available to seagrasses and affects seagrass growth.\60\ This 
reduction of seagrass communities, in turn, results in harmful, adverse 
impacts such as destabilization of sediments, which causes the release 
of more nutrients into the water column.\61\
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    \58\ Vitousek, P.M., J.D. Aber, R.W. Howarth, G.E. Likens, P.A. 
Matson, D.W. Schindler, W.H. Schlesinger, and D.G. Tilman. 1997. 
Human alteration of the global nitrogen cycle: Sources and 
consequences. Ecological Applications 7(3):737-750.
    Bricker, S.B., J.G. Ferreira, and T. Simas. 2003. An integrated 
methodology for assessment of estuarine trophic status. Ecological 
Modelling 169(1):39-60.
    Bricker, S.B., B. Longstaff, W. Dennison, A. Jones, K. Boicourt, 
C. Wicks, and J. Woerner. 2008. Effects of nutrient enrichment in 
the nation's estuaries: A decade of change. Harmful Algae 8(1):21-
32.
    Boyer, J.N., C.R. Kelble, P.B. Ortner, and D.T. Rudnick. 2009. 
Phytoplankton bloom status: Chlorophyll a biomass as an indicator of 
water quality condition in the southern estuaries of Florida, USA. 
Ecological Indicators 9(6, Supplement 1):S56-S67.
    \59\ FFWCC. 2003. Conserving Florida's Seagrass Resources: 
Developing a Coordinated Statewide Management Program. Florida Fish 
and Wildlife Conservation Commission, Florida Marine Research 
Institute, St. Petersburg, FL.
    \60\ Duarte, C.M. 1991. Seagrass depth limits. Aquatic Botany 
40(4):363-377.
    \61\ Boyer, J.N., C.R. Kelble, P.B. Ortner, and D.T. Rudnick. 
2009. Phytoplankton bloom status: Chlorophyll a biomass as an 
indicator of water quality condition in the southern estuaries of 
Florida, USA. Ecological Indicators 9(6, Supplement 1):S56-S67.
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    The role that nitrogen and phosphorus pollution plays in the 
decline of seagrass has been studied extensively in Florida.\62\ In a 
report published by USGS in 2001, six of nine Florida estuaries located 
along the Gulf Coast showed declines in seagrass coverage, the 
predominant causes of which were nitrogen and phosphorus pollution, 
dredging, propeller scarring, hydrologic alterations, increased 
turbidity, and chronic light reduction.\63\ Florida Fish & Wildlife 
Conservation Commission has noted several areas of significant seagrass 
decline between 1950 and 2000, including 72 percent loss in St. Joseph 
Sound, 43 percent loss in the northern section of Biscayne Bay near 
Miami, 40 percent loss in Tampa Bay, 30 percent loss in the Indian 
River Lagoon, and 29 percent loss in Charlotte Harbor. These losses 
coincided with population growth in these watersheds, and resulted from 
human activities such as fertilizer use in residential and agricultural 
areas and construction projects which contribute high levels of 
suspended sediments.\64\ Several studies have attributed declines in 
seagrass to excess chlorophyll a and phytoplankton in the water column 
which can increase light attenuation. One study conducted from 1989-
1991 found that excess chlorophyll a caused light attenuation of 16 to 
28 percent across Charlotte Harbor and Tampa Bay. In the same study, 
the authors noted an overall improvement in seagrass recolonization and 
areal cover in Hillsborough Bay and other parts of Tampa Bay starting 
in the late 1980s coinciding with decreased nutrient loading, which 
resulted in decreased concentrations of chlorophyll a and increased 
water clarity.\65\ A later study, which conducted sampling monthly 
between June 1998 and July 1999, estimated that phytoplankton biomass 
contributed approximately 29 percent of total water column light 
attenuation in Lemon Bay, Florida. The authors predicted a continuation 
in the potential decline of seagrasses with increased urbanization.\66\
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    \62\ Dawes, C.J., R.C. Phillips, and G. Morrison. 2004. Seagrass 
Communities of the Gulf Coast of Florida: Status and Ecology, Final 
Report. Technical Publication 03-04. Florida Fish and 
Wildlife Conservation Commission, Fish and Wildlife Research 
Institute, and the Tampa Bay Estuary Program, St. Petersburg, FL.
    Tomasko, D.A., C.A. Corbett, H.S. Greening, and G.E. Raulerson. 
2005. Spatial and temporal variation in seagrass coverage in 
Southwest Florida: assessing the relative effects of anthropogenic 
nutrient load reductions and rainfall in four contiguous estuaries. 
Marine Pollution Bulletin 50:797-805.
    Orth, R.J., T.J.B. Carruthers, W.C. Dennison, C.M. Duarte, J.W. 
Fourqurean, K.L. Heck Jr., A.R. Hughes, G.A. Kendrick, W.J. 
Kenworthy, S. Olyarnik, F.T. Short, M. Waycott, and S.L. Williams. 
2006. A global crisis for seagrass ecosystems. Bioscience 56:987-
996.
    Burkholder, J.M., D.A. Tomasko, and B.W. Touchette. 2007. 
Seagrasses and eutrophication. Journal of Experimental Marine 
Biology and Ecology 350:46-72.
    Collado-Vides, L., V.G. Caccia, J.N. Boyer, and J.W. Fourqurean. 
2007. Tropical seagrass-associated macroalgae distributions and 
trends relative to water quality. Estuarine, Coastal and Shelf 
Science 73:680-694.
    \63\ USGS. 2001. Seagrass Habitat In the Northern Gulf of 
Mexico: Degradation, Conservation, and Restoration of a Valuable 
Resource. 855-R-04-001. U.S. Geological Survey, Gulf of Mexico 
Habitat Program Team. http://gulfsci.usgs.gov/gom_ims/pdf/pubs_gom.pdf. Accessed July 2011.
    \64\ FFWCC. 2002. Florida's Seagrass Meadows: Benefitting 
Everyone. Florida Fish and Wildlife Conservation Commission, St. 
Petersburg, FL. http://www.sarasotabay.org/documents/seagrassbrochure.pdf. Accessed July 2011.
    \65\ McPherson, B.F., and R.L. Miller. 1994. Causes of Light 
Attenuation in Tampa Bay and Charlotte Harbor, Southwestern Florida. 
Water Resources Bulletin 30(1):43-53.
    \66\ Tomasko, D.A., D.L. Bristol, and J.A. Ott. 2001. Assessment 
of present and future nitrogen loads, water quality, and seagrass 
(Thalassia testudinum) depth distribution in Lemon Bay, Florida. 
Estuaries 24(6A):926-938.
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    Lastly, excessive algal growth also leads to low dissolved oxygen 
(DO) potentially creating hypoxic and anoxic conditions that cannot 
support aquatic life and thereby can change the balance of natural 
populations of aquatic fauna expected to occur.\67\ Hypoxia is 
typically defined as DO < 2 mg/L, and anoxia as DO < 0.1 mg/L.\68\ The 
cause and effect relationship between nitrogen and phosphorus pollution 
and marine hypoxia is clear and well documented in the scientific 
literature.\69\ Increased nitrogen and phosphorus inputs lead to 
excessive algal growth and organic matter loading to bottom waters. 
Bacterial decomposition of the organic matter consumes oxygen and 
depletes the water column of DO.\70\ In estuaries and coastal waters, 
low DO is one of the most widely reported consequences of nitrogen and 
phosphorus pollution and one of the best predictors of a range of 
biotic impairments.\71\ Low DO causes negative impacts to aquatic life 
ranging from mortality to chronic impairment of growth and 
reproduction.\72\ When nitrogen and phosphorus pollution creates 
adverse conditions that result in large hypoxic zones, substantial 
negative changes in fish, benthic, and plankton communities may 
occur.\73\ This includes avoidance of these areas by fish, mobile 
benthic invertebrates migrating from the hypoxic area, and fish kills 
in some systems when fish and other mobile aquatic organisms have 
nowhere to migrate away from the areas

[[Page 74934]]

with low DO.\74\ This can result in negative changes to the benthic 
invertebrate community structure of estuaries and coastal areas, with 
increases of organisms more tolerant of low DO.\75\ Even intermittent 
hypoxia can cause shifts in the benthic assemblage to favor resistant 
or tolerant organisms, which are less desirable food sources, creating 
unbalanced benthic communities in the hypoxic zone because fish avoid 
the area.\76\ When hypoxia extends into shallow waters, it affects 
spawning and nursery areas for many important fish species by reducing 
the habitat available that protects smaller fish and aquatic organisms, 
especially juveniles, from predation.\77\ Hypoxia has been implicated 
in a recent increase and late-summer dominance of hypoxia-tolerant 
gelatinous zooplankton (jellyfish and ctenophores) in the Chesapeake 
Bay and other eastern estuaries.\78\ Reduced fishery production in 
hypoxic zones has been documented in the United States and 
worldwide.\79\
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    \67\ Vitousek, P.M., J.D. Aber, R.W. Howarth, G.E. Likens, P.A. 
Matson, D.W. Schindler, W.H. Schlesinger, and D.G. Tilman. 1997. 
Human alteration of the global nitrogen cycle: Sources and 
consequences. Ecological Applications 7(3):737-750.
    \68\ USEPA. 1999. The Ecological Condition of Estuaries in the 
Gulf of Mexico. EPA 620-R-98-004. U.S. Environmental Protection 
Agency, Office of Research and Development, National Health and 
Environmental Effects Research Laboratory, Gulf Ecology Division, 
Gulf Breeze, FL.
    \69\ Conley, D., J. Carstensen, R. Vaquer-Sunyer, and C. Duarte. 
2009. Ecosystem thresholds with hypoxia. Hydrobiologia 629(1):21-29.
    Conley, D.J., H.W. Paerl, R.W. Howarth, D.F. Boesch, S.P. 
Seitzinger, K.E. Havens, C. Lancelot, and G.E. Likens. 2009. 
Controlling Eutrophication: Nitrogen and Phosphorus. Science 
323(5917):1014-1015.
    Diaz, R.J. 2001. Overview of hypoxia around the world. Journal 
of Environmental Quality 30(2):275-281. Diaz, R.J., and R. 
Rosenberg. 2008. Spreading dead zones and consequences for marine 
ecosystems. Science 321(5891):926-929.
    \70\ Clement, C., S.B. Bricker and D.E. Pirhalla. 2001. 
Eutrophic Conditions in Estuarine Waters. In: NOAA's State of the 
Coast Report. National Oceanic and Atmospheric Administration, 
Silver Spring, MD. http://state-of-coast.noaa.gov/bulletins/html/eut_18/eut.html. Accessed December 2011.
    \71\ Bricker, S.B., J.G. Ferreira, and T. Simas. 2003. An 
integrated methodology for assessment of estuarine trophic status. 
Ecological Modelling 169(1):39-60.
    Bricker, S.B., C.G. Clement, D.E. Pirhalla, S.P. Orlando, and 
D.R.G. Farrow. 1999. National Estuarine Eutrophication Assessment, 
Effects of Nutrient Enrichment in the Nation's Estuaries. National 
Oceanic and Atmospheric Administration, National Ocean Service, 
Special Projects Office and the National Centers for Coastal Ocean 
Science. Silver Spring, MD.
    \72\ USEPA. 2001. Nutrient Criteria Technical Guidance Manual, 
Estuarine and Coastal Marine Waters. EPA-822-B-01-003. U.S. 
Environmental Protection Agency, Office of Water, Washington, DC.
    \73\ Howell, P., and D. Simpson. 1994. Abundance of marine 
resources in relation to dissolved oxygen in Long Island Sound. 
Estuaries 17(2):394-402.
    Kidwell, D.M., A.J. Lewitus, S. Brandt, E.B. Jewett, and D.M. 
Mason. 2009. Ecological impacts of hypoxia on living resources. 
Journal of Experimental Marine Biology and Ecology 381(Supplement 
1):S1-S3.
    \74\ Howell, P., and D. Simpson. 1994. Abundance of marine 
resources in relation to dissolved oxygen in Long Island Sound. 
Estuaries 17(2):394-402.
    Kidwell, D.M., A.J. Lewitus, S. Brandt, E.B. Jewett, and D.M. 
Mason. 2009. Ecological impacts of hypoxia on living resources. 
Journal of Experimental Marine Biology and Ecology 381(Supplement 
1):S1-S3.
    \75\ Baker, S., and R. Mann. 1992. Effects of hypoxia and anoxia 
on larval settlement, juvenile growth, and juvenile survival of the 
oyster Crassostrea virginica. Biological Bulletin 182(2):265-269.
    Baker, S., and R. Mann. 1994. Feeding ability during settlement 
and metamorphosis in the oyster Crassostrea virginica (Gmelin, 1791) 
and the effects of hypoxia on post-settlement ingestion rates. 
Journal of Experimental Marine Biology and Ecology 181(2):239-253.
    Baker, S.M., and R. Mann. 1994. Description of metamorphic 
phases in the oyster Crassostrea virginica and effects of hypoxia on 
metamorphosis. Marine Ecology Progress Series 104:91-99.
    Baustian, M., and N. Rabalais. 2009. Seasonal composition of 
benthic macroinfauna exposed to hypoxia in the northern Gulf of 
Mexico. Estuaries and Coasts 32(5):975-983.
    Breitburg, D. 2002. Effects of hypoxia, and the balance between 
hypoxia and enrichment, on coastal fishes and fisheries. Estuaries 
25(4):767-781.
    \76\ Kidwell, D.M., A.J. Lewitus, S. Brandt, E.B. Jewett, and 
D.M. Mason. 2009. Ecological impacts of hypoxia on living resources. 
Journal of Experimental Marine Biology and Ecology 381(Supplement 
1):S1-S3.
    \77\ Breitburg, D. 2002. Effects of hypoxia, and the balance 
between hypoxia and enrichment, on coastal fishes and fisheries. 
Estuaries 25(4):767-781.
    \78\ Grove, M., and D.L. Breitburg. 2005. Growth and 
reproduction of gelatinous zooplankton exposed to low dissolved 
oxygen. Marine Ecology Progress Series 301:185-198.
    \79\ Diaz, R.J., and R. Rosenberg. 2008. Spreading dead zones 
and consequences for marine ecosystems. Science 321(5891):926-929.
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    Hypoxia and anoxia in bottom waters result in anoxia in the surface 
sediments, which has geochemical consequences including acidification 
and release of toxic hydrogen sulfide, soluble reactive phosphorus, and 
ammonia.\80\ The sediment of hypoxic zones then becomes a potential 
source of nutrients that can increase the degree of eutrophication. 
Systems that have had persistent and chronic hypoxia often fail to 
recover quickly even after pollution loadings have been reduced.\81\ 
Reduced oxygen also affects a variety of other biogeochemical processes 
that can negatively impact water quality, such as the chemical form of 
metals in the water column.\82\
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    \80\ Diaz, R.J., and R. Rosenberg. 2008. Spreading dead zones 
and consequences for marine ecosystems. Science 321(5891):926-929.
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interactions. Marine Ecology Progress Series 303:1-29.
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water hypoxia effects on sediment-water interface nitrogen 
transformations in a seasonally hypoxic, shallow bay (Corpus Christi 
Bay, TX, USA). Estuaries and Coasts 31(3):521-531.
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Lohrenz, W. Chou, W. Zhai, J.T. Hollibaugh, Y. Wang, P. Zhao, X. 
Guo, K. Gundersen, M. Dai, and G. Gong.. 2011. Acidification of 
subsurface coastal waters enhanced by eutrophication. Nature 
Geoscience 4:766-770.
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Christensen, T. Dalsgaard, J.L.S. Hansen, and A.B. Josefson. 2007. 
Long-term changes and impacts of hypoxia in Danish coastal water. 
Ecological Applications 17(sp5):S165-S184.
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consequences for marine ecosystems. Science 321(5891):926-929.
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Reactions. Chapter 7 In: Water Chemistry, pp. 316-430. John Wiley 
and Sons, New York.
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    The harmful, adverse impacts of nitrogen and phosphorus pollution 
on aquatic life have been manifested throughout Florida. The State has 
been negatively impacted by algal blooms for many years. Red algae, 
Laurencia intricata and Spyridia filamentosa; brown algae, Dictyota sp. 
and Sargassum filipendula; and green algae, Enteromorpha sp., Codium 
isthmocladum, and Halimeda sp. grow in the Florida Bay area.\83\ At 
times their increased growth has threatened the commercially important 
fish, lobster, and shrimp nurseries in the area.\84\ Southern Palm 
Beach and northern Broward counties have been negatively impacted by 
algal mats made up of Caulerpa species since the 1990s. Caulerpa 
species can become overgrown or displace coral, other macroalgae, or 
sponges. Off Palm Beach County, dive operators and fishermen have 
reported large amounts of Caulerpa brachypus driving fish and lobster 
away from reefs. Researchers in Florida (e.g., Florida Sea Grant, 
University of Florida IFAS Extension, University of Central Florida, 
Tampa Bay Estuary Program) and nationally (e.g., National Sea Grant, 
NOAA) have noted the spread of a related green alga (Caulerpa 
taxifolia) along the California coast, which is illustrative of the 
potential for future further spread of C. brachypus in Florida coastal 
waters. California is spending millions to eradicate the C. 
taxifolia.\85\ Gambierdiscus toxicus (a ciguatoxin producer) is found 
from Palm Beach to the Dry Tortugas and Florida Bay and is suspected to 
have caused fish kills and disease events.\86\ Blooms of Lyngbya 
majuscula were reported in Charlotte Harbor, Cedar Key, Sebastian 
Inlet, Sarasota Bay, Tampa Bay, Terra Ceia Bay, Palma Sola, Manatee 
River, and northwest Bradenton in 1999, 2000, and 2002. Lyngbya 
majuscula can form sizeable, floating mats that emit foul odors.\87\ In 
1991, widespread and persistent blooms of cyanobacteria in Florida Bay 
coincided with massive sponge die-offs, which negatively impacted the 
behavior and abundance of populations of juvenile Caribbean spiny 
lobsters.\88\ Two Pseudo-nitzschia species found in Florida are P. 
calliantha, which was observed at bloom levels in the northern Indian 
River Lagoon, and P.

[[Page 74935]]

pseudodelicatissima.\89\ Pseudo-nitzschia spp. has been observed in 
Tampa Bay since the 1960s. Pseudo-nitzschia spp. cause amnesic 
shellfish poisoning in humans and mortality of marine mammals and 
seabirds.\90\
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    \83\ Anderson, D.M., ed. 1995. ECOHAB: The Ecology and 
Oceanography of Harmful Algal Blooms: A National Research Agenda. 
Woods Hole Oceanographic Institution, Woods Hole, MA.
    \84\ Anderson, D.M., ed. 1995. ECOHAB: The Ecology and 
Oceanography of Harmful Algal Blooms: A National Research Agenda. 
Woods Hole Oceanographic Institution, Woods Hole, MA.
    \85\ Jacoby, C., B. Lapointe, and L. Creswell. No date. Are 
native and nonindigenous seaweeds overgrowing Florida's east coast 
reefs? SGEF-156. Florida Sea Grant College Program. http://nsgl.gso.uri.edu/flsgp/flsgpg01015.pdf. Accessed January 2012.
    Jacoby, C., and L. Walters. 2009. Can We Stop ``Killer Algae'' 
from Invading Florida? (March 2009 rev.) SGEF-155. Florida Sea Grant 
College Program. http://edis.ifas.ufl.edu/pdffiles/sg/sg07200.pdf. 
Accessed April 2012.
    \86\ FFWCC. No date. Gambierdiscus toxicus. Florida Fish and 
Wildlife Conservation Commission. http://myfwc.com/media/202186/g_toxicus_1054.pdf. Accessed January 2012.
    \87\ FFWCC. No date. Blue-Green Algal Blooms in Coastal Florida; 
1999, 2000, and 2002. Florida Fish and Wildlife Conservation 
Commission. http://myfwc.com/research/redtide/archive/historical-events/blue-green-algal-blooms-coastal-fl/. Accessed January 2012.
    \88\ Butler, M.J., J.H. Hunt, W.F. Herrnking, M.J. Childress, R. 
Bertelsen, W. Sharp, T. Matthews, J.M. Field, and H.G. Marshall. 
1995. Cascading disturbances in Florida Bay, USA: cyanobacteria 
blooms, sponge mortality, and implications for juvenile spiny 
lobsters Panulirus argus. Marine Ecology Progress Series 129:119-
125.
    \89\ Phlips, E.J., S. Badylak, M. Christman, J. Wolny, J. Brame, 
J. Garland, L. Hall, J. Hart, J. Lansberg, M. Lasi, J. Lockwood, R. 
Paperno, D. Scheidt, A. Staples, K. Steidinger. 2011. Scales of 
temporal and spatial variability in the distribution of harmful 
algae species in the Indian River Lagoon, Florida, USA. Harmful 
Algae 10:277-290.
    Phlips, E.J., S. Badylak, S. Youn, and K. Kelley. 2004. The 
occurrence of potentially toxic dinoflagellates and diatoms in a 
subtropical lagoon, the Indian River Lagoon, Florida, USA. Harmful 
Algae 3(1):39-49.
    \90\ Badylak, S., E.J. Phlips, P. Baker, J. Fajans, and R. 
Boler. 2007. Distributions of phytoplankton in Tampa Bay estuary, 
U.S.A. 2002-2003. Bulletin of Marine Science 80(2):295-317.
    Lopez, C.B., Q. Dortch, E.B. Jewett, and D. Garrison. 2008. 
Scientific Assessment of Marine Harmful Algal Blooms. Interagency 
Working Group on Harmful Algal Blooms, Hypoxia, and Human Health of 
the Joint Subcommittee on Ocean Science and Technology, Washington, 
DC. http://www.cop.noaa.gov/stressors/extremeevents/hab/habhrca/assess_12-08.pdf. Accessed April 2012.
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    In addition to being negatively indirectly impacted by algal toxins 
and decline of seagrass, aquatic life in Florida is directly impacted 
by hypoxia. In June 2011, a fish kill in Marco Island, Florida was 
attributed to low dissolved oxygen, resulting from a ``mixed'' bloom of 
non-toxic algae and diatoms.\91\ In 2010, there were reports of algal 
blooms and fish kills in the St. Johns River.\92\ Spring releases of 
water from Lake Okeechobee into the St. Lucie Canal resulted in 
floating mats of toxic cyanobacteria, Microcystis aeruginosa, prompting 
Martin and St. Lucie county health departments to issue public health 
warnings.\93\ A large Microcystis bloom was documented in the Lower St. 
Johns River in 2005, covering a 100 mi (160 km) stretch from 
Jacksonville to Crescent City.\94\ Toxic cyanobacteria Anabaena 
circinalis and Cylindrospermopsis raciborskii have been implicated in 
fish kills in the Lower St. Johns River basin.\95\ In addition, in June 
2009, a large algal bloom stretching more than 14 mi (23 km) was 
documented in Tampa Bay. This was linked to surface water runoff of 
nutrients and pollutants (e.g., fertilizers, yard waste, animal feces) 
that were washed into the bay from recent heavy rains.\96\
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    \91\ Fish kill in island canals appears over. 2011, June 2. 
Marconews.com -Marco Eagle. http://www.marconews.com/news/2011/jun/02/dead-fish-bad-smell-permeate-parts-island/?print=1. Accessed 
January 2012.
    \92\ Patterson, S. 2010, July 23. St John's River Looks Sick, 
Nelson says. The Florida Times Union. http://jacksonville.com/news/metro/2010-07-23/story/st-johns-looks-sick-nelson-says. Accessed 
September 2010.
    Patterson, S. 2010, July 21. Foam on St. John's River Churns Up 
Environmental Interest. The Florida Times Union. http://jacksonville.com/news/metro/2010-07-21/story/foam-st-johns-churns-environmental-questions. Accessed October 2010.
    \93\ Killer, E. 2010, June 10. Blue-green Algae Found Floating 
Near Palm City as Lake Okeechobee Releases Continue. TCPalm. http://www.tcpalm.com/news/2010/jun/10/blue-green-algae-found-floating-near-palm-city-o/. Accessed October 2010.
    \94\ Aubel, M., P. D'Aiuto, A. Chapman, D. Casamatta, A. Reich, 
S. Ketchen, and C. Williams. 2006. Blue-Green Algae in St. Johns 
River, FL. Lakeline Summer 2006:40-45.
    \95\ Abbott, G. M., J. H. Landsberg, A. R. Reich, K. A. 
Steidinger, S. Ketchen, and C. Blackmore. 2009. Resource Guide for 
Public Health Response to Harmful Algal Blooms in Florida. FWRI 
Technical Report TR-14. Florida Fish and Wildlife Conservation 
Commission, Fish and Wildlife Research Institute, St. Petersburg, 
FL. http://myfwc.com/research/redtide/task-force/reports-presentations/resource-guide-for-public-health-response-to-harmful-algal-blooms-in-florida/. Accessed June 2011.
    http://www.lsjr.org/pdf/ResourceGuide_FL_algal_blooms_2009.pdf. Accessed June 2011.
    \96\ Pittman, C. 2009, June 26. Algae bloom one of largest in 
Tampa Bay history. St. Petersburg Times. http://www.tampabay.com/news/environment/water/article1013322.ece. Accessed July 2010.
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    Numerous algal blooms, some capable of producing toxins, foul 
odors, and fish kills, occurred in Florida coastal areas, estuaries, 
and canals in 2011. Green algae, known as June Grass, were found 
washing onto local beaches on Okaloosa Island. The algae adhere to 
swimmers, cover beaches and hinder fishing.\97\
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    \97\ Tammen, K. 2011, April 20. It's not even June and the June 
Grass is Back. Northwest Florida Daily News. http://www.nwfdailynews.com/news/grass-39438-island-okaloosa.html. Accessed 
April 2011.
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    In the Caloosahatchee River and estuary, high algae and salinity 
levels caused the Olga water treatment plant in Lee County to close in 
May 2011. Customers complained about unusual tastes and odors in their 
drinking water. The blue-green algae bloom significantly affected areas 
from the W.P. Franklin Lock and Dam, upstream through Alva and LaBelle, 
Florida. The bloom caused fish, bird and shellfish mortalities, and 
triggered the Lee County Health Department to issue warnings and 
advisories on water and fish consumption as well as swimming. Toxic 
blue-green algae species were identified in the bloom, including 
Anabaena, Oscillatoria and Aphanizomenon sp.\98\
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    \98\ Lee Closes a Water Plant; Blame Algae and Saltwater 
intrusion in Caloosahatchee. 2011, May 19. CBS Wink News Now. http://www.winknews.com/Local-Florida/2011-05-19/Lee-Closes-a-Water-Plant-Blame-Algae-and-Salt-water-intrusion-in-Caloosahatchee. Accessed 
December 2011.
    Lollar, K. 2011, June 6. Bacterial bloom stains waterway up to 
LaBelle. News-Press. http://www.marconews.com/news/2011/jun/02/dead-fish-bad-smell-permeate-parts-island/. Accessed June 2011.
    Crisis in the Caloosahatchee: Algal blooms in local waters. 
2011, June 8. Sanibel-Captiva Islander. http://sanibel-captiva-
islander.com/page/content.detail/id/511872/Crisis-in-the-
Caloosahatchee--Algal-blooms-in-local-waters.html?nav=5051. Accessed 
June 2011.
    Warning added for Lee County waters. 2011, June 16. CBS Wink 
News Now.
    http://www.winknews.com/Local-Florida/2011-06-16/Warning-added-for-Lee-County-waters. Accessed June 2011.
    Cornwell, B. 2011, June 22. Algae Bloom doesn't deter everyone. 
Fort Meyers Florida Weekly. http://fortmyers.floridaweekly.com/news/2011-06-22/Top_News/Algae_bloom_doesnt_deter_everyone.html. 
Accessed June 2011.
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    The Indian River Lagoon also experienced large and prolonged algae 
blooms. High levels of green algae Resultor sp. were found from 
Titusville to Melbourne and covering the entire Banana River. The algae 
were thought to be responsible for killing hundreds of fish and 
inhibiting seagrass growth.\99\ A large rust-colored bloom of 
Pyrodinium bahamense formed in Old Tampa Bay in August 2011; the bloom 
stretched from Safety Harbor to the Howard Frankland Bridge and was 
thought to be caused by a combination of heat, rain, and fertilizer 
runoff.\100\
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    \99\ Florida Today. 2011, July 18. Green algae killing fish, 
seagrass in northern Indian River Lagoon. 10 News WTSP--Tampa Bay. 
http://www.wtsp.com/rss/article/201465/19/Green-algae-killing-fish-seagrass-in-northern-Indian-River-Lagoon. Accessed December 2011.
    \100\ Reyes, R. 2011, August 31. Algae bloom continues to grow 
in Old Tampa Bay. Tampa Bay Online. http://www2.tbo.com/news/breaking-news/2011/aug/31/1/algae-bloom-continues-to-grow-in-old-tampa-bay-ar-254281/. Accessed December 2011.
    Harwell, D. 2011, August 27. Tampa Bay algae bloom threatens the 
estuary's fish. St. Petersburg Times. http://www.tampabay.com/news/environment/water/tampa-bay-algae-bloom-threatens-the-estuarys-fish/1188284. Accessed August 2011.
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c. Adverse Impacts of Nitrogen and Phosphorus Pollution on Human Health
    As noted previously in section II.A.1.b, nitrogen and phosphorus 
pollution have been explicitly linked to changes in natural algal 
species composition including increased growth or dominance of toxic or 
otherwise harmful algal species.\101\ Toxins produced by HABs have been 
linked, through recreational exposure, to adverse human health impacts 
through ingestion of contaminated seafood,

[[Page 74936]]

dermal reactions, and respiratory problems.\102\ Ingestion of seafood 
that is contaminated with toxins can cause gastrointestinal, 
neurological, cardiovascular, and hepatological illnesses. In some 
severe cases, ingestion of even a small amount of contaminated seafood 
can result in coma or death.\103\
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    \101\ Paerl, H.W. 1988. Nuisance phytoplankton blooms in 
coastal, estuarine, and inland waters. Limnology and Oceanography 
33(4):823-847.
    Anderson, D.M., P.M. Glibert, and J.M. Burkholder. 2002. Harmful 
algal blooms and eutrophication: Nutrient sources, composition, and 
consequences. Estuaries 25(4):704-726.
    Anderson, D.M., J.M. Burkholder, W.P. Cochlan, P.M. Glibert, 
C.J. Gobler, C.A. Heil, R.M. Kudela, M.L. Parsons, J.E.J. Rensel, 
D.W. Townsend, V.L. Trainer, and G.A. Vargo. 2008. Harmful algal 
blooms and eutrophication: Examining linkages from selected coastal 
regions of the United States. Harmful Algae 8(1):39-53.
    \102\ WHOI. 2006. Harmful Algae and Red Tides Primer. Woods Hole 
Oceanographic Institution, Woods Hole, MA.
    Anderson, D.M. 2004. The Growing Problem of Harmful Algae: Tiny 
plants pose a potent threat to those who live in and eat from the 
sea. Woods Hole Oceanographic Institution. Oceanus Magazine 43(1):1-
5.
    Graham, J. 2007. Harmful Algal Blooms. Fact Sheet 2006-3147. 
U.S. Geological Survey, Lawrence, KS CDC. 2004. About Harmful Algal 
Blooms. Centers for Disease Control and Prevention, Atlanta, GA 
Bronstein, A.C., D.A. Spyker, L.R. Cantilena, Jr., J.L. Green, B.H. 
Rumack, S.L. Giffin. 2009. 2008 Annual Report of the American 
Association of Poison Control Centers' National Poison Data System 
(NPDS): 26th Annual Report. Clinical Toxicology 48:979-1178.
    Landsberg, J., F.Van Dolah, and G. Doucette. 2005. Marine and 
estuarine harmful algal blooms: Impacts on human and animal health. 
Chapter 8 In: Oceans and Health: Pathogens in the Marine 
Environment. eds. S. Belkin and R.R. Colwell, pp.165-215. Springer, 
New York.
    NOAA. 2009. Marine Biotoxins. National Oceanic and Atmospheric 
Administration, Northwest Fisheries Science Center. http://www.nwfsc.noaa.gov/hab/habs_toxins/marine_biotoxins/index.html. 
Accessed December 2011.
    Anderson, D., P. Glibert, and J. Burkholder. 2002. Harmful Algal 
Blooms and Eutrophication: Nutrient Sources, Composition, and 
Consequences. Estuaries 25(4b):704-726.
    \103\ Bushaw-Newton, K.L., and K.G. Sellner. 1999. Harmful Algal 
Blooms. In: NOAA's State of the Coast Report. National Oceanic and 
Atmospheric Administration, Silver Spring, MD. http://oceanservice.noaa.gov/websites/retiredsites/sotc_pdf/hab.pdf. 
Accessed June 2011.
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    Nitrogen and phosphorus pollution has been linked to human health 
impacts in Florida, primarily through illnesses associated with HABs. 
Although marine HABs occur naturally, increased nutrient loadings and 
pollution have been linked to increased occurrence of some types of 
HABs.\104\ Significant HAB-caused toxins that have been found in 
Florida's marine waters include saxitoxins, brevetoxins, ciguatoxins, 
cyanotoxins, domoic acid, and okadaic acid.\105\
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    \104\ Lopez, C.B., Q. Dortch, E.B. Jewett, and D. Garrison. 
2008. Scientific Assessment of Marine Harmful Algal Blooms. 
Interagency Working Group on Harmful Algal Blooms, Hypoxia, and 
Human Health of the Joint Subcommittee on Ocean Science and 
Technology, Washington, DC.
    \105\ Abbott, G.M., J.H. Landsberg, A.R. Reich, K.A. Steidinger, 
S. Ketchen, and C. Blackmore. 2009. Resource Guide for Public Health 
Response to Harmful Algal Blooms in Florida. FWRI Technical Report 
TR-14. Florida Fish and Wildlife Conservation Commission, Fish and 
Wildlife Research Institute, St. Petersburg, FL. http://myfwc.com/research/redtide/task- force/reports-presentations/resource-guide-
for-public-health-response-to-harmful-algal-blooms-in-florida/. 
Accessed June 2011.
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    Ciguatoxins lead to Ciguatera fish poisoning (CFP), one of the most 
commonly reported food borne illnesses caused by a marine biotoxin in 
the United States,\106\ with 176 cases reported to U.S. poison centers 
in 2009 (22 percent of the total reported cases of food poisoning from 
seafood toxins).\107\ Ciguatoxins are bioaccumulative, causing 
gastrointestinal, neurological, or cardiovascular symptoms that vary in 
intensity.\108\ In Florida, CFP poses a significant risk to public 
health.\109\ One estimate indicates that approximately 1,300 cases of 
CFP (reported and unreported cases) occur annually in Florida.\110\ The 
Florida Department of Health (FDOH) reported 8 cases of CFP in 2005, 44 
cases in 2006, 34 cases in 2007, and 51 cases in 2008.\111\
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    \106\ Dickey, R.W., and S.M. Plakas. 2010. Ciguatera: A public 
health perspective. Toxicon 56:123-136.
    \107\ Bronstein, A.C., D.A. Spyker, L.R. Cantilena, Jr., J.L. 
Green, B.H. Rumack, and S.L. Giffin. 2009. 2008 Annual Report of the 
American Association of Poison Control Centers' National Poison Data 
System (NPDS): 26th Annual Report. Clinical Toxicology 48:979-1178.
    \108\ McKee D.B., L.E. Fleming, R. Tamer, R. Weisman, and D. 
Blythe. 2001. Physician diagnosis and reporting of ciguatera fish 
poisoning in an endemic area. In: Harmful Algal Blooms 2000: 
Proceedings of the Ninth International Conference on Harmful Algal 
Blooms, Hobart, Australia, 7-11 February 2000, eds. G.M. 
Hallegraeff, S.I. Blackburn, C.J. Bolch, and R.J. Lewis, pp. 451-
453. Intergovernmental Oceanographic Commission of UNESCO, Paris, 
France.
    \109\ Abbott, G. M., J. H. Landsberg, A.R. Reich, K.A. 
Steidinger, S. Ketchen, and C. Blackmore. 2009. Resource Guide for 
Public Health Response to Harmful Algal Blooms in Florida. FWRI 
Technical Report TR-14. Florida Fish and Wildlife Conservation 
Commission, Fish and Wildlife Research Institute, St. Petersburg, 
FL. http://myfwc.com/research/redtide/task-force/reports-presentations/resource-guide-for-public-health-response-to-harmful-algal-blooms-in-florida/. Accessed June 2011.
    \110\ Abbott, G. M., J. H. Landsberg, A.R. Reich, K.A. 
Steidinger, S. Ketchen, and C. Blackmore. 2009. Resource Guide for 
Public Health Response to Harmful Algal Blooms in Florida. FWRI 
Technical Report TR-14. Florida Fish and Wildlife Conservation 
Commission, Fish and Wildlife Research Institute, St. Petersburg, 
FL. http://myfwc.com/research/redtide/task- force/reports-
presentations/resource-guide-for-public-health-response-to-harmful-
algal-blooms-in-florida/. Accessed June 2011.
    \111\ Abbott, G. M., J.H. Landsberg, A.R. Reich, K.A. 
Steidinger, S. Ketchen, and C. Blackmore. 2009. Resource Guide for 
Public Health Response to Harmful Algal Blooms in Florida. FWRI 
Technical Report TR-14. Florida Fish and Wildlife Conservation 
Commission, Fish and Wildlife Research Institute, St. Petersburg, 
FL. http://myfwc.com/research/redtide/task-force/reports-presentations/resource-guide-for-public-health-response-to-harmful-algal-blooms-in-florida/. Accessed June 2011.
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    Saxitoxins lead to paralytic shellfish poisoning (PSP), which 
occurs when humans eat shellfish contaminated with saxitoxins. These 
toxins affect the nervous system and in severe cases cause respiratory 
paralysis.\112\ Between January 2002 and May 2004, 28 cases of 
saxitoxin poisoning associated with puffer fish caught in Florida's 
Indian River Lagoon (IRL) were reported. In 2002, the Florida Fish and 
Wildlife Conservation Commission banned the commercial and recreational 
harvest of puffer fish in several water bodies in Florida and made that 
ban permanent in 2004.\113\ Domoic acid, also produced by HABs, can 
also cause food poisoning, producing symptoms ranging from mild 
gastrointestinal discomfort to permanent brain damage and, in rare 
cases, death.\114\
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    \112\ Landsberg, J., F. Van Dolah, and G. Doucette. 2005. Marine 
and estuarine harmful algal blooms: Impacts on human and animal 
health. Chapter 8 In: Oceans and Health: Pathogens in the Marine 
Environment. eds. S. Belkin and R.R. Colwell, pp. 165-215. Springer, 
New York.
    \113\ Abbott, G.M., J.H. Landsberg, A.R. Reich, K.A. Steidinger, 
S. Ketchen, and C. Blackmore. 2009. Resource Guide for Public Health 
Response to Harmful Algal Blooms in Florida. FWRI Technical Report 
TR-14. Florida Fish and Wildlife Conservation Commission, Fish and 
Wildlife Research Institute, St. Petersburg, FL. http://myfwc.com/research/redtide/task-force/reports-presentations/resource-guide-for-public-health-response-to-harmful-algal-blooms-in-florida/. 
Accessed June 2011.
    Landsberg, J.H., S. Hall, J.N. Johannessen, K.D. White, S.M. 
Conrad, J.P. Abbott, L.J. Flewelling, R.W. Richardson, R.W. Dickey, 
E.L.E. Jester, S. M. Etheridge, J.R. Deeds, F.M. Van Dolah, T.A. 
Leighfield, Y. Zou, C.G. Beaudry, R.A. Benner, P.L. Rogers, P.S. 
Scott, K. Kawabata, J.L. Wolny, and K.A. Steidinger. 2006. Saxitoxin 
Puffer Fish Poisoning in the United States, with the First Report of 
Pyrodinium bahamense as the Putative Toxin Source. Environmental 
Health Perspectives 114(10):1502-1507.
    \114\ NOAA. 2009. Marine Biotoxins. National Oceanic and 
Atmospheric Administration, Northwest Fisheries Science Center. 
http://www.nwfsc.noaa.gov/hab/habs_toxins/marine_biotoxins/index.html. Accessed December 2011.
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    In addition, elevated levels of nitrate, a byproduct of nitrogen 
pollution in surface waters, can cause public health concerns if the 
water is a drinking water source, where \115\ nitrate is converted to 
harmful nitrite after ingestion.\116\ The primary human health concern 
with nitrates and nitrites in drinking water is methemoglobinemia, 
although adverse thyroid effects have been associated with elevated 
nitrates as well.\117\

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Methemoglobinemia, or ``blue baby syndrome,'' as the name implies, most 
often affects infants less than six months old (although adults can 
also be affected) when the ingested nitrate is converted to nitrite in 
the body that prevents hemoglobin in the blood from delivering oxygen 
effectively throughout the body. Methemoglobinemia is an acute disease 
and symptoms can develop rapidly in infants, usually over a period of 
days. Symptoms include shortness of breath and blueness of the skin, 
and even death in severe cases.\118\
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    \115\ FDEP. 1998. Ground-water Quality and Agricultural Land Use 
in the Polk County Very Intense Study Area (VISA). AMR 1998-2. 
Florida Department of Environmental Protection, Division of Water 
Facilities. http://www.dep.state.fl.us/water/monitoring/docs/facts/fs9802.pdf. Accessed September 2010.
    \116\ Gulis. G., M. Czompolyova, and J.R. Cerhan. 2002. An 
Ecologic Study of Nitrate in Municipal Drinking Water and Cancer 
Incidence in Trnava District, Slovakia. Environmental Research 
88:182-187.
    \117\ Fan, A.M., and V.E. Steinberg. 1996. Health implications 
of nitrate and nitrite in drinking water: An update on 
methemoglobinemia occurrence and reproductive and development 
toxicity. Regulatory Toxicology and Pharmacology 23(1 Pt 1):35-43.
    \118\ Manassaram, D.M., L.C. Backer, and D.M. Moll. 2006. A 
Review of Nitrates in Drinking Water: Maternal Exposure and Adverse 
Reproductive and Developmental Outcomes. Environmental Health 
Perspectives 114(3):320-327. FDEP. 2011. Drinking Water: Inorganic 
Contaminants. Florida Department of Environmental Protection. http://www.dep.state.fl.us/water/drinkingwater/inorg_con.htm. Accessed 
November 2011.
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    EPA developed a Maximum Contaminant Level (MCL) of 10 mg/L for 
nitrate in drinking water and an MCL of 1 mg/L for nitrite.\119\ 
Nitrates are found in groundwater and wells in Florida, ranging from 
the detection limit of 0.02 mg/L to over 20 mg/L. Elevated nitrate 
concentrations in groundwater are more common in rural agricultural 
areas which are often served by private wells. When nitrate occurs at 
concentrations greater than 1 mg/L, it is considered to be the result 
of human activities such as application of agricultural fertilizers, 
disposal of animal wastes, and use of septic tanks.\120\ Monitoring of 
Florida Public Water Supplies from 2004-2011 indicates that exceedances 
of the nitrate MCL reported by drinking water plants in Florida ranged 
from 19-34 annually.\121\ A study in the late 1980s conducted by 
Florida Department of Agriculture and Consumer Services (FDACS) and 
FDEP, analyzed 3,949 shallow drinking water wells for nitrate.\122\ 
Nitrate was detected in 2,483 wells (63%), with 584 wells (15%) above 
the MCL of 10 mg/L.
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    \119\ USEPA. 2007. Nitrates and Nitrites: TEACH Chemical 
Summary. U.S. Environmental Protection Agency. http://www.epa.gov/teach/chem_summ/Nitrates_summary.pdf. Accessed May 2012.
    \120\ DeSimone, L.A., P.A. Hamilton, and R.J. Gilliom. 2009. 
Quality of Water from Domestic Wells in Principal Aquifers of the 
United States, 1991-2004: Overview of Major Findings. Circular 
1332.U.S. Geological Survey, National Water Quality Assessment 
Program, Reston, VA. http://water.usgs.gov/nawqa/studies/domestic_wells/WaterWellJournalArticle_DeSimoneetal2009.pdf. Accessed 
November 2011.
    Spechler, R.M. 2010. Hydrogeology and Groundwater Quality of 
Highlands County, Florida. Scientific Investigations Report 2010-
5097. U.S. Geological Survey, Reston, VA
    Dubrovsky, N.M., K.R. Burow, G.M. Clark, J.M. Gronberg, P.A. 
Hamilton, K.J. Hitt, D.K. Mueller, M.D. Munn, B.T. Nolan, L.J. 
Puckett, M.G. Rupert, T.M. Short, NE. Spahr, L.A. Sprague, and W.G. 
Wilber. 2010. The Quality of our Nation's Waters--Nutrients in the 
Nation's Streams and Groundwater, 1992-2004. Circular 1350. U.S. 
Geological Survey, National Water Quality Assessment Program, 
Reston, VA. http://water.usgs.gov/nawqa/nutrients/pubs/circ1350. 
Accessed May 2012.
    \121\ FDEP. 2012. Chemical Data for 2004, 2005, 2006, 2007, 
2008, 2009, 2010, and 2011. Florida Department of Environmental 
Protection. http://www.dep.state.fl.us/water/drinkingwater/chemdata.htm. Accessed May 2012.
    \122\ Southern Regional Water Program. 2010. Drinking Water and 
Human Health in Florida. http://srwqis.tamu.edu/florida/program-information/florida-target-themes/drinking-water-and-human-health.aspx. Accessed May 2012.
    Obreza, T.A., and K.T. Morgan. 2008. Nutrition of Florida Citrus 
Trees. 2nd ed. SL 253. University of Florida, IFAS Extension. http://edis.ifas.ufl.edu/pdffiles/SS/SS47800.pdf. Accessed May 2012.
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d. Adverse Impacts of Nitrogen and Phosphorus Pollution on the Economy
    Excessive algal blooms result in a range of economic losses, 
including lost revenue from impacts to commercial fisheries, 
recreational fishing and boating trips, and tourism, as well as 
increased drinking water costs and reduced waterfront property 
values.\123\ More information concerning the costs and benefits of the 
numeric nutrient criteria proposed in this rule can be found in Section 
VI.
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    \123\ Dodds, W.K., W.W. Bouska, J.L. Eitzmann, T.J. Pilger, K.L. 
Pitts, A.J. Riley, J.T. Schloesser, and D.J. Thornbrugh. 2009. 
Eutrophication of U.S. Freshwaters: Analysis of Potential Economic 
Damages. Environmental Science and Technology 43(1):12-19.
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    The economic value of Florida's marine recreational fisheries is 
higher than any other state in the country. Recreational fishing 
contributed over $5 billion to Florida's economy in 2006. In the 2008-
2009 fiscal year, over 1 million individuals bought a marine 
recreational fishing license, generating over $29 million in 
revenue.\124\ Similarly, Florida has one of the nation's top producing 
commercial fisheries. In 2009, Florida's harvest of the top five 
commercial species of fish and shellfish was worth more than $55 
million combined. In total, commercial fishing contributed more than $1 
billion to the economy of Florida. Outdoor recreation in Florida 
(including wildlife-viewing, fishing, and water sports) generates $10.1 
billion annually.\125\ In 2006, over 3 million Florida residents and 
746,000 visitors participated in wildlife-viewing activities, for total 
retail sales of an estimated $3.1 billion.\126\
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    \124\ FFWCC. No Date. The Economic Impact of Saltwater Fishing 
in Florida. Florida Fish and Wildlife Conservation Commission. 
http://myfwc.com/conservation/value/saltwater-fishing. Accessed 
December 2011.
    \125\ FFWCC. No Date. Economic Impact of Outdoor Recreation. 
Florida Fish and Wildlife Conservation Commission.
    http://myfwc.com/conservation/value/outdoor-recreation. Accessed 
July 2011.
    \126\ USFWS. 2008. 2006 National Survey of Fishing, Hunting, and 
Wildlife-Associated Recreation: Florida. FHW/06-FL. U.S. Fish and 
Wildlife Service. http://www.census.gov/prod/2008pubs/fhw06-fl.pdf. 
Accessed July 2011.
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    At the county level, Monroe County's commercial tourism and fishing 
industries rely on finfish and shellfish from Florida Bay. Measurable 
economic losses associated with the changing environmental conditions 
of the Bay have occurred, primarily from the substantial decline in 
pink shrimp harvests due to loss of submerged aquatic vegetation 
(habitat), which was linked to nitrogen and phosphorus pollution as a 
contributing factor. From 1986 through the early 1990s, employment in 
commercial fishing declined by about 10 percent, while income of 
individuals in the industry declined by $16 million. These losses 
coincided with massive seagrass die-offs in the Bay and blue-green 
algae blooms.\127\
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    \127\ Gorte, R.W. 1994. The Florida Bay economy and changing 
environmental conditions. 94-435 ENR, CRS Report for Congress, 
Congressional Research Service, The Library of Congress.
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    HAB toxins can make seafood unsafe for human consumption, leading 
to an overall reduction in the amount of fish purchased due to the real 
or perceived threats of contamination.\128\ Potential economic impacts 
from nitrogen and phosphorus pollution in Florida include monetary 
losses due to depressed fisheries, tourism and property values, and 
elevated costs to address nutrient impacts (e.g., beach cleanup costs, 
HAB monitoring).
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    \128\ Anderson, D.M.. 2008. Hearing on ``Harmful Algal Blooms: 
The Challenges on the Nation's Coastlines''. Woods Hole 
Oceanographic Institution. http://www.whoi.edu/page.do?pid=8916&tid=282&cid=46007. Accessed December 2011.
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    Seagrass habitats are valuable components of Florida's estuarine 
and coastal waters. FDEP has estimated that each acre of seagrass is 
worth $20,255 per year, which would translate to a benefit of $44.6 
billion statewide.\129\

[[Page 74938]]

The nearly 2.2 million acres of seagrass beds in Florida's nearshore 
waters support fish and shellfish that are economically vital to 
commercial and recreational businesses in Florida.\130\ Some estuary 
experts have attempted to quantify the overall value of individual 
estuaries in Florida. For example, the Indian River Lagoon National 
Estuary Program estimated the total value of the Indian River Lagoon at 
$3.7 billion (2009 dollars). In the study, recreational and non-use 
values of the lagoon were estimated to increase by nearly $80 million 
per year (2009 dollars) if there were a significant increase in the 
amount and diversity of wildlife in the lagoon, as well as increased 
water quality throughout the system from restoration and water quality 
improvement projects.\131\
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    \129\ USGS. 2001. Seagrass Habitat In the Northern Gulf of 
Mexico: Degradation, Conservation, and Restoration of a Valuable 
Resource. U.S. Geological Survey, Gulf of Mexico Habitat Program 
Team,
    855-R-04-001. http://gulfsci.usgs.gov/gom_ims/pdf/pubs_gom.pdf. Accessed July 2011.
    Burkholder, J.M., D.A. Tomasko, and B.W. Touchette. 2007. 
Seagrasses and eutrophication. Journal of Experimental Marine 
Biology and Ecology 350:46-72.
    Waycott, M., C.M. Duarte, T.J.B. Carruthers, R.J. Orth, W.C. 
Dennison, S. Olyarnik, A. Calladine, J.W. Fourqurean, K.L. Heck, 
Jr., A.R. Hughes, G.A. Kendrick, W.J. Kenworthy, F.T. Short, and 
S.L. Williams. 2009. Accelerating loss of seagrasses across the 
globe threatens coastal ecosystems. Proceedings of the National 
Academy of Sciences of the United States of America 106(30):12377-
12381.
    Short, F.T., B. Polidoro, S.R. Livingstone, K.E. Carpenter, S. 
Bandeira, J.S. Bujang, H.P. Calumpong, T.J.B. Carruthers, R.G. 
Coles, W.C. Dennison, P.L.A. Erftemeijer, M.D. Fortes, A.S. Freeman, 
T.G. Jagtap, A.H.M. Kamal, G.A. Kendrick, W.J. Kenworthy, Y.A. La 
Nafie, I.M. Nasution, R.J. Orth, A. Prathep, J.C. Sanciangco, B. van 
Tussenbroek, S.G. Vergara, M. Waycott, and J.C. Zieman. 2011. 
Extinction risk assessment of the world's seagrass species. 
Biological Conservation144:1963-1971.
    Watson R.A., R.G. Coles, and W.J. Lee Long. 1993. Simulation 
estimates of annual yield and landed value for commercial penaeid 
prawns from a tropical seagrass habitat, Northern Queensland, 
Australia. Australian Journal of Marine and Freshwater Research 
44:211-219.
    Carlson, P., and L. Yarbro. 2008. Seagrass Mapping and 
Monitoring: Big Bend and Beyond. Presented at Florida Water 
Resources Monitoring Council Meeting, St. Petersburg, FL, September 
24-25, 2008.
    Costanza, R., R. d'Arge, R. de Groot, S. Farber, M. Grasso, B. 
Hannon, K. Limburg, S. Naeem, R.V. Neill, J. Paruelo, R.G. Raskin, 
P. Sutton, and M. van den Belt. 1997. The value of the world's 
ecosystem services and natural capital. Nature 387:253-260.
    \130\ FDEP. 2011. Celebrate Seagrass Awareness Month. Florida 
Department of Environmental Protection. http://www.dep.state.fl.us/coastal/news/articles/2011/1103_Seagrass.htm. Accessed June 2011.
    Scott, R. 2011. Seagrass Awareness Month. Proclamation by 
Governor Rick Scott of the State of Florida. Florida Department of 
Environmental Protection. http://www.dep.state.fl.us/coastal/habitats/seagrass/awareness/Proclamation_2011.pdf. Accessed June 
2011.
    \131\ USEPA. 2009. Determining an Estuary's Economic Value. EPA-
842F09001. U.S. Environmental Protection Agency, National Estuary 
Program, Washington, DC. http://water.epa.gov/type/oceb/nep/upload/2009_05_28_estuaries_inaction_Efficient_IndianRiver.pdf. 
Accessed July 2011.
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    According to a study on the impacts of HABs on beachfront tourism-
dependent businesses in the Ft. Walton Beach and Destin areas of 
Florida, HABs reduced restaurant and lodging revenues by $2.8 million 
and $3.7 million per month, respectively, representing a 29 percent to 
35 percent decline in average monthly revenues.\132\
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    \132\ Larkin, S.L., and C.M. Adams. 2007. Harmful algal blooms 
and coastal business: economic consequences in Florida. Society & 
Natural Resources 20(9):849-859.
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    A study by Mather Economics estimated the effects of water quality 
on real estate value in the South Florida Water Management District. 
The aggregate owner-occupied residential real estate value in the 16-
county South Florida Water Management District is approximately $976 
billion. If water quality (measured by dissolved oxygen levels) can be 
returned to 1970 levels as a result of restoring the Everglades (a 
potential 23.4 percent improvement in water quality), the study found 
that real estate values would increase by $16 billion.\133\
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    \133\ McCormick, B., R. Clement, D. Fischer, M. Lindsay, R. 
Watson. 2010. Measuring the Economic Benefits of America's 
Everglades Restoration: An Economic Evaluation of Ecosystem Services 
Affiliated with the World's Largest Ecosystem Restoration Project. 
Prepared for the Everglades Foundation, Palmetto Bay, FL, by Mather 
Economics, Roswell, GA.
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    In addition to negatively impacting Florida businesses, nitrogen 
and phosphorus pollution increases costs for beach cleanup, HAB 
monitoring, and wastewater treatment. For example, approximately 
$63,000 was spent annually from 1995-1997 to dispose of red seaweed and 
fish killed by HAB events that littered 17.5 miles of beach in Sarasota 
County.\134\
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    \134\ Hoagland, P., D.M. Anderson, Y. Kaoru, and A.W. White. 
2002. The economic effects of harmful algal blooms in the United 
States: estimates, assessment issues, and information needs. 
Estuaries 25:819-837.
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    In addition, there are increased costs due to the need to treat 
polluted sources of drinking water. As an example of increased costs 
for drinking water treatment, in 1991, Des Moines (Iowa) Water Works 
constructed a $4 million ion exchange facility to remove nitrate from 
its drinking water supply. This facility was designed to be used an 
average of 35-40 days per year to remove excess nitrate levels at a 
cost of nearly $3,000 per day.\135\ In another example, Fremont, Ohio 
(a city of approximately 20,000) has experienced high levels of nitrate 
from its drinking water source, the Sandusky River, resulting in 
numerous drinking water use advisories. An estimated $15 million is 
needed to build a reservoir (and associated piping) that will allow for 
selective withdrawal from the river to avoid elevated levels of nitrate 
and provide storage.\136\ By regulating allowable levels of chlorophyll 
a in Oklahoma drinking water reservoirs, the Oklahoma Water Resources 
Board estimated that the long-term cost savings in averted drinking 
water treatment for 86 systems would range between $106 million and 
$615 million if such regulations were implemented.\137\ These 
statistics are illustrative of what treatment to address nitrates and 
nitrites can cost. Any impacts in Florida would be site-specific and 
might or might not be comparable to these numbers.
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    \135\ Jones, C.S., D. Hill, and G. Brand. 2007. Use a 
multifaceted approach to manage high sourcewater nitrate. Opflow 
June:20-22.
    \136\ Taft, Jim, Association of State Drinking Water 
Administrators (ASDWA). 2009. Personal Communication.
    \137\ Moershel, Philip, Oklahoma Water Resources Board (OWRB) 
and Mark Derischweiler, Oklahoma Department of Environmental Quality 
(ODEQ). 2009. Personal Communication.
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B. Statutory and Regulatory Background

    Section 303(c) of the CWA (33 U.S.C. 1313(c)) directs states to 
adopt WQS for their navigable waters. CWA Section 303(c)(2)(A) and 
EPA's implementing regulations at 40 CFR 131 require, among other 
things, that state WQS include the designated use and criteria that 
protect those uses. EPA regulations at 40 CFR 131.11(a)(1) provide that 
states shall ``adopt those water quality criteria that protect the 
designated use'' and that such criteria ``must be based on sound 
scientific rationale and must contain sufficient parameters or 
constituents to protect the designated use.'' In addition, 40 CFR 
131.10(b) provides that ``[i]n designating uses of a water body and the 
appropriate criteria for those uses, the state shall take into 
consideration the water quality standards of downstream waters and 
ensure that its water quality standards provide for the attainment and 
maintenance of the water quality standards of downstream waters.''
    States are also required to review their water quality standards at 
least once every three years and, if appropriate, revise or adopt new 
standards (CWA section 303(c)(1)). Any new or revised water quality 
standards must be submitted to EPA for review and approval or 
disapproval (CWA section 303(c)(2)(A) and (c)(3)). In addition, CWA 
section 303(c)(4)(B) authorizes the Administrator to determine, even in 
the absence of a state submission, that a new or revised standard is 
needed to meet CWA requirements. The EPA approved the State of 
Florida's rules (which include criteria for certain estuaries and 
coastal marine waters) on November 30, 2012. The criteria proposed in 
this rulemaking protect the uses designated by the State of Florida and 
implement Florida's narrative nutrient provision at Subsection 62-
302.530(47)(b), F.A.C. for the purposes of the CWA. These criteria 
include numeric values that apply to Florida's

[[Page 74939]]

estuaries and coastal waters not covered by the newly-approved State 
WQS, south Florida inland flowing waters, and DPVs to ensure the 
attainment and maintenance of the water quality standards of downstream 
estuaries.\138\ As explained more fully in Section I.A, EPA does not 
intend to finalize these DPVs if the district court modifies the 
Consent Decree consistent with EPA's amended determination that numeric 
DPVs are not necessary to meet CWA requirements in Florida.
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    \138\ The criteria proposed in this rulemaking do not address or 
implement Florida's narrative nutrient provision at Subsection 62-
302.530(47)(a), F.A.C. Subsection 62-302.530(47)(a), F.A.C. remains 
in place as an applicable water quality standard for CWA purposes.
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C. Water Quality Criteria

    Water quality criteria include three components. The first 
component is ``magnitude,'' the concentration of a pollutant that can 
be maintained over time in the ambient receiving water without 
adversely affecting the designated use that the criteria is intended to 
support. The second component is ``duration,'' or the time period over 
which exposure is averaged (i.e., the averaging period) to limit the 
time of exposure to elevated concentrations. This accounts for the 
variability in the quality of the ambient water due to variations of 
constituent inputs, flow, and other factors. The third component is 
``frequency,'' or how often the magnitude/duration condition may be 
exceeded and still protect the designated use. Combining the criterion-
magnitude with the duration and frequency prevents harmful effects from 
infrequent exceedances of the criterion-magnitude by ensuring 
compensating periods of time during which the concentration is below 
the criterion-magnitude. When criterion-magnitudes are exceeded for 
short periods of time or infrequently, aquatic life can typically 
recover; that is, the designated uses of the water body are typically 
protected. Designated uses are typically not protected when criterion-
magnitudes are exceeded for longer periods of time (i.e., for longer 
than the specified duration) or more frequently (i.e., more often than 
the allowed frequency).\139\ Use of this magnitude-duration-frequency 
format allows for some exceedances of the criterion-magnitude 
concentrations while still protecting applicable designated uses, which 
is important for pollutants such as nitrogen and phosphorus because 
their concentrations can vary naturally in the environment.
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    \139\ USEPA. 1994. Water Quality Standards Handbook: Second 
Edition, Chapter 3--Water Quality Criteria. EPA-823-B-94-005a. U.S. 
Environmental Protection Agency, Office of Water, Washington, DC.
    USEPA 1991. Technical Support Document for Water Quality-based 
Toxics Control. Appendix D--Duration and Frequency. EPA/505/2-90-
001. U.S. Environmental Protection Agency, Office of Water, 
Washington, DC.
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    Under CWA section 304(a), EPA periodically publishes criteria 
recommendations for use by states in setting water quality criteria for 
particular parameters to protect recreational and aquatic life uses of 
waters. Where EPA has published recommended criteria, states have the 
option of adopting water quality criteria based on EPA's CWA section 
304(a) criteria guidance, section 304(a) criteria guidance modified to 
reflect site-specific conditions, or other scientifically defensible 
methods (40 CFR 131.11(b)(1)).
    For nitrogen and phosphorus pollution, EPA has published under CWA 
section 304(a) a series of peer-reviewed, national technical approaches 
and methods for the development of numeric nutrient criteria for lakes 
and reservoirs,\140\ rivers and streams,\141\ and estuarine and coastal 
marine waters.\142\ EPA based the methodologies used to develop numeric 
nutrient criteria for Florida in this proposed regulation on these 
published guidance documents, which identify three scientifically 
defensible approaches for deriving nutrient criteria: (1) The reference 
condition approach derives criteria from observations collected in 
reference water bodies or during reference time periods; (2) the 
mechanistic modeling approach represents contaminant loadings, 
hydrodynamics, and impacts in aquatic systems using equations that 
represent physical and ecological processes, calibrated using site-
specific data; and (3) the stressor-response approach estimates the 
relationship between nutrient concentrations and response measures 
related to a designated use of the water body. These three analytical 
approaches have been independently peer-reviewed and are appropriate 
for deriving scientifically defensible numeric nutrient criteria, 
taking into consideration the method-specific data needs and available 
data. In addition to these approaches, consideration of established 
(e.g., published and peer-reviewed) nutrient response thresholds is 
also an acceptable approach for deriving criteria.\143\
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    \140\ USEPA. 2000a. Nutrient Criteria Technical Guidance Manual: 
Lakes and Reservoirs. EPA-822-B-00-001. U.S. Environmental 
Protection Agency, Office of Water, Washington, DC.
    \141\ USEPA. 2000b. Nutrient Criteria Technical Guidance Manual: 
Rivers and Streams. EPA-822-B-00-002. U.S. Environmental Protection 
Agency, Office of Water, Washington, DC.
    \142\ USEPA. 2001. Nutrient Criteria Technical Manual: Estuarine 
and Coastal Marine Waters. EPA-822-B-01-003. U.S. Environmental 
Protection Agency, Office of Water, Washington, DC.
    \143\ USEPA. 2000a. Nutrient Criteria Technical Guidance Manual: 
Lakes and Reservoirs. EPA-822-B-00-001. U.S. Environmental 
Protection Agency, Office of Water, Washington, DC.
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    The criteria proposed in this rulemaking implement Florida's 
narrative nutrient provision at Subsection 62-302.530(47)(b), F.A.C., 
for the purposes of the CWA as numeric values that apply to, and 
protect, Class I, II, and III estuaries and coastal waters in Florida 
and south Florida inland flowing waters. In Florida, water quality 
criteria established for Class I, II, and III surface waters must 
protect ``fish consumption, recreation and the propagation and 
maintenance of a healthy, well-balanced population of fish and 
wildlife.'' \144\ Florida's existing narrative nutrient provision 
serves to protect Class I, II, and III waters from nitrogen and 
phosphorus pollution by requiring that ``[i]n no case shall nutrient 
concentration of a body of water be altered so as to cause an imbalance 
in natural populations of aquatic flora or fauna.''
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    \144\ Pursuant to Subsection 62-302.400(4), F.A.C.
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    After an extensive review of the latest scientific knowledge 
relating to the impacts of nutrient pollution on aquatic systems, EPA 
is proposing the use of three biological endpoints--maintenance of 
seagrasses, maintenance of balanced algal populations, and maintenance 
of aquatic life (fauna)--as the most sensitive to effectively derive 
numeric nutrient criteria that will protect Class I, II, and III 
designated uses from the harmful, adverse effects of nutrient 
pollution. The endpoint measures that EPA is proposing to use to 
determine the nutrient concentrations to protect these biological 
endpoints are light levels to maintain historic depth of seagrass 
colonization, chlorophyll a concentrations associated with balanced 
phytoplankton biomass, and sufficient DO to maintain aquatic life. Fish 
consumption relies on the presence of fish and aquatic life as well as 
the habitat that supports them, which in turn relies on seagrasses and 
limited occurrence of nuisance algal blooms. The protection of 
recreation (both fishing and swimming related uses) relies on the 
presence of fish and aquatic life as well as limited occurrence of 
nuisance algal blooms. Lastly, the protection of propagation and 
maintenance of a healthy, well-balanced population of fish and wildlife 
relies on the presence of fish and

[[Page 74940]]

aquatic life as well as the habitat that supports them.
    EPA's January 14, 2009 determination addressed Florida's narrative 
nutrient provision at Subsection 62-302.530(47)(b), F.A.C. As discussed 
earlier, EPA has proposed and promulgated criteria, in this and other 
proposals, to implement that provision, which provides that ``[i]n no 
case shall nutrient concentrations of a body of water be altered so as 
to cause an imbalance in natural populations of aquatic flora or fauna. 
The criteria proposed in this rulemaking do not address or implement 
Florida's narrative nutrient provision at Subsection 62-302.530(47)(a), 
F.A.C. which provides that ``[t]he discharge of nutrients shall 
continue to be limited as needed to prevent violations of other 
standards contained in this chapter. Human-induced nutrient enrichment 
(total nitrogen or total phosphorus) shall be considered degradation in 
relation to the provisions of Sections 62-302.300, 62-302.700, and 62-
4.242, F.A.C.'' Subsection 62-302.530(47)(a), F.A.C. remains in place 
as an applicable WQS for CWA purposes and could result in more 
stringent nitrogen and phosphorus limits than those proposed in this 
rule, where necessary to protect other applicable water quality 
standards in Florida.

D. EPA Determination Regarding Florida and Consent Decree

    On January 14, 2009, EPA determined under CWA section 303(c)(4)(B) 
that new or revised water quality standards in the form of numeric 
water quality criteria for nitrogen and phosphorus pollution are 
necessary to meet the requirements of the CWA in the State of Florida. 
EPA's determination is available at the following Web site: http://water.epa.gov/lawsregs/rulesregs/florida_consent.cfm.
    Subsequently, EPA entered into a Consent Decree with Florida 
Wildlife Federation, Sierra Club, Conservancy of Southwest Florida, 
Environmental Confederation of Southwest Florida, and St. Johns 
Riverkeeper, effective on December 30, 2009, which established a 
schedule for EPA to propose and promulgate numeric nutrient criteria 
for Florida's lakes, springs, flowing waters, estuaries, and coastal 
waters, as well as downstream protection values (DPVs) to protect 
downstream lakes and estuaries. The Consent Decree provided that if 
Florida submitted and EPA approved numeric nutrient criteria for the 
relevant water bodies before the dates outlined in the schedule, EPA 
would no longer be obligated to propose or promulgate criteria for 
those water bodies.

E. EPA's Rulemaking and Subsequent Litigation

    On December 6, 2010, EPA published a rule finalizing numeric 
nutrient criteria for Florida's lakes, springs, and flowing waters 
outside of the South Florida Nutrient Watershed Region (40 CFR 131.43). 
The 2010 ``inland waters rule'' was previously scheduled to take effect 
on March 6, 2012, with the exception of one provision that allowed 
entities to submit Site-Specific Alternative Criteria (SSAC) effective 
February 4, 2011. The March 6, 2012 effective date was subsequently 
extended on two occasions (77 FR 13497 and 77 FR 39949) such that the 
current effective date of the rule is January 6, 2013. Concurrently 
with this proposal, EPA is issuing a separate proposed rule to stay the 
inland waters rule until November 15, 2013. For more information on the 
proposed stay rule, see http://water.epa.gov/lawsregs/rulesregs/florida_inland.cfm.
    Following the publication of the inland waters rule, 12 cases were 
filed in the U.S. District Court for the Northern District of Florida 
challenging the rule. The cases, consolidated before Judge Robert 
Hinkle in the Tallahassee Division of the Northern District, were filed 
by environmental groups, Florida's State Department of Agriculture, the 
South Florida Water Management District, and various industry/
discharger groups. The challenges alleged that EPA's determination and 
final inland waters rule were arbitrary, capricious, an abuse of 
discretion, and not in accordance with the law for a variety of 
reasons. Oral argument in the case was held on January 9, 2012 before 
Judge Hinkle.
    On February 18, 2012, the Court upheld EPA's January 2009 
determination and the final numeric nutrient criteria for Florida's 
lakes and springs, as well as the site-specific alternative criteria 
(SSAC) provisions and the provisions for calculating DPVs using either 
modeling or a default option for an impaired lake that is not attaining 
its numeric nutrient criteria.\145\ With regard to EPA's numeric 
nutrient criteria for flowing waters (i.e., streams) and the default 
option to calculate DPVs for unimpaired lakes based on ambient stream 
nutrient concentrations at the point of entry to the lake, the Court 
found that EPA had not provided sufficient information in its final 
rule explaining why or how the criteria or DPV protect against harmful 
increases, as opposed to any increase, in nutrients. The Court observed 
that EPA's scientific approach to deriving stream criteria (i.e., the 
reference condition approach), including the criteria's duration and 
frequency components, ``are matters of scientific judgment on which the 
rule would survive arbitrary-or-capricious review.'' The Court also 
found, however, that EPA had not explained in sufficient detail how the 
stream criteria would prevent a ``harmful increase in a nutrient 
level''. In addition, the Court found that EPA had not explained in 
sufficient detail how exceedances of the default DPV for unimpaired 
lakes would lead to ``harmful effects'' in the downstream lake. Thus, 
the Court invalidated these two aspects of EPA's final rule and 
remanded them to the Agency for further action. Concurrently with this 
proposal, EPA is issuing a separate proposed rule for Florida's streams 
and DPVs for unimpaired lakes (Water Quality Standards for the State of 
Florida's Streams and Downstream Protection Values for Lakes: Remanded 
Provisions). For more information on the proposed rule for the remanded 
provisions, see http://water.epa.gov/lawsregs/rulesregs/florida_inland.cfm.
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    \145\ Case 4:08-cv-00324-RH-WCS, February 18, 2012.
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    On several occasions, the court granted EPA's request to modify the 
deadlines in the December 2009 Consent Decree.\146\ Under the revised 
Consent Decree, EPA is required to propose criteria for Florida's 
estuaries, coastal waters, and south Florida inland flowing waters by 
November 30, 2012 and to finalize such criteria by September 30, 2013.
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    \146\ http://water.epa.gov/lawsregs/rulesregs/florida_consent.cfm.
---------------------------------------------------------------------------

    In accordance with the January 14, 2009 determination, the December 
30, 2009 Consent Decree, and the subsequent modifications to the 
deadlines in the December 30, 2009 Consent Decree, EPA is proposing in 
this notice numeric nutrient criteria for estuaries and coastal waters 
in the State of Florida, and south Florida inland flowing waters. This 
proposed rule satisfies EPA's requirement to propose criteria for these 
three categories of Florida waters by November 30, 2012.

F. Florida Adoption of Numeric Nutrient Criteria and EPA Approval

    On June 13, 2012, FDEP submitted new and revised WQS for review by 
the EPA pursuant to section 303(c) of the CWA. These new and revised 
WQS are set out primarily in Rule 62-302 of the F.A.C. [Surface Water 
Quality Standards]. FDEP also submitted amendments to Rule 62-303, 
F.A.C. [Identification of Impaired Surface Waters], which sets out 
Florida's methodology for assessing whether

[[Page 74941]]

waters are attaining State WQS. On November 30, 2012, EPA approved the 
provisions of these rules submitted for review that constitute new or 
revised WQS (referred to in this preamble as the ``newly-approved State 
WQS'').
    Among the newly-approved State WQS are numeric criteria for 
nutrients that apply to a set of estuaries and coastal marine waters in 
Florida. Specifically, these newly-approved State WQS apply to 
Clearwater Harbor/St. Joseph Sound, Tampa Bay, Sarasota Bay, Charlotte 
Harbor/Estero Bay, Clam Bay, Tidal Cocohatchee River/Ten Thousand 
Islands, Florida Bay, Florida Keys, and Biscayne Bay. Under the Consent 
Decree, EPA is relieved of its obligation to propose numeric criteria 
for these waters.

III. Proposed Numeric Criteria for Florida's Estuaries, Coastal Waters, 
and South Florida Inland Flowing Waters

    In this notice of proposed rulemaking, EPA is proposing numeric 
nutrient criteria to protect against harmful increases in nutrients, 
and therefore, protect the designated uses of the State of Florida's 
Class I, II, and III waters, specifically Florida's estuaries and 
coastal waters (excluding those contained in Florida's newly-approved 
State WQS), and south Florida inland flowing waters. This proposed rule 
also includes downstream protection values (DPVs) to ensure the 
attainment and maintenance of WQS in downstream estuarine and south 
Florida marine waters. The proposed criteria and related provisions in 
this rule reflect a detailed consideration of the best available 
scientific research, data, and analyses related to the specific 
circumstances for deriving numeric nutrient criteria in the State of 
Florida. EPA's actions are consistent with and support existing Florida 
WQS regulations.
    EPA proposes developing numeric nutrient criteria to restore and 
maintain the balance of natural populations of aquatic flora and fauna 
in Florida waters. The analytical process that EPA used to derive the 
proposed criteria consisted of several steps that included (1) 
classification of the water body systems, (2) subdividing water body 
systems into smaller segments that have similar chemical, physical, and 
biological features, (3) review and analysis of biological endpoints, 
and (4) application of one or more analytical methodologies.
    After accounting for the spatial coverage of Florida's newly-
approved State WQS, EPA grouped Florida's remaining estuarine and 
coastal waters according to the natural geographic features of 
estuarine basins and their associated watersheds (classification). This 
resulted in 19 estuarine systems and three coastal systems. Next, EPA 
divided each resulting estuary and coastal system into segments on the 
basis of similar biological, chemical, and physical attributes 
(segmentation). Segmentation resulted in 89 estuarine segments among 
the 19 estuarine systems and 71 coastal segments among the three 
coastal systems. In the Big Bend region (Ochlockonee Bay to Springs 
Coast) EPA combined coastal waters with estuarine waters for analysis. 
The classification serves as an organizing framework for analyses, and 
the segmentation delineates areas in each estuary or coastal system 
where the numeric nutrient criteria apply.
    EPA is proposing to develop numeric nutrient criteria for Florida's 
estuarine and coastal waters based on three biological endpoints that 
are sensitive to changes in nitrogen and phosphorus concentrations. 
These biological endpoints reflect the water quality conditions 
necessary to ensure protection of balanced populations of aquatic flora 
and fauna: (1) Maintenance of seagrasses (as measured by water clarity 
sufficient to maintain historic depth of seagrass colonization), (2) 
maintenance of balanced algal populations (as measured by chlorophyll a 
concentrations associated with balanced phytoplankton biomass), and (3) 
maintenance of aquatic life (as measured by levels of dissolved oxygen 
sufficient to maintain aquatic life). For each water body, EPA derived 
numeric nutrient criteria based on the most nutrient sensitive of the 
three endpoints and the sufficiency of data available in each segment.
    For each estuary and coastal system, one of three analytical 
approaches was used to derive numeric nutrient criteria--reference 
condition, stressor-response (statistical modeling), and mechanistic 
modeling. In some cases, a secondary approach provided corroborating 
evidence for the results of the primary analytical methodology. EPA 
evaluated multiple lines of evidence to determine the analytical 
approach that was best suited for derivation of numeric nutrient 
criteria in each estuarine or coastal system. In general, and as 
discussed in more detail in later Sections of this proposed rule, the 
reference condition approach was applied when there were sufficient 
data available to characterize conditions that were representative of 
and protective of designated uses, the stressor-response approach was 
applied when there were sufficient data available to statistically 
quantify relationships between nutrient concentrations and the 
biological endpoints, and lastly, the mechanistic modeling approach was 
applied when there were sufficient data and information available to 
quantify the relationships between nutrient loads and the biological 
endpoints.
    For calculating DPVs for estuaries and south Florida marine waters, 
EPA is proposing four approaches for setting nitrogen and phosphorus 
protective levels in a hierarchy that reflects the data and scientific 
information available, including (1) water quality simulation modeling, 
(2) reference condition approach, (3) dilution models, and (4) the 
numeric nutrient criteria in the estuarine segment to which a 
freshwater stream or canal discharges.
    For south Florida EPA is proposing the use of downstream protection 
values (DPVs) to manage nitrogen and phosphorus pollution in the inland 
flowing waters and protect the water quality of estuaries and coastal 
waters downstream. As in estuarine and coastal systems, EPA followed a 
series of steps to derive criteria in south Florida inland flowing 
waters, including classification of water bodies, segmentation, review 
and analysis of biological endpoints, application of analytical 
methodologies, and development of DPVs. EPA defined south Florida 
inland flowing waters as inland predominantly fresh surface waters that 
have been classified as Class I or Class III, which encompasses the 
waters south of Lake Okeechobee, the Caloosahatchee River (including 
Estero Bay) watershed, and the St. Lucie watershed. EPA segmented south 
Florida waters by identifying 22 canal pour points that drain 
freshwater to each marine segment. To manage nitrogen and phosphorus 
pollution in the inland flowing waters and protect the water quality of 
estuaries and coastal waters downstream EPA then screened water quality 
data at each pour point to prevent the use of upstream water quality 
data that coincided with a documented downstream impact. EPA then 
calculated DPVs using the reference condition approach.
    In deriving scientifically sound numeric nutrient criteria for this 
proposed rulemaking, EPA relied on the local technical expertise of 
various scientific experts in Florida. EPA met and consulted with 
FDEP's scientific and technical experts during the development of these 
numeric nutrient criteria as part of an ongoing collaborative process 
to analyze, evaluate, and interpret a substantial amount of Florida-
specific data. EPA carefully evaluated the technical approaches and 
scientific analyses that FDEP presented as part of their draft

[[Page 74942]]

approaches to develop numeric nutrient criteria for estuaries within 
the State. Finally, EPA also carefully considered substantial 
stakeholder input from twelve public hearings conducted by FDEP during 
2010, in addition to working with scientists from several Florida 
National Estuary Programs (NEPs), Water Management Districts, 
universities, and other government agencies in Florida.
    To further ensure the best use of available data and scientific 
analyses for deriving criteria, the Agency submitted its potential 
methods and approaches for an independent, scientific peer review by 
EPA's Science Advisory Board (SAB) in November 2010. The SAB reviewed 
the document entitled, Methods and Approaches for Numeric Nutrient 
Criteria for Nitrogen/Phosphorus Pollution in Florida's Estuaries, 
Coastal Waters, and Southern Inland Flowing Waters, and submitted their 
final recommendations to EPA in July 2011.\147\ The SAB agreed that a 
dual nutrient strategy to derive criteria for both nitrogen and 
phosphorus is warranted. The SAB also found that all of the approaches 
that EPA proposed for use in this rulemaking (i.e., reference 
condition, stressor-response, and mechanistic modeling) have utility 
and recommended that a combination of approaches be used where data and 
models are available. The SAB provided numerous recommendations to 
strengthen the application of the approaches to develop numeric 
nutrient criteria for Florida waters that EPA has used to refine the 
methods and approaches for deriving the criteria proposed in this 
rulemaking.\148\
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    \147\ USEPA-SAB. 2011. Review of EPA's Draft Approaches for 
Deriving Numeric Nutrient Criteria for Florida's Estuaries, Coastal 
Waters, and Southern Inland Flowing Waters. EPA-SAB-11-010. U.S. 
Environmental Protection Agency, Science Advisory Board, Washington, 
DC.
    USEPA. 2010. Methods and Approaches for Deriving Numeric 
Criteria for Nitrogen/Phosphorus Pollution in Florida's Estuaries, 
Coastal Waters, and Southern Inland Flowing Waters. U.S. 
Environmental Protection Agency, Office of Water, Washington, DC.
    \148\ EPA response letter to SAB. http://yosemite.epa.gov/sab/
sabproduct.nsf/fedrgstr--activites/DCC3488B67473BDA852578D20058F3C9/
$File/EPA-SAB-11-010--Response--10-26-2011.pdf. Accessed May 2012.
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    Section III.A provides an overview of the technical elements used 
to support derivation of the numeric nutrient criteria proposed in this 
rulemaking for estuaries and coastal waters.\149\ The remainder of 
Section III specifically describes EPA's proposed numeric nutrient 
criteria for estuaries (Section III.B), coastal waters (Section III.C), 
and south Florida inland flowing waters (Section III.D). Also included 
are proposed DPVs for estuaries (Section III.B) and south Florida 
marine waters (Section III.D).
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    \149\ Additional details are provided in a separate document, 
the Technical Support Document for U.S. EPA's Proposed Rule for 
Numeric Nutrient Criteria for Florida's Estuaries, Coastal Waters, 
and Southern Inland Flowing Waters (TSD); located at 
www.regulations.gov, Docket ID No. EPA-HQ-OW-2010-0222.
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A. General Information and Approaches

    For each group of waters addressed in Section III, EPA is proposing 
to use system-specific approaches based on the classification and 
segmentation results for each system (described in detail in Sections 
III.B, III.C, and III.D) for the derivation of numeric nutrient 
criteria to ensure that the diversity of unique ecosystems found in 
each type of water body is taken into consideration. This system-
specific approach allows the Agency to consider the physical, chemical, 
and biological characteristics of a particular water body and to select 
a scientifically defensible approach, considering the data and 
information available for each system. This section describes the 
technical approaches EPA employed to derive the proposed criteria and 
DPVs, including (1) data and segmentation, (2) biological endpoints, 
and (3) analytical methodologies.
1. Data Sources and Segmentation
(a) Estuaries
    Florida's estuarine areas encompass approximately 1,950 square 
miles. EPA used the IWR Run 40 database \150\ to identify available 
data from a range of sampling sites in Florida's estuaries. To compute 
relationships between nutrient concentrations and chlorophyll a, EPA 
relied on measurements of Total Kjeldahl Nitrogen (TKN), TN, Nitrate-
Nitrite (NO3-NO2), TP, and chlorophyll a from the 
IWR Run 40 database. The resulting dataset included 180,814 water 
quality samples, collected at 13,648 sites. The Agency also analyzed 
additional data submitted by local experts and organizations.
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    \150\ Florida's IWR data are the chemical, physical and 
biological water quality data that FDEP uses to create its 
integrated reports. IWR Run 40. Updated through February 2010. FL 
IWR and STORET can be found at: http://www.dep.state.fl.us/WATER/STORET/INDEX.HTM.
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    The water quality and biological communities of an estuary are 
affected by multiple factors related to the shape and size of the 
estuary, its connections to the ocean, geology, climate, and watershed 
characteristics (e.g., watershed area and land use). Because each of 
these factors can vary from one system to another, causing the water 
quality and aquatic populations of flora and fauna in each estuary to 
be distinct, EPA proposes to classify 19 individual estuarine systems 
based on the natural geographic features of estuarine basins and their 
associated watersheds. This approach has been utilized previously in 
development of the NOAA Coastal Assessment Framework.\151\ This 
approach is also consistent with a watershed approach to water quality 
management, which EPA encourages as a way to integrate and coordinate 
efforts within a watershed in order to most effectively and efficiently 
assess conditions and implement controls.\152\
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    \151\ NOAA. 2007. NOAA's Coastal Geospatial Data Project, 
Coastal Assessment Framework (CAF). NOAA/NOS Special Projects 
Office--Coastal Geospatial Data Project. Silver Spring, MD. http://coastalgeospatial.noaa.gov/. Accessed May 2012.
    \152\ USEPA. 2008. Handbook for Developing Watershed Plans to 
Restore and Protect Our Waters. EPA 841-B-08-002. U.S. Environmental 
Protection Agency, Office of Water, Washington DC.
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    EPA is proposing to sub-divide each estuarine system into segments 
based on physical factors and long-term average salinity gradients. 
Estuaries are complex and dynamic systems that reflect the mixing of 
fresh and marine water, and different ecological zones correspond to 
differences in salinity within each estuary. The estuary segments are 
expected to have unique physical, chemical, and biological 
characteristics that may respond differently to nutrient inputs than 
other segments within the same estuary.\153\ EPA is proposing numeric 
nutrient criteria for 89 individual segments in 19 estuaries. A 
detailed description and detailed maps of EPA's proposed within-estuary 
segments are provided in the TSD (Volume 1: Estuaries, Section 1.3 and 
for each estuarine system in Section 2).
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    \153\ Telesh, I.V., and V.V. Khlebovich. 2010. Principal 
processes within the estuarine salinity gradient: A review. Marine 
Pollution Bulletin 61(4-6):149-155.
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(b) Coastal Waters
    There are substantial data available from satellite remote sensing 
that can be used in a scientifically defensible and reliable way in 
conjunction with available field monitoring data to derive numeric 
chlorophyll a criteria for coastal waters. Satellite remote sensing 
technologies have been widely used \154\ to measure chlorophyll a in 
approximately 3,865 square miles of coastal waters in Florida. These 
technologies allow consistent and

[[Page 74943]]

reliable monitoring of expansive areas of Florida's coastline.
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    \154\ Gregg, W.W., and NW. Casey. 2004. Global and regional 
evaluation of the SeaWiFS chlorophyll data set. Remote Sensing of 
Environment 93(4):463-479.
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    The data EPA used to derive numeric chlorophyll a criteria for 
Florida's coastal waters encompass a twelve year period of record 
(1998-2009). The length of this data record captures the long-term 
variability that has been observed in water quality within Florida's 
coastal waters and allows EPA to take advantage of the available remote 
sensing data. To obtain chlorophyll a measurements from satellite 
remote sensing (chlRS-a), EPA processed data from over 1,000 
8-day composites of remotely sensed images from satellite ocean color 
data. The eight-day binning period is a standard approach based on the 
satellite orbit repeat period of 16 days for the Sea-viewing Wide 
Field-of-view Sensor (SeaWiFS) satellite.\155\ EPA also obtained field 
monitoring TN, TP, and chlorophyll a data from FDEP IWR Run 40, the 
Northeastern Gulf of Mexico Chemical Oceanography and Hydrography Study 
(NEGOM), the Ecology and Oceanography of Harmful Algal Blooms Research 
Program (ECOHAB), the Florida Fish and Wildlife Conservation Commission 
Fish and Wildlife Research Institute (FWRI), NOAA Oceanographic Data 
Center (NODC), Mote Marine Laboratory, and the SeaWiFS Bio-optical 
Archive and Storage System (SeaBASS). Field monitoring data included 
over 5,500 chlorophyll a measurements, which were reduced to 1,947 
measurements after screening for data quality, as described later in 
this proposed rule.
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    \155\ Campbell, J.W., J.M. Blaisdell, and M. Darzi. 1995. Volume 
32, Level-3 SeaWiFS Data Products: Spatial and Temporal Binning 
Algorithms. In: SeaWiFS Technical Report Series. eds. Hooker, S.B., 
E.R. Firestone, and J.G. Acker. NASA Technical Memorandum 104566, 
Vol. 32. National Aeronautics and Space Administration. Greenbelt, 
MD.
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    EPA is not proposing to derive TN and TP criteria for Florida's 
coastal waters due to lack of sufficient field monitoring data for TN 
and TP. Although it would be a more reliable indicator to include TN 
and TP in combination with chlorophyll a, EPA believes that the 
chlorophyll a criteria should protect these Florida waters because 
chlorophyll a can be a sensitive biological parameter that would serve 
as a signal to the State that nutrient pollution is creating an 
imbalance in the natural populations of aquatic flora and fauna in 
Florida's coastal waters. Where EPA has not derived criteria for 
certain parameters in this proposed rule, due to insufficient 
scientific evidence to support a protective threshold for numeric 
nutrient criteria (e.g., TN and TP for the majority of Florida's 
coastal waters), EPA or the State may consider deriving criteria in the 
future for those parameters.
    To ensure data quality, EPA screened available field monitoring 
data to find samples with, at a minimum, metadata for date, time, 
latitude, longitude, and chlorophyll a or light attenuation 
information. Where multiple samples of chlorophyll a at different 
depths existed, EPA selected the sample closest to the surface in order 
to provide a better comparison to the remotely sensed data. The 
monitoring sampling times were also compared to the satellite overpass 
times. EPA used samples falling within a plus or minus three hour time 
window to minimize variability between the sample time and satellite 
overpass time. EPA then compared the satellite chlRS-a data 
to the field monitored chlorophyll a data. From this assessment EPA 
determined that chlRS-a accurately represents chlorophyll a 
in coastal waters.
    For the purposes of deriving criteria for coastal waters using 
remote sensing data, EPA is proposing to exclude chlRS-a 
measurements taken during known bloom events of Karenia brevis from the 
statistical distribution of coastal data. K. brevis is a dinoflagellate 
responsible for red tide. Satellites can detect K. brevis blooms when 
cell counts are above 50,000 cells/L. EPA flagged coastal segments with 
cell counts greater than 50,000 cells/L during an 8-day composite and 
did not include them in the chlRS-a distributions used in 
criteria derivation.\156\ In addition, the same segment was flagged one 
week prior to and after a bloom detection to provide a temporal buffer 
as blooms are transported along the coast. This proposed approach is 
consistent with recommendations from the Agency's Science Advisory 
Board, which recommended EPA screen out these data points, as they are 
likely not representative of reference conditions.\157\ Analyses of 
cumulative distributions of chlRS-a show they are minimally 
affected by inclusion or removal of observations affected by K. brevis.
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    \156\ Heil, C.A., and K.A. Steidinger. 2009. Monitoring, 
management, and mitigation of Karenia blooms in the Eastern Gulf of 
Mexico. Harmful Algae 8:611-617.
    \157\ USEPA-SAB. 2011. Review of EPA's draft Approaches for 
Deriving Numeric Nutrient Criteria for Florida's Estuaries, Coastal 
Waters, and Southern Inland Flowing Waters. EPA-SAB-11-010. U.S. 
Environmental Protection Agency, Science Advisory Board, Washington, 
DC.
---------------------------------------------------------------------------

    EPA classified Florida's coastal waters into three main areas: The 
Florida Panhandle, West Florida Shelf, and Atlantic Coast. These three 
coastal areas were subdivided into a total of 71 segments based on 
FDEP's Water Body Identification System (WBIDs), physical factors, the 
optical properties of the coastal areas, water quality characteristics, 
and the jurisdictional limits of the Clean Water Act (i.e., three 
nautical mile seaward limit). A detailed description of EPA's data 
screening process and a map of the coastal waters are provided in the 
TSD (Volume 2: Coastal Waters, Section 1.3).
(c) Request for Comment on Data and Segmentation
    EPA believes the proposed data and segmentation approaches provide 
a strong foundation for the derivation of numeric nutrient criteria 
that will protect the designated uses in Florida's estuaries and 
coastal waters. EPA requests comment on all aspects of these 
approaches. Additionally, the Agency is soliciting additional relevant 
data and information to assist in the derivation of numeric nutrient 
criteria. Relevant data and information includes, but is not limited 
to: Monitoring data for DO, chlorophyll a, TN, TP, TKN, dissolved 
organic nitrogen, dissolved organic phosphorus, dissolved inorganic 
nitrogen, dissolved inorganic phosphorus, and NO3-
NO2. EPA also invites comment on the timeframe of the data 
used to derive criteria for each of the water body types. In addition, 
EPA requests comment on excluding chlRS-a measurements taken 
during known bloom events of K. brevis from the statistical 
distribution of coastal data. EPA also solicits additional available 
scientific data and information that could be used in the derivation of 
numeric criteria for nitrogen and phosphorus in coastal waters.
    Even though waters were assigned to segments to ensure homogeneity 
of water quality across different locations within a segment, EPA 
recognizes that limited variability may still exist across locations 
within a given segment. EPA also solicits comment on and requests any 
additional available information regarding the ability of the proposed 
segmentation approaches to account for the unique water quality 
conditions that can be found in estuarine and coastal waters throughout 
the State. Finally, EPA is proposing to derive numeric nutrient 
criteria using a system-specific approach. EPA requests comment on the 
spatial scale of the proposed criteria and whether a broader spatial 
approach would be more appropriate.
2. Biological Endpoints
    When deriving numeric nutrient criteria, it is important to 
identify nutrient-sensitive biological endpoints

[[Page 74944]]

relevant to particular estuarine and coastal systems. These biological 
endpoints serve as sensitive measures to identify protective 
concentrations of TN, TP, and chlorophyll a that, in turn, will support 
balanced natural populations of aquatic flora and fauna and protect the 
State's designated uses. EPA conducted an extensive evaluation of 
available scientific literature to select appropriate biological 
endpoints, reviewing over 800 documents. From this review of the latest 
scientific knowledge, EPA has determined that maintenance of 
seagrasses, maintenance of balanced algal populations, and maintenance 
of aquatic life are three sensitive biological endpoints, which can be 
measured by water clarity (as it relates to light levels sufficient to 
maintain historic depth of seagrass colonization), chlorophyll a, and 
DO, respectively, and appropriately used in derivation of numeric 
nutrient criteria that protect the State's designated uses from harmful 
increases in nitrogen and phosphorus concentrations. The selection of 
these biological endpoints was based upon their scientific 
defensibility; sensitivity to harmful, adverse effects caused by the 
pollutants nitrogen and phosphorus; and the sufficiency of data 
available for each.
    EPA derived TN, TP, and chlorophyll a criteria to: (1) Maintain 
water clarity to achieve seagrass depth of colonization targets, (2) 
reduce the risk of phytoplankton blooms, and (3) maintain dissolved 
oxygen concentrations sufficient for balanced, natural aquatic life in 
Florida's estuaries and coastal waters. As set out more fully in the 
following discussion, these three biological endpoints provide a 
scientifically defensible basis upon which to derive numeric nutrient 
criteria that protect balanced natural populations of aquatic flora and 
fauna over the full range of estuarine and coastal conditions across 
Florida; waters that achieve these endpoints support designated uses.
(a) Maintenance of Seagrasses
    EPA selected the maintenance of seagrasses, as measured by water 
clarity to maintain historic depth of seagrass colonization, as one 
biological endpoint and corresponding endpoint measure to derive 
numeric nutrient criteria for estuaries. Healthy populations of 
seagrasses serve as widely recognized indicators of biological 
integrity in estuarine systems and, in turn, of balanced natural 
populations of aquatic flora and fauna.\158\
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    \158\ Ferdie, M., and J.W. Fourqurean. 2004. Responses of 
seagrass communities to fertilization along a gradient of relative 
availability of nitrogen and phosphorus in a carbonate environment. 
Limnology and Oceanography 49(6):2082-2094.
    Orth, R.J., T.J.B. Carruthers, W.C. Dennison, C.M. Duarte, J.W. 
Fourqurean, K.L. Heck, A.R. Hughes, G.A. Kendrick, W.J. Kenworthy, 
S. Olyarnik, F.T. Short, M. Waycott, and S.L. Williams. 2006. A 
global crisis for seagrass ecosystems. BioScience 56(12):987-996.
    Doren, R.F., J.C. Trexler, A.D. Gottlieb, and M.C. Harwell. 
2009. Ecological indicators for system-wide assessment of the 
greater everglades ecosystem restoration program. Ecological 
Indicators 9:S2-S16.
    Gibson, G.R., M.L. Bowman, J. Gerritsen, and B.D. Snyder. 2000. 
Estuarine and Coastal Marine Waters: Bioassessment and Biocriteria 
Technical Guidance. EPA 822-B-00-024. U.S. Environmental Protection 
Agency, Office of Water, Washington, DC. http://water.epa.gov/scitech/swguidance/standards/criteria/aqlife/biocriteria/upload/2009_04_22_biocriteria_States_estuaries_estuaries.pdf. 
Accessed November 2011.
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    Because of the unique conditions that are created within seagrass 
communities, populations of other aquatic floral and faunal species 
benefit from the presence and abundance of seagrasses.\159\ For 
example, seagrasses act as nurseries for many species by providing 
refuge from predators. Seagrasses also improve water quality by 
trapping suspended sediments, preventing sediment resuspension, and 
retaining nutrients. Florida's NEPs and FDEP have also used endpoints 
based on seagrasses to derive their recommended estuarine criteria 
because of seagrass sensitivity to nutrient pollution.
---------------------------------------------------------------------------

    \159\ Orth, R.J., T.J.B. Carruthers, W.C. Dennison, C.M. Duarte, 
J.W. Fourqurean, K.L. Heck Jr., A.R. Hughes, G.A. Kendrick, W.J. 
Kenworthy, S. Olyarnik, F.T. Short, M. Waycott, and S.L. Williams. 
2006. A global crisis for seagrass ecosystems. Bioscience 
56(12):987-996.
---------------------------------------------------------------------------

    Seagrass communities depend on a variety of physical, chemical, and 
biological conditions to thrive. Among these, adequate underwater light 
availability (as measured by water clarity) is one critical factor for 
seagrass health. The relationship between water clarity and the depth 
to which seagrasses grow, known as the depth of colonization, has been 
well-documented.\160\ When seagrasses receive sufficient sunlight, 
seagrass biomass remains constant or increases over time. Conversely, 
when incoming light is blocked by substances in the water column, such 
as phytoplankton, suspended solids, or color, seagrass growth slows or 
stops. Studies on seagrasses have documented the relationship of 
nutrient pollution-related accelerated algal growth to declines in 
available light and subsequent declines in seagrass communities.\161\ 
Since the area within an estuary available for seagrass growth is 
partially a function of the total area with enough sunlight at 
sufficient depths to sustain growth, as water clarity decreases and 
reduces the amount of sunlight that can reach the seagrasses, the 
available area for seagrass growth also decreases. Hence, the greater 
the water clarity (and associated available light), the deeper the 
water that can support seagrass communities and, therefore, the greater 
the extent of seagrass coverage.
---------------------------------------------------------------------------

    \160\ Dennison, W.C. 1987. Effects of light on seagrass 
photosynthesis, growth, and depth distribution. Aquatic Botany 
27:15-26.
    Dennison, W.C., R.J. Orth, K.A. Moore, J.C. Stevenson, V. 
Carter, S. Kollar, P.W. Bergstrom, and R.A. Batiuk. 1993. Assessing 
water quality with submersed aquatic vegetation. BioScience 
43(2):86-94.
    Duarte, C.M. 1991. Seagrass depth limits. Aquatic Botany 
40(4):363-377.
    Gallegos, C.L. 1994. Refining habitat requirements of submersed 
aquatic vegetation: Role of optical models. Estuaries 17(1):187-199.
    Gallegos, C.L., and W.J. Kenworthy. 1996. Seagrass depth limits 
in the Indian River Lagoon (Florida, USA): Application of an optical 
water quality model. Estuarine, Coastal and Shelf Science 42(3):267-
288.
    Gallegos, C.L. 2005. Optical water quality of a blackwater river 
estuary: the Lower St. Johns River, Florida, USA. Estuarine, Coastal 
and Shelf Science 63(1-2):57-72.
    Steward, J.S., R.W. Virnstein, L.J. Morris, and E.F. Lowe. 2005. 
Setting seagrass depth, coverage, and light targets for the Indian 
River Lagoon system, Florida. Estuaries and Coasts 28(6):923-935.
    \161\ Ferdie, M., and J.W. Fourqurean. 2004. Responses of 
seagrass communities to fertilization along a gradient of relative 
availability of nitrogen and phosphorus in a carbonate environment. 
Limnology and Oceanography 49(6):2082-2094.
    Orth, R.J., T.J.B. Carruthers, W.C. Dennison, C.M. Duarte, J.W. 
Fourqurean, K.L. Heck, A.R. Hughes, G.A. Kendrick, W.J. Kenworthy, 
S. Olyarnik, F.T. Short, M. Waycott, and S.L. Williams. 2006. A 
global crisis for seagrass ecosystems. BioScience 56(12):987-996.
---------------------------------------------------------------------------

    EPA reviewed studies that empirically assessed the relationship 
between seagrass growth and available light \162\ and is proposing 
that, for Florida, when an average value of 20 percent of the sunlight 
that strikes the water's surface (incident light) reaches the bottom of 
the water column (to the depth of seagrass colonization), sufficient 
light is available to maintain seagrasses. A similar value has been 
used in previous nutrient management efforts in Florida.\163\
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    \162\ Dennison, W.C., R.J. Orth, K.A. Moore, J.C. Stevenson, V. 
Carter, S. Kollar, P.W. Bergstrom, and R.A. Batiuk. 1993. Assessing 
water quality with submersed aquatic vegetation. BioScience 
43(2):86-94.
    Duarte, C.M. 1991. Seagrass depth limits. Aquatic Botany 
40(4):363-377.
    Gallegos, C.L. 1994. Refining habitat requirements of submersed 
aquatic vegetation: Role of optical models. Estuaries 17(1):187-199.
    Steward, J.S., R.W. Virnstein, L.J. Morris, and E.F. Lowe. 2005. 
Setting seagrass depth, coverage, and light targets for the Indian 
River Lagoon system, Florida. Estuaries and Coasts 28(6):923-935.
    \163\ Janicki, A.J., and D.L. Wade. 1996. Estimating critical 
external nitrogen loads for the Tampa Bay estuary: An empirically 
based approach to setting management targets. Technical Publication 
06-96. Prepared for Tampa Bay National Estuary Program, St. 
Petersburg, FL, by Coastal Environmental, Inc., St. Petersburg, FL.

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[[Page 74945]]

    EPA is also proposing that protecting and maintaining water clarity 
sufficient to support an appropriate depth of colonization provides the 
greatest protection of balanced natural populations of aquatic flora 
and fauna since maintenance of seagrass habitat is critical to 
ecosystem conditions. EPA used available historical seagrass coverage 
data (including the earliest available, generally 1940-1960, or more 
recent, 1992) to compute the historical maximum depth of seagrass 
colonization as a reference. In all cases the most recent (2000-2010) 
seagrass coverage was also evaluated to determine existing depth of 
colonization, and to relate this value to existing water quality. To 
compute seagrass depth of colonization, EPA overlaid seagrass coverage 
data and bathymetric data compiled by NOAA using a Geographic 
Information System.\164\ EPA then used the data on seagrass coverage to 
determine the maximum depths that seagrasses have been able to grow in 
each estuary, where applicable (this approach was not used in some 
estuaries in Florida that do not have historical evidence of seagrass 
colonization), in order to identify a reference point for a healthy 
level of seagrass colonization. Because seagrass habitats support a 
rich array of biological uses,\165\ EPA is proposing to derive numeric 
nutrient criteria to maintain a comparable depth of seagrass 
colonization to the reference level (i.e. seagrasses growing at the 
deepest observed depth of colonization) to ensure protection of 
balanced natural populations of aquatic flora and fauna. EPA chose to 
use the historical maximum observed depth, and resulting areal 
coverage, because increasing nutrients beyond the point that is 
protective of maximum coverage of seagrass is likely to cause a decline 
in seagrass coverage. Because a wide variety of organisms rely on 
healthy seagrass communities, a decrease in seagrass coverage to levels 
below the maximum observed depth will result in a decline in overall 
system health and biodiversity.\166\ EPA calculated a water clarity 
target that would ensure 20% percent of incident light at the surface 
would be able to reach the reference depth of colonization. Finally, 
EPA used this water clarity target to derive numeric criteria for TN, 
TP, and chlorophyll a to support balanced natural populations of 
aquatic flora and fauna. (More detail on the importance of seagrass can 
be found in the TSD, Volume 1: Estuaries, Section 1.2.1).
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    \165\ Hughes, A.R., S.L. Williams, C.M. Duarte, K.L. Heck, Jr., 
and M. Waycott. 2009. Associations of concern: declining seagrasses 
and threatened dependent species. Frontiers in Ecology and the 
Environment 7(5):242-246.
    \166\ Hughes, A.R., S.L. Williams, C.M. Duarte, K.L. Heck, Jr., 
and M. Waycott. 2009. Associations of concern: declining seagrasses 
and threatened dependent species. Frontiers in Ecology and the 
Environment 7(5):242-246.
    Orth, R.J., T.J.B. Carruthers, W.C. Dennison, C.M. Duarte, J.W. 
Fourqurean, K.L. Heck, A.R. Hughes, G.A. Kendrick, W.J. Kenworthy, 
S. Olyarnik, F.T. Short, M. Waycott, and S.L. Williams. 2006. A 
global crisis for seagrass ecosystems. BioScience 56(12):987-996.
    FFWCC. 2003. Conserving Florida's Seagrass Resources: Developing 
a Coordinated Statewide Management Program. Florida Fish and 
Wildlife Conservation Commission, Florida Marine Research Institute. 
St. Petersburg, FL.
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    (b) Maintenance of Balanced Algal Populations
    Based upon EPA's extensive review of current scientific literature, 
EPA selected maintenance of balanced algal populations, as measured by 
the chlorophyll a concentrations associated with balanced phytoplankton 
biomass, as the second biological endpoint and corresponding endpoint 
measure to derive numeric nutrient criteria for estuaries and coastal 
waters. The maintenance of balanced algal populations is an important 
sensitive biological endpoint because of its responsiveness to nutrient 
enrichment, integral role in aquatic food webs, well-established use as 
an integrative measure of aquatic ecosystem condition, and correlation 
with changes in floral composition and subsequent faunal response.\167\ 
Chlorophyll a is the endpoint measure of balanced algal populations, 
and has a long history of use in aquatic ecology as a measure of 
phytoplankton biomass and production.\168\ Elevated chlorophyll a 
concentrations resulting from nutrient pollution-enhanced algal growth 
and accumulation are a well-documented symptom of eutrophication and 
the harmful, adverse impacts of nitrogen and phosphorus pollution 
across the nation, and specifically in Florida (refer to Section II.A 
for additional information).\169\ In most of Florida's coastal and 
estuarine waters, healthy biological communities depend on balanced 
natural populations of algae because algae are integral components of 
aquatic food webs and aquatic nutrient cycling.\170\
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    \167\ Boyer, J.N., C.R. Kelble, P.B. Ortner, and D.T. Rudnick. 
2009. Phytoplankton bloom status: Chlorophyll a biomass as an 
indicator of water quality condition in the southern estuaries of 
Florida, USA. Ecological Indicators 9s:S56-S67.
    Hagy, J.D., J.C. Kurtz, and R.M. Greene. 2008. An approach for 
developing numeric nutrient criteria for a Gulf coast estuary. EPA 
600R-08/004. U.S. Environmental Protection Agency, Office of 
Research and Development, National Health and Environmental Effects 
Research Laboratory, Gulf Breeze, FL.
    Bricker, S.B., C.G. Clement, D.E. Pirhalla, S.P. Orlando, and 
D.R.G. Farrow. 1999. National Estuarine Eutrophication Assessment. 
Effects of Nutrient Enrichment in the Nation's Estuaries. National 
Oceanic and Atmospheric Administration, National Ocean Service, 
Special Projects Office and the National Centers for Coastal Ocean 
Science, Silver Spring, MD.
    See Section B.3 in Appendix B of USEPA. 2010. Methods and 
Approaches for Deriving Numeric Criteria for Nitrogen/Phosphorus 
Pollution in Florida's Estuaries, Coastal Waters, and Southern 
Inland Flowing Waters. U.S. Environmental Protection Agency, Office 
of Water, Washington, DC.
    \168\ Wetzel, R.G. 2001. Limnology: Lakes and River Ecosystems. 
3rd ed. Academic Press, San Diego, CA.
    Kalff, J. 2002. Limnology: Inland Water Ecosystems. Prentice-
Hall, Inc., Upper Saddle River, New Jersey.
    \169\ Elser, J.J., M.E.S. Bracken, E.E. Cleland, D.S. Gruner, 
W.S. Harpole, H. Hillebrand, J.T. Ngai, E.W. Seabloom, J.B. Shurin, 
and J.E. Smith. 2007. Global analysis of nitrogen and phosphorus 
limitation of primary production in freshwater, marine, and 
terrestrial ecosystems. Ecology Letters 10:1135-1142.
    Smith, V.H. 2006. Responses of estuarine and coastal marine 
phytoplankton to nitrogen and phosphorus enrichment. Limnology and 
Oceanography 51(1 part 2):377-384
    \170\ Hauxwell, J., C. Jacoby, T. Frazer, and J. Stevely. 2001. 
Nutrients and Florida's Coastal Waters: The Links Between People, 
Increased Nutrients and Changes to Coastal Aquatic Systems. Florida 
Sea Grant Report No. SGEB-55. Florida Sea Grant College Program, 
University of Florida, Gainesville, FL. http://edis.ifas.ufl.edu/pdffiles/SG/SG06100.pdf. Accessed June 2011.
    NOAA. 2011. Overview of Harmful Algal Blooms. National Oceanic 
and Atmospheric Administration, Center for Sponsored Coastal 
Research. http://www.cop.noaa.gov/stressors/extremeevents/hab/default.aspx. Accessed June 2011.
---------------------------------------------------------------------------

    Elevated chlorophyll a concentrations resulting from nitrogen and 
phosphorus pollution alter the trophic state of estuarine and coastal 
waters and increase the frequency and magnitude of algal blooms. EPA 
evaluated the available scientific literature to determine chlorophyll 
a concentrations indicative of phytoplankton blooms associated with 
imbalance in natural populations of aquatic flora and fauna. Published 
reports on chlorophyll a concentrations in estuarine waters across the 
nation, including Florida estuaries, reflect the range of natural 
trophic states and enrichment. These studies suggest that low algal 
bloom conditions are defined as maximum chlorophyll a concentrations 
less than or equal to 5 [micro]g/L, medium bloom conditions are defined 
as maximum chlorophyll a concentrations from greater than 5 to 20 
[micro]g/L, high bloom conditions are defined as maximum chlorophyll a 
concentrations from greater than 20 to 60 [micro]g/L, and 
hypereutrophic conditions are defined by maximum bloom concentrations

[[Page 74946]]

above 60 [micro]g/L.\171\ Two Florida estuaries, Florida Bay and 
Pensacola Bay, were analyzed as a part of a larger NOAA national survey 
of estuaries. The authors reported the average chlorophyll a 
concentrations were 20 [micro]g/L or less for seven of ten large 
estuaries nationally, and were especially low for Florida Bay (8 
[micro]g/L) and Pensacola Bay (10 [micro]g/L).\172\ Other literature 
regarding phytoplankton blooms indicated similar results.\173\
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    \171\ Bricker, S.B., J.G. Ferreira, and T. Simas. 2003. An 
integrated methodology for assessment of estuarine trophic status. 
Ecological Modelling 169(1):39-60.
    \172\ Glibert, P.M., C.J. Madden, W. Boynton, D. Flemer, C. 
Heil, and J. Sharp, eds. 2010. Nutrients in Estuaries: A Summary 
Report of the National Estuarine Experts Workgroup, 2005-2007. 
Report to U.S. Environmental Protection Agency, Office of Water, 
Washington DC.
    \173\ OECD. 1982. Eutrophication of Waters: Monitoring, 
Assessment and Control. Organisation for Economic Cooperation and 
Development, Paris, France.
    Painting, S.J., M.J. Devlin, S.J. Malcolm, E.R. Parker, D.K. 
Mills, C. Mills, P. Tett, A. Wither, J. Burt, R. Jones, and K. 
Winpenny. 2007. Assessing the impact of nutrient enrichment in 
estuaries: susceptibility to eutrophication. Marine Pollution 
Bulletin 55:74-90.
    Painting, S.J., M.J. Devlin, S.I. Rogers, D.K. Mills, E.R. 
Parker, and H.L. Rees. 2005. Assessing the suitability of OSPAR 
EcoQOs for eutrophication vs. ICES criteria for England and Wales. 
Marine Pollution Bulletin 50:1569-1584.
    Tett, P., R. Gowen, D. Mills, T. Fernandes, L. Gilpin, M. 
Huxham, K. Kennington, P. Read, M. Service, M. Wilkinson, and S. 
Malcolm. 2007. Defining and detecting undesirable disturbance in the 
context of marine eutrophication. Marine Pollution Bulletin 55:282-
297.
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    Chlorophyll a concentrations associated with hypereutrophic 
conditions (>60 [micro]g/L) reflect a trophic state that is unnatural 
for Florida estuaries. While some estuaries in the State are more 
productive than others, high chlorophyll a concentrations (20 to 60 
[micro]g/L) also do not appear to reflect balanced conditions in 
Florida, especially given observed ranges in Florida. Concentrations of 
chlorophyll a in this high range are associated more frequently with 
loss of seagrass and a shift of algal populations to monoculture or, in 
other words, a loss in the balance of diverse populations of aquatic 
flora.\174\ Moreover, this concentration range was also associated with 
conditions where other uses, including recreation, are adversely 
affected. Based on the range of chlorophyll a concentrations indicative 
of natural algal bloom conditions characteristic of Florida estuaries, 
as well as the literature on concentrations associated with harmful, 
adverse conditions for estuarine biota and other use support, EPA is 
proposing a chlorophyll a concentration of 20 [micro]g/L as the water 
quality target to define a nuisance algal bloom. Thus, estuarine waters 
with chlorophyll a concentrations that exceed this water quality target 
threshold are indicative of imbalanced populations of aquatic flora and 
fauna (More detail regarding EPA's analysis can be found in the TSD, 
Volume 1: Estuaries, Section 1.2.2).
---------------------------------------------------------------------------

    \174\ Bricker, S.B., J.G. Ferreira, and T. Simas. 2003. An 
integrated methodology for assessment of estuarine trophic status. 
Ecological Modelling 169(1):39-60.
---------------------------------------------------------------------------

    EPA also considered the available scientific research described in 
this section to establish an allowable frequency of occurrence of 
phytoplankton blooms, represented by chlorophyll a levels greater than 
20 [mu]g/L, to further define this endpoint measure. EPA is proposing a 
value of 10% as an allowable frequency of occurrence of phytoplankton 
blooms, that is, chlorophyll a measurements may not exceed 20 [mu]g/L 
more than 10% of the time. This frequency is also consistent with 
current nutrient management practices in Florida, such as those 
utilized in approved Florida TMDLs.
(c) Maintenance of Aquatic Life
    EPA selected maintenance of aquatic life, as measured by the 
sufficiency of dissolved oxygen (DO) to maintain aquatic life, as a 
third biological endpoint and corresponding endpoint measure to derive 
numeric nutrient criteria for estuaries. DO concentrations are a well-
known indicator of the health of estuarine and coastal biological 
communities. Aquatic animals including fish, benthic 
macroinvertebrates, and zooplankton depend on adequate levels of DO to 
survive and grow. These levels may differ depending on the species and 
life stage of the organism (e.g., larval, juvenile, and adult).\175\
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    \175\ Diaz, R.J. 2001. Overview of hypoxia around the world. 
Journal of Environmental Quality 30(2):275-281.
    Diaz, R.J., and R. Rosenberg. 2008. Spreading dead zones and 
consequences for marine ecosystems. Science 321(5891):926-929.
---------------------------------------------------------------------------

    To derive the DO endpoint, EPA conducted an analysis of the 
dissolved oxygen requirements of sensitive species in Florida using the 
Virginian Province dissolved oxygen evaluation procedure.\176\ This 
analysis derives DO levels that protect both larval recruitment and 
growth for aquatic organisms. EPA used the results of this analysis to 
determine the dissolved oxygen water quality targets considered for 
numeric nutrient criteria development that would protect sensitive 
aquatic species in Florida estuaries. EPA is proposing that satisfying 
three different DO requirements in Florida's estuarine waters would 
meet the needs of resident sensitive aquatic species, and thus support 
the maintenance of aquatic life. These requirements are an 
instantaneous DO concentration of 4.0 mg/L, a daily average DO 
concentration of 5.0 mg/L, and a bottom water average DO concentration 
of 1.5 mg/L. Both the instantaneous minimum of 4.0 mg/L and the daily 
average of 5.0 mg/L are spatial averages over the water column for each 
estuarine segment. These values and interpretations are consistent with 
existing Florida DO criteria (Subsection 62-302.530(30), F.A.C.) and 
FDEP's assessment procedures (Subsection 62-303.320(5), F.A.C.). (More 
detail on both the existing Florida DO criteria and EPA's analysis can 
be found in the TSD, Volume 1: Estuaries, Sections 1.2.3 and 1.4.1).
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    \176\ Vincent, A.M., J. Flippin, E. Leppo, and J.D. Hagy III. 
Dissolved oxygen requirements of Florida-resident saltwater species 
applied to water quality criteria development. In review.
    USEPA. 2000. Ambient Aquatic Life Water Quality Criteria for 
Dissolved Oxygen (Saltwater): Cape Cod to Cape Hatteras. EPA-822-R-
00-012. U.S. Environmental Protection Agency, Office of Water, 
Washington DC.
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(d) Other Endpoints Considered by EPA
    EPA considered, but is not proposing to use, the following 
nutrient-sensitive biological endpoints: (1) Harmful algal blooms 
(HABs), (2) coral, (3) epiphytes, (4) macroinvertebrate and fish 
indices, (5) macroalgae, (6) Spartina marshes (salt-marshes), and (7) 
the Eastern oyster (Crassostrea virginica). EPA did not select these 
biological endpoints because there was an absence of sufficient data to 
quantify the link between measurements of these endpoints and nitrogen 
and phosphorus concentrations. Additional details on these alternative 
endpoints are provided in Appendix B in the Methods and Approaches for 
Deriving Numeric Criteria for Nitrogen/Phosphorus Pollution in 
Florida's Estuaries, Coastal Waters, and Southern Inland Flowing 
Waters.\177\
---------------------------------------------------------------------------

    \177\ USEPA. 2010. Methods and Approaches for Deriving Numeric 
Criteria for Nitrogen/Phosphorus Pollution in Florida's Estuaries, 
Coastal Waters, and Southern Inland Flowing Waters. U.S. 
Environmental Protection Agency, Office of Water, Washington, DC.
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(e) Request for Commerce on Endpoints
    EPA believes that maintenance of seagrasses, maintenance of 
balanced algal populations, and maintenance of aquatic life are the 
three most appropriate nutrient-sensitive biological endpoints to use 
to derive numeric nutrient criteria to ensure that nutrient 
concentrations in a body of water

[[Page 74947]]

protect balanced natural populations of aquatic flora and fauna, and in 
turn support designated uses. EPA requests comment regarding the 
biological endpoints and endpoint measures selected. EPA also solicits 
additional scientific information on other appropriate endpoints that 
can be used to protect fish consumption, recreation, and the 
propagation and maintenance of a healthy, well-balanced population of 
fish and wildlife in Florida's Class II and III estuarine and coastal 
waters.
3. Analytical Methodologies
    EPA used three analytical approaches to derive TN, TP, and 
chlorophyll a numeric nutrient criteria for different types of waters 
in Florida. In most of Florida coastal waters, EPA is proposing to use 
a reference condition approach that utilizes data from waters that 
support balanced natural populations of aquatic flora and fauna to 
derive numeric nutrient criteria. In Florida estuaries (including some 
coastal waters in the Big Bend Coastal region), EPA is proposing to use 
statistical and mechanistic models to determine protective 
concentrations of TN, TP, and chlorophyll a linked to biological 
endpoints. Where sufficient data were not available to apply 
statistical models (i.e., stressor-response approach) in all segments 
in an estuary, EPA used mechanistic model predictions to derive 
criteria. In these instances, EPA analyzed the available stressor-
response analysis as a second line of evidence, in segments where the 
data were available.
(a) Reference Condition Approach
    EPA is proposing to use the reference condition approach to derive 
numeric nutrient criteria in coastal waters that support balanced 
natural populations of aquatic flora and fauna. EPA is proposing this 
approach to derive numeric chlorophyll a criteria for Florida's coastal 
waters because the scientific data and information available were 
insufficient to establish accurate quantifiable relationships between 
TN and TP concentrations and harmful, adverse effects due to the 
limited TN and TP data available. Therefore, EPA is proposing to rely 
upon the reference condition approach to identify numeric chlorophyll a 
criteria concentrations that protect the designated uses, and avoid any 
adverse change in natural populations of aquatic flora or fauna in 
Florida's coastal waters.
    The reference condition approach, which has been well documented, 
peer reviewed, and developed in a number of different contexts,\178\ is 
used to derive numeric nutrient criteria that are protective of 
applicable designated uses by identifying numeric nutrient criteria 
concentrations occurring in least-disturbed, healthy coastal waters 
that are supporting designated uses.
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    \178\ USEPA. 2000a. Nutrient Criteria Technical Guidance Manual: 
Lakes and Reservoirs. EPA-822-B-00-001. U.S. Environmental 
Protection Agency, Office of Water, Washington, DC.
    USEPA. 2000b. Nutrient Criteria Technical Guidance Manual: 
Rivers and Streams. EPA-822-B-00-002. U.S. Environmental Protection 
Agency, Office of Water, Washington, DC.
    Stoddard, J.L., D.P. Larsen, C.P. Hawkins, R.K. Johnson, and 
R.H. Norris. 2006. Setting expectations for the ecological condition 
of streams: The concept of reference condition. Ecological 
Applications 16:1267-1276.
    Herlihy, A.T., S.G. Paulsen, J. Van Sickle, J.L. Stoddard, C.P. 
Hawkins, L.L. Yuan. 2008. Striving for consistency in a national 
assessment: The challenges of applying a reference-condition 
approach at a continental scale. Journal of the North American 
Benthological Society 27:860-877.
    USEPA. 2001. Nutrient Criteria Technical Manual: Estuarine and 
Coastal Marine Waters. EPA-822-B-01-003. U.S. Environmental 
Protection Agency, Office of Water, Washington, DC.
    USEPA-SAB. 2011. Review of EPA's draft Approaches for Deriving 
Numeric Nutrient Criteria for Florida's Estuaries, Coastal Waters, 
and Southern Inland Flowing Waters. EPA-SAB-11-010. U.S. 
Environmental Protection Agency, Science Advisory Board, Washington, 
DC.
---------------------------------------------------------------------------

    To derive the proposed numeric nutrient criteria using the 
reference condition approach, EPA first selected reference conditions 
in Florida's coastal waters where the Agency was confident that 
designated uses are protected. EPA reviewed available monitoring 
information, peer-reviewed literature, and technical reports to ensure 
that, where applicable, seagrass beds are healthy, DO is adequate for 
sensitive species, phytoplankton biomass is balanced, and that any 
other information relating to the ecosystem indicates that the waters 
are supporting balanced natural populations of aquatic flora and fauna. 
EPA also removed data during periods of temporary known human 
disturbances (e.g., bridge and roadway construction) where natural 
populations were temporarily affected. Finally, EPA reviewed CWA 
section 303(d) listings, and removed data associated with impairment 
listings for chlorophyll a, dissolved oxygen, and nutrients, as well as 
data from coastal segments adjacent to CWA section 303(d) impaired 
estuary waters, such that the resulting data would reflect unimpaired 
conditions. EPA only removed data from the period of impairment. The 
result of this rigorous analysis was a set of reference waters that, 
although not pristine, reflected healthy conditions that were 
supporting designated uses, and thus free from harmful, adverse effects 
on natural populations of aquatic flora and fauna due to nutrient 
pollution. EPA has confidence that these reference waters are 
supporting designated uses and balanced natural populations of flora 
and fauna, and has confidence that if the criteria are attained or 
maintained at the concentrations that are among the highest observed in 
these waters, then designated uses and natural populations of aquatic 
flora and fauna will be protected in coastal waters. Further details 
regarding data screening can be found in the TSD (Volume 2: Coastal 
Waters, Section 1.4).
    After selecting the reference waters, EPA calculated the annual 
geometric mean concentrations of chlorophyll a for each year of the 
data record and for each segment.\179\ EPA then calculated a normal 
distribution based on the annual geometric mean chlorophyll a 
concentrations. From this distribution, which represents the population 
of water quality observations in each segment, EPA selected the 90th 
percentile as the applicable criteria for each segment. EPA selected 
the 90th percentile as an appropriate concentration to specify the 
criterion-magnitude because the Agency is confident that the 
distribution reflects minimally-impacted, biologically healthy 
reference conditions, which support the State's Class II and III 
designated uses. The use of the 90th percentile of chlorophyll a is 
also supported by several eutrophication assessment frameworks in 
Europe and the U.S, such as the Oslo-Paris Commission ``Common 
Procedure'' (OSPAR), Water Framework Directive of the EU, Assessment of 
Estuarine Trophic Status in the US, and the Marine Strategy Framework 
Directive used by the European Commission, which identify the 90th 
percentile as representative of a chlorophyll a concentration above 
which eutrophication is considered ecologically problematic or where an 
undesirable disturbance to aquatic life and water quality from 
eutrophication are highly likely to appear.\180\ For

[[Page 74948]]

further information on the use of the reference approach see the TSD 
(Volume 2, Coastal Waters, Section 1.5.1).
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    \179\ Geometric means were used for averages in the reference 
condition, statistical modeling, and mechanistic modeling approaches 
because concentrations were log-normally distributed.
    \180\ OSPAR Commission. 2005. Common Procedure for the 
Identification of the Eutrophication Status of the OSPAR Maritime 
Area (Reference Number: 2005-3). OSPAR Commission, London.
    Ferreira, J.G., J.H. Andersen, A. Borja, S.B. Bricker, J. Camp, 
M.C. da Silva, E. Garc[eacute]s, A-S. Heiskanen, C. Humborg, L. 
Ignatiades, C. Lancelot, A. Menesguen, P. Tett, N. Hoepffner, and U. 
Claussen. 2011. Overview of eutrophication indicators to assess 
environmental status within the European Marine Strategy Framework 
Directive. Estuarine, Coastal and Shelf Science 93(2):117-131.
    Bricker, S.B., J.G. Ferreira, and T. Simas. 2003. An integrated 
methodology for assessment of estuarine trophic status. Ecological 
Modelling 169:39-60.
    European Commission. 2003. Common Implementation Strategy for 
the Water Framework Directive (2000/60/EC): Guidance Document No. 5, 
Transitional and Coastal Waters-Typology, Reference Conditions and 
Classification Systems. European Commission, Working Group 2.4--
COAST, Office for Official Publications of the European Communities, 
Luxembourg.
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    EPA chose not to select the extreme upper end of the distribution 
(95th or 100th percentile). This is because these highest observed 
annual average concentrations (i.e., 95th or 100th percentile) have 
rarely been observed at any reference site and are most likely to be 
heavily influenced by extreme event factors (e.g., hurricanes, 
droughts). Thus these highest observed concentrations could be outliers 
that are not representative of conditions that would typically support 
designated uses and natural populations of aquatic flora and fauna. 
Therefore, EPA has less confidence that such highest observed 
concentrations would continue to be supportive of designated uses and 
natural populations of aquatic flora and fauna if maintained in all 
coastal waters at all times.
    Alternatively, the selection of a much lower percentile, such as a 
representation of the central tendency of the distribution (i.e., 50th 
percentile), would not be appropriate because it would imply that half 
of the conditions observed at reference sites would not support 
designated uses and natural populations of aquatic flora and fauna, 
when EPA's analysis indicates that they do. By setting the criteria at 
the 90th percentile of the reference condition distribution, EPA 
believes the designated uses, i.e., natural populations of aquatic 
flora and fauna, will be protected when these concentrations are 
attained for the majority of coastal water segments. For those coastal 
water segments that are shown to accommodate or require higher or lower 
concentrations, the SSAC provision is provided in EPA's proposed rule 
as discussed in Section V.C.
(b) Statistical Modeling
    EPA evaluated the data available for each estuary segment in terms 
of temporal and spatial representativeness to establish whether there 
were sufficient data to use a statistical model. Where enough 
monitoring data in estuaries were available, EPA developed statistical 
models (i.e., stressor-response relationships) \181\ that quantified 
relationships between TN, TP, chlorophyll a, and the selected endpoint 
measures (i.e., water clarity to maintain maximum depth of seagrass 
colonization and chlorophyll a concentrations associated with balanced 
phytoplankton biomass). There were not enough temporally-resolved DO 
monitoring data, particularly in pre-dawn hours when dissolved oxygen 
concentrations are typically lower than during that day,\182\ in any of 
the estuaries to permit the use of statistical models to derive 
criterion values associated with sufficient DO to support aquatic life. 
Where the available endpoints were shown to be sufficiently sensitive, 
EPA used these relationships to calculate TN, TP, and chlorophyll a 
concentrations that achieved the selected water quality targets for 
these endpoints, which serve as measures of balanced natural 
populations of aquatic flora and fauna.
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    \181\ USEPA. 2010. Using stressor-response relationships to 
derive numeric nutrient criteria. EPA-820-S-10-001. U.S. 
Environmental Protection Agency, Office of Water, Office of Science 
and Technology, Washington, DC.
    \182\ D'Avanzo, C., and J.N. Kremer. 1994. Diel Oxygen Dynamics 
and Anoxic Events in an Eutrophic Estuary of Waquoit Bay, 
Massachusetts. Estuaries and Coasts 17(1B):131-139.
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    To determine chlorophyll a concentrations supportive of the water 
clarity depth target to achieve the healthy seagrass endpoint in a 
segment, EPA estimated the relationship between annual geometric mean 
chlorophyll a concentrations and annual geometric mean water clarity 
for each segment. Then, EPA computed the chlorophyll a criterion as the 
chlorophyll a concentration that was associated with the water clarity 
target. In other words, the chlorophyll a criterion was determined such 
that the water quality target for water clarity was achieved on an 
annual average basis.\183\ In some segments, increased annual geometric 
mean chlorophyll a concentrations were not associated with decreased 
annual geometric mean water clarity, possibly because other factors, 
such as suspended sediment or colored dissolved organic material, more 
strongly affected water clarity.\184\ In these segments, EPA determined 
that the water clarity endpoint was not sufficiently sensitive to 
increased chlorophyll a, and therefore, this endpoint was not used to 
derive a chlorophyll a criterion, and associated TN and TP criteria in 
that segment.
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    \183\ Dennison, W.C. 1987. Effects of light on seagrass 
photosynthesis, growth, and depth distribution. Aquatic Botany 
27:15-26.
    \184\ Gallegos, C.L. 2005. Optical water quality of a blackwater 
river estuary: the Lower St. Johns River, Florida, USA. Estuarine, 
Coastal and Shelf Science 63(1-2):57-72.
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    EPA also used stressor-response relationships to derive chlorophyll 
a criteria to maintain balanced algal populations. To this end, EPA 
used logistic regression to estimate the relationship between annual 
geometric mean chlorophyll a concentrations and the probability of any 
single chlorophyll a measurement exceeding EPA's proposed water quality 
target of 20 [micro]g/L during the year. Then, EPA derived a 
chlorophyll a criterion from this relationship by selecting the annual 
geometric mean chlorophyll a concentration that ensured that any single 
chlorophyll a measurement would not exceed 20 [micro]g/L more than 10% 
of the time.
    After calculating chlorophyll a candidate criteria values necessary 
to meet the water quality targets for the two biological endpoints for 
which data were available (maintenance of seagrasses and maintenance of 
balanced algal populations), in each water body segment, EPA selected 
the more stringent of the two as the proposed criterion for that 
segment to ensure that the proposed chlorophyll a criterion would 
protect both endpoints.
    To calculate TN and TP criteria associated with the chlorophyll a 
criterion, EPA estimated the relationship between annual geometric mean 
TN and TP concentrations and annual geometric mean chlorophyll a 
concentrations for each segment. EPA then used these relationships to 
compute the TN and TP concentrations that were required to maintain 
average chlorophyll a concentrations at the chlorophyll a criterion. In 
some estuary segments, increased TN or TP concentrations were not 
associated with increased chlorophyll a concentrations, possibly 
because of differences in the proportion of TP or TN that was composed 
of biologically unavailable forms of phosphorus or nitrogen, or because 
of unique physical or hydrological characteristics of the estuary 
segment.\185\ In these segments, EPA determined that chlorophyll a 
concentrations were not sufficiently sensitive to increases in TN or TP 
concentrations, and therefore, this approach was not used to derive 
criteria for these segments.
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    \185\ USEPA. 2001. Nutrient Criteria Technical Manual: Estuarine 
and Coastal Marine Waters. EPA-822-B-01-003. U.S. Environmental 
Protection Agency, Office of Water, Washington, DC.

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[[Page 74949]]

    In instances where one of the endpoints was not sufficiently 
sensitive to increases in TN or TP concentrations the relationship of 
the other endpoint to TN or TP was examined. If both endpoints were 
insensitive to TN or TP, then the statistical models were not used to 
derive candidate criteria for the particular nutrient.
    In a limited number of estuary segments, EPA found that the TN, TP, 
or chlorophyll a concentrations that were associated with achieving the 
water quality targets for the biological endpoints were outside 
(greater than or less than) the range of TN, TP, or chlorophyll a 
concentrations observed in the available data for the estuary. In other 
words, in these situations, using statistical models to derive numeric 
nutrient criteria would require EPA to extrapolate the TN, TP, and 
chlorophyll a relationships beyond the range of available data. Because 
of the uncertainty inherent in conducting such extrapolations, EPA is 
proposing instead to set numeric nutrient criteria derived from these 
statistically modeled relationships at the 90th percentile or 10th 
percentile limit of the distribution of available data instead of 
deriving criteria outside the range of data observations.\186\ For 
example, if the statistically modeled value for TP associated with 
achieving all water quality targets to meet the biological endpoints in 
an estuary segment was less than the 10th percentile of annual average 
values of TP observed in that segment, EPA is proposing to set the 
criterion value at the 10th percentile of annual average values of TP. 
This approach defines criterion values that maintain balanced natural 
populations of aquatic flora and fauna within the limits of available 
data and is consistent with EPA's reasoning for the selection of the 
90th percentile when using the reference condition approach. EPA 
requests comment on whether to extrapolate stressor-response 
relationships beyond the range of available data. For further 
information on the use of statistical modeling approach, see the TSD 
(Volume 1: Estuaries, Section 1.4.2 and Appendix B).
---------------------------------------------------------------------------

    \186\ USEPA. 2010. Using Stressor-response Relationships to 
Derive Numeric Nutrient Criteria. EPA-820-S-10-001. U.S. 
Environmental Protection Agency, Office of Water, Washington, DC.
---------------------------------------------------------------------------

(c) Mechanistic Modeling
    EPA also quantified relationships between nitrogen and phosphorus 
loads and the three biological endpoints using a coupled system of 
watershed models and estuarine hydrodynamic and water quality models. 
These models simulated the physical, chemical, and biological processes 
in a watershed-estuarine system. EPA first used the watershed models to 
develop estimates of TN, TP, and freshwater inputs to the estuary. 
Next, EPA used the estuarine hydrodynamic and water quality models to 
simulate estuarine water quality responses to the watershed inputs, 
including changes in estuarine TN, TP, and chlorophyll a 
concentrations, water clarity, and DO. Then, EPA utilized these models 
to determine concentrations of TN and TP that would protect the most 
nutrient-sensitive biological endpoint to derive the numeric nutrient 
criteria.
    To select the appropriate models, EPA developed an inventory of 
watershed and estuary models that have been applied previously to 
estuaries in Florida, including models developed by FDEP.\187\ Based on 
the results of the review, EPA selected the Loading Simulation Program 
in C++ (LSPC) \188\ to simulate freshwater flows and nutrient loading 
from watersheds, the Environmental Fluid Dynamics Code (EFDC) \189\ to 
simulate estuarine hydrodynamics, and the Water Quality Analysis 
Simulation Program (WASP) \190\ to simulate estuarine water 
quality.\191\
---------------------------------------------------------------------------

    \187\ Wolfe, S.H. 2007. An Inventory of Hydrodynamic, Water 
Quality, and Ecosystem Models of Florida Coastal and Ocean Waters. 
Florida Department of Environmental Protection, Tallahassee, 
Florida.
    \188\ USEPA. 2011. Loading Simulation Program in C++ (LSPC). 
http://www.epa.gov/athens/wwqtsc/html/lspc.html. Accessed December 
2011.
    \189\ USEPA. 2011. Environmental Fluid Dynamics Code (EFDC). 
http://www.epa.gov/athens/wwqtsc/html/efdc.html. Accessed December 
2011.
    \190\ USEPA. 2011. Water Quality Analysis Simulation Program 
(WASP). http://www.epa.gov/athens/wwqtsc/html/wasp.html. Accessed 
December 2011.
    \191\ USEPA. 2010. Methods and Approaches for Deriving Numeric 
Criteria for Nitrogen/Phosphorus Pollution in Florida's Estuaries, 
Coastal Waters, and Southern Inland Flowing Waters. U.S. 
Environmental Protection Agency, Office of Water, Washington, DC.
---------------------------------------------------------------------------

    LSPC can continuously simulate the hydrologic and water quality 
processes on pervious and impervious land surfaces, in streams, and in 
well-mixed impoundments throughout the watershed and can provide daily 
estimates of stream flow, TN, and TP concentrations entering the 
estuary. In addition, LSPC is publicly available and has been peer 
reviewed.\192\ LSPC has been successfully applied for water quality 
management purposes to many watersheds throughout the southeastern 
United States and Florida. Therefore, EPA is proposing to apply the 
LSPC model to the watersheds in Florida outside of the South Florida 
Nutrient Watershed Region.
---------------------------------------------------------------------------

    \192\ USEPA-SAB. 2011. Review of EPA's draft Approaches for 
Deriving Numeric Nutrient Criteria for Florida's Estuaries, Coastal 
Waters, and Southern Inland Flowing Waters. EPA-SAB-11-010. U.S. 
Environmental Protection Agency, Science Advisory Board, Washington, 
DC.
---------------------------------------------------------------------------

    EFDC and WASP have been applied in conjunction to simulate 
hydrodynamics and water quality (respectively) for many water quality 
management projects throughout the southeastern United States and 
Florida. EFDC and WASP are also publicly available and have undergone 
peer review.\193\ Based on the extensive use of these models for 
similar applications and their acceptance in the scientific community, 
EPA is proposing to use the EFDC and WASP models to derive numeric 
nutrient criteria for Florida's estuaries.
---------------------------------------------------------------------------

    \193\ USEPA-SAB. 2011. Review of EPA's draft Approaches for 
Deriving Numeric Nutrient Criteria for Florida's Estuaries, Coastal 
Waters, and Southern Inland Flowing Waters. EPA-SAB-11-010. U.S. 
Environmental Protection Agency, Science Advisory Board, Washington, 
DC.
---------------------------------------------------------------------------

    For estuaries where monitoring data were insufficient to calculate 
criteria using the statistical models, EPA mechanistically modeled the 
conditions in each system and corresponding watershed that occurred 
from 2002-2009 using all available, screened data. EPA evaluated data 
over the historic period of record and is proposing to use 2002 through 
2009 as a representative modeling period because complete, continuous 
flow and water quality data were available. This period also reflects 
the range of hydrology and meteorology observed over the historic 
period of record across the Florida estuaries.
    EPA then used relationships between TN, TP, and biological 
endpoints quantified by the mechanistic models to derive numeric 
nutrient criteria. That is, EPA determined the concentrations of TN and 
TP that were associated with meeting all biological endpoints in each 
segment.
    Because estuaries differ in their physical, chemical, and 
hydrological characteristics, EPA expected that differences would exist 
in the degree to which different biological endpoints respond to 
changes in nutrient concentration. For example, in certain estuaries, 
high concentrations of colored dissolved organic material (CDOM) occur 
naturally and reduce water clarity. Because of the influence of CDOM in 
these estuarine systems, changes in TN, TP, and chlorophyll a are not 
strongly associated with changes in water clarity. In these systems, 
the water clarity endpoint does not appear to be sensitive to changes 
in nutrients,

[[Page 74950]]

and therefore, the water clarity endpoint does not provide useful 
information for the purposes of deriving numeric nutrient criteria in 
these systems. In each estuarine system, EPA used output from 
mechanistic models and available monitoring data to evaluate the 
sensitivity of each endpoint measure to changes in nutrients. This 
analysis was used to determine which endpoints were most critical to 
determine protective nutrient concentrations. Endpoints that were found 
to be insensitive to changes in nutrient concentrations in a particular 
estuarine system were not considered further in deriving numeric 
nutrient criteria for a system. Numeric nutrient criteria for each 
system were based on the modeled scenario in which the remaining 
endpoint measures were met during the modeled period, calculated as 
annual geometric means for each year during the modeled period. 
Criteria were calculated using the 90th percentile of the annual 
geometric means from the modeled years for the model scenario meeting 
all appropriate endpoints. EPA selected the 90th percentile to account 
for natural variability in the data to represent the upper bound of 
conditions supporting designated uses. The selection of the 90th 
percentile is appropriate for the same reasons as when using the 
reference condition approach. For further information on the use of the 
mechanistic modeling approach, see the TSD (Volume 1: Estuaries, 
Section 1.4.1).
(d) Request for Comment on Analytical Methodologies
    EPA believes that the three proposed analytical methodologies used 
in combination result in numeric nutrient criteria that are supportive 
of balanced natural populations of aquatic flora and fauna, and thus 
protect Class II and III estuarine and coastal waters in the State of 
Florida from nutrient pollution. These analytical methodologies 
utilized the latest scientific knowledge, nutrient sensitive endpoints, 
and the best available data. The Agency requests comment on the 
application of the proposed methodologies and whether these 
methodologies are appropriate to derive criteria protective of 
designated uses in Florida's estuaries and coastal waters. 
Specifically, EPA is soliciting comment and any scientific information 
on the use of these approaches in areas where there may be other 
factors present in addition to nutrients that may also affect the three 
biological endpoints by attenuating light in similar ways as 
chlorophyll a (e.g., colored dissolved organic matter (CDOM) or 
suspended sediments). EPA is also requesting comment on the procedures 
used to screen data to identify reference conditions that are 
supporting balanced natural populations of aquatic flora and fauna.

B. Proposed Numeric Criteria for Estuaries

1. Introduction
    EPA is proposing to use a system-specific approach to derive 
numeric nutrient criteria for estuaries to ensure that the unique 
physical, chemical, and biological characteristics of each estuarine 
ecosystem are taken into consideration.\194\
---------------------------------------------------------------------------

    \194\ USEPA. 2001. Nutrient Criteria Technical Manual: Estuarine 
and Coastal Marine Waters. EPA-822-B-01-003. U.S. Environmental 
Protection Agency, Office of Water, Washington, DC. Glibert, P.M., 
C.J. Madden, W. Boynton, D. Flemer, C. Heil, and J. Sharp, eds. 
2010. Nutrients in Estuaries: A Summary Report of the National 
Estuarine Experts Workgroup, 2005-2007. Report to U.S. Environmental 
Protection Agency, Office of Water, Washington DC.
---------------------------------------------------------------------------

2. Proposed Numeric Criteria (Estuaries)
    EPA is proposing numeric TN, TP, and chlorophyll a criteria for 89 
discrete segments within 19 estuarine systems in Florida (Table III.B-
1). These include Class II and III waters under Florida law (Section 
62-302.400, F.A.C.); EPA did not find any Class I estuarine waters in 
Florida. The 19 estuaries include seven systems in the Florida 
Panhandle region, four systems in the Big Bend region, and eight 
systems along the Atlantic coast. Maps showing the locations of these 
estuarine systems and EPA's proposed within-estuary segments are 
provided in the TSD (Volume 1: Estuaries, Section 1.3 and Section 2).
    In some areas a gap may exist between maps used by Florida and EPA 
to show where criteria apply. In areas where a gap exists between EPA's 
proposed criteria and Florida's numeric criteria, EPA proposes that 
Florida's numeric criteria from the adjacent estuary or marine segment 
apply (see Section 62-302.532, F.A.C. for values). EPA proposes that 
Florida's criteria from the northernmost segment of Clearwater Harbor/
St Joseph Sound (Subsection 62-302.532(a)1., F.A.C.) apply to the 
waters between that segment and the southernmost segment of EPA's 
Springs Coast estuary system. EPA proposes that Florida's numeric 
criteria from the northernmost segment of Biscayne Bay (Subsection 62-
302.532(h)5., F.A.C.) apply to the waters of the intercoastal waterway 
between that segment and the southernmost segment of EPA's Lake Worth 
Lagoon estuary system.
    In other areas a gap may exist within estuaries covered by 
Florida's numeric criteria. In these areas, EPA proposes that Florida's 
criteria from the adjacent estuary or marine segment to the south apply 
to that gap. EPA proposes that Florida's criteria from (1) the upper 
Lemon Bay segment (Subsection 62-302.532(d)2., F.A.C.) apply to the 
segment between the upper Lemon Bay segment and the Dona/Roberts Bay 
segment (Subsection 62-302.532(d)1., F.A.C.), (2) the Tidal Cocohatchee 
River segment (Subsection 62-302.532(e)1., F.A.C.) apply to the waters 
between the Tidal Cocohatchee River segment and the Estero Bay segment 
(Subsection 62-302.532(d)9., F.A.C.), (3) the Clam Bay segment 
(Subsection 62-302.532(j)., F.A.C.) apply between the Clam Bay segment 
and the Tidal Cocohatchee River segment (Subsection 62-302.532(e)1., 
F.A.C.), and (4) the Naples Bay segment (Subsection 62-302.532(e)4., 
F.A.C.) apply to the segment between the Naples Bay segment and the 
Clam Bay Segment (Subsection 62-302.532(j)., F.A.C.). For further 
information regarding the derivation and protectiveness of Florida's 
criteria, see http://water.epa.gov/lawsregs/rulesregs/florida_index.cfm.

                     Table III.B-1--EPA's Proposed Numeric Criteria for Florida's Estuaries
                                [In geographic order from northwest to northeast]
----------------------------------------------------------------------------------------------------------------
                                                                                 Proposed Criteria
                                                                 -----------------------------------------------
                     Segment                        Segment ID                                    Chl-a*  ([mu]g/
                                                                    TN*  (mg/L)     TP*  (mg/L)         L)
----------------------------------------------------------------------------------------------------------------
Perdido Bay:
    Upper Perdido Bay...........................            0101            0.59           0.042             5.2

[[Page 74951]]

 
    Big Lagoon..................................            0102            0.26           0.019             4.9
    Central Perdido Bay.........................            0103            0.47           0.031             5.8
    Lower Perdido Bay...........................            0104            0.34           0.023             5.8
Pensacola Bay:
    Blackwater Bay..............................            0201            0.53           0.022             3.9
    Upper Escambia Bay..........................            0202            0.43           0.025             3.7
    East Bay....................................            0203            0.50           0.021             4.2
    Santa Rosa Sound............................            0204            0.34           0.018             4.1
    Lower Escambia Bay..........................            0205            0.44           0.023             4.0
    Upper Pensacola Bay.........................            0206            0.40           0.021             3.9
    Lower Pensacola Bay.........................            0207            0.34           0.020             3.6
    Santa Rosa Sound............................            0208            0.33           0.020             3.9
    Santa Rosa Sound............................            0209            0.36           0.020             4.9
Choctawhatchee Bay:
    Eastern Choctawhatchee Bay..................            0301            0.47           0.025             8.1
    Central Choctawhatchee Bay..................            0302            0.36           0.019             3.8
    Western Choctawhatchee Bay..................            0303            0.21           0.012             2.4
St. Andrews Bay:
    East Bay....................................            0401            0.31           0.014             4.6
    St. Andrews Sound...........................            0402            0.14           0.009             2.3
    Eastern St. Andrews Bay.....................            0403            0.24           0.021             3.9
    Western St. Andrews Bay.....................            0404            0.19           0.016             3.1
    Southern St. Andrews Bay....................            0405            0.15           0.013             2.6
    North Bay 1.................................            0406            0.22           0.012             3.7
    North Bay 2.................................            0407            0.22           0.014             3.7
    North Bay 3.................................            0408            0.21           0.016             3.4
    West Bay....................................            0409            0.23           0.022             3.8
St. Joseph Bay:
    St. Joseph Bay..............................            0501            0.25           0.018             3.8
Apalachicola Bay:
    St. George Sound............................            0601            0.53           0.019             3.6
    Apalachicola Bay............................            0602            0.51           0.019             2.7
    East Bay....................................            0603            0.76           0.034             1.7
    St. Vincent Sound...........................            0605            0.52           0.016            11.9
    Apalachicola Offshore.......................            0606            0.30           0.008             2.3
Alligator Harbor:
    Alligator Harbor............................            0701            0.36           0.011             2.8
    Alligator Offshore..........................            0702            0.33           0.009             3.1
    Alligator Offshore..........................            0703            0.33           0.009             2.9
Ochlockonee Bay\+\:
    Ochlockonee-St. Marks Offshore..............            0825            0.79           0.033             2.7
    Ochlockonee Offshore........................            0829            0.47           0.019             1.9
    Ochlockonee Bay.............................            0830            0.66           0.037             1.8
    St. Marks River Offshore....................            0827            0.51           0.022             1.7
    St. Marks River.............................            0828            0.55           0.030             1.2
Big Bend/Apalachee Bay\+\:
    Econfina Offshore...........................            0824            0.59           0.028             4.6
    Econfina....................................            0832            0.55           0.032             4.4
    Fenholloway.................................            0822            1.15           0.444             1.9
    Fenholloway Offshore........................            0823            0.48           0.034            10.3
    Steinhatchee-Fenholloway Offshore...........            0821            0.40           0.023             4.1
    Steinhatchee River..........................            0819            0.67           0.077             1.0
    Steinhatchee Offshore.......................            0820            0.34           0.018             3.5
    Steinhatchee Offshore.......................            0818            0.39           0.032             4.8
Suwannee River\+\:
    Suwannee Offshore...........................            0817            0.78           0.049             5.2
Springs Coast\+\:
    Waccasassa River Offshore...................            0814            0.38           0.019             3.9
    Cedar Keys..................................            0815            0.32           0.019             4.1
    Crystal River...............................            0812            0.35           0.013             1.3
    Crystal-Homosassa Offshore..................            0813            0.36           0.013             2.1
    Homosassa River.............................            0833            0.47           0.032             1.9
    Chassahowitzka River........................            0810            0.32           0.010             0.7
    Chassahowitzka River Offshore...............            0811            0.29           0.009             1.7
    Weeki Wachee River..........................            0808            0.32           0.010             1.6
    Weeki Wachee Offshore.......................            0809            0.30           0.009             2.1
    Pithlachascotee River.......................            0806            0.50           0.022             2.4
    Pithlachascotee Offshore....................            0807            0.32           0.011             2.5

[[Page 74952]]

 
    Anclote River...............................            0804            0.48           0.037             4.7
    Anclote Offshore............................            0805            0.31           0.011             3.2
    Anclote Offshore South......................            0803            0.29           0.008             2.6
----------------------------------------------------------------------------------------------------------------
Clearwater Harbor/St. Joseph Sound:                             See Section 62-302.532(1)(a) F.A.C.
----------------------------------------------------------------------------------------------------------------
Tampa Bay:                                                      See Section 62-302.532(1)(b) F.A.C.
----------------------------------------------------------------------------------------------------------------
Sarasota Bay:                                                   See Section 62-302.532(1)(c) F.A.C.
----------------------------------------------------------------------------------------------------------------
Charlotte Harbor/Lemon Bay:                                     See Section 62-302.532(1)(d) F.A.C.
----------------------------------------------------------------------------------------------------------------
Lake Worth Lagoon/Loxahatchee:
    North Lake Worth Lagoon.....................            1201            0.55           0.067             4.7
    Central Lake Worth Lagoon...................            1202            0.57           0.089             5.3
    South Lake Worth Lagoon.....................            1203            0.48           0.034             3.6
    Lower Loxahatchee...........................            1301            0.68           0.028             2.7
    Middle Loxahatchee..........................            1302            0.98           0.044             3.9
    Upper Loxahatchee...........................            1303            1.25           0.072             3.6
St. Lucie:
    Lower St. Lucie.............................            1401            0.58           0.045             5.3
    Middle St. Lucie............................            1402            0.90           0.120             8.4
    Upper St. Lucie.............................            1403            1.22           0.197             8.9
Indian River Lagoon:
    Mosquito Lagoon.............................            1501            1.18           0.078             7.5
    Banana River................................            1502            1.17           0.036             5.7
    Upper Indian River Lagoon...................            1503            1.63           0.074             9.2
    Upper Central Indian River Lagoon...........            1504            1.33           0.076             9.2
    Lower Central Indian River Lagoon...........            1505            1.12           0.117             8.7
    Lower Indian River Lagoon...................            1506            0.49           0.037             4.0
Halifax River:
    Upper Halifax River.........................            1601            0.75           0.243             9.4
    Lower Halifax River.........................            1602            0.63           0.167             9.6
Guana, Tolomato, Matanzas, Pellicer:
    Upper GTMP..................................            1701            0.77           0.144             9.5
    Lower GTMP..................................            1702            0.53           0.108             6.1
Lower St. Johns River:
    Lower St. Johns River.......................            1801            0.75           0.095             2.5
    Trout River.................................            1802            1.09           0.108             3.6
    Trout River.................................            1803            1.15           0.074             7.7
Nassau River:
    Lower Nassau................................            1901            0.33           0.113             3.2
    Middle Nassau...............................            1902            0.40           0.120             2.4
    Upper Nassau................................            1903            0.75           0.125             3.4
St. Marys River:
    Lower St. Marys River.......................            2002            0.27           0.045             3.0
    Middle St. Marys River......................            2003            0.44           0.036             2.7
----------------------------------------------------------------------------------------------------------------
\1\ Chlorophyll a is defined as corrected chlorophyll, or the concentration of chlorophyll a remaining after the
  chlorophyll degradation product, phaeophytin a, has been subtracted from the uncorrected chlorophyll a
  measurement.
* For a given water body, the annual geometric mean of TN, TP, or chlorophyll a, concentrations shall not exceed
  the applicable criterion concentration more than once in a three-year period.
\+\ In these four areas (collectively referred to as the ``Big Bend region''), coastal and estuarine waters are
  combined. Criteria for the Big Bend region apply to the coastal and estuarine waters in that region.

(a) Summary of Approaches (Estuaries)
(1) Proposed Approach (Estuaries)
    In estuaries where sufficient monitoring data were available to 
statistically quantify relationships between TN, TP, chlorophyll a, and 
biological endpoints, and the endpoints available to derive criteria 
were shown to be sufficiently sensitive (i.e., Choctawhatchee Bay; St. 
Joseph Bay; Suwannee River; Indian River Lagoon; Halifax River; and the 
Guana, Tolomato, Matanzas, and Pellicer (GTMP) estuarine system), 
statistical models were used to derive the proposed numeric nutrient 
criteria. In three of the estuaries, Choctawhatchee Bay, St. Joseph 
Bay, and Indian River Lagoon, there were sufficient available data for 
water clarity associated with historic depth of seagrasses, and 
chlorophyll a concentrations associated with balanced phytoplankton 
biomass targets, and these biological endpoints were sensitive to 
changes in nutrients in most segments, so proposed criteria were 
derived that were protective of these endpoints. In the Suwannee River, 
the water clarity endpoint was not sensitive to changes in nutrients, 
so proposed criteria were derived that were protective of the 
chlorophyll a target

[[Page 74953]]

associated with balanced phytoplankton biomass. In the Halifax River 
and GTMP, seagrass has not been historically present, so the proposed 
criteria were derived that are protective of the chlorophyll a target 
associated with balanced phytoplankton biomass.
    In all other estuaries mechanistic models were used to quantify the 
relationship between nutrient loads and biological endpoints. EPA then 
used the models to derive proposed numeric nutrient criteria that 
protect the endpoints. For each estuary, the endpoints that were shown 
to be sufficiently sensitive to nutrient changes above non-
anthropogenic nutrient levels were used, as described in Section 
III.A.3.c. The endpoints for each of the estuaries where mechanistic 
models were used to derive criteria are noted in the following 
discussion.
    In Perdido Bay, Apalachicola Bay, three segments in Lake Worth 
Lagoon/Loxahatchee (Lake Worth Lagoon, segments 1201, 1202, and 1203), 
and St. Lucie, all three biological endpoints were found to be 
sensitive to changes to nutrients, and so proposed criteria were 
derived that were protective of historic depth of seagrasses (water 
clarity), chlorophyll a concentrations associated with balanced 
phytoplankton biomass, and dissolved oxygen concentrations sufficient 
to maintain aquatic life.
    In St. Andrews Bay, 2 segments in the Springs Coast (Anclote River/
Anclote Offshore, segments 0804 and 0805) and 3 segments in Lake Worth 
Lagoon/Loxahatchee (Lower, Middle, and Upper Loxahatchee, segments 
1301, 1302, and 1303), dissolved oxygen concentrations were found to be 
insensitive to changes in nutrients. Proposed criteria were derived 
that were protective of historic depth of seagrasses (water clarity) 
and chlorophyll a concentrations associated with balanced phytoplankton 
biomass.
    In Pensacola Bay, 3 segments in Ochlockonee Bay (Ochlockonee-St. 
Marks Offshore/Ochlockonee Offshore/Ochlockonee Bay, segments 0825, 
0829, and 0830), and 4 segments in Big Bend/Apalachee Bay (Econfina/
Econfina Offshore, segments 0824, 0832; Steinhatchee-Fenholloway 
Offshore, segment 0821; Steinhatchee Offshore, segment 0818), and 1 
segment in Springs Coast (Anclote Offshore South, segment 0803), water 
clarity was found to be insensitive to changes in nutrients. In 
Alligator Harbor and 2 segments in Springs Coast (Waccasassa River 
Offshore/Cedar Keys, segments 0814, 0815), there was not enough 
available information to derive seagrass depth targets. As a result, 
the proposed criteria were derived to be protective of water quality 
targets for chlorophyll a concentrations associated with balanced 
phytoplankton biomass and dissolved oxygen concentrations sufficient to 
maintain aquatic life.
    In 2 segments in Ochlockonee Bay (St. Marks Offshore/St. Marks 
River, segments 0827, 0828), 2 segments in Big Bend/Apalachee Bay 
(Steinhatchee River/Steinhatchee Offshore, segments 0819, 0820), and 2 
segments in Springs Coast (Pithlachascotee River/Pithlachascotee 
Offshore, segments 0806, 0807), dissolved oxygen and water clarity were 
both found to be insensitive to changes in nutrients. In 2 segments in 
Big Bend/Apalachee Bay (Fenholloway/Fenholloway Offshore, segments 
0822, 0823) and 7 segments in Springs Coast (Crystal River/Crystal-
Homosassa Offshore/Homosassa River, segments 0812, 0813, 0833; 
Chassahowitzka River/Chassahowitzka Offshore, segments 0810, 0811; and 
Weeki Wachee/Weeki Wachee Offshore, segments 0808, 0809), dissolved 
oxygen was found to be insensitive to changes in nutrients and there 
was not enough available information to derive seagrass depth targets. 
In Nassau River and St. Marys River, dissolved oxygen was found to be 
insensitive to changes in nutrients and seagrass has not been 
historically present. For all of these estuaries, proposed criteria 
were derived that were protective of chlorophyll a concentrations 
associated with balanced phytoplankton biomass.
    In the Lower St. Johns River, seagrass has not been historically 
present, so proposed criteria were derived that were protective of 
chlorophyll a associated with balanced phytoplankton biomass and 
dissolved oxygen concentrations sufficient to maintain aquatic life. 
For this system, EPA used the dissolved oxygen from the Site-Specific 
Alternative Criteria, developed by FDEP and adopted for the marine 
portion of the Lower St. Johns River, as an additional DO endpoint with 
which to derive the proposed criteria to support dissolved oxygen 
concentrations sufficient to maintain aquatic life.\195\ This DO 
criterion, adopted as a water quality standard specific to this system, 
was used as an alternative target to the daily water column average DO 
concentration of 5.0 mg/L.
---------------------------------------------------------------------------

    \195\ FDEP. 2006. Site Specific Alternative Dissolved Oxygen 
Criterion to Protect Aquatic Life in the Marine Portions of the 
Lower St. Johns River Technical Support Document. Appendix L In: 
FDEP. 2008. TMDL Report: Total Maximum Daily Load for Nutrients for 
the Lower St. Johns River. Florida Department of Environmental 
Protection, Tallahassee, FL.
---------------------------------------------------------------------------

    EPA considered several alternative approaches for deriving 
estuarine numeric nutrient criteria, including approaches proposed by 
the St. Johns River Water Management District for estuaries within 
their jurisdiction (Lower St. Johns River, Mosquito Lagoon, Tolomato-
Matanzas estuary, Halifax River estuary, Indian River Lagoon, and 
Banana River). While some of these approaches segmented Florida's 
estuaries differently than the segmentation approach EPA is proposing, 
all the alternative approaches used multiple biological endpoints and 
analytical methods to determine the health of each system and derive 
criteria. EPA solicits comments on the alternative approaches described 
in more detail in the following sections. Additional details on these 
approaches are provided in the TSD (Volume 1: Estuaries, Section 2).
(2) Alternative for St. Johns River Water Management District Waters
    The St. Johns River Water Management District (SJRWMD) submitted 
proposed approaches to EPA for several estuaries within their 
jurisdiction. These included the St. Johns River, Mosquito Lagoon, 
Tolomato-Matanzas estuary, Halifax River estuary, Indian River Lagoon, 
and Banana River. In general, SJRWMD proposed a weight of evidence 
approach employing several analytical techniques to derive numeric 
nutrient criteria for each of the systems. The following paragraphs 
outline the methods proposed for each of these systems.
    The SJRWMD has proposed the use of the values for TN, TP, and 
chlorophyll a for the Lower St. Johns River (LSJR) that have already 
been developed as part of an existing TMDL to support designated uses 
in the river. The LSJR is defined as the main stem segments of the 
river between the juncture with the Ocklawaha River and the river mouth 
at Mayport, with the marine portion occurring between Julington Creek 
and the mouth. A SSAC was developed for DO in the marine portion of the 
river. It was approved by EPA in 2006 and is in effect as a WQS. The 
TMDL contains TN and TP protective loads in the freshwater portion of 
the LSJR and a TN protective load in the saline portion of the LSJR. 
These loads are set at a level necessary to achieve the marine DO SSAC 
and protect the statewide standard for DO in the freshwater section. 
The TMDL also contains a water quality target for chlorophyll a that is 
intended to implement the State's narrative nutrient criterion.
    Similar to the modeling approach proposed by EPA for Florida 
estuaries, TN, TP, and chlorophyll a criteria were derived for the LSJR 
using linked watershed, hydrodynamic, and water

[[Page 74954]]

quality models. Non-point nutrient inputs from the watershed to the 
river were determined for each sub-basin in the LSJR using the 
Pollutant Load Screening Model (PLSM), estimates of atmospheric 
deposition, and estimates of loading from tributaries and upstream. 
Within the river, hydrodynamics were modeled using the Environmental 
Fluid Dynamics Code (EFDC) model and water quality processes were 
modeled using the U.S. Army Corps of Engineers Quality Integrated 
Compartment Model (CE-QUAL-ICM), Version 2. The models were calibrated 
for the period from January 1, 1995 to November 30, 1998. TMDL model 
scenarios were assessed on an annual basis to determine if chlorophyll 
a levels exceeded the chlorophyll a threshold of 40 [mu]g/L less than 
10% of the time that was set as the water quality target to prevent 
undesirable shifts in algal community composition.
    For Mosquito Lagoon, a suite of five approaches are considered to 
develop a weight of evidence by which numeric nutrient criteria can be 
developed. These approaches are based upon one of three relationships: 
(1) The link between nutrients, phytoplankton growth (as shown by 
chlorophyll a), and the trophic state of a system; (2) the link between 
nutrients, phytoplankton growth (as shown by chlorophyll a), the 
effects of phytoplankton on light attenuation in the water column, and 
the light requirements of seagrasses; or (3) the connection between TP 
and harmful algal bloom (HAB) occurrence. The first and primary 
approach uses a reference period from 2004-2008 to calculate annual 
median and maximum wet season medians of chlorophyll a, TN, and TP. The 
reference time period was selected because the TN, TP, and chlorophyll 
a observed during that period were low, the rainfall amounts during 
that period were representative of typical rainfall over time, and the 
Trophic State Index value for that time period was greater than 50, 
which is considered to be ``good'' (mesotrophy to oligo-mesotrophy).
    The second approach draws upon an optical model linking chlorophyll 
a to previously established light attenuation targets as a way to 
predict annual median chlorophyll a in southern Mosquito Lagoon that 
would be protective of seagrass and serve as a basis for criteria 
derivation. A third approach derives a TP level that corresponds to 
minimum ``bloom'' levels of the dinoflagellate Pyrodinium bahamense, 
the common HAB species seen primarily in the southern Lagoon. A fourth 
line of evidence applied to the Mosquito Lagoon is multivariate 
geometric mean function regression models relating TN and TP to 
chlorophyll a on an annual basis and during the wet season. The final 
method is based on two general nutrient models.\196\ Targets for 
chlorophyll a are set based on the reference period mentioned earlier 
for the north and central segments and the optical model for the 
southern segments. The reference method is used to derive the TN, TP, 
and chlorophyll a criteria for the Mosquito Lagoon with the other four 
methods providing supporting evidence. Two criteria magnitudes for TN, 
TP, and chlorophyll a are presented; one an annual median value and the 
other a wet season (July-September) median value.
---------------------------------------------------------------------------

    \196\ Steward, J.S., and E.F. Lowe. 2010. General empirical 
models for estimating nutrient load limits for Florida's estuaries 
and inland waters. Limnology and Oceanography 55(1):433-445. 
Dettmann, E.H. 2001. Effect of water residence time on annual export 
and denitrification of nitrogen in estuaries: A model analysis. 
Estuaries 24(4):481-490.
---------------------------------------------------------------------------

    The approaches used for the Indian River Lagoon (IRL) and Banana 
River Lagoon (BRL) are similar to those used for Mosquito Lagoon. The 
approaches are based upon a weight of evidence relying on two general 
ecological relationships: (1) The link between nutrients, phytoplankton 
growth (as shown by chlorophyll a), and the trophic state of a system; 
and (2) the link between nutrients, phytoplankton growth (as shown by 
chlorophyll a), the effects of phytoplankton on light attenuation in 
the water column, the light requirements of seagrasses, and the 
previously established depth limit for seagrasses. The influence of TP 
on HAB events is also discussed as an ancillary line of evidence. As a 
first line of evidence loading limits are derived based on analyses 
done for TMDLs in 2009. The loading limits were established using 
regression models that regress seagrass depth limit targets against 
loading of TN and TP.\197\ The second method used annual medians of 
data from reference segments that meet desired depth thresholds 
established by the TMDL analyses. The third approach relies upon an 
optical model similar to the one described earlier for the Mosquito 
Lagoon using data from 1996-2007. A model was built for each of the 
sub-lagoons: The BRL, North IRL, and Central IRL (divided into 
Sebastian and South Central reaches). An optical model is in 
development for the North Central reach. The fourth approach also 
applies two general models to data specific to the IRL and BRL.\198\ 
Where the Dettmann (2001) model could not be used to predict TN 
concentrations, a TN:TP ratio for the given sublagoon was applied to 
the TP limit to calculate TN limits. The fifth approach relies upon the 
relationship between HAB occurrence and TP concentrations. Targets for 
chlorophyll a are presented as a range of values established using the 
optical model approach and the reference segment approach. Proposed TN 
and TP loading criteria are based on the loading limits established 
using the TMDL analyses. Primary proposed TN and TP criteria 
concentrations are calculated based on the reference segment method. 
Alternate criteria are proposed using a convergence of the 
concentrations calculated by the reference segment method and general 
models. Two criteria magnitudes are proposed, one for an annual median 
and the other for a wet season (June-October) monthly maximum.
---------------------------------------------------------------------------

    \197\ Steward J.S., R.V. Virnstein, L.J. Morris, and E.F. Lowe. 
2005. Setting Seagrass Depth, Coverage, and Light targets for the 
Indian River Lagoon system, Florida. Estuaries 6:923-935.
    \198\ Steward, J.S., and E.F. Lowe. 2010. General empirical 
models for estimating nutrient load limits for Florida's estuaries 
and inland waters. Limnology and Oceanography 55(1):433-445. 
Dettmann, E.H. 2001. Effect of water residence time on annual export 
and denitrification of nitrogen in estuaries: A model analysis. 
Estuaries 24:481-490.
---------------------------------------------------------------------------

    The SJRWMD proposed criteria for the Tolomato and Matanzas Estuary 
(TME) using a weight of evidence approach and methods similar to those 
used in the other estuaries. TN and TP concentrations and chlorophyll a 
target concentrations are based on an approach that analyzes water 
quality and estimated current loading during a reference period from 
2000-2009. The period of reference was selected based on a desirable 
TSI score (<50), rainfall amounts typical of average conditions, and 
completeness of the data record. Criteria magnitudes are proposed as an 
annual median or mean and a maximum wet season (June-September) median 
or mean. The reference period approach of criteria derivation for the 
TME is supported by an additional line of evidence using regression 
analyses of chlorophyll a versus TN and TP. Target chlorophyll a values 
are based on the reference period analyses. The general nutrient models 
of Steward and Lowe (2010) and Dettmann (2001) are also used as an 
additional method by which to estimate loading limits and 
concentrations associated with those limits.
    The SJRWMD also derived proposed criteria for the Halifax River 
Estuary. SJRWMD derived criteria using three methods. The first is a 
reference condition based on the period from 2000-2008. This period is 
selected because of the low TN levels compared

[[Page 74955]]

to the previous decade, the low chlorophyll a concentrations which are 
consistent with chlorophyll a targets established for other estuaries 
throughout the State, and the ``good'' trophic status shown by TSI 
values less than 50. Concentrations are calculated using annual median 
concentrations and maximum wet-season median concentrations (as the 
highest monthly values from July-September) of TN, TP, and chlorophyll 
a. Simple linear regressions are used as a second line of evidence to 
calculate TN and TP criteria based on chlorophyll a targets established 
by the reference period calculations. The general nutrient models of 
Steward and Lowe (2010) and Dettmann (2001) are used as a final method 
by which to estimate loading limits and concentrations associated with 
those limits. Proposed loading and concentration criteria for the North 
Halifax River Estuary are based on the loading and concentration 
estimates of the general nutrient models, with estimates of loadings 
from wastewater treatment facilities in the estuary removed to 
represent reference conditions. The current estimated concentrations 
(ca. 2004) of TN and TP based on the reference approach are proposed as 
criteria for the South Halifax River Estuary. Target chlorophyll a 
values for both segments are calculated using the reference period 
approach.
    EPA is also considering the use of approaches outlined in Steward 
et al. (2005) to derive criteria in Indian River Lagoon. In particular 
EPA is considering using the depth of colonization within reference 
segments as ``upper restoration depths'' and the highest value observed 
for a specific segment as a minimum target for that segment. For more 
information regarding the derivation of these criteria, please see the 
TSD (Volume 1: Estuaries, Sections 2.18.9 (Indian River Lagoon), 2.19.9 
(Halifax River), 2.20.9 (GTMP), and 2.21.9 (St Johns River)).
(3) Request for Comment on Proposed and Alternative Approaches
    EPA believes that the proposed approach for each estuarine system 
is appropriate, scientifically defensible, and results in numeric 
nutrient criteria that protect the State's designated uses to ensure 
that nutrient concentrations of a body of water support balanced 
natural populations of aquatic flora and fauna. EPA requests comment on 
this system-specific approach and the resulting numeric nutrient 
criteria. EPA also solicits additional available scientific information 
that can be used to derive numeric nutrient criteria to provide 
protection of fish consumption, recreation, and the propagation and 
maintenance of a healthy, well-balanced population of fish and wildlife 
and protect Florida's Class II and III estuarine waters from nitrogen 
and phosphorus pollution.
    In addition, EPA requests comment on the alternative approaches 
developed by the St. Johns River Water Management District for waters 
under their jurisdiction. Specifically, EPA requests comment on the 
scientific defensibility of these approaches, as well as whether 
application of these approaches will result in numeric nutrient 
criteria that will protect Class II and III estuarine waters in the 
State of Florida. EPA also requests comment on promulgating the 
alternative criteria in lieu of EPA's proposed criteria.
(b) Proposed Criteria Duration and Frequency (Estuaries)
    Aquatic life water quality criteria include magnitude, duration, 
and frequency components. For EPA's proposed TN, TP, and chlorophyll a 
criteria for estuarine waters, the criterion-magnitude values 
(expressed as concentrations) are provided in Table III.B-1, the 
criterion-duration (or averaging period) is specified as annual, and 
the criterion-frequency is specified as a no-more-than-once-in-three-
years excursion frequency of the annual geometric mean. EPA is 
proposing a criteria-duration of one year, in which sampled nutrient 
concentrations are summarized as annual geometric means to be 
consistent with the data set used to derive these criteria, which 
relied on either annual average nutrient concentrations or annual 
nutrient loading to the water body. EPA's proposed excursion frequency 
of no-more-than-once-every-three-years is intended to minimize negative 
effects on designated uses as it will allow water bodies enough time to 
recover from occasionally elevated levels of nitrogen and phosphorus 
concentrations.\199\ These duration and frequency components of the 
criteria are identical to those finalized in EPA's rule for Florida's 
lakes and flowing waters (40 CFR section 131.43), which will add 
consistency to the implementation of these criteria with those 
established in the previous rulemaking for upstream waters. Finally, 
the 3-year evaluation period provides a sufficient representation of 
average water body characteristics in the majority of cases, because it 
balances both short-term and long-term variation, while not imposing 
undue monitoring expectations. EPA requests comment on the frequency 
and duration components of these criteria and whether the three 
components of the criteria (magnitude, duration, and frequency) taken 
in combination will ensure protection of the designated uses of these 
waters.
---------------------------------------------------------------------------

    \199\ Boynton, W.R., J.D. Hagy, L. Murray, C. Stokes, and W.M. 
Kemp. 1996. A comparative analysis of eutrophication patterns in a 
temperate coastal lagoon. Estuaries 19(2B):408-421.
---------------------------------------------------------------------------

(c) Proposed DPVs (Estuaries)
    EPA is proposing a procedure to establish numeric TN and TP 
criteria for streams in Florida to protect the downstream estuarine 
water bodies that ultimately receive nitrogen and phosphorus pollution 
from these streams. These numeric nutrient criteria, which EPA refers 
to as Downstream Protection Values, or DPVs, would apply at each 
stream's point of entry into the downstream water, referred to as the 
pour point. However, as explained more fully in Section I.A, EPA does 
not intend to finalize these DPVs if the district court modifies the 
Consent Decree consistent with EPA's amended determination that numeric 
DPVs are not necessary to meet CWA requirements in Florida. EPA 
selected the pour point as the location to apply DPVs because the 
downstream waters respond to the nutrient inputs from the pour point, 
and all contributions from the network of flowing waters above this 
point affect the water quality at the pour point. If the DPV is not 
attained at the point of entry into the estuary, then the collective 
set of streams in the upstream watershed does not attain the DPV, for 
purposes of CWA section 303(d).
    The Agency is proposing a hierarchical procedure that includes four 
approaches for setting TN and TP DPVs. EPA's intention in proposing the 
four approaches is to provide a range of methods for the State to 
derive TN and TP DPVs that reflect the data and scientific information 
available. Water quality modeling is the most rigorous and most data-
demanding method, and will generally result in the most refined DPVs. 
Water quality modeling is EPA's preferred method for establishing DPVs 
and is listed first in the hierarchy. It is followed by less rigorous 
methods that are also less data-demanding. Using a procedure from a 
lower tier of the hierarchy requires less data, but also generally 
results in more stringent DPVs to account for the uncertainties 
associated with these less refined procedures. The methods available to 
derive DPVs should be considered in the following order:
    1. Water quality simulation models to derive TN and TP values,

[[Page 74956]]

    2. Reference condition approach based on TN and TP concentrations 
at the stream pour point, coincident in time with the data record from 
which the downstream receiving estuary segment TN and TP criteria were 
developed using the same data quality screens and reference condition 
approach,
    3. Dilution models based on the relationship between salinity and 
nutrient concentration in the receiving segment, and
    4. The TN and TP criteria from the receiving estuary segment to 
which the freshwater stream discharges, in cases where data are too 
limited to apply the first three approaches.
    All four approaches are briefly described in the following 
discussion. A more detailed description of the approaches, as well as 
the TN and TP DPVs that result from using each of the approaches, is 
provided in the technical support document (Volume 1: Estuaries, 
Section 1.6).
    EPA believes that the first approach, the use of water quality 
simulation models, is the most refined method to define a DPV at the 
stream's pour point that will support balanced natural populations of 
aquatic flora and fauna in the downstream estuary. This approach may be 
appropriate when water quality simulation models are available, such as 
in the estuarine systems where mechanistic models were used to derive 
criteria. The modeled nutrient loads entering the estuaries that result 
in attainment of the biological endpoints within the estuaries can be 
used to derive DPVs by computing the annual geometric mean TN and TP 
concentrations that correspond with the modeled loads at the pour point 
of each stream for each of the years 2002 through 2009. Because EPA 
used coupled watershed and estuarine models to establish the estuary 
criteria (in some locations), EPA is confident that the watershed 
modeling provides concentrations that are protective of corresponding 
estuarine biological endpoints. Therefore EPA selected the 90th 
percentile from the distribution of annual geometric means of modeled 
loads as the DPV to be consistent with the use of the 90th percentile 
used to derive the criteria protective of the estuary using the 
mechanistic models (Volume 1: Estuaries, Section 1.6).
    EPA is proposing the second DPV approach, a reference condition 
approach, for estuarine systems where water quality simulation models 
are not available, and where a reference condition approach is used to 
derive estuary TN, TP, and chlorophyll a criteria. Since the downstream 
estuary is supporting balanced natural populations of aquatic flora and 
fauna during the reference condition period, the nutrient loads passing 
through the pour points into the estuary during that same period should 
be protective of the estuary. Therefore, EPA believes it would be 
appropriate in these cases to derive reference condition-based DPVs 
using water quality data at the pour point of the freshwater streams, 
coincident in time with the data record from which EPA derived the 
downstream estuary segment TN and TP criteria. EPA proposes that the 
same data screens and reference condition approach be applied to the 
pour point data as were applied to the estuary data when deriving DPVs 
using this approach. This will prevent deriving a DPV using upstream 
water quality data that coincided with a documented downstream impact 
(e.g., CWA section 303(d) listing for nutrients in the estuary segment) 
and ensure mathematical consistency between the DPVs and estuarine 
criteria.
    EPA is proposing the third DPV approach for estuarine systems where 
water quality simulation models are not available. For example, this 
approach may be appropriate in the Indian River Lagoon, the Halifax 
River, and the GTMP estuarine systems where EPA used statistical models 
to derive the criteria protective of the estuary. In these areas, EPA 
believes it would be appropriate to derive DPVs using dilution models 
based on the relationship between salinity and nutrient concentration. 
The concept is that the tidal mixing or dilution can be estimated from 
the estuarine salinity. By plotting observed estuarine TN or TP versus 
the estuarine salinity and fitting a linear regression, the TN or TP at 
various levels of salinity can be determined. This regression model can 
then be used to determine the TN or TP concentration at the pour point 
that will ensure attainment and maintenance of the estuarine numeric 
nutrient criteria concentration. The TN and TP DPV for the inflowing 
canal or stream can be determined from the point on the regression line 
having the same salinity as the pour point, which is by definition 2.7 
psu.
    EPA's fourth proposed approach for establishing DPVs is to apply 
the downstream receiving estuary segment TN and TP criteria as shown in 
Table III.B-1 to the pour point as the DPVs. This is the simplest 
approach and may be appropriate where data are too limited to apply the 
first three approaches. As noted in Table III.B-1, Florida derived 
numeric nutrient criteria for Clearwater Harbor, Tampa Bay, Sarasota 
Bay, and Charlotte Harbor estuaries that can be found in Section 62-
302.532(a)-(d), F.A.C. Therefore, the applicable DPVs for those four 
estuaries would be Florida's estuary criteria in Section 62-302.532(a)-
(d), F.A.C. if using this fourth proposed approach for establishing 
DPVs.
    EPA believes the proposed approaches for deriving DPVs establish a 
decision-making framework that is binding, clear, predictable, and 
transparent. Therefore, EPA is proposing that DPVs derived using these 
approaches do not require EPA approval under Clean Water Act section 
303(c) to take effect.\200\ A DPV calculated under options 2, 3, and 4 
may be more stringent than a DPV calculated using a water quality 
model. These alternative options are intended to ensure that water 
quality standards are not only restored when found to be impaired, but 
are maintained when found to be attained, consistent with the CWA. 
Higher levels of TN and/or TP may be allowed in watersheds where it is 
demonstrated that such higher levels will fully protect the estuary's 
WQS. To the extent that it is determined that the alternative option 
DPVs for a given estuary are over-protective, applying a water quality 
model as set out in EPA's option 1 would result in a more refined 
definition of the DPV for that estuary.
---------------------------------------------------------------------------

    \200\ 65 FR 24641, 24648 (April 27, 2000).
---------------------------------------------------------------------------

    EPA believes that these proposed approaches to establish DPVs are 
appropriate, scientifically defensible, and result in numeric values 
that will ensure the attainment and maintenance of the downstream 
estuarine criteria. EPA requests comment on these approaches. EPA also 
requests comment on the alternative approach of finalizing the numeric 
TN and TP DPVs that EPA calculated using these approaches (as provided 
in Volume 1: Estuaries, Section 1.6 of the technical support document) 
in place of the proposed approaches. Finally, EPA solicits additional 
available scientific information that can be used to ensure attainment 
and maintenance of the downstream estuarine criteria. Commenters who 
submitted comments or scientific information related to DPVs for 
estuaries during the public comment period for EPA's proposed inland 
waters rule (75 FR 4173) should reconsider their previous comments in 
light of the new information presented in this proposal and must re-
submit their comments during the public comment period for this 
rulemaking to receive EPA response.

[[Page 74957]]

(d) Proposed Approach and Criteria for Tidal Creeks
    Tidal creeks are relatively small coastal tributaries that lie at 
the transition zone between terrestrial uplands and the open estuary. 
They are small sub-estuaries that exhibit a wide range of salinities 
typical of larger estuaries, but on a smaller scale. Tidal creeks are 
important spawning and nursery areas for aquatic life in adjacent 
estuary and coastal systems. They typically receive freshwater flow 
from streams and groundwater, similar to estuaries, but have less 
developed drainage systems. Alternatively, some tidal creeks are 
dominated by mangroves and other wetland vegetation with no freshwater 
stream inputs, and serve as conduits for tidal water to enter and leave 
wetland areas. Water quality and biological conditions are different in 
tidal creeks compared to estuarine systems due to relatively small 
drainage areas, narrow stream channels, shallow depths, and the 
influence of adjacent marsh and mangrove habitats.
    EPA reviewed the available scientific information and has 
determined that there are insufficient data and research at this time 
to develop separate numeric nutrient criteria specifically for tidal 
creeks. EPA, therefore, proposes to apply the TN and TP criteria 
developed for either the adjacent freshwater or estuarine segments to 
each tidal creek in Florida, depending on the tidal creek's salinity 
levels. If the mean chloride concentration of the tidal creek is < 
1,500 mg/L, EPA proposes to apply the TN and TP criteria from the 
adjacent freshwater segment (as defined in 40 CFR 131.43).\201\ If the 
mean chloride concentration of the tidal creek is > 1,500 mg/L, EPA 
proposes to apply the chlorophyll a, TN, and TP criteria from the 
adjacent estuary segment (as defined in Section III.B of this proposed 
rulemaking). Alternatively, EPA requests comment on applying the more 
stringent of the two sets of criteria, freshwater or estuarine, to 
tidal creeks with varying salinity levels. For more information please 
see the TSD (Volume 1: Estuaries, Section 3.1).
---------------------------------------------------------------------------

    \201\ EPA did not establish chlorophyll a criteria for 
freshwater streams due to lack of available approaches to interpret 
existing data to infer scientifically supported thresholds for these 
nutrient-specific response variables in Florida streams.
---------------------------------------------------------------------------

    As a second alternative option, EPA could use the mean salinities 
for each tidal creek to interpolate TN and TP concentrations between 
freshwater and estuarine criteria from adjacent freshwater and 
estuarine segments. TN and TP vary predictably along a salinity 
gradient, allowing for this interpolation where salinity data are 
available. The calculation EPA could use for this interpolation is 
provided in the TSD (Volume 1: Estuaries, Section 3.1).
    EPA believes that the proposed approach for tidal creeks is 
appropriate, scientifically defensible, and results in numeric nutrient 
criteria that protect the State's designated uses and ensure that 
nutrient concentrations of a body of water support balanced natural 
populations of aquatic flora and fauna. EPA requests comment on the 
proposed option and the alternative. EPA also requests additional 
available scientific information that can be used to provide protection 
for fish consumption, recreation, and the propagation and maintenance 
of a healthy, well-balanced population of fish and wildlife to protect 
Florida's tidal creeks from nitrogen and phosphorus pollution.
(e) Proposed Approach and Criteria for Marine Lakes
    Marine lakes are coastal lakes and ponds with groundwater or 
intermittent surface water connections to marine water. They do not 
have a permanent surface connection to tidal waters. They are small and 
shallow, and generally round or elliptical in shape, as they were 
formed from depressions that became isolated from marine waters by sand 
and dune formation. Some marine lakes are stratified by a salinity 
gradient where a freshwater layer at the surface is separated from a 
denser saline layer below. Similar to inland lakes, marine lakes in 
Florida are generally oligotrophic under undisturbed conditions with 
low nitrogen and phosphorus concentrations and low productivity. Their 
oligotrophic nature and stratification make them susceptible to the 
adverse effects of nitrogen and phosphorus pollution. EPA analyzed the 
data from over 50 marine lakes in Florida and found that chlorophyll a 
responded to TN and TP in a similar fashion, based on color and 
alkalinity, as freshwater inland lakes. Details and supporting 
documentation are provided in the TSD (Volume 1: Estuaries, Section 
3.2).
    EPA is proposing to apply the criteria developed for freshwater 
inland lakes in EPA's December 6, 2010 rulemaking for Florida's lakes 
and flowing waters (40 CFR 131.43) to protect the designated uses in 
marine lakes since marine lakes have a similar trophic condition 
expectation and chlorophyll a response to nutrient concentrations. The 
criteria EPA proposes to apply to marine lakes are those found in 40 
CFR 131.43 and replicated in Table III.B-2.

                    Table III.B-2--EPA's Proposed Numeric Criteria for Florida's Marine Lakes
----------------------------------------------------------------------------------------------------------------
                                                           EPA final       EPA final TN and TP criteria [Range]
   Long term average lake color \a\ and alkalinity        Chl[dash]a     ---------------------------------------
                                                        \b,*\[micro]g/L         TN mg/L             TP mg/L
----------------------------------------------------------------------------------------------------------------
Colored lakes \c\...................................                  20    1.27 [1.27-2.23]    0.05 [0.05-0.16]
Clear lakes, high alkalinity \d\....................                  20    1.05 [1.05-1.91]    0.03 [0.03-0.09]
Clear lakes, low alkalinity \e\.....................                   6    0.51 [0.51-0.93]    0.01 [0.01-0.03]
----------------------------------------------------------------------------------------------------------------
\a\ Platinum-cobalt units (PCU) assessed as true color free from turbidity.
\b\ Chl-a is defined as corrected chlorophyll, or the concentration of chl-a remaining after the chlorophyll
  degradation product, phaeophytin a, has been subtracted from the uncorrected chl-a measurement.
\c\ Long-term color > 40 PCU and alkalinity > 20 mg/L CaCO3.
\d\ Long-term color <= 40 PCU and alkalinity > 20 mg/L CaCO3.
\e\ Long-term color <= 40 PCU and alkalinity <= 20 mg/L CaCO3
* For a water body, the annual geometric mean of chl-a, TN or TP concentrations shall not exceed the applicable
  criterion concentration more than once in a three-year period.


[[Page 74958]]

    EPA believes that the proposed approach for marine lakes is 
appropriate, scientifically defensible, and results in numeric nutrient 
criteria that protect the State's designated uses and ensure that 
nutrient concentrations of a body of water support balanced natural 
populations of aquatic flora and fauna. EPA requests comment on the 
proposed approach. EPA also solicits additional available scientific 
information that can be used to provide protection for fish 
consumption, recreation, and the propagation and maintenance of a 
healthy, well-balanced population of fish and wildlife to protect 
Florida's marine lakes from nitrogen and phosphorus pollution.

C. Proposed Numeric Criteria for Coastal Waters

1. Introduction
    EPA is defining coastal waters in this proposed rulemaking as 
marine waters that start at the land margin and extend up to three 
nautical miles from shore, with chloride concentrations greater than 
1,500 mg/L, excluding estuaries. Unlike estuaries, which are typically 
highly influenced by freshwater flows and can be organized within 
boundaries, coastal waters are less confined, with open connections to 
ocean waters, and have localized influences from freshwater sources 
near the estuary/coastal boundary (i.e., estuary pass).
    EPA is proposing to derive chlorophyll a criteria for coastal 
waters using satellite remote sensing, where possible. This approach is 
possible for all coastal waters except those in the Big Bend Coastal 
region. In the Big Bend Coastal region (waters offshore of Apalachicola 
Bay, Alligator Harbor, Ochlockonee Bay, Big Bend/Apalachee Bay, 
Suwannee River, and Springs Coast), seagrass beds and CDOM export from 
rivers confound interpretation of satellite data and derivation of 
chlRS-a. EPA's proposed approach and criteria for the Big 
Bend Coastal region is discussed in Section III.B.
2. Proposed Numeric Criteria (Coastal Waters)
    EPA is proposing numeric chlorophyll a criteria, as measured by 
remotely sensed numeric chlorophyll a (chlRS-a), for 71 
segments in three coastal regions of Florida classified as Class III 
waters under Florida law (Section 62-302.400, F.A.C.). A map showing 
the locations of the coastal segments can be found in the TSD (Volume 
2: Coastal Waters, Section 1.3). EPA's proposed coastal criteria are 
listed in Table III.C-1.

                   Table III.C-1--EPA's Proposed Numeric Criteria for Florida's Coastal Waters
----------------------------------------------------------------------------------------------------------------
                                                 Coastal                                       ChlorophyllRS -
               Coastal region                  segment\+\         Approximate location        a\1\*  (mg/m\3\)
----------------------------------------------------------------------------------------------------------------
Panhandle..................................               1  Alabama border...............                  2.41
                                                          2  Pensacola Bay Pass...........                  2.57
                                                          3  .............................                  1.44
                                                          4  .............................                  1.16
                                                          5  .............................                  1.06
                                                          6  .............................                  1.04
                                                          7  .............................                  1.14
                                                          8  Choctawhatchee Bay Pass......                  1.23
                                                          9  .............................                  1.08
                                                         10  .............................                  1.09
                                                         11  .............................                  1.11
                                                         12  .............................                  1.18
                                                         13  .............................                  1.45
                                                         14  St. Andrews Bay Pass.........                  1.74
                                                         15  St. Joseph Bay Pass..........                  2.75
                                                         16  .............................                  2.39
                                                         17  Southeast St. Joseph Bay.....                  3.47
West Florida Shelf.........................              18  .............................                  3.96
                                                         19  Tampa Bay Pass...............                  4.45
                                                         20  .............................                  3.37
                                                         21  .............................                  3.25
                                                         22  .............................                  2.95
                                                         23  .............................                  2.79
                                                         24  .............................                  2.98
                                                         25  .............................                  3.24
                                                         26  Charlotte Harbor.............                  4.55
                                                         27  .............................                  4.22
                                                         28  .............................                  3.67
                                                         29  .............................                  4.16
                                                         30  .............................                  5.70
                                                         31  .............................                  4.54
                                                         32  .............................                  4.03
                                                         33  Fort Myers...................                  4.61
Atlantic Coast.............................              34  Biscayne Bay.................                  0.92
                                                         35  .............................                  0.26
                                                         36  .............................                  0.26
                                                         37  .............................                  0.24
                                                         38  .............................                  0.21
                                                         39  .............................                  0.21
                                                         40  .............................                  0.20
                                                         41  .............................                  0.20
                                                         42  .............................                  0.21
                                                         43  .............................                  0.25
                                                         44  .............................                  0.57

[[Page 74959]]

 
                                                         45  St. Lucie Inlet..............                  1.08
                                                         46  .............................                  1.42
                                                         47  .............................                  1.77
                                                         48  .............................                  1.55
                                                         49  .............................                  1.44
                                                         50  .............................                  1.53
                                                         51  .............................                  1.31
                                                         52  .............................                  1.40
                                                         53  .............................                  1.80
                                                         54  Canaveral Bight..............                  2.73
                                                         55  .............................                  2.33
                                                         56  .............................                  2.28
                                                         57  .............................                  2.06
                                                         58  .............................                  1.92
                                                         59  .............................                  1.76
                                                         60  .............................                  1.72
                                                         61  .............................                  2.04
                                                         62  .............................                  1.92
                                                         63  .............................                  1.86
                                                         64  .............................                  1.95
                                                         65  .............................                  2.41
                                                         66  .............................                  2.76
                                                         67  .............................                  2.80
                                                         68  .............................                  3.45
                                                         69  Nassau Sound.................                  3.69
                                                         70  .............................                  3.78
                                                         71  Georgia border...............                  4.22
----------------------------------------------------------------------------------------------------------------
\1\ ChlorophyllRS-a is remotely sensed calculation of chlorophyll a concentrations.
* For a given water body, the annual geometric mean of the chlorophyll a concentration shall not exceed the
  applicable criterion concentration more than once in a three-year period.
\+\ Please see TSD for location of Coastal Segments (Volume 2: Coastal Waters, Section 1.3).

    As discussed in Section III.A.1.b, EPA is not proposing TN and TP 
criteria for Florida's coastal waters.
(a) Summary of Approaches
(1) Proposed Approach (Coastal Waters)
    EPA conducted a comprehensive review of water body-specific water 
quality and impairment information as detailed in Section III.A.3.a. 
EPA determined through this review that at most times, Florida coastal 
waters appear to be supporting balanced natural populations of aquatic 
flora and fauna. EPA removed data from criteria computations in the 
limited instances where the Agency found that coastal waters were 
listed on the State's CWA section 303(d) list to ensure the resulting 
dataset was representative of times and locations that these waters 
were supporting balanced natural populations of aquatic flora and 
fauna. Therefore, EPA is proposing to use a reference condition 
approach using data collected from satellite remote sensing of 
chlorophyll a.
    To derive proposed criteria for coastal areas, EPA chose to use 
chlRS-a measurements from the SeaWiFS satellite because it 
had the longest and earliest historical record.\202\ From the satellite 
measurements, screened to reflect conditions supportive of balanced 
natural populations of flora and fauna, EPA calculated criteria as the 
90th percentile of the annual geometric means of chlRS-a 
values over the 1998-2009 period in each coastal segment (For a 
discussion of EPA's selection of the 90th percentile to derive the 
proposed coastal criteria, see Section III.A.3.a and the TSD (Volume 2: 
Coastal Waters)).
---------------------------------------------------------------------------

    \202\ NOTE: SeaWiFS was replaced by MODIS and MERIS satellite 
generated data. EPA has developed an approach that can utilize any 
new satellite data sources for ongoing assessment purposes.
---------------------------------------------------------------------------

(b) Request for Comment on Proposed Approach
    EPA believes that the proposed approach for coastal waters is 
appropriate, scientifically defensible, and results in numeric nutrient 
criteria that protect the State's designated uses and ensure that 
nutrient concentrations of a body of water support balanced natural 
populations of aquatic flora and fauna. EPA requests comment on this 
approach and the resulting numeric nutrient criteria. EPA also solicits 
additional available scientific information that can be used to provide 
protection of fish consumption, recreation and the propagation and 
maintenance of a healthy, well-balanced population of fish and wildlife 
and protect Florida's Class III coastal waters from nitrogen and 
phosphorus pollution.
(c) Proposed Criteria Duration and Frequency (Coastal Waters)
    For EPA's proposed chlorophyll a criteria for coastal waters, the 
criterion-magnitude values (expressed as concentrations) are provided 
in Table III.C-1, the criterion-duration (or averaging period) is 
specified as annual, and the criterion-frequency is specified as no-
more-than-once-every-three-years. EPA is proposing a criteria-duration 
of one year, in which sampled chlorophyll a concentrations are 
summarized as annual geometric means, to be consistent with the data 
set used to derive these criteria, which relied on annual average 
concentrations. EPA's proposed excursion frequency of no-more-than-
once-every-three-years is intended to minimize negative effects on 
designated uses as it will allow water bodies enough time to recover 
from occasionally elevated chlorophyll a

[[Page 74960]]

concentrations.\203\ These duration and frequency components of the 
criteria are identical to those finalized in EPA's rule for Florida's 
lakes and flowing waters (40 CFR 131.43), which will add consistency to 
the implementation of these criteria with those established in the 
previous rulemaking. Finally, the 3-year evaluation period provides a 
sufficient representation of average water body characteristics in the 
majority of cases, because it balances both short-term and long-term 
variation, while not imposing undue monitoring expectations. EPA 
requests comment on the frequency and duration components of these 
criteria and whether the three components of the criteria (magnitude, 
duration and frequency) taken in combination will ensure protection of 
the designated uses of these waters.
---------------------------------------------------------------------------

    \203\ Boynton, W.R., J.D. Hagy, L. Murray, C. Stokes, and W.M. 
Kemp. 1996. A comparative analysis of eutrophication patterns in a 
temperate coastal lagoon. Estuaries 19(2B):408- 421.
---------------------------------------------------------------------------

D. Proposed Numeric Criteria for South Florida Inland Flowing Waters

1. Proposed Numeric Criteria (South Florida Inland Flowing Waters)
    For purposes of this proposal, EPA is defining ``south Florida 
inland flowing waters'' as inland predominantly fresh surface waters 
that have been classified as Class I or Class III in the South Florida 
Nutrient Watershed Region, which encompasses the waters south of Lake 
Okeechobee, the Caloosahatchee River (including Estero Bay) watershed, 
and the St. Lucie watershed. This area contains more than 1,700 miles 
(2,736 km) of canals, dikes, and levees that control the movement of 
freshwater in south Florida. Some of the significant land management 
units within south Florida include the Everglades Agricultural Area, 
the Loxahatchee National Wildlife Refuge (Water Conservation Area 1), 
Water Conservation Areas 2 and 3, Big Cypress National Preserve, 
Everglades National Park, Biscayne Bay National Park, and the Florida 
Keys National Marine Sanctuary. A map showing this region is provided 
in the TSD (Volume 3: South Florida Inland Flowing Waters, Section 3).
    EPA is proposing that TN and TP DPVs be derived using the 
approaches outlined in Section III.D.2 for 22 pour points in south 
Florida, outside of the Everglades Protection Area (EvPA) and 
Everglades Agricultural Area (EAA), where inland flowing waters 
discharge into south Florida marine waters (Biscayne Bay, Florida Bay, 
and marine waters on the southeast and southwest coasts). For south 
Florida, EPA is proposing the use of DPVs to manage nitrogen and 
phosphorus pollution in the inland flowing waters and protect the water 
quality of estuaries and coastal waters downstream. Therefore, the 
applicable numeric nutrient criteria for south Florida inland flowing 
waters, outside the lands of the Miccosukee and Seminole Tribes, EvPA, 
and the EAA, would consist solely of the south Florida marine water 
DPVs. The calculated DPVs using the approaches in Section III.D.2 for 
the 22 pour points are presented in the TSD (Volume 3: South Florida 
Inland Flowing Waters, Section 2).
    The proposed approaches to derive DPVs that EPA is proposing for 
south Florida inland flowing waters do not apply to flowing waters 
(canals) within the EvPA or the EAA. There is an existing TP criterion 
of 0.010 mg/L (10 ppb) that currently applies to the marshes and 
adjacent canals within the EvPA (Section 61-302.540, F.A.C.). EPA 
approved that TP criterion in 2005 as protective of the waters in the 
EvPA. EPA's approval was upheld by the U.S. District Court in 
Miccosukee Tribe of Indians of Florida, et al. v. U.S. EPA.\204\ For 
this proposal, EPA has determined that the existing TP criterion 
continues to be protective of the designated uses of the flowing waters 
in the EvPA and that no additional numeric nutrient criteria are 
necessary at this time for the EvPA. While the existing TP criterion 
does not apply directly to the flowing waters of the EAA, EPA has also 
determined that the TP criterion will serve to be protective of the 
designated uses of the flowing waters in the EAA. Most of the water 
flowing from the EAA currently passes through stormwater treatment 
areas (STAs) that have been specifically constructed to remove 
phosphorus from the water before it enters the EvPA. The waters 
discharging from the STAs are subject to CWA discharge permits that 
must include limits as stringent as necessary to meet the 10 ppb TP 
criterion in the EvPA. Efforts to reduce phosphorus upstream of the 
STAs (i.e., in the EAA) are currently underway to ensure the water 
discharged from the STAs will meet the TP criterion in the EvPA. Based 
on the combination of the actions that will be necessary to ensure that 
waters from the EAA do not cause an impairment of the downstream waters 
in the EvPA, EPA has determined that the existing TP criterion is the 
only numeric nutrient criterion that is necessary to protect the 
flowing waters of the EAA as well as the EvPA. Development of water 
quality standards for the EvPA and restoration actions within the EAA 
to attain the TP criterion have been and remain subject to the 
oversight of two federal district courts. EPA believes its decision not 
to propose additional numeric nutrient criteria for these areas is 
appropriate given the ongoing restoration efforts in the Everglades. 
For further information about ongoing EPA and FDEP actions related to 
Everglades restoration see: (1) http://www.epa.gov/aboutepa/states/fl.html, and (2) http://depnewsroom.wordpress.com/hot-topics/everglades/.
---------------------------------------------------------------------------

    \204\ Miccosukee Tribe of Indians of Fla., et al. v. U.S. EPA, 
No. 1:04-cv-21448 ASG, 2008 WL 2967654 (S.D. Fla. July 29, 2008).
---------------------------------------------------------------------------

2. Proposed DPVs (South Florida)
    EPA is proposing a procedure to establish numeric TN and TP 
criteria for south Florida inland flowing waters to protect the 
downstream marine waters that ultimately receive nitrogen and 
phosphorus pollution from upstream sources. However, as explained more 
fully in Section I.A, EPA does not intend to finalize these DPVs if the 
district court modifies the Consent Decree consistent with EPA's 
amended determination that numeric DPVs are not necessary to meet CWA 
requirements in Florida. Like the DPVs that EPA is proposing to protect 
estuaries in Florida, EPA is proposing the DPVs for south Florida 
inland flowing waters that will apply at each stream or canal's point 
of entry into the downstream south Florida marine water. If the DPV is 
not attained at the pour point into the applicable marine water 
segment, then the collective set of flowing waters, including canals, 
in the upstream watershed does not attain the DPV, for purposes of CWA 
section 303(d).
    The Agency is proposing a hierarchical procedure that includes four 
approaches for setting TN and TP DPVs. These are the same approaches 
EPA is proposing for the State to derive DPVs for Florida estuaries to 
reflect the data and scientific information available. The methods 
available to derive DPVs should be considered in the following order:
    1. Water quality simulation models to derive TN and TP values,
    2. Reference condition approach based on TN and TP concentrations 
at the stream pour point, coincident in time with the data record from 
which the downstream receiving marine water segment TN and TP criteria 
were developed using the same data quality screens and reference 
condition approach,
    3. Dilution models based on the relationship between salinity and

[[Page 74961]]

nutrient concentration in the receiving segment, and
    4. The TN and TP criteria from the receiving marine water segment 
to which the freshwater stream discharges, in cases where data are too 
limited to apply the first three approaches.
    EPA's intention in proposing the four approaches is to provide a 
range of methods for deriving TN and TP DPVs that reflect the degree of 
data and scientific information available. Water quality modeling is 
the most rigorous and most data-demanding method, and will generally 
result in the most refined DPVs. Water quality modeling is EPA's 
preferred method for establishing DPVs and is listed first in the 
hierarchy. Due to the highly modified and managed canal systems in 
south Florida, EPA did not develop mechanistic models for the region, 
however, EPA is including the option for use if mechanistic models are 
developed for south Florida in the future. EPA's lead approach for 
calculating DPVs in south Florida is the reference condition approach. 
This approach is followed by less rigorous methods that are also less 
data-demanding. Using a procedure from a lower tier of the hierarchy 
requires less data, but also generally results in more stringent DPVs 
to account for the uncertainties associated with these less refined 
procedures.
    All four approaches are briefly described in the following 
discussion. A more detailed description of the approaches, as well as 
the TN and TP DPVs that result from using the lead approach, the 
reference condition approach, is provided in the technical support 
document (Volume 3: South Florida Inland Flowing Waters, Section 2).
    EPA believes that the first approach, the use of water quality 
simulation models, is the most refined method to define a DPV at the 
stream's pour point that will support balanced natural populations of 
aquatic flora and fauna in the downstream marine water. This approach 
may be appropriate when water quality simulation models are available, 
such as in the estuarine systems where mechanistic models were used to 
derive the criteria protective of the estuary.
    EPA is proposing the second DPV approach, the reference condition 
approach, where a reference condition approach is used to derive TN, 
TP, and chlorophyll a criteria in the downstream marine water, as the 
lead approach for calculating DPVs in south Florida. Florida derived 
numeric nutrient criteria for TN, TP, and chlorophyll a in south 
Florida marine waters using a ``Maintain Healthy Conditions Approach,'' 
which derives criteria reflective of ambient water quality conditions 
(Section 62-302.532, F.A.C.). This approach is akin to EPA's reference 
condition approach, which is designed to develop numeric nutrient 
criteria that are protective of applicable designated uses by 
identifying numeric nutrient criteria concentrations occurring in 
least-disturbed waters that are supporting designated uses. Since the 
downstream marine water is supporting balanced natural populations of 
aquatic flora and fauna during the reference condition period, the 
nutrient loads passing through the pour points into the marine water 
during the same period should be protective of the marine water. 
Therefore, EPA believes it would be appropriate in these cases to 
derive reference condition-based DPVs using water quality data at the 
pour point of the freshwater streams, coincident in time with the data 
record from which the downstream marine water segment TN and TP 
criteria were derived. EPA proposes that water quality data used to 
calculate DPVs at each pour point be screened to prevent the use of 
upstream water quality data that coincided with a documented downstream 
impact. This will prevent deriving a DPV using upstream water quality 
data that coincided with a documented downstream impact (e.g., CWA 
section 303(d) listing for nutrients in the marine water segment) and 
ensure mathematical consistency between the DPVs and marine water 
criteria.
    The third DPV approach is also available for south Florida marine 
systems where water quality simulation models are not available. In 
these areas, EPA believes it would be appropriate to derive DPVs using 
dilution models based on the relationship between salinity and nutrient 
concentration. The concept is that the tidal mixing or dilution can be 
estimated from the marine water salinity. By plotting observed marine 
water TN or TP versus the marine water salinity and fitting a linear 
regression, the TN or TP at various levels of salinity can be 
determined. This regression model can then be used to determine the TN 
or TP concentration at the pour point associated with the average 
marine water salinity that will ensure the attainment and maintenance 
of the marine water numeric nutrient criteria concentration.
    EPA's fourth approach for establishing DPVs is to apply the 
downstream receiving marine water segment TN and TP criteria to the 
pour point as the DPVs. This is the simplest approach and may be 
appropriate where data are too limited to apply the first three 
approaches. Florida derived numeric nutrient criteria for south Florida 
marine waters that can be found in Section 62-302.532(e)-(h), F.A.C. 
Therefore, the applicable DPVs for those south Florida marine waters 
would be Florida's criteria in Section 62-302.532(e)-(h), F.A.C. if 
using this fourth proposed approach for establishing DPVs.
    EPA believes the proposed approaches for deriving DPVs establish a 
decision-making framework that is binding, clear, predictable, and 
transparent. Therefore, EPA is proposing that DPVs derived using these 
approaches do not require EPA approval under Clean Water Act section 
303(c) to take effect.\205\ A DPV calculated under options 2, 3, and 4 
may be more stringent than a DPV calculated using a water quality 
model. These alternative options are intended to ensure that water 
quality standards are not only restored when found to be impaired, but 
are maintained when found to be attained, consistent with the CWA. 
Higher levels of TN and/or TP may be allowed in watersheds where it is 
demonstrated that such higher levels will fully protect the marine 
water's WQS. To the extent that it is determined that the alternative 
option DPVs for a given marine water are over-protective, applying a 
water quality model as set out in EPA's option 1 would result in a more 
refined definition of the DPV for that marine water.
---------------------------------------------------------------------------

    \205\ 65 FR 24641, 24647 (April 27, 2000).
---------------------------------------------------------------------------

    EPA believes that these proposed approaches to establish DPVs are 
appropriate, scientifically defensible, and result in numeric values 
that will ensure the attainment and maintenance of the downstream south 
Florida marine water criteria. EPA requests comment on these 
approaches. EPA also requests comment on the alternative approach of 
finalizing the numeric TN and TP DPVs that EPA calculated using these 
approaches (as provided in Volume 3: South Florida Inland Flowing 
Waters, Section 2 of the technical support document) in place of the 
proposed approaches. Finally, EPA solicits additional available 
scientific information that can be used to ensure attainment and 
maintenance of the downstream south Florida marine water criteria. 
Commenters who submitted comments or scientific information related to 
DPVs for estuaries during the public comment period for EPA's proposed 
inland waters rule (75 FR 4173) should reconsider their previous 
comments in light of the new information presented in this proposal and 
must re-submit their comments

[[Page 74962]]

during the public comment period for this rulemaking to receive EPA 
response.
(a) Alternative Approach (South Florida Inland Flowing Waters)
    As an alternative to EPA's proposed DPV-only approach for south 
Florida inland flowing waters, EPA developed protective instream TN and 
TP criteria for Class I and III flowing waters (including canals and 
streams) in three inland subregions in south Florida (Biscayne, Palm 
Beach, and West) that are outside the lands of the Miccosukee and 
Seminole Tribes, EAA, and EvPA. EPA's alternative criteria for south 
Florida inland flowing waters are listed in Table III.D-1.

  Table III.D-1--EPA's Alternative Numeric Criteria for South Florida's
                          Inland Flowing Waters
------------------------------------------------------------------------
                                                        TN (mg/  TP (mg/
                       Subregion                           L)       L)
------------------------------------------------------------------------
Biscayne..............................................        2    0.052
Palm Beach............................................        2    0.052
West..................................................        2    0.052
------------------------------------------------------------------------

    EPA defined the boundaries of these three subregions based on 
patterns in geology/soils, hydrology, and vegetation. EPA compiled data 
for these subregions from IWR Run 40 and the South Florida Water 
Management District's DBHydro database. EPA screened the data to 
include freshwater locations and Class III waters, resulting in 4,758 
daily averages with matched chl-a, TN, and TP data.
    Next, EPA chose to evaluate algal biomass, as indicated by 
chlorophyll a concentrations, as a sensitive endpoint for numeric 
nutrient criteria development. Nutrient pollution can increase biomass 
of primary producers, especially algae, and have subsequent negative 
impacts on recreation and aquatic life. The application of algal 
biomass as an endpoint for criteria derivation in south Florida inland 
flowing waters, including canals, might be appropriate given the 
following observations: (1) Flow in these water bodies is frequently 
reduced, leading to long residence times; (2) canopy cover is reduced 
both naturally and through manipulation, reducing light limitation; and 
(3) nutrient concentrations are elevated. Because both average 
chlorophyll a concentrations and instantaneous chlorophyll a 
concentrations (e.g. bloom conditions) can impact recreation and 
aquatic life, EPA chose to derive TN and TP criteria to reduce the 
likelihood of increased nuisance algal blooms by relating maximum 
chlorophyll a to average annual chlorophyll concentrations. EPA defined 
nuisance algal bloom conditions as concentrations above 30 [micro]g/L 
using trophic state boundaries, user perception studies, and observed 
impacts. EPA evaluated existing scientific literature on the frequency 
of occurrence of chlorophyll a levels, and selected a 10 percent 
occurrence of nuisance algal blooms as the maximum allowable frequency 
to prevent impairment of recreation and aquatic life in the three south 
Florida inland subregions.\206\
---------------------------------------------------------------------------

    \206\ Havens, K.E. and W.W. Walker. 2002. Development of a total 
phosphorus concentration goal in the TMDL process for Lake 
Okeechobee, Florida (USA). Lake and Reservoir Management 18(3):227-
238.
---------------------------------------------------------------------------

    EPA then used statistical models to derive TN and TP criteria to 
limit the frequency of occurrence of nuisance algal blooms in these 
waters, defined by chlorophyll a concentrations above 30 [micro]g/L. 
The resulting TN and TP criteria represent the annual geometric mean of 
TN and TP concentrations from flowing waters in each of the three 
subregions that are associated with a 10 percent or lower frequency of 
nuisance algal bloom occurrence. If EPA were to finalize this 
alternative approach instead of EPA's lead approach, these TN and TP 
criteria would apply throughout the flowing waters in each of the three 
subregions, not just at the pour points. If criteria are calculated 
using this alternative approach, DPVs for protecting downstream south 
Florida marine waters will still be calculated using the hierarchical 
approach in Section III.D.2, unless, as described more in Section I.A, 
the district court modifies the Consent Decree consistent with EPA's 
amended determination that numeric DPVs are not necessary to meet CWA 
requirements in Florida. Additional details on this alternative 
approach are provided in the TSD (Volume 3: South Florida Inland 
Flowing Waters, Section 3).
(b) Request for Comment on Proposed and Alternative Approaches
    EPA believes that the proposed approach for south Florida inland 
flowing waters is appropriate, scientifically defensible, and results 
in the protection of south Florida inland flowing waters. EPA requests 
comment on this approach. EPA also solicits additional available 
scientific information that can be used to provide protection of fish 
consumption, recreation and the propagation and maintenance of a 
healthy, well-balanced population of fish and wildlife in south 
Florida's Class I and III inland flowing waters from nitrogen and 
phosphorus pollution.
    In addition, EPA requests comment on the alternative approach of 
deriving instream criteria for south Florida inland flowing waters 
outside of the lands of the Miccosukee and Seminole Tribes, EvPA, and 
EAA. Specifically, EPA requests comment on the scientific defensibility 
of this alternative approach as well as whether application of this 
approach will result in numeric nutrient criteria that protect the 
State's designated uses and ensure that nutrient concentrations of a 
body of water support balanced natural populations of aquatic flora and 
fauna.
    Commenters who submitted comments or scientific information related 
to numeric nutrient criteria for south Florida inland flowing waters 
during the public comment period for EPA's proposed inland waters rule 
(75 FR 4173) should reconsider their previous comments in light of the 
new information presented in this proposal and must re-submit their 
comments during the public comment period for this rulemaking to 
receive EPA response.

F. Applicability of Criteria When Final

    EPA proposes that the numeric nutrient criteria for Florida's 
estuaries, coastal waters, and south Florida inland flowing waters 
described in this rule be effective for CWA purposes 60 days after EPA 
publishes final criteria, and apply in addition to any other criteria 
for Class I, II, or Class III waters already adopted by the State and 
submitted to EPA (and for those adopted after May 30, 2000, approved by 
EPA). EPA requests comment on this proposed effective date.
    Additionally, EPA also requests comment on the alternative of a 
delayed effective date, such as the 15-month delayed effective date 
that EPA promulgated in the final inland waters rule. EPA subsequently 
further extended the effective date of the 2010 rule to allow time for 
FDEP to finalize and EPA to review Florida's own numeric nutrient 
criteria rulemaking and reduce any administrative confusion and 
inefficiency that should occur if Federal criteria took effect while 
FDEP was finalizing or EPA was reviewing the State rulemaking. 
Florida's newly-approved State WQS include a schedule for future State 
rulemaking whereby they will develop numeric nutrient criteria for 
additional estuaries by June 30, 2013 and again by June 30, 2015. If 
Florida is on schedule toward adoption of protective and approvable 
standards for their additional waters, EPA may consider delaying the 
effective date of

[[Page 74963]]

its final rule to after June 30, 2015 to allow time for Florida to 
finalize and EPA to review the State's numeric nutrient criteria.
    For water bodies that Florida has designated as Class I, II, and 
III, any final EPA numeric nutrient criteria will be applicable CWA 
water quality criteria for purposes of implementing CWA programs 
including permitting under the NPDES program, as well as monitoring and 
assessment, and establishment of TMDLs. The proposed criteria in this 
rule, when finalized, would be subject to Florida's general rules of 
applicability to the same extent as are other State-adopted and/or 
federally-promulgated criteria for Florida waters. Furthermore, states 
have discretion to adopt general policies that affect the application 
and implementation of WQS (40 CFR 131.13). There are many applications 
of criteria in Florida's water quality programs. Therefore, EPA 
believes that it is not necessary for purposes of this proposed rule to 
enumerate each of them, nor is it necessary to restate any otherwise 
generally applicable requirements.
    It is important to note that no existing TMDL for waters in Florida 
will be rescinded or invalidated as a result of finalizing this 
proposed rule, nor will this proposed rule when finalized have the 
effect of withdrawing any prior EPA approval of a TMDL in Florida. 
Neither the CWA nor EPA regulations require TMDLs to be completed or 
revised within any specific time period after a change in water quality 
standards occurs. TMDLs are typically reviewed as part of states' 
ongoing water quality assessment programs. Florida may review TMDLs at 
its discretion based on the State's priorities, resources, and most 
recent assessments. NPDES permits are subject to five-year permit 
cycles, and in certain circumstances are administratively continued 
beyond five years. In practice, States often prioritize their 
administrative workload in permits. This prioritization could be 
coordinated with TMDL review. Because current nutrient TMDLs were 
established to protect Florida's waters from the effects of nitrogen 
and phosphorus pollution, the same goal as EPA's numeric nutrient 
criteria, the Agency believes that, absent specific new information to 
the contrary, it is reasonable to presume that basing NPDES permit 
limits on those TMDLs will result in effluent limitations as stringent 
as necessary to meet the federal numeric nutrient criteria.

IV. Under what conditions will EPA either not finalize or withdraw 
these Federal standards?

    Under the CWA, Congress gave states primary responsibility for 
developing and adopting water quality standards for their navigable 
waters (CWA section 303(a)-(c)). On June 13, 2012, FDEP submitted new 
and revised WQS for review by the EPA pursuant to section 303(c) of the 
CWA. On November 30, 2012, EPA approved the provisions of these rules 
submitted for review that constitute new or revised WQS (see Section 
II.F for additional information). Florida continues to have the option 
to adopt and submit to EPA numeric nutrient criteria for any of the 
State's Class I, Class II, and Class III waters that are not covered in 
their June 13, 2012 submission to EPA, consistent with CWA section 
303(c) and implementing regulations at 40 CFR 131. Although EPA is 
proposing numeric nutrient criteria for Florida estuaries, coastal 
waters, and south Florida inland flowing waters, if EPA approves 
criteria that are legally effective under Florida law for any other 
waters covered in this proposed rule as fully satisfying the CWA before 
publication of the final rulemaking, EPA will not proceed with the 
final rulemaking for those waters. Also, EPA will not proceed with 
final rulemaking for numeric DPVs, provided that the district court 
modifies the Consent Decree consistent with EPA's amended determination 
that numeric DPVs are not necessary to meet CWA requirements in Florida 
(see Section I.A for more information).
    Pursuant to 40 CFR 131.21(c), if EPA finalizes this proposed rule, 
EPA's promulgated WQS become applicable WQS for purposes of the CWA on 
their effective date unless or until EPA withdraws those federally-
promulgated WQS. Withdrawing the Federal standards for the State of 
Florida would require rulemaking by EPA pursuant to the requirements of 
the Administrative Procedure Act (5 U.S.C.551 et seq.). EPA would 
undertake such a rulemaking to withdraw the Federal criteria if and 
when Florida adopts and EPA approves numeric nutrient criteria that 
fully meet the requirements of section 303(c) of the CWA and EPA's 
implementing regulations at 40 CFR 131. If Florida adopts and EPA 
approves nutrient criteria that meet these requirements for a subset of 
waters, EPA would withdraw the Federal standards for that subset of 
waters.

V. Alternative Regulatory Approaches and Implementation Mechanisms

A. Designating Uses

    Under CWA section 303(c)(2)(A), states shall adopt designated uses 
after taking ``into consideration the use and value of water for public 
water supplies, protection and propagation of fish, shellfish, and 
wildlife, recreation in and on the water, agricultural, industrial and 
other purposes including navigation.'' Designated uses ``shall be such 
as to protect the public health or welfare, enhance the quality of 
water and serve the purposes of [the CWA].'' (CWA section 
303(c)(2)(A)). EPA's regulation at 40 CFR 131.3(f) defines ``designated 
uses'' as ``those uses specified in water quality standards for each 
water body or segment whether or not they are being attained.'' A 
``use'' is a particular function of, or activity in, waters of the 
United States that requires a specific level of water quality to 
support it. In other words, designated uses are a state's concise 
statements of its management objectives and expectations for individual 
surface waters.
    In the context of designating uses, states often work with 
stakeholders to identify a collective goal for their waters that the 
state intends to strive for as it manages water quality. States may 
evaluate the attainability of these goals and expectations to ensure 
they have designated appropriate uses (40 CFR 131.10(g)). EPA's 
regulations at 40 CFR 131 interpret and implement CWA sections 
101(a)(2) and 303(c)(2)(A) to require that states adopt designated uses 
that provide water quality for the protection and propagation of fish, 
shellfish, and wildlife and for recreation in and on the water 
(referred to as uses specified in section 101(a)(2) of the Act), 
wherever attainable (40 CFR 131.2; 131.5(a)(4); 131.6(a),(f); 
131.10(g),(j)). Where states do not designate uses specified in 
101(a)(2) of the Act, or remove such uses, they must demonstrate that 
the uses are not attainable consistent with the use attainability 
analysis (UAA) provisions of 40 CFR 131.10, specifically 131.10(g). A 
state may remove protection for a use specified in CWA section 
101(a)(2) if it can show, based on a UAA consistent with 131.10, that 
the use is not attainable. States may include waters located in the 
same watershed in a single UAA, provided that there is site-specific 
information to show how each individual water fits into the group in 
the context of any single UAA and how each individual water meets the 
applicable requirements of 40 CFR

[[Page 74964]]

131.10(g) for removing or modifying a use.
    EPA's proposed numeric nutrient criteria for estuaries, coastal 
waters, and south Florida inland flowing waters will apply to those 
waters designated by Florida as Class I (Potable Water Supplies), Class 
II (Shellfish Propagation or Harvesting), and Class III (Recreation, 
Propagation and Maintenance of a Healthy, Well-Balanced Population of 
Fish and Wildlife). If Florida removes the Class I, Class II, and/or 
Class III designated use for any particular water body ultimately 
affected by this rule such that it is no longer designated as either 
Class I, II, or III, and EPA approves such a removal because it is 
consistent with CWA section 303(c) and regulations at 40 CFR 131, then 
the federally-promulgated numeric nutrient criteria would not apply to 
that water body. Only the water quality criteria associated with the 
revised designated use would apply to that water body.

B. Variances

    A variance may be described as a time-limited designated use and 
criteria that target a specific pollutant(s), source(s), water 
body(ies) and/or water body segment(s). Variances constitute new or 
revised water quality standards subject to the procedural and 
substantive requirements applicable to removing a designated use.\207\ 
Thus, EPA may only approve a variance if it is based on the same 
factors, set out at 40 CFR 131.10(g), that are required to revise a use 
specified in CWA section 101(a)(2) through a UAA.
---------------------------------------------------------------------------

    \207\ In re Bethlehem Steel Corporation, General Counsel Opinion 
No. 58. March 29, 1977 (1977 WL 28245 (E.P.A. G.C.)). USEPA. 1994. 
Water Quality Standards Handbook: Second Edition. EPA-823-B-94-005a. 
U.S. Environmental Protection Agency, Office of Water, Washington, 
DC.
---------------------------------------------------------------------------

    Typically, variances are time-limited, but may be renewed. 
Temporarily modifying the designated use for a particular water body 
through a variance process allows a state to identify an interim 
designated use and associated criteria to serve as the basis for NPDES 
permit limits and certifications under CWA section 401 during the term 
of the variance while maintaining the designated use and associated 
criteria as the ultimate goal. A state should seek a variance instead 
of removing or revising the designated use where the state believes the 
designated use and associated criteria can be attained at some point in 
the future. By maintaining the designated use, and associated criteria, 
and by specifying a point in the future when the designated use will be 
fully applicable in all respects, the state ensures that further 
progress will be made in improving water quality and attaining the 
ultimate goal.
    A variance may be written to address a specific geographic area, a 
specific pollutant or pollutants, and/or a specific discharger. All 
other applicable water quality standards not specifically modified by 
the variance, including any other criteria adopted to protect the 
designated use, remain applicable. State variance procedures, as part 
of state water quality standards, must be consistent with the 
substantive requirements of 40 CFR 131. Each variance must be submitted 
to EPA as a revised water quality standard for review and approval or 
disapproval pursuant to CWA section 303(c).
    For purposes of this proposal, EPA is proposing criteria that apply 
to use designations that Florida has already established. EPA believes 
that the State continues to have sufficient authority under 131.10 to 
grant variances under its variance procedures to Class I, Class II or 
Class III uses and associated criteria. For this reason, EPA is not 
proposing a Federal variance procedure.

C. Site-Specific Alternative Criteria

    Site-specific alternative criteria (SSAC) are alternative values to 
otherwise applicable water quality criteria that would be applied on a 
watershed, area-wide, or water body-specific basis that meet the 
regulatory test of protecting the water's designated use, having a 
basis in sound science, and ensuring the protection and maintenance of 
downstream water quality standards. SSAC may be more or less stringent 
than the otherwise applicable criteria. In either case, because the 
SSAC must protect the same designated use and must be based on sound 
science according to the requirements of 40 CFR 131.11(a), there is no 
need to modify the designated use or conduct a UAA. A SSAC may be 
appropriate when additional scientific data and analyses can bring 
increased precision or accuracy to expressing the concentration of a 
water quality parameter that is protective of the designated use.
    In EPA's 2010 rulemaking for Florida's lakes and flowing waters 
outside of the South Florida Nutrient Watershed Region, EPA promulgated 
a procedure whereby EPA's Region 4 Regional Administrator may establish 
a SSAC after making available the proposed SSAC and supporting 
documentation for public comment (40 CFR 131.43(e)). This procedure 
became effective for CWA purposes on February 4, 2011. Under this 
provision, any entity, including the State, can submit a proposed 
Federal SSAC directly to EPA for the Agency's review and assessment as 
to whether an adjustment to the applicable Federal numeric nutrient 
criteria is warranted. The Federal SSAC process is separate and 
distinct from the State's SSAC processes in its water quality 
standards.
    The current Federal SSAC procedure allows EPA to determine that a 
revised site-specific chlorophyll a, TN, TP, or nitrate+nitrite numeric 
criterion should apply in lieu of the generally applicable criteria 
promulgated in the final rule for Florida's lakes and flowing waters 
where that SSAC is demonstrated to be protective of the applicable 
designated use(s). The promulgated procedure provides that EPA will 
solicit public comment on its determination. Because EPA's rule 
established this procedure, implementation of this procedure does not 
require withdrawal of the associated federally-promulgated criteria for 
the Federal SSAC to be effective for purposes of the CWA. EPA has 
promulgated similar procedures for EPA's granting of variances and 
SSACs in other federally-promulgated water quality standards.\208\
---------------------------------------------------------------------------

    \208\ See 40 CFR 131.33(a)(3), 40 CFR 131.34(c), 40 CFR 
131.36(c)(3)(iii), 40 CFR 131.38(c)(2)(v), 40 CFR 131.40(c).
---------------------------------------------------------------------------

    As outlined in 40 CFR 131.43(e) and in the draft ``Technical 
Assistance for Developing Nutrient Site-Specific Alternative Criteria 
in Florida'' (June 2011), the process for obtaining a Federal SSAC 
includes the following steps. First, an entity seeking a SSAC compiles 
the supporting data, conducts the analyses, develops the expression of 
the criterion, and prepares the supporting documentation demonstrating 
that alternative numeric nutrient criteria are protective of the 
applicable designated use. The ``entity'' may be the State, a city or 
county, a municipal or industrial discharger, a permittee, a consulting 
firm acting on the behalf of a client, or any other individual or 
organization. The entity requesting the SSAC bears the burden of 
demonstrating that any proposed SSAC meets the requirements of the CWA 
and EPA's implementing regulations, specifically 40 CFR 131.11. Second, 
if the entity is not the State, the entity must provide notice of the 
proposed SSAC to the State, including all supporting documentation so 
that the State may provide comments on the proposal to EPA. Third, 
EPA's Region 4 Regional Administrator will evaluate the technical basis 
and protectiveness of the proposed SSAC and decide whether to publish a 
public notice and take

[[Page 74965]]

comment on the proposed SSAC. The Regional Administrator may decide not 
to publish a public notice and instead return the proposal to the 
entity submitting the proposal, with an explanation as to why the 
proposed SSAC application did not provide sufficient information for 
EPA to determine whether it meets CWA requirements or not. If EPA 
solicits public comment on a proposed SSAC, upon review of comments, 
the Regional Administrator may determine that the Federal SSAC is or is 
not appropriate to account for site-specific conditions and make that 
determination publicly available together with an explanation of the 
basis for the decision.
    Since the SSAC provision in EPA's 2010 rule became effective, 
numerous entities have contacted EPA regarding a possible interest in 
obtaining a federal SSAC. However, following discussions with EPA, it 
became clear that a different water quality standards mechanism, such 
as a designated use change or variance, would be more appropriate in 
their particular situation. On March 9, 2011, EPA received a SSAC 
request from a pulp and paper mill that discharges to the Fenholloway 
River. Since the SSAC was derived from data in a nearby reference 
stream, the Econfina River, the TN and TP SSAC were requested to apply 
to both the Econfina and Fenholloway Rivers. Additional information was 
submitted by the requestor during 2011 and 2012 to address questions 
posed by EPA. At this time, EPA does not have sufficient information to 
move forward with proposing or establishing the TP or TN SSAC for the 
Fenholloway and Econfina Rivers.
    EPA believes that there is benefit in extending this procedure for 
EPA adoption of Federal SSAC that will adjust the numeric nutrient 
criteria proposed in this rule. EPA is therefore proposing that a 
similar procedure promulgated in 40 CFR 131.43(e) apply to estuaries, 
coastal waters, and south Florida inland flowing waters. EPA requests 
comment on the following proposed application of the SSAC procedure.
    To successfully develop a Federal SSAC for a given estuary, coastal 
water, or south Florida inland flowing water, a thorough analysis is 
necessary that indicates how the alternative concentration of TN, TP, 
or chlorophyll a supports both the designated use(s) of the water body 
itself, and provides for the attainment and maintenance of the WQS of 
downstream water bodies, where applicable. This analysis should have 
supporting documentation that consists of examining indicators of 
longer-term response to multiple stressors, such as seagrass health, as 
well as indicators of shorter-term response specific to nitrogen and 
phosphorus pollution, such as chlorophyll a concentrations associated 
with balanced phytoplankton biomass or sufficient dissolved oxygen to 
maintain aquatic life.
    EPA is proposing seven approaches for developing SSAC for 
estuaries, coastal waters, and south Florida inland flowing waters that 
are similar to the four approaches EPA finalized in the 2010 rule for 
Florida's lakes and flowing waters. The first five proposed approaches 
are replicating the approaches EPA used to develop estuary, tidal 
creek, marine lake, coastal, and south Florida inland flowing water 
criteria, respectively, and applying these methods to a smaller subset 
of waters or water body segments. To understand the necessary steps in 
this analysis, interested parties should refer to the complete 
documentation of these approaches in the Technical Support Document for 
this proposed rule.
    The sixth proposed approach for developing SSAC is to conduct a 
biological, chemical, and physical assessment of water body conditions. 
A detailed description of the supporting rationale must be included in 
the documentation submitted to EPA. The components of this approach 
could include, but are not limited to, evaluation of: seagrass health, 
presence or absence of native flora and fauna, chlorophyll a 
concentrations or phytoplankton density, average daily dissolved oxygen 
fluctuation, organic versus inorganic components of total nitrogen, 
habitat assessment, and hydrologic disturbance. This approach could 
apply to any water body type, with specific components of the analysis 
tailored for the situation.
    The proposed seventh approach for developing SSAC is a general 
provision for using another scientifically defensible approach that is 
protective of the designated use. This provision allows applicants to 
make a complete demonstration to EPA using methods not otherwise 
described in the rule or its statement of basis, consistent with 40 CFR 
131.11(b)(1)(iii). This approach could potentially include use of 
mechanistic models or other data and information.

D. Compliance Schedules

    A compliance schedule, or schedule of compliance, refers to ``a 
schedule of remedial measures included in a `permit,' including an 
enforceable sequence of interim requirements * * * leading to 
compliance with the CWA and regulations.'' (40 CFR 122.2, CWA section 
502(17)). In an NPDES permit, Water Quality-Based Effluent Limitations 
(WQBELs) are effluent limits based on applicable water quality 
standards for a given pollutant in a specific receiving water (NPDES 
Permit Writers Manual, EPA-833-B-96-003, December, 1996). EPA 
regulations provide that schedules of compliance may only be included 
in permits if they are determined to be ``appropriate'' given the 
circumstances of the discharge and are to require compliance ``as soon 
as possible'' (40 CFR 122.47).\209\
---------------------------------------------------------------------------

    \209\ Hanlon, Jim. USEPA Office of Wastewater Management. 2007, 
May 10. Memorandum to Alexis Stauss, Director of Water Division EPA 
Region 9, on ``Compliance Schedules for Water Quality-Based Effluent 
Limitations on NPDES Permits.''
---------------------------------------------------------------------------

    Florida has adopted a regulation authorizing compliance schedules. 
That regulation, Subsection 62-620.620(6), F.A.C., is not affected by 
this proposed rule. The complete text of the Florida rules concerning 
compliance schedules is available at https://www.flrules.org/gateway/RuleNo.asp?ID=62-620.620. Florida is, therefore, authorized to grant 
compliance schedules, as appropriate, under its rule for WQBELs based 
on EPA's federally-promulgated numeric nutrient criteria.

VI. Economic Analysis

    The CWA provides a comprehensive framework for the protection and 
restoration of the health of the Nation's waters. EPA determined in 
2009 that addressing the significant number of Florida waters impaired 
by nitrogen and phosphorus required the establishment of numeric 
nutrient criteria as part of Florida water quality standards adopted 
under the CWA. State implementation of numeric nutrient criteria in the 
proposed rule may result in an incremental level of controls needed for 
compliance with CWA programs, or require them sooner than would occur 
under current CWA programs. These controls include new or revised 
National Pollutant Discharge Elimination System (NPDES) permit 
conditions for point source dischargers and controls on other sources 
of nitrogen and phosphorus (e.g., agriculture, urban runoff, and septic 
systems) through the development of Total Maximum Daily Loads (TMDLs) 
and Basin Management Action Plans (BMAPs).
    EPA conducted an analysis to estimate both the increase in the 
number of impaired waters that may be identified as a result of the 
proposed rule, and the potential annual cost of CWA pollution control 
actions likely to

[[Page 74966]]

be implemented by the State of Florida and private parties to assure 
attainment of applicable State water quality designated uses. It is 
important to note that the costs of pollution controls needed to attain 
water quality standards for nutrients for waters already identified as 
impaired by the State (including waters with and without TMDLs in 
place) are not included in EPA estimates of the cost of the rule. EPA's 
analysis is fully described in the document entitled Economic Analysis 
of Proposed Water Quality Standards for the State of Florida's 
Estuaries, Coastal Waters, and South Florida Inland Flowing Waters 
(hereinafter referred to as the Economic Analysis), which can be found 
in the docket and record for this proposed rule. This analysis shows 
that the incremental costs associated with the proposed rule range 
between $239.0 million and $632.4 million per year (2010 dollars) and 
monetized benefits may be in the range from $39.0 to $53.4 million 
annually.

1. NRC Review of Phase 1 Cost Estimates

    On December 6, 2010 EPA published a final rule to set numeric 
nutrient criteria for lakes and streams in Florida designed to protect 
those waters for their State-designated uses, such as swimming, 
fishing, or as drinking water sources (Phase 1 rule). EPA developed an 
economic analysis to provide the public with information on potential 
costs and benefits that may be associated with Florida's implementation 
of EPA's rule. EPA's estimate of the annual costs of that rule ranged 
from $135.5 to $206.1 million; stakeholder estimates of the same cost 
categories ranged from $8 to $13 billion annually. While these costs 
are not directly related to today's proposed rule, EPA determined that 
an independent peer review of its economic analysis for the Phase 1 
rule would provide important information on the disparity between EPA's 
cost estimates and those of some stakeholders, and would be helpful to 
inform and improve its analysis of today's proposed rule. Accordingly, 
EPA requested the National Research Council (NRC) of the National 
Academies to review EPA's economic analysis for the Phase 1 rule. The 
NRC Committee completed its ``Review of the EPA's Economic Analysis of 
Final Water Quality Standards for Nutrients for Lakes and Flowing 
Waters in Florida'' in June. The Committee was charged with reviewing 
and commenting on three specific areas:
    (1) EPA's assumption that only newly impaired waters should be 
analyzed,
    (2) EPA's decision to estimate costs associated only with sources 
affecting newly impaired waters, by sector, and
    (3) EPA's assumptions about levels of control by point and nonpoint 
sources, including the use of variances and other flexibilities for 
more cost-effective approaches and whether to implement reverse osmosis 
and other stringent control technologies.
    NRC answered the first charge, agreeing with EPA's assumption that 
only newly impaired waters should be analyzed. NRC also addressed the 
second charge, but took exception with EPA's approach to not estimating 
costs for unassessed waters or for septic systems affecting impaired 
springsheds. NRC also suggested that EPA underestimated the affected 
acres in agriculture. The Committee did not offer specific suggestions 
for how to compute the increased acreage that should be analyzed. 
However, on the cost side, they suggest including costs associated with 
installation of regional treatment systems on agricultural lands.
    As for the third charge, the Committee largely addressed this by 
examining the details of EPA's unit costs, including comments 
suggesting ways in which EPA underestimated or overestimated costs. The 
Committee did not directly address EPA's assumptions regarding the use 
of SSACs, variances and use designations, except to propose an 
alternative cost estimating framework based on predicting the future 
time path of waters progressing through the stages of listing as 
impaired, TMDL development, and BMAP implementation, with and without 
the rule. The Committee generally concluded that EPA's cost estimates 
were likely too low, while the stakeholder estimates were too high.
    In response to the NRC review, EPA has attempted to incorporate 
many of the recommendations and suggestions made throughout the NRC 
report including: Using the HUC-12 watershed unit of analysis; 
analyzing potential costs for unassessed waters that could be 
incrementally impaired; analyzing costs for each industrial plant 
rather than extrapolating the results from a small sample; reviewing 
actual experience from existing TMDLs to identify BMPs sufficient to 
meet numeric targets; considering permeable reactive barriers for 
septic systems and their installation costs; and considering 
uncertainty in government expenditures. EPA has addressed these 
recommendations and suggestions in this analysis of costs for the 
coastal and estuary criteria.
    The NRC Committee also described an approach for EPA to consider in 
analyzing the impacts of its numeric nutrients criteria rules by 
tracing out two time-paths of costs and benefits: one time-path for the 
baseline and one reflecting the proposed rule. The costs and benefits 
of the proposed rule could then be analyzed as the present value of the 
difference in the two time-paths of costs and benefits, respectively. 
To execute this approach, EPA would need to model not just its 
projection of the eventual controls that would be implemented under the 
proposed rule, but its predictions of the prioritization of watersheds 
that Florida would adopt to determine the timing of controls. NRC 
suggested that EPA could engage external stakeholders in a 
collaborative process to determine a collective set of assumptions to 
use as part of this analytical approach (or at least to ``isolate and 
possibly reconcile'' areas of disagreement). EPA acknowledges the merit 
of this approach, and notes that it is consistent with EPA's intent 
that its numeric nutrients criteria simply interpret Florida's current 
narrative nutrient criterion, by providing the often time-consuming 
first step of the science-based modeling necessary for developing a 
TMDL. The ultimate effect of the EPA's proposal would be to improve the 
efficiency and effectiveness of Florida's WQS program with regard to 
nutrients. However, given the exigencies of the consent decree and the 
timing of the NRC review, EPA determined that it was not possible to 
adopt the NRC's alternative approach for this proposal. The NRC's 
alternative approach was presented as a finding, rather than a 
recommendation, because the NRC acknowledged that time and budget 
constraints might render this approach unworkable for the current rule.
    Considering the exigencies, EPA took the approach of estimating 
costs and benefits for a representative future year, using current 
water quality data as a basis for projecting what incremental water 
quality controls would need to be implemented during this future year 
to meet the new criteria. An approach that compares two complete future 
time-paths (with and without the proposed rule) requires taking the 
difference between those two time-paths, discounting over time, and 
summing in order to express the impacts in present value terms. In 
contrast, EPA's approach identifies waters that would be newly 
identified as impaired and the controls that would be needed to meet 
the new criteria. EPA then annualizes the costs of these controls over 
an appropriate time horizon. As such, the two approaches are not 
directly comparable.

[[Page 74967]]

Nonetheless, EPA believes its approach sheds light on the costs and 
benefits associated with its numeric nutrients criteria rules and 
complies with the Executive Order requirements for conducting economic 
analysis of regulations. As noted above, EPA has made significant 
changes to its approach to address the NRC recommendations that are 
applicable to it.

2. Baseline for Cost Analysis

    EPA is promulgating numeric nutrient criteria to supplement the 
State of Florida's current narrative nutrient criteria. The incremental 
impacts of the proposed rule are the potential costs and benefits 
associated with implementation of the proposed numeric criteria, 
including DPVs, for estuaries, coastal waters, and south Florida inland 
flowing waters, above and beyond the costs associated with State 
implementation of its current narrative nutrient criterion. The 
baseline incorporates requirements associated with restoration of 
already identified impaired waters, including waters for which TMDLs 
are approved and waters for which TMDLs are not yet developed. Because 
the numeric nutrients criteria proposed here interpret Florida's 
existing narrative criterion, which is also the basis for existing 
TMDLs, the analysis assumes that these TMDLs would be adopted as site-
specific criteria. Thus, there would be no additional costs or benefits 
associated with the proposed rule for these waters. The baseline for 
this analysis also includes EPA's previously promulgated numeric 
nutrient criteria for Florida's lakes and flowing waters.
    For waters that the State of Florida has already identified as 
impaired but for which it has not yet developed TMDLs, EPA expects that 
the effect of this proposed rule will be to shorten the time and reduce 
the resources necessary for the State of Florida to develop TMDLs and 
BMAPs. For waters that the State of Florida has developed TMDLs, EPA 
has looked at the proposed criteria to compare these to the target 
loadings in the TMDLs and has not found a consistent pattern of 
existing TMDLs being either more or less stringent than would be 
required to meet the criteria proposed in this rule. For already 
impaired waters and waters already under a TMDL, EPA assumed that no 
additional controls on nonpoint sources to these waters would be needed 
as a consequence of this rule. However, there may be an incremental 
impact of the proposed rule for any point source dischargers to these 
waters that have or may receive waste load allocations for just one 
nutrient pollutant if those waters are not attaining criteria for the 
other as a result of this proposed rule. These costs are included in 
this economic analysis.
    For waters not currently impaired under the baseline, EPA uses 
current water quality measurements to predict which waters would be 
deemed unimpaired as a result of the proposed rule (and therefore need 
not be analyzed for nonpoint source control costs). EPA acknowledges 
that these conditions could change in the future. To the extent that 
the experience in implementation of the proposed rule deviates from 
these specific assumptions about the baseline, EPA's estimates of the 
costs and benefits may be under- or overestimated. See Section 2 of the 
Economic Analysis for a full description of the baseline. EPA requests 
comment on its assumptions regarding the baseline.

3. Incremental Costs

    The likely effect of this proposed rule will be the assessment and 
identification of additional waters that are impaired and not meeting 
the numeric water quality criteria in the proposed rule. The 
incremental impact of the proposed rule includes the costs for controls 
on point and nonpoint sources, developing and implementing TMDLs to 
attain the proposed criteria, and the monetary value (benefits) of the 
resulting potential increase in water quality. The economic analysis 
describes these potential incremental impacts of the proposed rule. It 
is important to note that EPA took care not to include costs for the 
estuarine and coastal marine waters contained in Florida's newly-
approved State WQS.
    To develop these estimates, EPA first assessed State control 
requirements associated with current water quality, existing impaired 
waters, and existing TMDLs, as well as existing regulations specific to 
estuaries, coastal waters and south Florida inland flowing waters (the 
baseline). EPA then identified the costs and benefits associated with 
additional pollution controls to meet EPA's proposed numeric criteria, 
beyond pollution controls currently needed or in place. To estimate 
incremental costs to municipal and industrial dischargers, EPA gathered 
publicly available facility information and data on potential control 
technologies, and used Florida Department of Environmental Protection 
(FDEP) point source implementation procedures to estimate the change in 
WQBELs and treatment controls that could result from the proposed rule. 
EPA assessed potential non-point source control costs by using publicly 
available information and data to determine land uses near waters that 
would likely be identified as impaired under the proposed rule. EPA 
used current FDEP data on stormwater controls and Florida Department of 
Agricultural and Consumer Services (FDACS) manuals to estimate costs of 
implementing stormwater and agricultural best management practices 
(BMPs) to attain the proposed numeric criteria. EPA also estimated the 
potential costs associated with upgrades of homeowner septic systems 
and potential government costs of developing additional TMDLs for water 
identified as impaired under this rule. Finally, EPA qualitatively and 
quantitatively described and estimated some of the potential benefits 
of complying with the new water quality standards. Although it is 
difficult to predict with certainty how the State of Florida will 
implement these new water quality standards, the result of this 
analysis represent EPA's best estimates of costs and benefits of the 
State of Florida's likely actions to implement this proposed rule.
A. Incrementally Impaired Waters
    Compared to current conditions, potentially incrementally impaired 
waters are those waters that exceed EPA's proposed criteria for which 
FDEP has not already developed a TMDL or listed as impaired for 
nutrients. To estimate incremental costs associated with attainment of 
criteria, EPA first removed any waters for which the State of Florida 
has already determined to be impaired or established a TMDL and/or 
BMAP, because it considers these waters part of the baseline for this 
analysis. BMAPs are iterative and are updated on a continual basis 
until the TMDL targets are met. EPA assumes that controls will be 
implemented through these mechanisms until the TMDLs are met. Although 
additional costs to address baseline impairments may be needed in the 
future (after this rule is promulgated), EPA does not believe that 
these costs should be attributed to this proposed rule, but are instead 
part of the baseline. As discussed above, the State of Florida is not 
required to revise any existing TMDL as a result of this rule, and 
WQBELs in NPDES permits that are consistent with an existing EPA 
approved TMDL meet the requirements of the CWA. TMDL nutrient criteria 
have been shown to be both more stringent and less stringent when 
compared to criteria under this proposed rule and EPA has provided 
SSACs as a mechanism to approve the standards in existing TMDLs and 
BMAPs. Thus, EPA does not anticipate that this rule will result in 
increased nonpoint source controls costs for

[[Page 74968]]

watersheds that already have an EPA-approved TMDL.
    After excluding waters already identified as impaired under 
Florida's existing narrative criteria, EPA next identified estuarine 
and coastal segments that do not meet the numeric criteria of this 
proposed rule. EPA then assumed identified waterbodies (WBIDs \210\) 
that overlap those segments may be identified as incrementally 
impaired. EPA then identified the watersheds that contain or surround, 
in the case of coastal waters, those incrementally impaired WBIDs.
---------------------------------------------------------------------------

    \210\ WBID is a waterbody identification number assigned by 
Florida, in order to delineate the boundaries of Florida's waters.
---------------------------------------------------------------------------

    EPA analyzed FDEP's database of ambient water quality monitoring 
data and compared monitoring data for each segment with EPA's proposed 
criteria for TN and TP to identify incrementally impaired waters. EPA 
compiled the most recent five years of monitoring data and determined 
if there was sufficient data available to calculate more than one 
annual geometric mean in a consecutive three year period. With 
sufficient data, EPA calculated the annual geometric mean for each 
segment identified by EPA segment boundaries, and identified waters as 
incrementally impaired if they exceeded the applicable criteria in this 
proposed rule. The results of this analysis are shown in Table VI(A).

               Table VI(A)(1)--Number of WBIDs Summary of Data Analysis for Proposed Criteria \1\
----------------------------------------------------------------------------------------------------------------
                                                                            Not currently impaired
                                                                              under the baseline
                                                                Baseline  --------------------------
                        Criteria type                           impaired       Data                     Total
                                                                  \2\       available     Data not
                                                                               \3\       available
----------------------------------------------------------------------------------------------------------------
Coastal.....................................................            0            5           68           73
Estuaries...................................................           42          121           95          258
                                                             ---------------------------------------------------
    Total...................................................           42          126          163          331
----------------------------------------------------------------------------------------------------------------
Source: FDEP IWR run 44.
\1\ Represents number of WBIDs, based on 10% of WBID area overlapping segments for which EPA is proposing
  numeric nutrient criteria.
\2\ On 303(d) list as impaired for nutrients or covered under a nutrient-related TMDL. EPA did not assess these
  waters further for attainment of the proposed criteria.
\3\ WBIDs in segments for which at least two geometric means in a consecutive three year period can be
  calculated based on having at least four samples in a given year, with one sample in winter and summer.

    Controls may also be needed to meet the proposed criteria in a 
portion of the 163 WBIDs for which EPA does not have data if subsequent 
data would indicate impairment. These 163 WBIDs are variously located 
in the same watersheds as WBIDs that are baseline impaired or 
incrementally impaired by this proposed rule, or in watersheds either 
with no known impaired WBIDs or for which none of the WBIDs have 
sufficient data to determine impairment status. Without additional 
information about these waters, EPA determined the number of impaired-
though-unassessed waters as a range. As a low estimate, it is possible 
that none of the unassessed waters would be impaired. Given the 
targeting scheme for Florida's IWR data, these unassessed waters likely 
have a lower probability of impairment than assessed waters, and zero 
represents the lower bound. For the high end of the range, EPA 
considered a proportional impairment rate of assessed waters. The 
impairment rate of unassessed waters may be anywhere in between.
    While helpful in establishing the number of waterbodies that may be 
incrementally impaired, the assumption of proportional impairment does 
not produce information on location needed to estimate associated 
costs. The majority of unassessed waters lie along the coast and in 
close proximity to baseline impaired and impaired assessed waters. 
Hence, for this analysis, EPA assumed that impairment in unassessed 
waters would most likely be near baseline impairments and impaired 
assessed waters, since the loads causing impairment in these assessed 
waters could also affect the downstream unassessed waters. For coastal 
waters and south Florida waters, EPA used GIS to locate waters within 
or adjacent to the same watersheds associated with baseline impairments 
and impaired assessed waters. For estuaries, the number of unassessed 
waters estimated to be impaired (based on the assumption of 
proportional impairment) would not fit within the same watersheds 
associated with baseline impairments and impaired assessed waters. 
Therefore, EPA used GIS analysis to identify a buffer around the 
watersheds associated with baseline impairments and impaired assessed 
waters that would just include the estimated number of impaired 
unassessed waters. EPA found that a buffer size of 0.7 miles 
encompassed the estimated number of impaired unassessed waters. A 
smaller buffer (e.g., 0.5 mile) would not include enough unassessed 
waters. A larger buffer (e.g., 1 mile) would include too many 
unassessed waters. EPA then used this 0.7 mile buffer to identify the 
associated incremental watersheds that may need nonpoint source 
controls. EPA has estimated the acres of various land uses within these 
watersheds and reported as the upper bound in the Additional Unassessed 
Water column of Table VI(A)(2).

[[Page 74969]]



  Table VI(A)(2)--Summary of Land Use in Incrementally Impaired Watersheds for the Analysis of Costs Under the
                                                  Proposed Rule
                                                     [Acres]
----------------------------------------------------------------------------------------------------------------
                                                                           Additional
                 Land use type                   Assessed waters \1\  unassessed water \2\          Total
----------------------------------------------------------------------------------------------------------------
Agriculture...................................                15,312              0-22,828         15,312-38,140
Communications and Utilities..................                 3,337               0-3,315           3,337-6,652
Forest........................................               199,432             0-256,137       199,432-455,569
Industrial....................................                 2,025               0-6,703           2,025-8,729
Other.........................................                 9,276              0-11,306          9,276-20,582
Transportation Corridors......................                 9,177               0-3,636          9,177-12,813
Urban.........................................               128,787              0-86,508       128,787-215,295
Water.........................................               220,728             0-102,615       220,728-323,343
Wetlands......................................               196,545             0-322,355       196,545-518,899
                                               -----------------------------------------------------------------
    Total.....................................               784,619             0-815,403     784,619-1,600,022
----------------------------------------------------------------------------------------------------------------
\1\ Total acreage of 12-digit HUC watersheds surrounding the incrementally impaired WBIDs based on sufficient
  data, excluding watersheds for which EPA has already estimated a need for controls.
\2\ Acreage surrounding potential incrementally impaired unassessed waters not associated with baseline
  impairment or incremental impairment under the proposed rule based on sufficient data.

    The costs associated with the additional controls that would be 
necessary in the watersheds not already included in the cost analysis 
because of known incremental impaired waters will be included in the 
remainder of this section.
B. Point Source Costs
    Point sources of wastewater must have a National Pollution 
Discharge Elimination System (NPDES) permit to discharge into surface 
waters. EPA identified point sources potentially discharging nitrogen 
and phosphorus to estuaries, coastal waters, and south Florida inland 
flowing waters by evaluating the Integrated Compliance Information 
System-National Pollutant Discharge Elimination System (ICIS-NPDES) 
database. EPA identified all facilities with any permitted discharge to 
estuarine, coastal, and south Florida inland flowing waters with an 
existing effluent limit or monitoring requirement for nitrogen or 
phosphorus, as well as those with the same industry code as any point 
source with an identified nutrient monitoring requirement. This 
analysis identified 121 point sources as having the potential to 
discharge nitrogen and/or phosphorus. Table VI(B) summarizes the number 
of point sources with the potential to discharge nitrogen and/or 
phosphorus.

            Table VI(B)--NPDES-Permitted Wastewater Dischargers Potentially Affected by Proposed Rule
----------------------------------------------------------------------------------------------------------------
                                                                       Major           Minor
                       Discharger Category                          Dischargers     Dischargers        Total
                                                                        \a\             \b\
----------------------------------------------------------------------------------------------------------------
Municipal Wastewater............................................              53              31              84
Industrial Wastewater...........................................              19              18              37
                                                                 -----------------------------------------------
    Total.......................................................              72              49             121
----------------------------------------------------------------------------------------------------------------
\a\ Facilities discharging greater than one million gallons per day or likely to discharge toxic pollutants in
  toxic amounts.
\b\ Facilities discharging less than one million gallons per day and not likely to discharge toxic pollutants in
  toxic amounts.

1. Municipal Waste Water Treatment Plant (WWTP) Costs
    EPA considered the costs of known nitrogen and phosphorus treatment 
options for municipal WWTPs. Nitrogen and phosphorus removal 
technologies that are available can reliably attain annual average 
total nitrogen (TN) concentration of approximately 3.0 mg/L or less and 
annual average total phosphorus (TP) concentration of approximately 0.1 
mg/L or less.\211\ EPA considered wastewater treatment to these 
concentrations to be the target levels for the purpose of this 
analysis. The NRC suggested that there is uncertainty associated with 
this assumption because dischargers to impaired waters typically 
receiving WQBELs equal to the numeric water quality criteria (NRC, 
2012; p. 48). However, procedures for determining appropriate WQBELs 
include an evaluation of effluent quality and assimilative capacity of 
the receiving water. Specifically for nutrients, EPA found no 
implementation evidence in Florida to support the assumption that the 
criteria would be adopted as end-of-pipe limits. Instead, based on the 
State of Florida protocol \212\ and the examples from existing nutrient 
TMDLs, EPA assumed for this analysis that state implementation of the 
proposed rule will not result in criteria end-of-pipe effluent 
limitations for municipal WWTPs.
---------------------------------------------------------------------------

    \211\ U.S. EPA, 2008, ``Municipal Nutrient Removal Technologies 
Reference Document. Volume 1--Technical Report,'' EPA 832-R-08-006.
    \212\ Florida Department of Environmental Protection (FDEP). 
2006a. TMDL Protocol. Version 6.0. Task Assignment 003.03/05-003.
---------------------------------------------------------------------------

    The NPDES permitting authority determines the need for WQBELs for 
point sources on the basis of determining their reasonable potential to 
exceed water quality criteria. To determine reasonable potential on a 
facility-specific basis, data such as instream nutrient concentrations 
and low flow conditions would be necessary. However, because most WWTPs 
are likely to discharge nutrients at concentrations above applicable TN 
and/or TP criteria, EPA assumed that all WWTPs have reasonable 
potential to exceed the numeric criteria. The NRC supported this 
assumption.
    For municipal wastewater, EPA estimated costs to reduce effluent

[[Page 74970]]

concentrations to 3 mg/L or less for TN and 0.1 mg/L or less for TP 
using advanced biological nutrient removal (BNR). Although reverse 
osmosis and other treatment technologies may have the potential to 
reduce nitrogen and phosphorus concentrations even further, EPA 
believes that implementation of reverse osmosis applied on such a large 
scale has not been demonstrated.\213\ The NRC supported this assumption 
(NRC, 2012; p. 46) but said that in some instances, treatment to levels 
beyond the controls of advanced BNR would be required (NRC, 2012; p. 
48). Such levels have not been required for WWTPs by the State of 
Florida in the past, including for those WWTPs under TMDLs with 
nutrient targets comparable to the criteria in this proposed rule. EPA 
believes that should state-of-the-art BNR technology, together with 
other readily available and effective physical and chemical treatment 
(including chemical precipitation and filtration), fall short of 
compliance with permit limits associated with meeting the new numeric 
nutrient criteria, then it is reasonable to assume that entities would 
first seek out alternative compliance mechanisms such as reuse, site-
specific alternative criteria, variances, and designated use 
modifications. In addition, under a TMDL, FDEP could allocate greater 
load reductions to nonpoint sources based on baseline contributions and 
existing controls, thus resulting in fewer reductions required from 
point source dischargers. EPA acknowledges that if its assumptions 
about the availability of reuse, SSACs, variances and designated use 
changes are incorrect, then the costs presented here are 
underestimates.
---------------------------------------------------------------------------

    \213\ Treatment using reverse osmosis also requires substantial 
amounts of energy and creates disposal issues as a result of the 
large volume of concentrate generated.
---------------------------------------------------------------------------

    To estimate compliance costs for WWTPs, EPA identified current WWTP 
treatment capabilities using FDEP's Wastewater Facility Regulation 
(WAFR) database, and information obtained from NPDES permits and/or 
water quality monitoring reports. Table VI(B)(1) summarizes EPA's best 
estimate of the number of potentially affected municipal WWTPs that may 
require additional treatment for nitrogen and/or phosphorus to meet the 
numeric criteria supporting State designated uses.
---------------------------------------------------------------------------

    \214\ Florida Department of Environmental Protection (FDEP). 
2009. Wastewater Facility Information: Wastewater Facility 
Regulation (WAFR) database. http://www.dep.state.fl.us/water/wastewater/facinfo.htm. Accessed June 2009.

 Table VI(B)(1)--Summary of Potential for Additional Nutrient Controls for Municipal Wastewater Treatment Plants
                                                       \a\
----------------------------------------------------------------------------------------------------------------
                                                               Number of dischargers
                                 -------------------------------------------------------------------------------
         Discharge type             Additional      Additional      Additional    No incremental
                                   reduction in    reduction in    reduction in      controls          Total
                                   TN and TP \a\    TN only \b\     TP only \c\     needed \d\
----------------------------------------------------------------------------------------------------------------
Major...........................               7               0              22              22              51
Minor...........................              17               0               1              10              28
                                 -------------------------------------------------------------------------------
    Total.......................              24               0              23              32              79
----------------------------------------------------------------------------------------------------------------
Source: Based on treatment train descriptions in FDEP's Wastewater Facility Regulation database \214\ and
  permits, WLAs in TMDLs and existing regulations, assuming dischargers would have to install advanced BNR for
  compliance under the rule.
\a\ Includes dischargers without treatment processes capable of achieving the target levels or existing WLA for
  TN and TP, or for which the treatment train description is missing or unclear.
\b\ Includes dischargers with chemical precipitation only.
\c\ Includes dischargers with Modified Ludzack-Ettinge (MLE), four-stage Bardenpho, and BNR specified to achieve
  less than 3 mg/L, or those with WLA under a TMDL for TN only.
\d\ Includes dischargers with anaerobic-anoxic oxidation (A\2\/O), modified Bardenpho, modified University of
  Cape Town (UCT), oxidation ditches, or other BNR coupled with chemical precipitation, those with WLAs under a
  TMDL for both TN and TP, those discharging to waters on the 303(d) list for nutrients or DO, and those ocean
  dischargers covered under the Grizzle-Figg Act that will cease discharge completely by 2025.

    An EPA study provides unit cost estimates for BNR for various TN 
and TP performance levels.\215\ To estimate costs for WWTPs, EPA used 
the average capital and average operation and maintenance (O&M) unit 
costs for technologies that achieve an annual average of 3 mg/L or less 
for TN and/or 0.1 mg/L or less for TP. NRC noted that these unit costs 
were significantly lower than those estimated by the Florida Water 
Environment Association Utility Council (FWEAUC) and suggested to 
verify the unit costs against FWEAUC's unit costs. Multiplying these 
unit costs by facility flow reported in EPA's PCS database, EPA 
estimated that total costs could be approximately $44.1 million per 
year (2010 dollars).\216\
---------------------------------------------------------------------------

    \215\ USEPA. 2008. Municipal Nutrient Removal Technologies 
Reference Document. Volume 1--Technical Report. EPA 832-R-08-006. 
U.S. Environmental Protection Agency, Office of Wastewater 
Management, Municipal Support Division.
    \216\ Estimated capital costs annualized at 7% over 20 years, 
plus estimated annual O&M.
---------------------------------------------------------------------------

    EPA also conducted a sensitivity analysis to address the potential 
for dischargers under TMDLs that establish WLAs for TN or TP (and not 
both pollutants), such that incremental costs could be required under 
the proposed rule to control the other pollutant. The results of this 
analysis suggest a range of additional costs from $3.6 million to $5.6 
million annually (see section 5.3 of the Economic Analysis). Thus, 
estimated total cost could range from approximately $47.7 million to 
$49.7 million per year.
2. Industrial Point Source Costs
    Incremental costs for industrial dischargers are likely to be 
facility-specific and depend on process operations, existing treatment 
trains, and composition of waste streams. EPA identified 36 industrial 
dischargers potentially affected by the proposed rule. Of those, 4 are 
subject to an existing nutrient TMDL, and 4 discharge to waters 
currently listed as impaired. As with WWTPs, EPA assumed that costs to 
industrial dischargers under an existing nutrient TMDL with WLAs for 
both nitrogen and phosphorus and costs at facilities discharging to 
currently impaired waters are not attributable to this proposed rule 
because those costs would be incurred absent the rule (under the 
baseline).
    To estimate potential costs to the remaining 28 potentially 
affected industrial facilities (Table VI(B)(2)), EPA used effluent data 
for flows, TN, and TP

[[Page 74971]]

from Discharge Monitoring Reports in EPA's ICIS-NPDES database and 
other information in NPDES permits to determine whether or not they 
have reasonable potential to cause or contribute to an exceedance of 
the proposed criteria in this proposed rule. Because the numeric 
nutrient criteria are annual geometric means, EPA assumed that any 
discharger with an average TN or TP concentration greater than the 
proposed criterion would have reasonable potential. For those 
facilities with reasonable potential, EPA further analyzed their 
effluent data and estimated potential revised water quality based 
effluent limits (WQBELs) for TN and TP. If the data indicated that the 
facility would not be in compliance with the revised WQBEL, EPA 
estimated the additional nutrient controls those facilities would 
likely implement to allow receiving waters to meet designated uses and 
the costs of those controls. Although reverse osmosis and other 
treatment technologies have the potential to reduce nitrogen and 
phosphorus concentrations even further, EPA believes that 
implementation of reverse osmosis applied on such a large scale has not 
been demonstrated as likely or necessary.\217\ If BNR or other more 
conventional cost-effective treatment technologies would not meet the 
revised WQBELs, EPA believes it is reasonable to assume that entities 
would first seek out other available compliance mechanisms such as 
reuse, site-specific alternative criteria, variances, and designated 
use modifications. In addition, under a TMDL FDEP could allocate 
greater load reductions to nonpoint sources based on baseline 
contributions resulting in fewer reductions from point source 
dischargers.
---------------------------------------------------------------------------

    \217\ Treatment using reverse osmosis also requires substantial 
amounts of energy and creates disposal issues as a result of the 
large volume of concentrate that is generated.
---------------------------------------------------------------------------

    Using this method, EPA estimated that the potential costs for 
industrial dischargers could be approximately $15.2 million annually 
(2010 dollars). Note that a number of the dischargers would not incur 
incremental costs, while others would incur costs of implementing 
controls such as chemical precipitation, filtration, and/or BNR. NRC 
said that the use of similar unit costs for industrial flows as EPA had 
used for municipal waste water treatment facilities did not capture the 
higher costs associated with lower flows and therefore industrial costs 
are underestimated. The source EPA used to find unit costs included 
plant costs with low flows that EPA was able to compare to plant costs 
with high flows, as NRC suggested. EPA found no pattern for higher or 
lower costs and therefore did not change its unit costs. The NRC also 
suggested EPA should include costs for flow equalization at some 
industrial facilities. EPA does not have enough flow data to estimate 
flow equalization costs, but did use the 90th percentile flows as the 
basis for costs for dischargers with variable flows (see Cost 
Calculations for Industrial Dischargers). EPA considers the use of the 
90th percentile flow together with an allowance for contingencies to 
provide sufficient costs allowance to cover the cost of equalization 
should that be necessary at individual facilities.

                   Table VI(B)(2)--Potential Incremental Costs for Industrial Dischargers \a\
----------------------------------------------------------------------------------------------------------------
                                                                                     Number of     Total annual
                       Industrial category                         Total number     facilities    costs (million
                                                                   of facilities  with costs \b\     2010$/yr)
----------------------------------------------------------------------------------------------------------------
Chemicals and Allied Products...................................               1               0            $0.0
Electric Services...............................................               8               2             0.5
Food............................................................               2               1             0.2
Mining..........................................................               0               0             0.0
Other...........................................................              14               1             0.0
Pulp and Paper..................................................               3               3            14.5
                                                                 -----------------------------------------------
    Total.......................................................              28               7            15.2
----------------------------------------------------------------------------------------------------------------
\a\ May not add due to rounding.
\b\ In most cases, only a few facilities are projected to incur costs; others do not.

C. Non-Point Source Costs
    To estimate the potential incremental costs associated with 
controlling nitrogen and phosphorus pollution from non-point sources, 
EPA identified land areas near incrementally impaired waters using GIS 
analysis. EPA identified the 12-digit hydrologic units (HUC-12s) in 
Florida that contain, or in the case of coastal waters, surround an 
incrementally impaired WBID (WBIDs are GIS polygons for water 
assessment), and excluded those HUC-12s that are included in the 
baseline or cost analysis for in the Inland Rule. EPA then identified 
all the 12-digit HUCs that drain to any remaining unassessed WBIDs that 
may become incrementally impaired should they be assessed in the 
future. EPA then identified land uses in these HUCs using GIS analysis 
of data obtained from the State of Florida. By using the HUC-12 
delineation, EPA has addressed the NRC recommendation that EPA use the 
more refined HUC-12 delineation instead of the larger HUC-10 
delineation.
1. Costs for Urban Runoff
    EPA's GIS analysis indicates that urban land (excluding land for 
industrial uses covered under point sources) accounts for approximately 
128,800 acres to 215,300 acres of the land near incrementally impaired 
waters. EPA's analysis indicates that urban runoff is already regulated 
on a portion of this land under EPA's stormwater program requiring 
municipal separate storm sewer system (MS4) NPDES permits. Florida has 
a total of 27 large (Phase I) permitted MS4s serving greater than 
100,000 people and 132 small (Phase II) permitted MS4s serving fewer 
than 100,000 people. MS4 permits generally do not have numeric nutrient 
limits, but instead rely on implementation of BMPs to control 
pollutants in stormwater to the maximum extent practicable. Even those 
MS4s in Florida discharging to impaired waters or under a TMDL 
currently do not have numeric limits for any pollutant.
    In addition to EPA's stormwater program, several existing State 
rules are intended to reduce pollution from urban runoff and were 
included in the baseline for EPA's proposed rule. For

[[Page 74972]]

example, Florida's Urban Turf Fertilizer rule (administered by FDACS) 
requires a reduction in the amount of nitrogen and phosphorus that can 
be applied to lawns and recreational areas. Florida's 1982 stormwater 
rule (Chapter 403 of Florida statues) requires stormwater from new 
development and redevelopment to be treated prior to discharge through 
the implementation of BMPs. The rule also requires that older systems 
be managed as needed to restore or maintain the beneficial uses of 
waters, and that water management districts establish and implement 
other stormwater pollutant load reduction goals. In addition, the 
``Water Resource Implementation Rule'' (Chapter 62-40, F.A.C.) 
establishes that stormwater design criteria adopted by FDEP and the 
water management districts shall achieve at least 80% reduction of the 
average annual load of pollutants that cause or contribute to 
violations of water quality standards (95% reduction for outstanding 
natural resource waters). This rule sets design criteria for new 
development that is not based on impairment status of downstream 
waters. For NPDES permits, reasonable potential exists for any effluent 
concentrations above the criteria even if the water is attaining 
standards. Therefore, EPA assumed that post-1982 developed land already 
has controls to meet 80% reductions and only older developed land would 
need an incremental level of control. The rule also states that the 
pollutant loadings from older stormwater management systems shall be 
reduced as necessary to restore or maintain the designated uses of 
waters. As the proposed numeric nutrients criteria interpret the 
existing narrative criterion, EPA assumes any such reductions requiring 
costs are not a consequence of the proposed criteria. The NRC suggested 
that existing State rules are not being fully complied with and EPA 
should not consider them to be part of the baseline. EPA's assumption 
of compliance with the 1982 Stormwater Rule is based on FDEP's economic 
analysis indicating that post-1982 development would not need 
additional controls. Given the State's cyclical monitoring schedule, 
existing ambient monitoring data may not yet fully reflect nutrient 
reductions because the rule has only been in effect since July 2009. 
Other controls that target the quantity of stormwater runoff from low-
density residential land may not be as cost effective as the Urban Turf 
Fertilizer Rule. Thus, EPA did not estimate an incremental level of 
control to be needed for low-density residential land.
    Identifying water as impaired under the proposed rule could result 
in changes to MS4 NPDES permit requirements for urban runoff, so that 
Florida waters meet the proposed criteria. However, the combination of 
additional pollution controls required will likely depend on the 
specific nutrient reduction targets, the controls already in place, and 
the relative amounts of nitrogen and phosphorus pollution contained in 
urban runoff at each particular location. Because stormwater programs 
are usually implemented using an iterative approach--with the 
installation of controls followed by monitoring and re-evaluation--
estimating the complete set of pollution controls required to meet a 
particular water quality target would require detailed site-specific 
analysis.
    Although it is difficult to predict the complete set of potential 
additional stormwater controls that may be required to meet the numeric 
criteria that supports State designated uses in incrementally impaired 
waters, EPA estimated potential costs for additional treatment by 
assessing the amount of urban land that may require additional 
stormwater controls. FDEP has previously assumed that all urban land 
developed after adoption of Florida's 1982 stormwater rule would be in 
compliance with the Phase 1 rule and EPA believes it is reasonable to 
make a similar assumption for this proposed rule.\218\ Using this 
assumption, EPA used GIS analysis of land use data obtained from the 
State of Florida \219\ to identify the amount of remaining urban land 
located near incrementally impaired waters. For Phase I MS4s, EPA used 
a range of acres with 46,700 acres as the upper bound and zero acres as 
the lower bound, because Phase I MS4 urban areas already must implement 
controls to the ``maximum extent practicable.'' As such, these 
municipalities may not need to achieve additional reductions if 
existing requirements are already fully implemented. EPA similarly 
estimated ranges of acreage needing stormwater controls for Phase II 
MS4 areas, and non-MS4 urban areas. GIS analysis of land use data 
indicates that land in Phase II MS4 and non-MS4 urban areas are low 
density residential. For the urban land that is not low density 
residential, some additional structural BMPs may be necessary to comply 
with EPA's numeric nutrient criteria. Because nutrient reductions from 
low density residential land under the existing Urban Turf Fertilizer 
Rule are likely sufficient, and the State of Florida asserts that urban 
land developed after 1982 (77.9% of urban land) would not need 
additional controls for compliance with EPA's numeric nutrient 
criteria, EPA estimated that approximately 27,700 to 43,100 acres of 
Phase II MS4 urban land and 19,600 to 28,900 acres of urban land 
outside of MS4 areas may require additional stormwater controls to meet 
EPA's numeric nutrient criteria. The actual acreage may be somewhere 
within the range. Using this procedure, EPA estimated that 47,300 to 
118,700 acres may require additional stormwater controls.
---------------------------------------------------------------------------

    \218\ FDEP. 2010. FDEP Review of EPA's ``Preliminary Estimate of 
Potential Compliance Costs and Benefits Associated with EPA's 
Proposed Numeric Nutrient Criteria for Florida'': Prepared January 
2010 by the Environmental Protection Agency. Florida Department of 
Environmental Protection, Division of Environmental Assessment and 
Restoration.
    \219\ Florida Geographic Data Library, 2009.
---------------------------------------------------------------------------

    The cost of stormwater pollution controls can vary widely. FDEP 
tracks the cost of stormwater retrofit projects throughout the State 
that it has provided grant funding for.\220\ EPA estimated control 
costs based on the average unit costs, $19,300, across all projects 
from FDEP (2012c) to account for the mix of project types likely to be 
installed based on their current prevalence in grant funding throughout 
the state. The NRC suggested that higher pollutant removals may be 
obtained by more advanced stormwater control measures such as 
bioretention or other vegetated infiltration, which may be more costly 
than the current set of FDEP-funded projects. NRC (2009) indicates 
annual per-acre costs could range from $300 per acre to $3,500 per 
acre.\221\ EPA does not have the necessary information to exactly 
compare this source with EPA's average unit costs of $19,300, but 
believes EPA's unit costs are captured within the higher end of the 
range. Given that the costs may be comparable to the NRC suggested 
projects and the retrofit data is specific to projects that Florida has 
already implemented therefore making them more likely to be implemented 
for future projects, EPA continues to use costs from the Florida 
specific retrofit project data.
---------------------------------------------------------------------------

    \220\ FDEP. 2010. ``Appendix 3: Cost Analysis for Municipal 
Discharge using 30 Year Annualization and Florida MS4 Numeric 
Nutrient Criteria Cost Estimation,'' In: FDEP Review of EPA's 
``Preliminary Estimate of Potential Compliance Costs and Benefits 
Associated with EPA's Proposed Numeric Nutrient Criteria for 
Florida'': Prepared January 2010 by the Environmental Protection 
Agency. Florida Department of Environmental Protection, Division of 
Environmental Assessment and Restoration.
    \221\ NRC (2009) does not provide the discount rate, useful 
life, or annual O&M costs it uses to estimate annual costs.

---------------------------------------------------------------------------

[[Page 74973]]

    EPA multiplied the average capital costs per acre ($19,300) of the 
FDEP projects by the number of acres potentially requiring controls to 
estimate the potential incremental stormwater capital costs associated 
with the proposed rule. EPA then used FDEP's estimate of operation and 
maintenance (O&M) costs (at 5% of capital costs), and annualized 
capital costs using FDEP's discount rate of 7% over 20 years. This 
analysis indicates that urban runoff control costs could range from 
approximately $131.9 million to $330.9 million. Table VI(C)(2) 
summarizes these estimates.

                          Table VI(C)(1)--Estimated Incremental Urban Stormwater Costs
----------------------------------------------------------------------------------------------------------------
                                    Estimated acres
                                      potentially        Capital costs         O&M costs         Annual costs
         Urban land type           needing controls     (million $) \2\   (million $/yr) \3\  (million $/yr) \4\
                                          \1\
----------------------------------------------------------------------------------------------------------------
MS4 Phase I Urban...............            0-46,700           $0-$901.4            $0-$45.1         $0.0-$130.2
MS4 Phase II Urban..............       27,700-43,100         534.0-832.8           26.7-41.6          77.1-120.3
Non-MS4 Urban...................       19,600-28,900         379.2-557.5           19.0-27.9           54.8-80.5
                                 -------------------------------------------------------------------------------
    Total.......................      47,300-118,700       913.2-2,291.7          45.7-114.6         131.9-330.9
----------------------------------------------------------------------------------------------------------------
\1\ Phase I MS4s range represents implementation of BMPs to the MEP resulting in compliance with EPA's rule or
  controls needed on all pre-1982 developed land that is not low density residential; Phase II MS4s and urban
  land outside of MS4s represent controls needed on all pre-1982 developed land that is not low density
  residential. Assumes that up to 46% of land associated with unassessed waters would require controls.
\2\ Represents acres needing controls multiplied by median unit costs of stormwater retrofit costs from FDEP
  (2010b).
\3\ Represents 5% of capital costs.
\4\ Capital costs annualized at 7% over 20 years plus annual O&M costs.

2. Agricultural Costs
    EPA's GIS analysis of land use indicates that agriculture accounts 
for about 15,312 to 38,140 acres of land near incrementally impaired 
waters. This differs substantially from the Inland Rule where over 
800,000 acres of agricultural land use were identified in watersheds 
draining to potentially incrementally impaired WBIDs, because 
agriculture is a much more prevalent land use inland than near the 
coast. Agricultural runoff can be a source of nitrogen and phosphorus 
to estuaries, coastal waters and south Florida inland flowing waters 
through the application of fertilizer to crops and pastures and from 
animal wastes. For waters impaired by nitrogen and phosphorus 
pollution, the 1999 Florida Watershed Restoration Act established that 
agricultural BMPs should be the primary instrument to implement TMDLs. 
Thus, additional waters identified by the State as impaired under the 
proposed rule may result in State requirements or provisions to reduce 
the discharge of nitrogen and/or phosphorus to incrementally impaired 
waters through the implementation of BMPs. The NRC suggested that for 
Phase I, the incremental agricultural land area identified was likely 
underestimated. EPA addressed this finding by including land area 
associated with potentially impaired unassessed waters in this 
analysis.
    EPA estimated the potential costs of additional agricultural BMPs 
by evaluating land use data. BMP programs designed for each type of 
agricultural operation and their costs were taken from a study of 
agricultural BMPs to help meet TMDL targets in the Caloosahatchee 
River, St. Lucie River, and Lake Okeechobee watersheds. Three types of 
BMP programs were identified in this study. The first program, called 
the ``Owner Implemented BMP program,'' consists of a set of BMPs that 
land owners might implement without additional incentives. The second 
program, called the ``Typical BMP program,'' is the set of BMPs that 
land owners might implement under a reasonably funded cost share 
program or a modest BMP strategy approach. The third program, called 
the ``Alternative BMP program,'' is a more expensive program designed 
to supplement the ``Owner Implemented BMP program'' and ``Typical BMP 
program'' if additional reductions are necessary.
    The BMPs in the ``Owner Implemented BMP Program'' and ``Typical BMP 
Program'' are similar to the BMPs verified as effective by FDEP and 
adopted by FDACS. EPA did not find BMPs in the ``Alternative BMP 
Program'' similar to the BMPs in the FDACS BMP manual, despite the NRC 
suggestion that the ``Alternative BMP Program'' would be needed to meet 
NNC. EPA has also found no indication that the ``Alternative BMP 
Program,'' which includes edge-of-farm stormwater chemical treatment, 
has been implemented through TMDLs to meet water quality standards for 
nutrients in watersheds with significant contributions from agriculture 
(e.g., Lake Okeechobee). EPA also found that TMDLs cite the Florida 
Department of Agriculture and Consumer Services' (FDACS) BMP manual as 
a source of approved BMPs. Therefore, for purposes of this analysis, 
EPA believes it is reasonable to assume that nutrient controls for 
agricultural sources are best represented by the combination of the 
``Owner Implemented BMP Program'' and ``Typical BMP Program'' and not 
the more stringent ``Alternative BMP Program'' controls. This 
assumption corroborates EPA's intent for the nutrient criteria to 
provide the same level of protection as Florida's narrative criteria.
    Table VI(C)(2) summarizes the potential incremental costs of BMPs 
on agricultural lands in the watersheds of incrementally impaired 
estuaries, coastal waters and south Florida inland flowing waters for 
each agricultural category. This analysis indicates that incremental 
agricultural costs resulting from the proposed numeric nutrient 
criteria may be estimated at $0.3--$0.7 million per year.

[[Page 74974]]



                          Table VI(C)(2)--Potential Incremental Agricultural BMP Costs
----------------------------------------------------------------------------------------------------------------
                                                                ``Owner implemented BMP       Total ``Owner
                                           Area potentially          Program'' plus          Implemented BMP
        Agricultural category              needing controls     ''Typical BMP Program''  Program'' and ''Typical
                                             (acres) \a\         Unit Costs  (2010$/ac/    BMP  Program'' costs
                                                                        yr) \b\                 (2010$/yr)
----------------------------------------------------------------------------------------------------------------
Animal Feeding.......................                    20-39                   $18.56                $400-$700
Citrus...............................                        0                   156.80                       $0
Fruit Orchards \c\...................                      0-7                   156.80                $0-$1,100
Cow Calf Production, Improved                      1,115-4,568                    15.84          $17,700-$72,400
 Pastures............................
Cow Calf Production, Rangeland and                 1,145-1,995                     4.22            $4,800-$8,400
 Wooded Pasture......................
Cow Calf Production, Unimproved                      299-1,346                     4.22            $1,300-$5,700
 Pastures............................
Cropland and Pasture Land (general)              10,195-18,467                    27.26        $277,900-$503,300
 \d\.................................
Dairies..............................                        0                   334.40                       $0
Field Crop (Hayland) Production......                479-1,397                    18.56           $8,900-$25,900
Horse Farms..........................                   34-123                    15.84              $500-$1,900
Ornamental Nursery...................                      4-8                    70.00                $300-$600
Floriculture \e\.....................                        0                    70.00                       $0
Row Crop.............................                  228-246                    70.40          $16,100-$17,300
Sod/Turf Grass.......................                        0                    35.20                       $0
Other Areas \f\......................                565-1,069                    18.56          $10,500-$19,800
                                      --------------------------------------------------------------------------
    Total \g\........................            14,085-29,265  .......................        $338,300-$657,200
----------------------------------------------------------------------------------------------------------------
Note: Detail may not add to total due to independent rounding.
\a.\ Low end of range represents acres associated with impaired assessed waters assuming none of the unassessed
  waters would be impaired under the proposed rule; high end of range represent low end plus controls on the
  watersheds associated with impaired unassessed waters (estimated based on proportional impairment to assessed
  waters) for which EPA has not already identified a need for controls for baseline or impaired assessed waters.
  Based on GIS analysis of land use data from five water management districts (for entire State)
\b.\ Cost estimates from SWET (2008); representative of 2010 prices (personal communication with D. Bottcher,
  2010).
\c.\ Owner/typical BMP unit costs based on costs for citrus crops.
\d.\ Owner/typical BMP unit costs based on average costs for improved pastures, unimproved/wooded pasture, row
  crops, and field crops.
\e.\ Owner/typical BMP unit costs based on costs for ornamental nurseries.
\f.\ Includes FLUCCS Level 3 codes 2230, 2400, 2410, and 2540.
\g.\ Excludes land not in production.

3. Septic System Costs
    Some nutrient reductions from septic systems may be necessary for 
incrementally impaired waters to meet the numeric nutrient criteria in 
this proposed rule. Several nutrient-related TMDLs in Florida identify 
septic systems as a significant source of nitrogen and phosphorus 
pollution. Some of the ways to address pollution from septic systems 
may include greater use of inspection programs and repair of failing 
systems, upgrading existing systems to advanced nutrient removal, 
installation of decentralized cluster systems where responsible 
management entities would ensure reliable operation and maintenance, 
and connecting households and businesses to wastewater treatment 
plants. Because of the cost, time, and issues associated with new 
wastewater treatment plant construction, EPA assumed that the most 
likely strategy to reduce nutrient loads from septic systems would be 
to upgrade existing conventional septic systems to advanced nutrient 
removal systems.
    Septic systems in close proximity to surface waters are more likely 
to contribute nutrient loads to waters than distant septic systems. 
Florida Administrative Code provides that in most cases septic systems 
should be at least 75 feet from surface waters (F.A.C. 64e-6.005(3)). 
In addition, many of Florida's existing nutrient-related TMDLs identify 
nearby failing septic systems as contributing to nutrient impairments 
in surface waters.
    For this economic analysis, EPA assumed that some septic systems 
located near incrementally impaired waters may be required to upgrade 
to advance nutrient removal systems. However, the distance that septic 
systems can be safely located relative to these surface waters depends 
on a variety of site-specific factors. Because of this uncertainty, EPA 
assumed that septic systems located within 500 feet of any water (based 
on land use types) in watersheds containing or, in the case of coastal 
waters, surrounding incrementally impaired estuaries, coastal waters or 
south Florida inland flowing waters may need to be upgraded from 
conventional to advanced nutrient removal systems. The NRC agreed with 
the 500-ft threshold, but found that the exclusion of septic systems in 
springsheds is a deficiency of EPA's analysis. This proposed rule does 
not include criteria for springsheds.
    EPA used GIS analysis of data obtained from the Florida Department 
of Health \222\ that provides the location of active septic systems in 
the State to identify the potentially affected septic systems. This 
analysis yielded 5,952 to 10,784 active septic systems that may be 
affected by the proposed rule.
---------------------------------------------------------------------------

    \222\ FDOH. 2010. Bureau of Onsite Sewage GIS Data Files. 
Florida Department of Health, Division of Environmental Health. 
http://www.doh.state.fl.us/Environment/programs/EhGis/EhGisDownload.htm.
---------------------------------------------------------------------------

    EPA evaluated the cost of upgrading existing septic systems to 
advanced nutrient removal systems. The NRC also recommended that EPA 
consider permeable reactive barriers (PRB) in their technology costs 
and take into account any additional Florida-specific costs related to 
septic system upgrades (e.g., performance-based treatment systems, 
under Florida regulations, need to be designed by Florida licensed 
professional engineers). EPA included this technology in the cost 
analysis, resulting in the range of upgrade capital costs from $3,300 
to $8,800 per system. See the Economic Analysis for further detail. For 
O&M costs, EPA relied on a study that compared the annual costs 
associated with various septic system treatment technologies including 
conventional onsite sewage treatment and disposal system and fixed film 
activated sludge systems. Based on this study, EPA estimated the 
incremental

[[Page 74975]]

O&M costs for an advanced system to be $650 per year.\223\ In addition, 
homeowners would also incur a biennial permit fee of $100 (or $50 per 
year) for the upgraded system. Thus, based on annual O&M costs of $700 
and annualizing capital costs at 7% over 20 years, total annual costs 
could range from approximately $1,000 to $1,500 for each upgrade. EPA 
estimated the total annual costs of upgrading septic systems by 
multiplying this range of unit costs with the number of systems 
identified for upgrade. Using this method, total annual costs for 
upgrading septic systems in incrementally impaired watersheds could 
range from $6.0 million to $16.2 million.
---------------------------------------------------------------------------

    \223\ Chang, N., M. Wanielista, A. Daranpob, F. Hossain, Z. 
Xuan, J. Miao, S. Liu, Z. Marimon, and S. Debusk. 2010. Onsite 
Sewage Treatment and Disposal Systems Evaluation for Nutrient 
Removal. FDEP Project WM 928. Report Submitted to Florida 
Department of Environmental Protection, by Stormwater Management 
Academy, Civil, Environmental, and Construction Engineering 
Department, University of Central Florida.
---------------------------------------------------------------------------

D. Governmental Costs
    The proposed rule may result in the identification of incrementally 
impaired waters that would require the development of additional TMDLs. 
As the principal State regulatory agency implementing water quality 
standard, FDEP may incur costs associated with developing additional 
TMDLs. EPA's analysis identified 95 (based on the analysis of assessed 
waters) to 183 (including potentially impaired unassessed waters) 
incrementally impaired waters (WBIDs).
    Because current TMDLs for estuaries and coastal waters in Florida 
include an average of approximately four WBIDs each, EPA estimates that 
the State of Florida may need to develop and adopt approximately 24 to 
46 additional TMDLs. The NRC recommended applying Florida-specific TMDL 
development costs from a FDEP report detailing FDEP TMDL program costs. 
EPA used a range of costs from a 2001 EPA study that found the cost of 
developing a TMDL at different levels of aggregation and the Florida-
specific TMDL cost estimates are within this range of 
costs.224, 225 For this analysis, EPA used the estimates for 
a single cause of impairment and adjusted the costs to account for the 
possibility that a TMDL may need to address more than one pollutant 
(because most of the incrementally impaired waters in EPA's analysis 
exceeded the criteria for more than one pollutant). Under this 
assumption, EPA estimated the average TMDL cost to be approximately 
$47,000 ($28,000 on average for one pollutant, plus $6,000 on average 
for the other pollutant and adjusted to 2010 dollars). EPA also 
estimated unit costs based on the high end of typical TMDL development 
costs, plus an additional $6,000 for the second nutrient. Escalating to 
2010 dollars, the high range of TMDL development cost of $212,000. For 
24 to 46 TMDLs, total costs for incremental TMDL development could be 
$1.1 million to $10.2 million.
---------------------------------------------------------------------------

    \224\ USEPA. 2001. The National Costs of the Total Maximum Daily 
Load Program (Draft Report). EPA-841-D-01-003. U.S. Environmental 
Protection Agency, Office of Water, Washington DC.
    \225\ EPA did not adjust these estimates to account for 
potential reductions in resources required to develop TMDLs given 
that scientifically based numeric targets were developed as part of 
this proposed rule. Costs for these TMDLs are thus likely to be an 
overestimate.
---------------------------------------------------------------------------

    FDEP currently operates its TMDL schedule on a five-phase cycle 
that rotates through Florida's five basins over five years. Under this 
schedule, completion of TMDLs for high priority waters will take 9 
years; it will take an additional 5 years to complete the process for 
medium priority waters. Assuming all the incremental impairments are 
high priority and FDEP develops the new TMDLs over a 9-year period, 
annual costs could be $0.1 to $1.1 million.
    Should the State of Florida submit current TMDL targets as Federal 
site specific alternative criteria (SSAC) for EPA review and approval, 
EPA believes it is reasonable to assume that information used in the 
development of the TMDLs will substantially reduce the time and effort 
needed to provide a scientifically defensible justification for such 
applications. If EPA's assumption is incorrect and there were to be 
increased costs for the SSAC process, EPA expects that such cost 
underestimation would be cancelled out by continuing to include the 
costs of developing the scientifically based numeric targets for new 
TMDLs. Thus, EPA did not separately analyze any incremental costs 
associated with SSAC.
    Similarly, state and local agencies regularly monitor TN and TP in 
ambient waters. These data are the basis for the extensive IWR database 
maintained by the State of Florida. Because Florida is currently 
monitoring TN, TP, and chlorophyll-a concentrations in many waters, EPA 
assumed that the rule is unlikely to have a significant impact on costs 
related to water quality monitoring activities.
E. DPVs
    EPA is proposing several options for DPVs. For this analysis, EPA 
assumed that the DPVs equal the numeric nutrient criteria for the 
segment to which the stream discharges. If the State of Florida were to 
choose any of the other three proposed options for DPVs, then these 
costs may be over- or underestimated. To estimate whether the DPVs are 
being met, EPA used the same minimum data requirements (e.g., four data 
points in one year with at least one data point each in summer and 
winter seasons) and attainment criteria (no more than one exceedance in 
a three-year period) for evaluating the criteria. EPA used data from 
estuary pour points from any station within 500 feet of and within the 
same WBID as the pour point. For south Florida pour points EPA did not 
use the data from the technical report, but used all data from the WBID 
in which the pour point is located to assess impairment.
    For this analysis, EPA assumed that any WBID containing a pour 
point exceeding the criteria would be designated as impaired. EPA then 
identified the watersheds that contain or surround, in the case of 
coastal waters, those incrementally impaired WBIDs. See Appendix G of 
the economic analysis for more information.

Table VI(E). Summary of Potential Incremental Costs Associated with DPVs
------------------------------------------------------------------------
                                                               Total
                                                             potential
                     Source category                        incremental
                                                            annual cost
                                                             ($/year)
------------------------------------------------------------------------
Municipal Wastewater....................................     $29.4-$29.6
Industrial Dischargers..................................            $0.0
Urban Stormwater........................................     $9.5-$185.1
Agriculture.............................................       $0.5-$0.9
Septic Systems..........................................       $2.0-$3.0
Government/Program Implementation \1\...................       $0.0-$0.1
                                                         ---------------
    Total...............................................    $41.4-$218.6
------------------------------------------------------------------------
\1.\ Assuming 3 TMDLs for 13 WBIDs (approximately 4 WBIDs per TMDL) over
  a 9-year period.

F. Summary of Costs
    Table VI(F) summarizes EPA's estimates of potential incremental 
costs associated with additional State and private sector activities to 
meet the numeric criteria supporting State designated uses. Note, these 
total costs include costs associated with unassessed waters. Because of 
uncertainties in the pollution controls ultimately implemented by the 
State of Florida, actual costs may vary depending on the site-specific 
source reductions needed to meet the new numeric criteria.

[[Page 74976]]



    Table VI(F)--Summary of Potential Annual Costs \1\ (2010 dollars)
------------------------------------------------------------------------
                                                           Annual Cost
                         Sector                           (millions) \2\
------------------------------------------------------------------------
Municipal Wastewater...................................      $44.1-$49.7
Industrial Dischargers.................................            $15.2
Urban Stormwater.......................................    $131.9-$330.9
Agriculture............................................        $0.3-$0.7
Septic Systems.........................................       $6.0-$16.2
Government/Program Implementation (TMDLs)..............        $0.1-$1.1
Downstream Protection Values...........................     $41.4-$218.6
                                                        ----------------
    Total..............................................   $239.0--$632.4
------------------------------------------------------------------------
\1.\ Includes costs for assessed, unassessed, and DPVs.
\2.\ Low end of range represents estimated costs under the assumption
  that none of the unassessed waters would be impaired under the
  proposed rule; high end of range represents costs associated with the
  assumption of proportional impairment of unassessed waters.

    EPA also calculated the potential costs to Florida households. 
Given the uncertainty regarding the magnitude of the estimated costs 
ultimately borne by households, EPA sought to minimize that uncertainty 
with a selective though matched set of potential costs and potentially 
affected households. Although GIS analysis could be used to overlay 
maps of affected populations and facilities with incrementally impaired 
watersheds, a simpler more direct approach is to assume that all 
households in Florida are either served by a wastewater treatment plant 
or septic system, and pay taxes that would support implementation 
programs conducted by the State. In addition, because the sector with 
the largest costs is urban stormwater, EPA decided to include this 
sector as well. Thus, EPA decided to look at the total costs of the two 
rules across all households in Florida. Also, given the cost-pass-
through of agriculture costs and industrial costs to consumers outside 
the State of Florida, EPA did not consider them for the estimate of 
average costs per households in Florida. Therefore, EPA also calculated 
the total costs for municipal wastewater and stormwater controls, 
septic upgrades, and government/program implementation costs for both 
the proposed rule and the Inland rule and compared this sum to the 
total number of households in the State. This may underestimate actual 
household costs if some costs are not borne equally by households 
statewide, but instead are concentrated within the watersheds for which 
controls are needed. EPA's total estimated annual cost for compliance 
with this proposed rule, and the Inland rule, represents $44 to $108 
per household per year for both rules across all households in Florida. 
This equals $3.60 to $9 per month per household in Florida. Please 
refer to Section 13 in the Economic Analysis for more information.
    EPA also considered whether the potential costs of this proposed 
rule could result in employment impacts. Environmental regulations can 
both increase and decrease employment, and whether the net effect is 
positive or negative depends on many factors. See Chapter 13 of the 
Economic Analysis for further discussion.
G. Benefits
    Since elevated concentrations of nutrients in surface waters can 
result in adverse ecological effects, human health impacts, and 
negative economic impacts, EPA expects the proposed numeric nutrient 
criteria to result in significant ecological, human health, and 
economic benefits to Florida. For example, excess nutrients in water 
can cause eutrophication, which can lead to harmful (sometimes toxic) 
algal blooms, loss of rooted plants, and decreased dissolved oxygen. In 
turn, these results can lead to adverse impacts on aquatic life, 
fishing, swimming, wildlife watching, camping, and drinking water. 
Excess nutrients can also cause: nuisance surface scum, reduced food 
for herbivorous wildlife, fish kills, alterations in fish communities, 
and unsightly shorelines that can decrease property values. Excessive 
nutrient loads can also lead to harmful algal blooms (HABs), which can 
cause a range of adverse human health effects including dermal, 
gastrointestinal, neurological, and respiratory problems, and in severe 
cases, may even result in fatalities.
    Nutrient impairment is currently a major concern for many bays, 
estuaries, and coasts within the United States, and is particularly 
severe for many Florida waters. FDEP's 2010 report identifies 
approximately 569 square miles (364,160 acres) of estuaries (about 23 
percent of assessed estuarine area) and 102 square miles (65,280 acres) 
of coastal waters (about 1.5 percent of assessed coastal waters) as 
impaired by nutrients. These impairments may have a significant impact 
on the value of environmental goods and services provided by the 
affected waterbodies. For example, the losses of submerged aquatic 
vegetation resulting from eutrophication can have significant economic 
impacts. In 2009, Florida seagrass communities supported an estimated 
harvest of $23 million for just six species of commercial fish and 
shellfish.\226\
---------------------------------------------------------------------------

    \226\ Crist, C. 2010. Seagrass Awareness Month. Proclamation by 
the Governor Charlie Crist of the State of Florida. Florida 
Department of Environmental Protection.
---------------------------------------------------------------------------

    In Florida's environment and economy, the tourism-focused goods and 
services provided by its bays, estuaries, and coastal waters are 
particularly valuable. The tourism industry of Florida's nearshore 
counties contributes approximately $12.4 billion (2004 dollars) to the 
State's economy annually.\227\ Coral reefs are especially important 
contributors to Florida's tourism sector. Reef-related recreational 
expenditures on activities such as snorkeling, scuba diving, fishing, 
and glass bottom boating in four counties in southeastern Florida for a 
one year period in 2000-2001 totaled $5.4 billion.\228\
---------------------------------------------------------------------------

    \227\ NOEP. 2006. Coastal Economy Data. National Ocean Economics 
Program. www.oceaneconomics.org/Market/coastal/coastalEcon.asp.
    \228\ Johns, G.M., V.R. Leeworthy, F.W. Bell, and M.A. Bonn. 
2001. Socioeconomic Study of Reefs in SoutheastFlorida. Final Report 
prepared by Hazen and Sawyer, Hollywood, FL, for Broward County, 
Palm Beach County, Miami-Dade County, Monroe County, Florida Fish 
and Wildlife Conservation Commission, and National Oceanic and 
Atmospheric Administration.
---------------------------------------------------------------------------

    The proposed rule will help reduce nitrogen and phosphorus 
concentrations in Florida's estuaries, coastal waters and south Florida 
inland flowing waters. In turn, this reduction will improve ecological 
function and prevent further degradation that can result in substantial 
economic benefits to Florida citizens. EPA's economic analysis document 
describes in detail many of the potential benefits associated with 
meeting the numeric criteria in the proposed rule for nitrogen and 
phosphorus, including reduced human health risks, ecological benefits 
and functions, improved recreational opportunities, aesthetic 
enhancements and others.
1. Monetized Benefits Estimates
    Reducing nutrient concentrations will increase services provided by 
water resources to recreational users. For example, some coastal waters 
that are not usable for recreation may become available following 
implementation of the rule, thereby expanding recreation options for 
residential users and tourists. Other waters that are available for 
recreation can become more attractive for users by making recreational 
trips more enjoyable. Individuals may also take trips more frequently 
if they enjoy their recreational activities more. In addition to 
recreational improvements, the

[[Page 74977]]

proposed rule is expected to generate nonuse benefits from bequest, 
altruism, and existence motivations. Individuals may value the 
knowledge that water quality is being maintained, ecosystems are being 
protected, and populations of individual species are healthy, 
independently from any use value.
    EPA used a benefits transfer function based on meta-analysis of 
surface water valuation studies to estimate both use and nonuse 
benefits from improvements in surface water. This approach is based on 
the method used to quantify nonmarket benefits in the 2009 
Environmental Impact and Benefits Assessment for Final Effluent 
Guidelines and Standards for the Construction and Development Category 
(EPA, 2009), also used in the economic analysis of the Inland Rule. The 
approach quantifies benefits based on reach-specific baseline water 
quality and the estimated change in pollutant concentrations. The 
approach translates reductions in nutrients into an indicator of 
overall water quality (via a ``water quality ladder,'' or WQL) and 
values these improvements in terms of household willingness to pay 
(WTP) for the types of uses (e.g., as fishing and swimming) that are 
supported by different water quality levels.
    EPA calculated the baseline WQL scores for incrementally affected 
waters by comparing the water quality observations to criteria. For 
coastal waters, only Chl-a criteria are applicable, and for these 
waters, EPA estimated baseline WQL scores based on Chl-a exceedances 
only. For other marine waters, EPA developed estimates of baseline 
water quality based on comparing the water quality observations to the 
applicable criteria in the following order: (1) Exceedances of proposed 
TN criteria; (2) exceedances of proposed TP criteria; and (3) 
exceedances of proposed Chl-a criteria. The baseline WQL score is based 
on the percent exceedance of the applicable criterion value. EPA 
assumes all incrementally impaired waters will meet the proposed 
criteria and estimated the potential changes for each waterbody. EPA 
estimated that up to 163 unassessed WBIDs may be incrementally 
impaired, but water quality data for these waters are not available. To 
estimate the potential benefits associated with these potentially 
impaired unassessed waters, EPA estimated the same percent exceedance 
of the potentially impaired assessed waters. Because EPA's estimates of 
monetized benefits only reflect the water quality improvements for 
WBIDs, and not HUC-12s, these potential benefits are underestimated and 
should not be directly compared to costs, which include HUC-12 costs. 
EPA then estimated monetized benefit values of these water quality 
improvements using benefits transfer based on a meta-regression of 45 
studies that value water quality improvements in surface waters. Using 
the meta-analysis EPA estimated a household WTP function with 
independent variables that characterize (1) the underlying study and 
methodology used, (2) demographic and other characteristics of the 
surveyed populations, (3) geographic region and scale, and (4) resource 
characteristics and improvements. More details on the meta-analysis can 
be found in the Economic Analysis.
    Using this function, EPA derived household WTP estimates for both 
full time and part time residents of the State. EPA estimated that 
seasonal residents live in the State for approximately four months of 
the year; therefore EPA weighted household WTP values for seasonal 
residents by one third. EPA then weighted household WTP estimates by 
the percentage of State water miles that are expected to improve. EPA 
estimated total benefits by multiplying the weighted household WTP 
value with the total number of benefiting households. EPA estimated the 
number of full time residents by dividing the total State population by 
average household size for the State as provided by the U.S. Census 
Bureau's 2010 American Community Survey (U.S. Census Bureau, 2010). The 
number of part-time households in Florida is based on Smith and House 
(2006), who used survey data to estimate the number, timing, and 
duration of temporary moves to Florida at peak seasons. EPA used the 
Smith and House (2006) results and U.S. Census Bureau (2010) statistics 
on household size to estimate the number of part-time households in 
Florida. Total monetized benefits, including monetized benefits of 
unassessed waters, may be in the range from $39.0 million to $53.4 
million annually, as shown in Table VI(F). The range reflects EPA's 
assumptions regarding the location of unassessed waters that might be 
incrementally impaired.
    Because EPA's estimates of monetized benefits only reflect use and 
nonuse values associated with water quality improvements to Florida 
residents (full and part time), these potential benefits are likely 
underestimated compared to costs. The population considered in the 
benefits analysis of the rule does not include households outside of 
Florida that may also hold values for water resources in the State of 
Florida. Even if per household values for out-of-State residents are 
small, they may be significant in the aggregate if these values are 
held by a substantial number of out-of-State households. EPA notes that 
four times as many out-of-State and foreign tourists visit the State's 
saltwater beaches each year as State residents do. Not including out-
of-State residents in the analysis is likely to result in an 
underestimation of the total benefits of improved water quality. 
Although these monetized benefits estimates do not account for all 
potential economic benefits arising from the proposed rule, they help 
to demonstrate the economic importance of restoring and protecting 
Florida waters from the impacts of nitrogen and phosphorus pollution.

    Table VI(F)--Potential Annual State Benefits Associated With the
      Proposed Criteria Including Unassessed Waters (2010 dollars)
------------------------------------------------------------------------
                                     Average benefit     Total benefits
           WTP estimate                per mile \1\      (millions) \2\
------------------------------------------------------------------------
Lower 5% Bound....................             $8,200        $17.2-$23.6
Mean..............................             18,500        $39.0-$53.4
Upper 95% Bound...................             34,500        $72.5-$99.4
------------------------------------------------------------------------
\1\ Total benefits divided by 2,102 incrementally impaired assessed
  miles.
\2\ Benefits per mile times the number of incrementally impaired miles;
  based on between 2,102 and 2,882 potentially improved miles. The low
  end of the range represents assessed waters only, and the high end of
  the range includes unassessed waters.


[[Page 74978]]

VII. Statutory and Executive Order Reviews

A. Executive Orders 12866 (Regulatory Planning and Review) and 13563 
(Improving Regulation and Regulatory Review)

    Under Executive Order 12866 (58 FR 51735, October 4, 1993), this 
action is a ``significant regulatory action.'' Accordingly, EPA 
submitted this action to the Office of Management and Budget (OMB) for 
review under Executive Orders 12866 and 13563 (76 FR 3821, January 21, 
2011) and any changes made in response to OMB recommendations have been 
documented in the docket for this action. This proposed rule does not 
establish any requirements directly applicable to regulated entities or 
other sources of nitrogen and phosphorus pollution. Moreover, existing 
narrative water quality criteria in State law already require that 
nutrients not be present in waters in concentrations that cause an 
imbalance in natural populations of flora and fauna in estuaries and 
coastal waters in Florida and in south Florida inland flowing waters.

B. Paperwork Reduction Act

    This action does not impose any direct new information collection 
burden under the provisions of the Paperwork Reduction Act, 44 U.S.C. 
3501 et seq. Actions to implement these standards may entail additional 
paperwork burden. Burden is defined at 5 CFR 1320.3(b). This action 
does not include any information collection, reporting, or record-
keeping requirements.

C. Regulatory Flexibility Act

    The Regulatory Flexibility Act (RFA) generally requires an agency 
to prepare a regulatory flexibility analysis of any rule subject to 
notice and comment rulemaking requirements under the Administrative 
Procedure Act or any other statute unless the agency certifies that the 
rule will not have significant economic impact on a substantial number 
of small entities. Small entities include small businesses, small 
organizations, and small governmental jurisdictions.
    For purposes of assessing the impacts of this action on small 
entities, small entity is defined as: (1) A small business as defined 
by the Small Business Administration's (SBA) regulations at 13 CFR 
121.201; (2) a small governmental jurisdiction that is a government of 
a city, county, town, school district or special district with a 
population of less than 50,000; and (3) a small organization that is 
any not-for-profit enterprise that is independently owned and operated 
and is not dominant in its field.
    Under the CWA water quality standards program, states must adopt 
water quality standards for their waters and must submit those water 
quality standards to EPA for review and approval or disapproval; if the 
Agency disapproves a state standard and the state does not adopt 
appropriate revisions to address EPA's disapproval, EPA must promulgate 
standards consistent with the statutory and regulatory requirements. 
EPA also has the authority to promulgate water quality standards in any 
case where the Administrator determines that a new or revised standard 
is necessary to meet the requirements of the CWA. State standards 
approved by EPA (or EPA-promulgated standards) are implemented through 
various water quality control programs including the NPDES program, 
which limits discharges to navigable waters except in compliance with 
an NPDES permit. The CWA requires that all NPDES permits include any 
limits on discharges that are necessary to meet applicable water 
quality standards.
    Thus, under the CWA, EPA's promulgation of water quality standards 
establishes standards that the State of Florida implements through the 
NPDES permit process. The State has discretion in developing discharge 
limits, as needed to meet the standards. This proposed rule does not 
itself establish any requirements that are applicable to small 
entities. As a result of this action, the State of Florida will need to 
ensure that permits it issues include any limitations on discharges 
necessary to comply with the standards established in the final rule. 
In doing so, the State will have a number of choices associated with 
permit writing (e.g., relating to compliance schedules, variances, 
etc.). While Florida's implementation of the rule may ultimately result 
in new or revised permit conditions for some dischargers, including 
small entities, EPA's action, by itself, does not impose any of these 
requirements on small entities; that is, these requirements are not 
self-implementing. Thus, I certify that this rule will not have a 
significant economic impact on a substantial number of small entities.

D. Unfunded Mandates Reform Act

    Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), Public 
Law 104-4, establishes requirements for Federal agencies to assess the 
effects of their regulatory actions on state, local, and tribal 
governments and the private sector. Under section 202 of the UMRA, EPA 
generally must prepare a written statement, including a cost-benefit 
analysis, for proposed and final rules that include a ''Federal 
mandate'' that may result in expenditures to state, local, and Tribal 
governments, in the aggregate, or to the private sector, of $100 
million or more in any one year. A ``Federal mandate,'' is any 
provision in federal statute or regulation that would impose an 
enforceable duty on State, local or Tribal governments or the private 
sector.\229\ Before promulgating an EPA rule for which a written 
statement is needed under section 202, section 205 of the UMRA 
generally requires EPA to identify and consider a reasonable number of 
regulatory alternatives and adopt the least costly, most cost-effective 
or least burdensome alternative that achieves the objectives of the 
rule. The provisions of section 205(a) do not apply when they are 
inconsistent with law. Moreover, section 205(b) allows EPA to adopt an 
alternative other than the least costly, most cost-effective or least 
burdensome alternative if the Administrator publishes with the final 
rule an explanation of why that alternative was not adopted. Before EPA 
establishes any regulatory requirements that may significantly or 
uniquely affect small governments, including Tribal governments, it 
must have developed under section 203 of the UMRA a small government 
agency plan. The plan must provide for notifying potentially affected 
small governments, enabling officials of affected small governments to 
have meaningful and timely input in the development of EPA regulatory 
proposals with significant Federal intergovernmental mandates, and 
informing, educating, and advising small governments on compliance with 
the regulatory requirements.
---------------------------------------------------------------------------

    \229\ A ``Federal mandate'' does not include conditions of 
Federal assistance and generally does not include duties arising 
from participation in a voluntary Federal program.
---------------------------------------------------------------------------

    This proposed rule contains no Federal mandates (under the 
regulatory provisions of Title II of the UMRA) for state, local, or 
Tribal governments or the private sector. As these water quality 
criteria are not self-implementing, EPA's proposed rule does not 
regulate or affect any entity. Because this proposed rule does not 
regulate or affect any entity, it therefore is not subject to the 
requirements of sections 202 and 205 of UMRA.
    EPA determined that this proposed rule contains no regulatory 
requirements that might significantly or uniquely affect small 
governments.

[[Page 74979]]

Moreover, water quality standards, including those promulgated here, 
apply broadly to dischargers and are not uniquely applicable to small 
governments. Thus, this proposed rule is not subject to the 
requirements of section 203 of UMRA.

E. Executive Order 13132 (Federalism)

    This action does not have federalism implications. It will not have 
substantial direct effects on the States, on the relationship between 
the national government and the States, or on the distribution of power 
and responsibilities among the various levels of government, as 
specified in Executive Order 13132. EPA's authority and responsibility 
to promulgate Federal water quality standards when state standards do 
not meet the requirements of the CWA is well established and has been 
used on various occasions in the past. The proposed rule would not 
substantially affect the relationship between EPA and the States and 
Territories, or the distribution of power or responsibilities between 
EPA and the various levels of government. The proposed rule would not 
alter Florida's considerable discretion in implementing these water 
quality standards. Further, this proposed rule would not preclude 
Florida from adopting water quality standards that EPA concludes meet 
the requirements of the CWA, either before or after promulgation of the 
final rule, which would eliminate the need for Federal standards. Thus, 
Executive Order 13132 does not apply to this proposed rule.
    Although section 6 of Executive Order 13132 does not apply to this 
action, EPA communicated with the State of Florida to discuss the 
Federal rulemaking process. In the spirit of Executive Order 13132, and 
consistent with EPA policy to promote communications between EPA and 
State and local governments, EPA specifically solicits comment on this 
proposed rule from State and local officials.

F. Executive Order 13175 (Consultation and Coordination With Indian 
Tribal Governments)

    Subject to the Executive Order 13175 (65 FR 67249, November 9, 
2000) EPA may not issue a regulation that has tribal implications, that 
imposes substantial direct compliance costs, and that is not required 
by statute, unless the Federal government provides the funds necessary 
to pay the direct compliance costs incurred by Tribal governments, or 
EPA consults with tribal officials early in the process of developing 
the proposed regulation and develops a tribal summary impact statement. 
EPA has concluded that this action may have tribal implications. 
However, the rule will neither impose substantial direct compliance 
costs on tribal governments, nor preempt Tribal law.
    In the State of Florida, there are two Indian tribes, the Seminole 
Tribe of Florida and the Miccosukee Tribe of Indians of Florida, with 
flowing waters. Both tribes have been approved for treatment in the 
same manner as a state (TAS) status for CWA sections 303 and 401 and 
have federally-approved water quality standards in their respective 
jurisdictions. These tribes are not subject to this proposed rule. 
However, this rule may impact the tribes because the numeric criteria 
for Florida will apply to waters adjacent to the tribal waters.
    EPA consulted with Tribal officials early in the process of 
developing this regulation to permit them to have meaningful and timely 
input into its development. At a consultation teleconference held on 
March 1, 2012, EPA summarized the available information regarding this 
proposed rule, and requested comments on the proposal and its possible 
effects on tribal waters. Information relevant to this proposed action 
and the related Tribal consultation is posted on the EPA Tribal Portal 
site at http://www.epa.gov/tribal/consultation/index.htm. EPA 
specifically solicits additional comment on this proposed rule from 
tribal officials.

G. Executive Order 13045 (Protection of Children From Environmental 
Health and Safety Risks)

    This action is not subject to EO 13045 (62 FR 19885, April 23, 
1997) because it is not economically significant as defined in EO 
12866, and because the Agency believes that this rule will result in 
the reduction of environmental health and safety risks that could 
present a disproportionate risk to children.

H. Executive Order 13211 (Actions That Significantly Affect Energy 
Supply, Distribution, or Use)

    This rule is not a ``significant energy action'' as defined in 
Executive Order 13211, ``Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use'' (66 FR 28355 
(May 22, 2001)), because it is not likely to have a significant adverse 
effect on the supply, distribution, or use of energy.

I. National Technology Transfer Advancement Act of 1995

    Section 12(d) of the National Technology Transfer and Advancement 
Act of 1995 (``NTTAA''), Public Law 104-113, section 12(d) (15 U.S.C. 
272 note) directs EPA to use voluntary consensus standards in its 
regulatory activities unless to do so would be inconsistent with 
applicable law or otherwise impractical. Voluntary consensus standards 
are technical standards (e.g., materials specifications, test methods, 
sampling procedures, and business practices) that are developed or 
adopted by voluntary consensus standards bodies. The NTTAA directs EPA 
to provide Congress, through OMB, explanations when the Agency decides 
not to use available and applicable voluntary consensus standards.
    This proposed rulemaking does not involve technical standards. 
Therefore, EPA is not considering the use of any voluntary consensus 
standards.

J. Executive Order 12898 (Federal Actions To Address Environmental 
Justice in Minority Populations and Low-Income Populations)

    Executive Order (EO) 12898 (Feb. 16, 1994) establishes Federal 
executive policy on environmental justice. Its main provision directs 
Federal agencies, to the greatest extent practicable and permitted by 
law, to make environmental justice part of their mission by identifying 
and addressing, as appropriate, disproportionately high and adverse 
human health or environmental effects of their programs, policies, and 
activities on minority populations and low-income populations in the 
United States.
    EPA has determined that this proposed rule does not have 
disproportionately high and adverse human health or environmental 
effects on minority or low-income populations because it would afford a 
greater level of protection to both human health and the environment if 
these numeric nutrient criteria are promulgated for Class I, Class II 
and Class III waters in the State of Florida.

List of Subjects in 40 CFR Part 131

    Environmental protection, Water quality standards, Nitrogen and 
phosphorus pollution, Nutrients, Florida.

    Dated: November 30, 2012.
Lisa P. Jackson,
Administrator.
    For the reasons set out in the preamble, EPA proposes to amend 40 
CFR part 131 as follows:

PART 131--WATER QUALITY STANDARDS

    1. The authority citation for part 131 continues to read as 
follows:


[[Page 74980]]


    Authority: 33 U.S.C. 1251 et seq.

Subpart D--[Amended]

    2. Section 131.45 is added to read as follows:


Sec.  131.45  Water Quality Standards for the State of Florida's 
Estuaries, Coastal Waters, and South Florida Inland Flowing Waters

    (a) Scope. This section promulgates numeric criteria for nitrogen 
and phosphorus pollution for Class I, Class II, and Class III waters in 
the State of Florida. This section also contains provisions for site-
specific alternative criteria.
    (b) Definitions.--(1) Canal means a trench, the bottom of which is 
normally covered by water with the upper edges of its two sides 
normally above water.
    (2) Coastal water means all marine waters that have been classified 
as Class II (Shellfish Propagation or Harvesting) or Class III 
(Recreation, Propagation and Maintenance of a Healthy, Well-Balanced 
Population of Fish and Wildlife) water bodies pursuant to Section 62-
302.400, F.A.C., extending to three nautical miles from shore that are 
not classified as estuaries.
    (3) Estuary means predominantly marine regions of interaction 
between rivers and nearshore ocean waters, where tidal action and river 
flow mix fresh and salt water. Such areas include bays, mouths of 
rivers, and lagoons that have been classified as Class II (Shellfish 
Propagation or Harvesting) or Class III (Recreation, Propagation and 
Maintenance of a Healthy, Well-Balanced Population of Fish and 
Wildlife) water bodies pursuant to Section 62-302.400, F.A.C., 
excluding wetlands.
    (4) Everglades Agricultural Area (EAA) means those lands described 
in Florida Statute Section 373.4592 (1994) subsection (15).
    (5) Everglades Protection Area (EvPA) means Water Conservation 
Areas 1 (which includes the Arthur R. Marshall Loxahatchee National 
Wildlife Refuge), 2A, 2B, 3A, and 3B, and the Everglades National Park.
    (6) Inland flowing waters means inland predominantly fresh surface 
water streams that have been classified as Class I (Potable Water 
Supplies) or Class III (Recreation, Propagation and Maintenance of a 
Healthy, Well-Balanced Population of Fish and Wildlife) water bodies 
pursuant to Section 62-302.400, F.A.C., excluding wetlands (e.g., 
sloughs).
    (7) Marine Lake means a slow-moving or standing body of marine 
water that occupies an inland basin that is not a stream, spring, or 
wetland.
    (8) Predominantly fresh waters means surface waters in which the 
chloride concentration at the surface is less than 1,500 milligrams per 
liter.
    (9) Predominantly marine waters means surface waters in which the 
chloride concentration at the surface is greater than or equal to 1,500 
milligrams per liter.
    (10) South Florida inland flowing waters means inland flowing 
waters in the South Florida Nutrient Watershed Region, which 
encompasses the waters south of Lake Okeechobee, the Caloosahatchee 
River (including Estero Bay) watershed, and the St. Lucie watershed.
    (11) State means the State of Florida, whose transactions with the 
U.S. EPA in matters related to 40 CFR 131.45 are administered by the 
Secretary, or officials delegated such responsibility, of the Florida 
Department of Environmental Protection (FDEP), or successor agencies.
    (12) Stream means a free-flowing, predominantly fresh surface water 
in a defined channel, and includes rivers, creeks, branches, canals, 
freshwater sloughs, and other similar water bodies.
    (13) Surface water means water upon the surface of the earth, 
whether contained in bounds created naturally or artificially or 
diffused. Water from natural springs shall be classified as surface 
water when it exits from the spring onto the Earth's surface.
    (14) Tidal creek means a relatively small coastal tributary with 
variable salinity that lies at the transition zone between terrestrial 
uplands and the open estuary.
    (c) Criteria for Florida Waters.
    (1) Criteria for Estuaries.
    The applicable total nitrogen (TN), total phosphorus (TP), and 
chlorophyll a criteria for estuaries are shown in Table 1.

                             Table 1--EPA's Numeric Criteria for Florida's Estuaries
                                  [In geographic order Northwest to Northeast]
----------------------------------------------------------------------------------------------------------------
                                                                                 Proposed Criteria
                                                                 -----------------------------------------------
                     Segment                        Segment ID                                    Chl-a*  ([mu]g/
                                                                    TN*  (mg/L)     TP*  (mg/L)         L)
----------------------------------------------------------------------------------------------------------------
Perdido Bay:
    Upper Perdido Bay...........................            0101            0.59           0.042             5.2
    Big Lagoon..................................            0102            0.26           0.019             4.9
    Central Perdido Bay.........................            0103            0.47           0.031             5.8
    Lower Perdido Bay...........................            0104            0.34           0.023             5.8
Pensacola Bay:
    Blackwater Bay..............................            0201            0.53           0.022             3.9
    Upper Escambia Bay..........................            0202            0.43           0.025             3.7
    East Bay....................................            0203            0.50           0.021             4.2
    Santa Rosa Sound............................            0204            0.34           0.018             4.1
    Lower Escambia Bay..........................            0205            0.44           0.023             4.0
    Upper Pensacola Bay.........................            0206            0.40           0.021             3.9
    Lower Pensacola Bay.........................            0207            0.34           0.020             3.6
    Santa Rosa Sound............................            0208            0.33           0.020             3.9
    Santa Rosa Sound............................            0209            0.36           0.020             4.9
Choctawhatchee Bay:
    Eastern Choctawhatchee Bay..................            0301            0.47           0.025             8.1
    Central Choctawhatchee Bay..................            0302            0.36           0.019             3.8
    Western Choctawhatchee Bay..................            0303            0.21           0.012             2.4
St. Andrews Bay:
    East Bay....................................            0401            0.31           0.014             4.6
    St. Andrews Sound...........................            0402            0.14           0.009             2.3
    Eastern St. Andrews Bay.....................            0403            0.24           0.021             3.9

[[Page 74981]]

 
    Western St. Andrews Bay.....................            0404            0.19           0.016             3.1
    Southern St. Andrews Bay....................            0405            0.15           0.013             2.6
    North Bay 1.................................            0406            0.22           0.012             3.7
    North Bay 2.................................            0407            0.22           0.014             3.7
    North Bay 3.................................            0408            0.21           0.016             3.4
    West Bay....................................            0409            0.23           0.022             3.8
St. Joseph Bay:
    St. Joseph Bay..............................            0501            0.25           0.018             3.8
Apalachicola Bay:
    St. George Sound............................            0601            0.53           0.019             3.6
    Apalachicola Bay............................            0602            0.51           0.019             2.7
    East Bay....................................            0603            0.76           0.034             1.7
    St. Vincent Sound...........................            0605            0.52           0.016            11.9
    Apalachicola Offshore.......................            0606            0.30           0.008             2.3
Alligator Harbor:
    Alligator Harbor............................            0701            0.36           0.011             2.8
    Alligator Offshore..........................            0702            0.33           0.009             3.1
    Alligator Offshore..........................            0703            0.33           0.009             2.9
Ochlockonee Bay \+\:
    Ochlockonee-St. Marks Offshore..............            0825            0.79           0.033             2.7
    Ochlockonee Offshore........................            0829            0.47           0.019             1.9
    Ochlockonee Bay.............................            0830            0.66           0.037             1.8
    St. Marks River Offshore....................            0827            0.51           0.022             1.7
    St. Marks River.............................            0828            0.55           0.030             1.2
Big Bend/Apalachee Bay \+\:
    Econfina Offshore...........................            0824            0.59           0.028             4.6
    Econfina....................................            0832            0.55           0.032             4.4
    Fenholloway.................................            0822            1.15           0.444             1.9
    Fenholloway Offshore........................            0823            0.48           0.034            10.3
    Steinhatchee-Fenholloway Offshore...........            0821            0.40           0.023             4.1
    Steinhatchee River..........................            0819            0.67           0.077             1.0
    Steinhatchee Offshore.......................            0820            0.34           0.018             3.5
    Steinhatchee Offshore.......................            0818            0.39           0.032             4.8
Suwannee River \+\:
    Suwannee Offshore...........................            0817            0.78           0.049             5.2
Springs Coast \+\:
    Waccasassa River Offshore...................            0814            0.38           0.019             3.9
    Cedar Keys..................................            0815            0.32           0.019             4.1
    Crystal River...............................            0812            0.35           0.013             1.3
    Crystal-Homosassa Offshore..................            0813            0.36           0.013             2.1
    Homosassa River.............................            0833            0.47           0.032             1.9
    Chassahowitzka River........................            0810            0.32           0.010             0.7
    Chassahowitzka River Offshore...............            0811            0.29           0.009             1.7
    Weeki Wachee River..........................            0808            0.32           0.010             1.6
    Weeki Wachee Offshore.......................            0809            0.30           0.009             2.1
    Pithlachascotee River.......................            0806            0.50           0.022             2.4
    Pithlachascotee Offshore....................            0807            0.32           0.011             2.5
    Anclote River...............................            0804            0.48           0.037             4.7
    Anclote Offshore............................            0805            0.31           0.011             3.2
    Anclote Offshore South......................            0803            0.29           0.008             2.6
Lake Worth Lagoon/Loxahatchee:
    North Lake Worth Lagoon.....................            1201            0.55           0.067             4.7
    Central Lake Worth Lagoon...................            1202            0.57           0.089             5.3
    South Lake Worth Lagoon.....................            1203            0.48           0.034             3.6
    Lower Loxahatchee...........................            1301            0.68           0.028             2.7
    Middle Loxahatchee..........................            1302            0.98           0.044             3.9
    Upper Loxahatchee...........................            1303            1.25           0.072             3.6
St. Lucie:
    Lower St. Lucie.............................            1401            0.58           0.045             5.3
    Middle St. Lucie............................            1402            0.90           0.120             8.4
    Upper St. Lucie.............................            1403            1.22           0.197             8.9
Indian River Lagoon:
    Mosquito Lagoon.............................            1501            1.18           0.078             7.5
    Banana River................................            1502            1.17           0.036             5.7
    Upper Indian River Lagoon...................            1503            1.63           0.074             9.2
    Upper Central Indian River Lagoon...........            1504            1.33           0.076             9.2
    Lower Central Indian River Lagoon...........            1505            1.12           0.117             8.7
    Lower Indian River Lagoon...................            1506            0.49           0.037             4.0

[[Page 74982]]

 
Halifax River:
    Upper Halifax River.........................            1601            0.75           0.243             9.4
    Lower Halifax River.........................            1602            0.63           0.167             9.6
Guana, Tolomato, Matanzas, Pellicer:
    Upper GTMP..................................            1701            0.77           0.144             9.5
    Lower GTMP..................................            1702            0.53           0.108             6.1
Lower St. Johns River:
    Lower St. Johns River.......................            1801            0.75           0.095             2.5
    Trout River.................................            1802            1.09           0.108             3.6
    Trout River.................................            1803            1.15           0.074             7.7
Nassau River:
    Lower Nassau................................            1901            0.33           0.113             3.2
    Middle Nassau...............................            1902            0.40           0.120             2.4
    Upper Nassau................................            1903            0.75           0.125             3.4
St. Marys River:
    Lower St. Marys River.......................            2002            0.27           0.045             3.0
    Middle St. Marys River......................            2003            0.44           0.036             2.7
----------------------------------------------------------------------------------------------------------------
\1\ Chlorophyll a is defined as corrected chlorophyll, or the concentration of chlorophyll a remaining after the
  chlorophyll degradation product, phaeophytin a, has been subtracted from the uncorrected chlorophyll a
  measurement.
* For a given water body, the annual geometric mean of TN, TP, or chlorophyll a, concentrations shall not exceed
  the applicable criterion concentration more than once in a three-year period.
\+\ In these four areas (collectively referred to as the ``Big Bend region''), coastal and estuarine waters are
  combined. Criteria for the Big Bend region apply to the coastal and estuarine waters in that region.

    (2) Criteria for Tidal Creeks.
    The applicable total nitrogen (TN), total phosphorus (TP), and 
chlorophyll a criteria for predominantly marine tidal creeks are shown 
in Sec.  131.45(c)(1), Table 1. The applicable TN and TP criteria for 
predominantly freshwater tidal creeks are shown in Table 2.

 Table 2--EPA's Numeric Criteria for Florida's Predominantly Freshwater
                              Tidal Creeks
------------------------------------------------------------------------
                                                     Instream protection
                                                       value criteria
             Nutrient watershed region             ---------------------
                                                     TN  (mg/   TP  (mg/
                                                       L) *       L) *
------------------------------------------------------------------------
Panhandle West \a\................................       0.67       0.06
Panhandle East \b\................................       1.03       0.18
North Central \c\.................................       1.87       0.30
West Central \d\..................................       1.65       0.49
Peninsula \e\.....................................       1.54       0.12
------------------------------------------------------------------------
Watersheds pertaining to each Nutrient Watershed Region (NWR) were based
  principally on the NOAA coastal, estuarine, and fluvial drainage areas
  with modifications to the NOAA drainage areas in the West Central and
  Peninsula Regions that account for unique watershed geologies. For
  more detailed information on regionalization and which WBIDs pertain
  to each NWR, see the Technical Support Document.
\a\ Panhandle West region includes: Perdido Bay Watershed, Pensacola Bay
  Watershed, Choctawhatchee Bay Watershed, St. Andrews Bay Watershed,
  Apalachicola Bay Watershed.
\b\ Panhandle East region includes: Apalachee Bay Watershed, and
  Econfina/Steinhatchee Coastal Drainage Area.
\c\ North Central region includes the Suwannee River Watershed.
\d\ West Central region includes: Peace, Myakka, Hillsborough, Alafia,
  Manatee, Little Manatee River Watersheds, and small, direct Tampa Bay
  tributary watersheds south of the Hillsborough River Watershed.
\e\ Peninsula region includes: Waccasassa Coastal Drainage Area,
  Withlacoochee Coastal Drainage Area, Crystal/Pithlachascotee Coastal
  Drainage Area, small, direct Tampa Bay tributary watersheds west of
  the Hillsborough River Watershed, Sarasota Bay Watershed, small,
  direct Charlotte Harbor tributary watersheds south of the Peace River
  Watershed, Caloosahatchee River Watershed, Estero Bay Watershed,
  Kissimmee River/Lake Okeechobee Drainage Area, Loxahatchee/St. Lucie
  Watershed, Indian River Watershed, Daytona/St. Augustine Coastal
  Drainage Area, St. Johns River Watershed, Nassau Coastal Drainage
  Area, and St. Marys River Watershed.
* For a given water body, the annual geometric mean of TN or TP
  concentrations shall not exceed the applicable criterion concentration
  more than once in a three-year period.

    (3) Criteria for Marine Lakes.
    The applicable total nitrogen (TN), total phosphorus (TP) and 
chlorophyll a criteria for marine lakes are shown in Table 3.

                           Table 3--EPA's Numeric Criteria for Florida's Marine Lakes
----------------------------------------------------------------------------------------------------------------
                                                           EPA final       EPA final TN and TP criteria  [range]
   Long term average lake color \a\ and alkalinity     Chl[dash]a \b,*\  ---------------------------------------
                                                            [mu]g/L            TN  mg/L            TP  mg/L
----------------------------------------------------------------------------------------------------------------
Colored lakes \c\...................................                  20                1.27                0.05
                                                                                 [1.27-2.23]         [0.05-0.16]

[[Page 74983]]

 
Clear lakes, high alkalinity \d\....................                  20                1.05                0.03
                                                                                 [1.05-1.91]         [0.03-0.09]
Clear lakes, low alkalinity \e\.....................                   6                0.51                0.01
                                                                                 [0.51-0.93]         [0.01-0.03]
----------------------------------------------------------------------------------------------------------------
\a\ Platinum-cobalt units (PCU) assessed as true color free from turbidity
\b\ Chl-a is defined as corrected chlorophyll, or the concentration of chl-a remaining after the chlorophyll
  degradation product, phaeophytin a, has been subtracted from the uncorrected chl-a measurement.
\c\ Long-term color > 40 PCU and alkalinity > 20 mg/L CaCO3
\d\ Long-term color <= 40 PCU and alkalinity > 20 mg/L CaCO3
\e\ Long-term color <= 40 PCU and alkalinity <= 20 mg/L CaCO3
* For a water body, the annual geometric mean of chl-a, TN or TP concentrations shall not exceed the applicable
  criterion concentration more than once in a three-year period.

    (4) Criteria for Coastal Waters.
    The applicable chlorophyll a criteria for coastal waters are shown 
in Table 4.

                          Table 4--EPA's Numeric Criteria for Florida's Coastal Waters
----------------------------------------------------------------------------------------------------------------
                                                 Coastal                                    ChlorophyllRS-a \1\*
               Coastal region                  segment \+\        Approximate location            (mg/m\3\)
----------------------------------------------------------------------------------------------------------------
Panhandle..................................               1  Alabama border...............                  2.41
                                                          2  Pensacola Bay Pass...........                  2.57
                                                          3  .............................                  1.44
                                                          4  .............................                  1.16
                                                          5  .............................                  1.06
                                                          6  .............................                  1.04
                                                          7  .............................                  1.14
                                                          8  Choctawhatchee Bay Pass......                  1.23
                                                          9  .............................                  1.08
                                                         10  .............................                  1.09
                                                         11  .............................                  1.11
                                                         12  .............................                  1.18
                                                         13  .............................                  1.45
                                                         14  St. Andrews Bay Pass.........                  1.74
                                                         15  St. Joseph Bay Pass..........                  2.75
                                                         16  .............................                  2.39
                                                         17  Southeast St. Joseph Bay.....                  3.47
West Florida Shelf.........................              18  .............................                  3.96
                                                         19  Tampa Bay Pass...............                  4.45
                                                         20  .............................                  3.37
                                                         21  .............................                  3.25
                                                         22  .............................                  2.95
                                                         23  .............................                  2.79
                                                         24  .............................                  2.98
                                                         25  .............................                  3.24
                                                         26  Charlotte Harbor.............                  4.55
                                                         27  .............................                  4.22
                                                         28  .............................                  3.67
                                                         29  .............................                  4.16
                                                         30  .............................                  5.70
                                                         31  .............................                  4.54
                                                         32  .............................                  4.03
                                                         33  Fort Myers...................                  4.61
Atlantic Coast.............................              34  Biscayne Bay.................                  0.92
                                                         35  .............................                  0.26
                                                         36  .............................                  0.26
                                                         37  .............................                  0.24
                                                         38  .............................                  0.21
                                                         39  .............................                  0.21
                                                         40  .............................                  0.20
                                                         41  .............................                  0.20
                                                         42  .............................                  0.21
                                                         43  .............................                  0.25
                                                         44  .............................                  0.57
                                                         45  St. Lucie Inlet..............                  1.08
                                                         46  .............................                  1.42

[[Page 74984]]

 
                                                         47  .............................                  1.77
                                                         48  .............................                  1.55
                                                         49  .............................                  1.44
                                                         50  .............................                  1.53
                                                         51  .............................                  1.31
                                                         52  .............................                  1.40
                                                         53  .............................                  1.80
                                                         54  Canaveral Bight..............                  2.73
                                                         55  .............................                  2.33
                                                         56  .............................                  2.28
                                                         57  .............................                  2.06
                                                         58  .............................                  1.92
                                                         59  .............................                  1.76
                                                         60  .............................                  1.72
                                                         61  .............................                  2.04
                                                         62  .............................                  1.92
                                                         63  .............................                  1.86
                                                         64  .............................                  1.95
                                                         65  .............................                  2.41
                                                         66  .............................                  2.76
                                                         67  .............................                  2.80
                                                         68  .............................                  3.45
                                                         69  Nassau Sound.................                  3.69
                                                         70  .............................                  3.78
                                                         71  Georgia border...............                  4.22
----------------------------------------------------------------------------------------------------------------
\1\ ChlorophyllRS-a is remotely sensed calculation of chlorophyll a concentrations.
* For a given water body, the annual geometric mean of the chlorophyll a concentration shall not exceed the
  applicable criterion concentration more than once in a three-year period.
\+\ Please see TSD for location of Coastal Segments (Volume 2: Coastal Waters, Section 1.3).

    (5) Criteria for South Florida Inland Flowing Waters.
    The applicable criteria for south Florida inland flowing waters 
that flow into downstream estuaries include the downstream protection 
value (DPV) for total nitrogen (TN) and total phosphorus (TP) derived 
pursuant to the provisions of Sec.  131.45(c)(6). These criteria are 
not applicable to waters within the lands of the Miccosukee and 
Seminole Tribes, the Everglades Protection Area (EvPA), or the 
Everglades Agricultural Area (EAA).
    (6) Criteria for Protection of Downstream Estuaries and South 
Florida marine waters. (i) A downstream protection value (DPV) for 
stream tributaries that flow into a downstream estuary or south Florida 
marine water (i.e., downstream water) is the allowable concentration of 
total nitrogen (TN) and/or total phosphorus (TP) applied at the point 
of entry into the downstream water. The applicable DPV for any stream 
flowing into a downstream water shall be determined pursuant to 
paragraphs (c)(6)(ii), (iii), (iv), or (v) of this section. The methods 
available to derive DPVs should be considered in the order listed. 
Contributions from stream tributaries upstream of the point of entry 
location must result in attainment of the DPV at the point of entry 
into the downstream water. If the DPV is not attained at the point of 
entry into the downstream water, then the collective set of streams in 
the upstream watershed does not attain the DPV, which is an applicable 
water quality criterion for the water segments in the upstream 
watershed. The State or EPA may establish additional DPVs at upstream 
tributary locations that are consistent with attaining the DPV at the 
point of entry into the downstream water. The State or EPA also have 
discretion to establish DPVs to account for a larger watershed area 
(i.e., include waters beyond the point of reaching water bodies that 
are not streams as defined by this rule).
    (ii) In instances where available data and/or resources provide for 
use of a scientifically defensible and protective system-specific 
application of water quality simulation models with results that 
protect the designated uses and meet all applicable numeric nutrient 
criteria for the downstream water, the State or EPA may derive the DPV 
for TN and TP from use of a system-specific application of water 
quality simulation models. The State or EPA may designate the wasteload 
and/or load allocations from a TMDL established or approved by EPA as 
DPV(s) if the allocations from the TMDL will protect the downstream 
water's designated uses and meet all applicable numeric nutrient 
criteria for the downstream water.
    (iii) When the State or EPA has not derived a DPV for a stream 
pursuant to paragraph (c)(6)(ii) of this section, and where a reference 
condition approach is used to derive the downstream water's TN, TP and 
chlorophyll a criteria, then the State or EPA may derive the DPV for TN 
and TP using a reference condition approach based on TN and TP 
concentrations from the stream pour point, coincident in time with the 
data record from which the downstream receiving water segment TN and TP 
criteria were developed, and using the same data screens and reference 
condition approach as were applied to the downstream water's data.
    (iv) When the State or EPA has not derived a DPV pursuant to 
paragraph (c)(6)(ii) or (c)(6)(iii) of this section, then the State or 
EPA may derive the DPV for TN and TP using dilution models based on the 
relationship between salinity and nutrient concentrations.
    (v) When the State or EPA has not derived a DPV pursuant to 
paragraph (c)(6)(ii), (c)(6)(iii), or (c)(6)(iv) of this section, then 
the DPV for TN and TP is the applicable TN and TP criteria for the 
receiving segment of the downstream water as described in Sec.  
131.45(c)(1), or as described in Section 62-302.532(a)-(h), F.A.C. for 
downstream waters where EPA-approved State criteria apply.

[[Page 74985]]

    (vi) The State and EPA shall maintain a record of DPVs they derive 
based on the methods described in paragraphs (c)(6)(ii), (iii), (iv), 
and (v) of this section, as well as a record supporting their 
derivation, and make such records available to the public. The State 
and EPA shall notify one another and provide a supporting record within 
30 days of derivation of DPVs pursuant to paragraphs (c)(6)(i), (ii), 
(iii), (iv), or (v) of this section. DPVs derived pursuant to these 
paragraphs do not require EPA approval under Clean Water Act Sec.  
303(c) to take effect.
    (d) Applicability. (1) The criteria in paragraphs (c)(1) through 
(6) of this section apply to certain Class I, Class II, and Class III 
waters in Florida, and apply concurrently with other applicable water 
quality criteria, except when:
    (i) State water quality standards contain criteria that are more 
stringent for a particular parameter and use;
    (ii) The Regional Administrator determines that site-specific 
alternative criteria apply pursuant to the procedures in paragraph (e) 
of this section; or
    (iii) The State adopts and EPA approves a water quality standards 
variance to the Class I, Class II, or Class III designated use pursuant 
to Sec.  131.13 that meets the applicable provisions of State law and 
the applicable Federal regulations at Sec.  131.10.
    (2) The criteria established in this section are subject to the 
State's general rules of applicability in the same way and to the same 
extent as are the other Federally-adopted and State-adopted numeric 
criteria when applied to the same use classifications.
    (e) Site-specific Alternative Criteria.
    (1) The Regional Administrator may determine that site-specific 
alternative criteria shall apply to specific surface waters in lieu of 
the criteria established in paragraph (c) of this section. Any such 
determination shall be made consistent with Sec.  131.11.
    (2) To receive consideration from the Regional Administrator for a 
determination of site-specific alternative criteria, an entity shall 
submit a request that includes proposed alternative numeric criteria 
and supporting rationale suitable to meet the needs for a technical 
support document pursuant to paragraph (e)(3) of this section. The 
entity shall provide the State a copy of all materials submitted to 
EPA, at the time of submittal to EPA, to facilitate the State providing 
comments to EPA. Site-specific alternative criteria may be based on one 
or more of the following approaches.
    (i) Replicate the process for developing the estuary criteria in 
paragraph (c)(1) of this section.
    (ii) Replicate the process for developing the tidal creek criteria 
in paragraph (c)(2) of this section.
    (iii) Replicate the process for developing the marine lake criteria 
in paragraph (c)(3) of this section.
    (iv) Replicate the process for developing the coastal criteria in 
paragraph (c)(4) of this section.
    (v) Replicate the process for developing the south Florida inland 
flowing water criteria in paragraph (c)(5) of this section.
    (vi) Conduct a biological, chemical, and physical assessment of 
water body conditions.
    (vii) Use another scientifically defensible approach protective of 
the designated use.
    (3) For any determination made under paragraph (e)(1) of this 
section, the Regional Administrator shall, prior to making such a 
determination, provide for public notice and comment on a proposed 
determination. For any such proposed determination, the Regional 
Administrator shall prepare and make available to the public a 
technical support document addressing the specific surface waters 
affected and the justification for each proposed determination. This 
document shall be made available to the public no later than the date 
of public notice issuance.
    (4) The Regional Administrator shall maintain and make available to 
the public an updated list of determinations made pursuant to paragraph 
(e)(1) of this section as well as the technical support documents for 
each determination.
    (5) Nothing in this paragraph (e) shall limit the Administrator's 
authority to modify the criteria in paragraph (c) of this section 
through rulemaking.
    (f) Effective date. This section is effective [date 60 days after 
publication of final rule].
[FR Doc. 2012-30117 Filed 12-17-12; 8:45 am]
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