[Federal Register Volume 77, Number 243 (Tuesday, December 18, 2012)]
[Proposed Rules]
[Pages 74985-75005]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-30114]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 131

[EPA-HQ-OW-2009-0596; FRL9678-6]
RIN 2040-AF39


Water Quality Standards for the State of Florida's Streams and 
Downstream Protection Values for Lakes: Remanded Provisions

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency (EPA or Agency) is 
proposing a rule that addresses an order by the U.S. District Court for 
the Northern District of Florida from February 18, 2012, which remanded 
to EPA two portions of its numeric water quality standards for 
nutrients in Florida that were promulgated and published on December 6, 
2010. For this proposal, EPA is re-proposing the same numeric nutrient 
criteria for total nitrogen (TN) and total phosphorus (TP) for Florida 
streams not covered by EPA-approved State rulemaking, as included in 
EPA's final rule, with further explanation of how the proposed numeric 
streams criteria will ensure the protection of the Florida's Class I 
and III designated uses. EPA is also proposing default approaches 
available for use when modeling cannot be performed to derive 
downstream protection values (DPVs) that will ensure the attainment and 
maintenance of the numeric nutrient criteria that protect Florida's 
lakes. The default approaches would be applicable to streams that flow 
into unimpaired lakes, but could also be used for streams that flow 
into impaired lakes.

DATES: EPA will accept public comments on this proposed rule until 
February 1, 2013. Because of EPA's obligation to sign a notice of final 
rulemaking on or before August 31, 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-
2009-0596, 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-2009-0596.
    4. Hand Delivery: EPA Docket Center, EPA West Room 3334, 1301 
Constitution Avenue NW., Washington, DC 20004, Attention Docket ID No. 
EPA-HQ-OW-2009-0596. 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-2009-
0596. EPA's policy is that all comments received will be included in 
the public docket without change and may be made available online at

[[Page 74986]]

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: For information concerning this 
rulemaking, contact Mario Sengco, U.S. EPA Headquarters, Office of 
Water, Mailcode: 4305T, 1200 Pennsylvania Avenue NW., Washington, DC 
20460; telephone numbers: 202-566-2676 or 202-564-1649; fax number: 
202-566-9981; email address: sengco.mario@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. How can I get copies of this document and other related 
information?
II. Background
    A. Nitrogen and Phosphorus Pollution in the United States and 
the State of Florida
    B. Statutory and Regulatory Background
    C. Water Quality Criteria
    D. EPA Determination Regarding Florida and EPA's Rulemaking
    E. EPA Promulgation of the Final Rule and Subsequent Litigation
    F. Florida Adoption of Numeric Nutrient Criteria and EPA 
Approval
III. Numeric Criteria for Flowing Waters and Downstream Protection 
of Lakes in the State of Florida
    A. Introduction
    B. EPA Derivation of Numeric Nutrient Criteria for Streams
    C. Reference Condition Approach for Developing Numeric Nutrient 
Criteria for Streams
    D. Proposed Numeric Criteria for the State of Florida's Streams
    E. Proposed Numeric Criteria To Ensure the Downstream Protection 
of the State of Florida's Lakes
    F. Applicability of Criteria When Final
IV. Under what conditions will Federal standards be either not 
finalized or withdrawn?
V. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review and 
Executive Order 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 Minority Populations and Low-Income 
Populations)

I. General Information

A. Executive Summary

    Florida is known for its abundant and aesthetically beautiful 
natural resources, in particular its water resources. Florida's water 
resources are very important to its economy, for example, its $6.5 
billion freshwater fishing industry.\1\ However, nitrogen and 
phosphorus pollution has contributed to severe water quality 
degradation in the State of Florida. 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,\2\ FDEP describes widespread 
water quality impairment in Florida due to nitrogen and phosphorus 
pollution. FDEP's 2012 report identifies approximately 1,918 miles of 
rivers and streams (about 14 percent of assessed river and stream 
miles), 378,435 acres of lakes (about 31 percent of assessed lake 
acres), 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. Despite FDEP's intensive efforts to diagnose, 
evaluate and address nitrogen and phosphorus pollution, substantial and 
widespread water quality degradation from nitrogen and phosphorus 
pollution has continued and remains a significant problem.
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    \1\ Florida Fish and Wildlife Conservation Commission. 2010. The 
economic impact of freshwater fishing in Florida. http://www.myfwc.com/CONSERVATION/Conservation_ValueofConservation_EconFreshwaterImpact.htm. Accessed August 2010.
    \2\ 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 Clean Water Act (CWA) 
section 303(c)(4)(B) that new or revised water quality standards (WQS) 
in the form of numeric water quality criteria are necessary to protect 
the designated uses from nitrogen and phosphorus pollution that Florida 
has set for its Class I and Class III waters.\3\ The Agency considered 
(1) the State's documented unique and threatened ecosystems, (2) the 
large number of impaired waters due to existing nitrogen and phosphorus 
pollution, and (3) the challenge associated with growing nitrogen and 
phosphorus pollution associated with expanding urbanization, continued 
agricultural development, and a significantly increasing population 
that the U.S. Census estimates is expected to grow over 75% between 
2000 and

[[Page 74987]]

2030.\4\ EPA also reviewed the State's regulatory accountability 
system, which represents a synthesis of both technology-based standards 
and point source control authority, as well as authority to establish 
enforceable controls for nonpoint source activities.
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    \3\ Class I is designated for potable water supplies. Class III 
is designated for recreation, propagation and maintenance of a 
healthy, well-balanced population of fish and wildlife. F.A.C. 
Section 62-302.400.
    \4\ U.S. Census Bureau, Population Division, Interim State 
Population Projections, 2005. http://www.census.gov/population/projections/SummaryTabA1.pdf.
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    In December 2009, 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, 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.
    On December 6, 2010 (75 FR 75762), EPA's final rule \5\ was 
published in the Federal Register and codified at 40 CFR 131.43. The 
final rule established numeric nutrient criteria, or numeric limits on 
the amount of nitrogen and phosphorus allowed in Florida's waters 
(i.e., lakes, streams and springs) while still protecting applicable 
designated uses.
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    \5\ Federal Register, Vol. 75, No. 233, 75762, December 6, 2010. 
Water Quality Standards for the State of Florida's Lakes and Flowing 
Waters.
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    Following the rule's publication, EPA soon received 12 challenges 
from a range of plaintiffs that included environmental groups, the 
State Department of Agriculture, the South Florida Water Management 
District and several industry/discharger groups. The challenges alleged 
that EPA's determination and final rule were arbitrary, capricious, an 
abuse of discretion, and not in accordance with the law. The U.S. 
District Court for the Northern District of Florida consolidated the 
suits and held oral argument on January 9, 2012.
    On February 18, 2012, the court issued its ruling.\6\ While 
upholding EPA's determination and much of its rule, the court 
invalidated EPA's numeric nutrient criteria for Florida's streams 
because it found that EPA had either ``aimed for the wrong target'' or 
not sufficiently explained what it did in aiming for the right target. 
The court observed that Florida's existing narrative criterion states, 
in relevant part, that ``nutrient concentrations of a body of water 
[must not] be altered so as to cause an imbalance in natural 
populations of aquatic flora or fauna.'' Fla. Admin. Code r. 62-
302.530(47)(b). Based on that narrative criterion, as implemented by 
FDEP, the court found that the correct target would be to avoid any 
harmful increase in nutrient levels, as opposed to any increase in 
nutrient levels. The court found that EPA had apparently derived stream 
numeric nutrient criteria to prevent any increase in nutrient levels, 
and had thus aimed at the wrong target. If EPA had derived stream 
numeric nutrient criteria to prevent any harmful increase, the court 
found that EPA had not provided a sufficient explanation for its 
action. For similar reasons, the court also invalidated EPA's default 
DPV for streams where the downstream lake is attaining its lake numeric 
nutrient criteria. Hence, the court ordered EPA to either ``sign for 
publication a proposed rule, or sign for publication a final rule, that 
sets numeric nutrient criteria for Florida streams'' by May 21, 2012. 
As to the DPV where a lake is attaining its lake numeric criteria, the 
same order applies unless EPA files a notice by May 21, 2012 that it 
has decided not to propose or adopt such DPV, with an explanation of 
that decision.
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    \6\ Florida Wildlife Federation, Inc., et. al. v. Jackson, Case 
4:08-cv-00324-RH-WCS, Doc. 351 (N.D.Fla. February 18, 2012).
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    On May 30, 2012, the court granted EPA's request to extend the 
deadline for signing a proposed rule to November 30, 2012. The court 
also ordered that the final rule must be signed for publication by 
August 31, 2013.
    For this proposal, EPA is re-proposing the same numeric nutrient 
criteria for TN and TP published in EPA's final rule on December 6, 
2010 (75 FR 75762), with further explanation on how the proposed 
streams criteria will ensure the protection of Florida's Class I and 
III designated uses and how the criteria are an appropriate translation 
of Florida's narrative nutrient criterion. This proposal also is 
consistent with the objective and requirements of the CWA and EPA's 
implementing regulations at 40 CFR part 131. EPA is also proposing 
default approaches available for use when modeling cannot be performed 
to derive DPVs that will ensure the attainment and maintenance of the 
numeric nutrient criteria that protect the designated uses of Florida's 
downstream lakes. These default approaches are applicable to streams 
that flow downstream into unimpaired lakes, but could also be used for 
streams that flow downstream into impaired lakes.
    On June 13, 2012, FDEP submitted new and revised water quality 
standards for review by the EPA pursuant to section 303(c) of the CWA. 
These new and revised water quality standards are set out primarily in 
Rule 62-302 of the Florida Administrative Code (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 
water quality standards. On November 30, 2012, EPA approved the 
provisions of these rules submitted for review that constitute new or 
revised water quality standards (hereafter referred to as the ``newly-
approved state water quality standards'').
    Among the newly-approved state water quality standards are numeric 
criteria for nutrients that apply to a set of streams, as that term is 
specifically defined in the newly-approved state water quality 
standards. Under the Consent Decree, EPA is relieved of its obligation 
to propose numeric criteria for nutrients for any waters for which FDEP 
submits and EPA approves new or revised water quality standards before 
EPA proposes. Thus, under normal circumstances, EPA would be clearly 
relieved of its obligation to propose numeric criteria for nutrients in 
streams Florida covered in its newly-approved state water quality 
standards.
    However, another provision included in Florida's Rule, specifically 
subsection 62-302.531(9), F.A.C., casts some doubt as to whether the 
newly approved state water quality standards will go into effect if EPA 
proposes and promulgates numeric nutrient criteria for streams not 
covered by the newly-approved State water quality standards. Therefore, 
it is unclear whether an EPA proposal to ``gap fill'', or establish 
numeric criteria for nutrients for Florida streams that FDEP does not 
cover in its Rule, would trigger 62-302.531(9), F.A.C. and result in 
Florida's streams criteria not taking effect.
    In addition, due to a recent administrative challenge filed in the 
State of Florida Department of Administrative Hearings, there is 
uncertainty as to whether FDEP will be able to implement its newly 
approved state water quality standards consistent with FDEP's 
``Implementation of Florida's Numeric Nutrient Standards'' 
(Implementation Document). Thus, EPA approved portions of Florida's new 
or revised water quality standards subject to the State being able to 
implement them as provided in its Implementation Document. If, as a 
result of legal challenge, FDEP is unable to implement

[[Page 74988]]

its Rule as provided in its Implementation Document, EPA would intend 
to revisit its November 30, 2012 approval of Florida's new or revised 
water quality standards. EPA has therefore reserved its authority to 
withdraw or modify that approval.
    In light of the above, EPA seeks comment on finalizing a rule that 
applies EPA's streams criteria to streams meeting EPA's definition of 
``stream'' that are not covered under Florida's numeric interpretation 
of narrative nutrient criteria at 62-302.531(2)(c), F.A.C. This would 
serve to fill gaps in coverage if Florida's streams criteria are in 
effect, or apply to all streams if Florida's streams criteria are not 
in effect for any reason, including those mentioned above.
    Finally, as described in EPA's November 30, 2012 approval of 
Florida's new or revised water quality standards, 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, however, 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.

B. Which water bodies are affected by this rule?

    The criteria in this proposed rulemaking apply to a group of inland 
waters of the United States within Florida. Specifically, these 
criteria apply to flowing waters (i.e., streams) located outside of the 
South Florida Region that are designated as either Class I or Class III 
not covered by the State of Florida's Rule.\7\ EPA notes if Florida's 
Rule will not take effect due to subsection 62-302.531(9), F.A.C., EPA 
would expect to finalize the criteria in this proposed rulemaking for 
all flowing waters (i.e., streams) located outside of the South Florida 
Region that are designated as either Class I or Class III. EPA solicits 
comment on this potential outcome.
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    \7\ For purposes of this rule, EPA has distinguished South 
Florida as those areas south of Lake Okeechobee and the 
Caloosahatchee River watershed to the west of Lake Okeechobee and 
the St. Lucie watershed to the east of Lake Okeechobee, hereinafter 
referred to as the South Florida Region.
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    Class I and Class III streams share water quality criteria 
established to ``protect recreation and the propagation and maintenance 
of a healthy, well-balanced population of fish and wildlife'' pursuant 
to Subsection 62-302.400(4), F.A.C.\8\ ``Stream'', as defined at 40 CFR 
131.43(b)(12) 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. EPA notes that as 
defined at 40 CFR 131.43(b)(8) and consistent with Section 62-302.200, 
F.A.C., ``predominantly fresh waters'' means surface waters in which 
the chloride concentration at the surface is less than 1,500 milligrams 
per liter (mg/L).
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    \8\ 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 Chapter 62-550, F.A.C., for additional details.
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    The definition of stream in the approved water quality standards 
for purposes of applying the numeric interpretation of the narrative 
nutrient criterion to streams is less inclusive than as defined at 40 
CFR 131.43(b)(12). Florida's stream definition for purposes of applying 
the numeric interpretation of the narrative nutrient criterion (see 
Subsection 62-302.200(36), F.A.C.) specifically excludes non-perennial 
water segments; tidally influenced segments; and ditches, canals and 
other conveyances that are man-made or predominantly channelized or 
physically altered, are used primarily for water management purposes, 
and have marginal or poor stream habitat components. Inland flowing 
waters that meet EPA's definition of stream yet do not meet Florida's 
definition of stream for purposes of applying the numeric 
interpretation of the narrative nutrient criterion are designated Class 
I or Class III waters in Florida water quality standards. If they are 
not Class I or Class III waters, then this proposed rule would not 
apply. Additionally, this rule does not apply to wetlands, including 
non-perennial stream segments that function as wetlands because of 
fluctuating hydrologic conditions that typically result in the 
dominance of wetland taxa.

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 
flowing waters of Florida could be indirectly affected by this 
rulemaking because WQS are used in determining National Pollutant 
Discharge Elimination System (NPDES) permit limits. Categories and 
entities that may ultimately be affected include:

------------------------------------------------------------------------
                                      Examples of potentially affected
             Category                             entities
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Industry..........................  Industries discharging nitrogen and
                                     phosphorus to flowing waters in the
                                     State of Florida.
Municipalities....................  Publicly-owned treatment works
                                     discharging nitrogen and phosphorus
                                     to flowing waters in the State of
                                     Florida.
Stormwater Management Districts...  Entities responsible for managing
                                     stormwater runoff in Florida.
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[[Page 74989]]

    This table is not intended to be exhaustive, but rather provides a 
guide for entities that may be directly or indirectly affected by this 
action. This table lists the types of entities of which EPA is now 
aware that potentially could be affected by this action. Other types of 
entities not listed in the table, such as nonpoint source contributors 
to nitrogen and phosphorus pollution in Florida's waters may be 
affected through implementation of Florida's water quality standards 
program (i.e., through Basin Management Action Plans (BMAPs)). Any 
parties or entities conducting activities within watersheds of the 
Florida waters covered by this rule, or who rely on, depend upon, 
influence, or contribute to the water quality of 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 
carefully examine the language in this proposal. 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. 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-2009-0596. 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 Confidential Business Information (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 
OW 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.regulations.gov. 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 earlier.

II. Background

A. Nitrogen and Phosphorus Pollution in the United States and the State 
of Florida

    Excess loading of nitrogen and phosphorus compounds \9\ is one of 
the most prevalent causes of water quality impairment in the United 
States. Nitrogen and phosphorus pollution problems have been recognized 
for decades in the U.S. For example, a 1969 report by the National 
Academy of Sciences noted that ``[t]he 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 negative changes in plant and animal 
life--harmful, adverse changes that often interfere with use of water, 
detract from natural beauty, and reduce property values.'' \10\ Inputs 
of nitrogen and phosphorus lead to over-enrichment in many of the 
Nation's waters and constitute a widespread, persistent, and growing 
problem.\11\ Nitrogen and phosphorus pollution in fresh water systems 
can significantly negatively impact aquatic life and long-term 
ecosystem health, diversity, and balance.\12\ More specifically, high 
nitrogen and phosphorus loadings can result in harmful algal blooms 
(HABs), reduced spawning grounds and nursery habitats, fish kills, and 
oxygen-starved hypoxic or ``dead'' zones.\13\ Public health concerns 
related to nitrogen and phosphorus pollution include methanoglobanemia 
due to impaired drinking water sources from high levels of nitrates, 
increase in bladder cancer due to possible formation of disinfection 
byproducts in drinking water, and neurotoxicity and kidney damage due 
to increased exposure to cyanotoxins produced by harmful algae and 
cyanobacteria.14 15 Degradation of water bodies from 
nitrogen and phosphorus pollution can result in economic costs. For 
example, given that freshwater fishing in Florida is a significant 
recreational and tourist attraction generating over six billion dollars 
annually,\16\ degradation of water quality in Florida to the point that 
sport fishing populations are negatively affected will also negatively 
affect this important part of Florida's economy. Elevated nitrogen and 
phosphorus levels can occur locally in a stream or ground water, or can 
accumulate downstream leading to degraded lakes, reservoirs, and 
estuaries where fish and aquatic life can no longer survive or spawn 
and the

[[Page 74990]]

designated use is no longer supported. For additional information on 
the sources, impacts (e.g., human health, aquatic life, environmental) 
and economic implications of nitrogen and phosphorus pollution, please 
refer to the December 6, 2010 final rule.\17\
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    \9\ To be used by living organisms, nitrogen gas must be fixed 
into its reactive forms; for plants, either nitrate or ammonia 
(Boyd, C.E. 1979. Water Quality in Warmwater Fish Ponds. Auburn 
University: Alabama Agricultural Experiment Station, Auburn, AL). 
Eutrophication is defined as the natural or artificial addition of 
nitrogen and phosphorus to bodies of water and to the effects of 
added nitrogen and phosphorus (National Academy of Sciences (U.S). 
1969. Eutrophication: Causes, Consequences, Correctives. National 
Academy of Sciences, Washington, DC.)
    \10\ National Academy of Sciences (U.S). 1969. Eutrophication: 
Causes, Consequences, Correctives. National Academy of Sciences, 
Washington, DC.
    \11\ GulfBase. 2009. Bays and Estuaries. http://www.gulfbase.org/bay/. Accessed April 2009.; NSTC. 2003. An 
Assessment of Coastal Hypoxia and Eutrophication in U.S. Waters. 
National Science and Technology Council, Committee on Environment 
and Natural Resources, Washington, DC. http://coastalscience.noaa.gov/documents/hypoxia.pdf. Accessed July 2009; 
USEPA, 2009. National Summary of State Information. U.S. 
Environmental Protection Agency, Washington, DC, http://iaspub.epa.gov/waters10/attains_nation_cy.control. Accessed June 
2009.
    \12\ USEPA, 2006. USEPA. 2006b. Wadeable Streams Assessment. EPA 
841-B-06-002. U.S. Environmental Protection Agency, Washington, DC; 
Chesapeake Bay Program, 2009. Underwater Bay Grasses. http://www.chesapeakebay.net/baygrasses.aspx?menuitem=14621. Accessed July 
2009.
    \13\ NOAA, 2009. Harmful Algal Blooms. National Oceanic and 
Atmospheric Administration, Silver Spring, MD. http://oceanservice.noaa.gov/topics/coasts/hab/. Accessed April 2009; 
Tomasko et al., 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.; Selman 
et al., 2008. Eutrophication and Hypoxia in Coastal Areas: A Global 
Assessment of the State of Knowledge. WRI Policy Note No. 1 World 
Resources Institute, Washington, DC; Mississippi River/Gulf of 
Mexico Watershed Nutrient Task Force, 2008. Gulf Hypoxia Action Plan 
2008 for Reducing, Mitigating and Controlling Hypoxia in the 
Northern Gulf of Mexico and Improving Water Quality in the 
Mississippi River Basin. Washington, DC.
    \14\ Villanueva, C.M. et al., 2006. Bladder Cancer and Exposure 
to Water Disinfection By-Products through Ingestion, Bathing, 
Showering, and Swimming in Pools. American Journal of Epidemiology 
165(2):148-156.
    \15\ USEPA. 2009. What is in Our Drinking Water? United States 
Environmental Protection Agency, Office of Research and Development. 
< http://www.epa.gov/extrmurl/research/process/drinkingwater.html>. 
Accessed December 2009.
    \16\ Florida Fish and Wildlife Conservation Commission. 2010. 
The economic impact of freshwater fishing in Florida. <http://www.myfwc.com/CONSERVATION/Conservation_ValueofConservation_EconFreshwaterImpact.htm. Accessed August 2010.
    \17\ 75 FR 75762, December 6, 2010. Water Quality Standards for 
the State of Florida's Lakes and Flowing Waters.
---------------------------------------------------------------------------

    Florida's flat topography causes water to move slowly over the 
landscape, allowing ample opportunity for nitrogen and phosphorus to be 
transported offsite and result in eutrophication. Florida's warm and 
wet, yet sunny, climate further contributes to increased run-off and 
ideal temperatures for subsequent eutrophication responses.\18\ As 
outlined in EPA's January 2009 determination, water quality degradation 
resulting from excess nitrogen and phosphorus loadings is a documented 
and significant environmental issue in Florida. For example, the 
Florida Department of Environmental Protection (FDEP) 2008 Integrated 
Water Quality Assessment notes: ``the close connection between surface 
and ground water, 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, phosphorus levels again began moving upward in 
2000, likely due to the cumulative impacts of nonpoint source pollution 
associated with increased population and development. Increasing 
pollution from urban stormwater and agricultural activities is having 
other significant effects. In many springs across the State, for 
example, nitrate levels have increased dramatically (two-fold to three-
fold) over the past 20 years, reflecting the close link between surface 
and ground water.'' \19\ To clarify current nitrogen and phosphorus 
pollution conditions in Florida, EPA analyzed recent STORET (Storage 
and Retrieval) data pulled from Florida's Impaired Waters Rule 
(IWR),\20\ which are the data Florida uses to create its integrated 
reports, and found increasing levels of nitrogen and phosphorus 
compounds in Florida waters over 12 years (1996-2008). Florida's IWR 
STORET data indicates that levels of total nitrogen (i.e., State-wide 
average) have increased by 20% from 1996 to 2008, and total phosphorus 
levels (i.e., State-wide average) have increased by 40% over the same 
time period.
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    \18\ Perry, W.B. 2008. Everglades restoration and water quality 
challenges in south Florida. Ecotoxicology 17:569-578.
    \19\ FDEP. 2008. Integrated Water Quality Assessment for 
Florida: 2008 305(b) Report and 303(d) List Update.
    \20\ IWR Run 40. Updated through February 2010.
---------------------------------------------------------------------------

    The combination of the factors reported by FDEP and listed earlier 
(including population increase, climate, stormwater runoff, 
agriculture, and topography) has contributed to significant harmful, 
adverse effects from nitrogen and phosphorus pollution (nutrient 
pollution) to Florida's waters.\21\ 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 \22\ identifies approximately 1,918 miles of rivers 
and streams (about 14 percent of assessed river and stream miles), 
378,435 acres of lakes (about 31 percent of assessed lake acres), 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.
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    \21\ FDEP. 2008. Integrated Water Quality Assessment for 
Florida: 2008 305(b) Report and 303(d) List Update.
    \22\ 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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    For additional information regarding the prevalence of nutrient 
pollution in various water bodies in Florida and negative implications 
of nutrient pollution in State waters, please refer to the December 6, 
2010 final rule.\23\
---------------------------------------------------------------------------

    \23\ 75 FR 75762, December 6, 2010. Water Quality Standards for 
the State of Florida's Lakes and Flowing Waters.
---------------------------------------------------------------------------

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. Section 303(c)(2)(A) and EPA's 
implementing regulations at 40 CFR part 131 require, among other 
things, that state WQS include the designated use or uses to be made of 
the waters 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 waterbody 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 required to review their WQS at least once every three 
years and, if appropriate, revise or adopt new standards. (See CWA 
section 303(c)(1)). Any new or revised WQS must be submitted to EPA for 
review and approval or disapproval. (See 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 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, 
into numeric values that apply to flowing waters not covered by the 
State's Rule outside of the South Florida Region and DPVs to ensure the 
attainment and maintenance of the water quality standards of downstream 
lakes.\24\ For a thorough review of the statutory and regulatory 
background for this proposed rule, refer to the December 6, 2010 final 
rule.
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    \24\ The criteria finalized 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 WQS for CWA purposes.
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C. Water Quality Criteria

    Under CWA section 304(a), EPA periodically publishes criteria 
recommendations (guidance) 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. (See 40 CFR 131.11(b)(1)). For 
nutrient

[[Page 74991]]

pollution, EPA has published under CWA section 304(a) a series of peer-
reviewed, national technical approaches and methods regarding the 
development of numeric nutrient criteria for lakes and reservoirs,\25\ 
rivers and streams,\26\ and estuarine and coastal marine waters.\27\ 
For an overview of EPA's recommended approaches for deriving numeric 
nutrient criteria in Florida lakes and flowing waters, please refer to 
the December 6, 2010 final rule.\28\ EPA believes that numeric nutrient 
criteria will expedite and facilitate the effective implementation of 
Florida's existing point and non-point source water quality programs 
under the CWA in terms of timely water quality assessments, TMDL 
development, NPDES permit issuance and, where needed, Basin Management 
Action Plans (BMAPs) to address nitrogen and phosphorus pollution.
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    \25\ 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.
    \26\ 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.
    \27\ 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.
    \28\ 75 FR, 75762, December 6, 2010. Water Quality Standards for 
the State of Florida's Lakes and Flowing Waters.
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D. EPA Determination Regarding Florida and EPA's Rulemaking

    On January 14, 2009, EPA determined under Clean Water Act (CWA) 
section 303(c)(4)(B) that new or revised water quality standards (WQS) 
in the form of numeric water quality criteria are necessary to protect 
the designated uses from nitrogen and phosphorus pollution that Florida 
has set for its Class I and Class III waters. EPA's determination is 
available at the following Web site: http://www.epa.gov/waterscience/standards/rules/fl-determination.htm.
    On August 19, 2009, 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, committing to the schedule stated in EPA's January 14, 
2009 determination to propose numeric nutrient criteria for lakes and 
flowing waters in Florida by January 14, 2010, and for Florida's 
estuarine and coastal waters by January 14, 2011, unless the State 
submits and EPA approves new or revised water quality standards 
pursuant to section 303(c)(3).\29\ The Consent Decree also required 
that EPA sign a notice of final rulemaking for the respective proposals 
by October 15, 2010, for lakes and flowing waters, and by October 15, 
2011, for estuarine and coastal waters, unless the State submits and 
EPA approves new or revised water quality standards pursuant to section 
303(c)(3). The Consent Decree, which became effective on December 30, 
2009, also included a commitment to develop numeric DPVs to protect 
downstream lakes and estuaries. To review the bases for EPA's 
determination, and the information it considered in making its 
determination, please see the December 6, 2010 final rule.
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    \29\ Florida Wildlife Federation, Inc., et. al. v. Jackson, Case 
4:08-cv-00324-RH-WCS, Doc. 90-2 (N.D.Fla. August 25, 2009).
---------------------------------------------------------------------------

E. EPA Promulgation of the Final Rule and Subsequent Litigation

    In accordance with the January 14, 2009 determination, the August 
19, 2009 Consent Decree, and subsequent revisions to that Consent 
Decree, EPA signed a notice of final rulemaking establishing numeric 
nutrient criteria for streams, lakes, and springs in the State of 
Florida \30\ on November 14, 2010. As stated in the final rule at 40 
CFR Sec.  131.43(f), the rule was scheduled to take effect on March 6, 
2012, except for the site-specific alternative criteria (SSAC) 
provision at 40 CFR 131.43(e), which took effect on February 4, 2011. 
EPA selected the March 6, 2012 effective date for the criteria part of 
the rule to allow time for EPA to work with stakeholders and the 
Florida Department of Environmental Protection (FDEP) on important 
implementation issues, to help the public and all affected parties 
better understand the final numeric nutrient criteria and the basis for 
those criteria, and for EPA to engage and support, in full partnership 
with FDEP, the general public, stakeholders, local governments, and 
sectors of the regulated community across the State in a process of 
public outreach education, discussion, and constructive planning. 75 FR 
75787. The effective date was subsequently extended (77 FR 13497 and 77 
FR 39949) such that the current effective date of the rule is January 
6, 2013. In addition to this proposal, EPA has proposed to stay the 
December 6, 2010 Final Rule (75 FR 75762) to November 15, 2013 (See 
http://water.epa.gov/lawsregs/rulesregs/florida_inland.cfm).
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    \30\ For purposes of this rule, EPA has distinguished South 
Florida as those areas south of Lake Okeechobee and the 
Caloosahatchee River watershed to the west of Lake Okeechobee and 
the St. Lucie watershed to the east of Lake Okeechobee, hereinafter 
referred to as the South Florida Region. Numeric criteria applicable 
to flowing waters in the South Florida Region will be addressed in 
the second phase of EPA's rulemaking regarding the establishment of 
estuarine and coastal numeric criteria. (Please refer to Section I.B 
for a discussion of the water bodies affected by this rule).
---------------------------------------------------------------------------

    Following the publication of the rule in the Federal Register on 
December 6, 2010, 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 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. See February 18, 2012 Court Order. For 
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 streams 
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.'' Order at 63. The Court also found, however, that 
EPA had not explained in sufficient detail how the streams criteria 
would prevent a ``harmful increase in a nutrient level''. Order at 63. 
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. Order at 63. Thus, 
the Court invalidated these two aspects of EPA's final rule and 
remanded them to the Agency for further action.
    The Court ordered that the upheld portions of EPA's final rule be 
codified at 40 CFR 131.43 with the exceptions of the streams criteria 
and the default DPV for unimpaired lakes. Order at 85. For

[[Page 74992]]

the exceptions, the Court ordered: ``By May 21, 2012, the Administrator 
must sign for publication a proposed rule, or sign for publication a 
final rule, that sets numeric nutrient criteria for Florida streams 
that are not in the South Florida region. By May 21, 2012, the 
Administrator must sign for publication a proposed rule, or sign for 
publication a final rule, that sets default downstream-protection 
criteria for unimpaired lakes, unless by that date the Administrator 
has filed a notice that she has decided not to propose or adopt such 
criteria, together with an explanation of the decision.'' Order at 85. 
After the May 21, 2012 deadline was jointly extended by the parties to 
June 4, 2012, on May 30, 2012, the court granted EPA's request to 
further extend the deadline for signing a proposed rule to November 30, 
2012. The court also ordered that EPA must sign a notice of final 
rulemaking by August 31, 2013. In accordance with the Court's Order, 
EPA is proposing numeric nutrient criteria for Florida's streams and 
three default approaches for deriving DPVs for unimpaired lakes (and 
impaired lakes) with this proposed rule.

F. Florida Adoption of Numeric Nutrient Criteria and EPA Approval

    On June 13, 2012, the Florida Department of Environmental 
Protection (FDEP) submitted new and revised water quality standards for 
review by the EPA pursuant to section 303(c) of the CWA. These new and 
revised water quality standards are set out primarily in Rule 62-302 of 
the Florida Administrative Code (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 water 
quality standards. On November 30, 2012, EPA approved the provisions of 
these rules submitted for review that constitute new or revised water 
quality standards (referred to in this preamble as the ``newly approved 
state water quality standards''). These newly-approved state water 
quality standards include provisions that set forth numeric 
interpretations of the narrative nutrient criterion in paragraph 62-
302.530(47)(b), F.A.C. for streams (Subsection 62-302.531(2)(c), F.A.C) 
that meet a specific definition (Section 62-302.200(36), F.A.C.).
    The numeric interpretation for stream protection in Florida's newly 
approved water quality standards uses biological information in 
combination with nutrient thresholds. Stream protection is achieved if 
(1) various measures of aquatic plant growth (e.g., ``floral metrics'') 
indicate ``no imbalances'' and EITHER (2) a measure of the faunal 
stream community health called the Stream Condition Index (SCI) is 
above a certain threshold OR (3) the nutrient thresholds for total 
phosphorus (TP) and total nitrogen (TN) for the relevant region are 
met. The nutrient thresholds in Florida's newly approved water quality 
standards are identical to the ``stand-alone'' streams criteria in this 
proposed rule. EPA's approval document is included in the set of 
materials provided in the docket for this proposed rule (Docket number 
EPA-HQ-OW-2009-0596, www.regulations.gov).

III. Numeric Criteria for Flowing Waters and Downstream Protection of 
Lakes in the State of Florida

A. Introduction

    In the December 2010 final rule, using the reference condition 
approach, EPA promulgated numeric nutrient criteria for Florida's 
streams based on the concentrations of total nitrogen (TN) and total 
phosphorus (TP) observed in a sample of least-disturbed streams. EPA 
set the numeric nutrient criteria so that the annual average 
concentrations of TN and TP most often observed in reference sites that 
are known to support the designated uses would not exceed the criteria. 
The court, however, found that EPA failed to explain ``how the 90% mark 
correlates with a harmful increase in nutrients'' (as opposed to any 
increase in nutrients). Order at 65. The court noted that it ``may well 
be that there is a sufficient correlation'' that above the criteria 
concentrations ``harmful change is likely.'' Order at 66. However, the 
court found that EPA had not adequately explained its decision and 
remanded to EPA for further action.\31\
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    \31\ As set out more fully in a subsequent section, EPA set 
criteria concentrations at the 90th percentile of the reference 
condition distribution in four of the five nutrient watershed 
regions defined in Florida. In the fifth region, known as the West 
Central region, EPA set criteria concentrations at the 75th 
percentile of the reference distribution. For ease of reference, 
where EPA refers to the ``upper percentile'' or the ``90th 
percentile'' in this preamble, unless the reference relates 
specifically to the basis for the criteria in the four nutrient 
watershed regions where EPA selected the 90th percentile, EPA is 
referring to both the 90th percentile that was applied in four 
regions and the 75th percentile that was applied in the West Central 
region.
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    In response to the court's remand, EPA has conducted a 
comprehensive review of available scientific data and information to 
more fully document the likelihood of harmful change occurring in the 
natural populations of aquatic flora and fauna of Florida streams at TN 
and TP concentrations above the proposed numeric nutrient criteria in 
today's proposal. EPA conducted this review to confirm whether its 
proposed numeric nutrient criteria are established at TN and TP 
concentrations sufficient (i.e., necessary) to protect against 
``harmful'' change in the biota.
    EPA's review confirmed its original decision that the criteria the 
Agency published in December 2010 were set at the appropriate levels to 
protect the applicable designated uses and translate Florida's 
narrative nutrient criterion for the purposes of the CWA. EPA has re-
selected the upper percentile of annual average TN and TP 
concentrations from its sample of reference sites as the level that the 
Agency is confident will avoid ``harmful'' increases in TN and TP, and 
thus a level at which designated uses are protected in Florida's 
streams. The reference sites (described more fully in the following 
sections) are least-disturbed and more closely represent minimally-
impacted conditions associated with a natural population of flora and 
fauna. By selecting a criterion-magnitude that was exceeded only 10% of 
the time \32\ on an annual average basis in the reference sites that 
were determined to support designated uses, EPA is confident that other 
streams attaining and maintaining those levels of TN and TP would also 
support applicable designated uses and not experience harmful change in 
the biota. EPA is, therefore, proposing TN and TP criteria at the same 
levels as EPA promulgated in the December 2010 final rule.
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    \32\ In the West Central Region, EPA selected a criterion-
magnitude that was exceeded only 25% of the time on an annual 
average basis across all sites.
---------------------------------------------------------------------------

    In its decision, the court, in discussing numeric criteria 
translating Florida's narrative criterion, stated that ``the right 
target was a criterion that would identify a harmful increase in a 
nutrient level--an increase that, in the language of Florida's 
narrative criterion, would create an `imbalance' in flora and fauna.'' 
Order at 63. That language could be read as requiring identification of 
the exact point where harmful change, or imbalance of flora or fauna, 
occurs as the appropriate level for numeric nutrient criteria. EPA 
evaluated whether available data allow derivation of criteria with such 
precision to set the criteria at a level where any increase at all 
would result in an imbalance of flora and fauna, and therefore 
impairment of Florida's designated uses. As set out more fully in 
subsequent sections, EPA concluded the data did not allow derivation of 
criteria with such

[[Page 74993]]

precision. In order to derive criteria with such precision, it would be 
necessary to have sufficient data to precisely model (either 
statistically or mechanistically) the stressor-response relationship in 
each stream reach within the State, due to the various confounding 
factors that introduce variability into that relationship within a 
given stream reach. Because EPA did not have such data available, EPA 
was not able to pinpoint the exact level at which any increase in 
nitrogen and phosphorus concentrations at all would result in such 
imbalance and designated use impairment.
    In determining appropriately protective criteria, EPA must ensure 
that such criteria comply with the CWA. The CWA envisions that water 
quality standards will be developed, based on available scientific 
knowledge and information, at levels that are sufficient to protect 
designated uses. See CWA section 303(c)(2)(A). 40 CFR 131.11(a)(1). The 
record supports EPA's conclusion that its proposed numeric streams 
criteria are based on sound scientific rationale and will protect 
Florida's designated uses. If commenters are aware of available data 
and/or information demonstrating that setting criteria at less 
stringent levels than those in this proposed rule would be protective 
of designated uses and protect against harmful increases of TN and TP, 
or that criteria must be set at more stringent levels in order to 
protect designated uses and protect against harmful increases of TN and 
TP, commenters should submit such scientific information and analyses 
to EPA during the comment period for EPA's consideration.
    Finally, EPA's approach to deriving numeric nutrient criteria is 
consistent with FDEP's approach to interpreting its narrative nutrient 
criterion and deriving numeric thresholds at the State level. FDEP 
recently established numeric interpretations of the State's narrative 
nutrient criterion.\33\ FDEP has approached the derivation of numeric 
TN and TP threshold values for streams in much the same way as EPA by 
aiming to prevent adverse effects to natural populations of aquatic 
flora and fauna.\34\ To set protective numeric threshold values for 
streams for TN and TP where the data were not available to ascertain an 
accurate quantifiable stressor-response relationship for streams, FDEP 
utilized a reference condition approach similar to the reference 
condition approach that EPA utilized in the December 2010 final rule. 
In the absence of a positive showing that some higher level of 
nutrients still protects designated uses and against harmful change in 
the biota in a particular stream, or a showing that some lower level of 
nutrients is needed to protect designated uses and natural populations 
of biota in a particular stream, both FDEP and EPA have determined that 
the upper percentile of reference streams is an appropriate and 
protective level of nutrients to properly protect designated uses and 
avoid any adverse change in natural populations of aquatic flora or 
fauna. In addition, EPA included a Site Specific Alternative Criteria 
(``SSAC'') provision in its December 2010 final rule for adoption of 
alternative criteria if a demonstration could be made that more or less 
stringent criteria are warranted for individual waters. Similarly, FDEP 
included a provision in its rule for adoption of SSAC, as well as a 
provision for adoption of other site-specific interpretations for 
individual waters.
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    \33\ See FDEP's Rule 62-302.531, F.A.C. at: http://www.dep.state.fl.us/water/wqssp/nutrients/docs/meetings/62_302_final.pdf, accessed on April 27, 2012.
    \34\ State of Florida Numeric Nutrient Criteria Development 
Plan, Prepared by: Bureau of Assessment and Restoration Support, 
Division of Environmental Assessment and Restoration, Florida 
Department of Environmental Protection Tallahassee, FL, March 2009; 
Technical Support Document: Development of Numeric Nutrient Criteria 
for Florida Lakes and Streams. Florida Department of Environmental 
Protection, Standards and Assessment Section, June 2009; Technical 
Support Document: Development of Numeric Nutrient Criteria for 
Florida Lakes, Spring Vents and Streams. Florida Department of 
Environmental Protection, Standards and Assessment Section, 2012.
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    Along with this proposed rule, EPA is providing a technical support 
document that discusses in more detail the scientific basis for the 
proposed criteria for streams and the default options to determine DPVs 
for unimpaired lakes. The technical support document helps explain how 
EPA's proposed numeric streams criteria would prevent harmful increases 
in TN and TP concentrations, which was specifically discussed by the 
Court in its decision invalidating EPA's numeric streams criteria and 
default DPV for unimpaired lakes.\35\
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    \35\ ``Technical Support Document for EPA's Proposed Rule for 
Numeric Nutrient Criteria to Protect Florida's Streams and the 
Downstream Protection of Unimpaired Lakes'' (``EPA Proposed Rule TSD 
for Florida's Streams and DPV for Unimpaired Lakes'').
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B. EPA Derivation of Numeric Nutrient Criteria for Streams

1. Components of 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 
duration of exposure to elevated concentrations. This accounts for the 
variability in the quality of the ambient water due to variations of 
constituent inputs, stream 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 the 
allowance of harmful effects by ensuring compensating periods of time 
during which the concentration is below the criterion-magnitude. Where 
criterion-magnitudes are exceeded for short periods of time or 
infrequently, water bodies can typically recover; that is, designated 
uses are typically protected. Designated uses are typically not 
protected when criteria-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).\36\
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    \36\ Water Quality Standards Handbook: Second Edition, Chapter 
3--Water Quality Criteria. EPA-823-B-94-005a. USEPA. 1994; Technical 
Support Document for Water Quality-based Toxics Control. Appendix 
D--Duration and Frequency. EPA/505/2-90-001. USEPA 1991.
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    Use of this magnitude-duration-frequency format allows for some 
exceedances of the criteria-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. The duration and frequency 
values associated with the numeric streams criteria EPA is proposing 
today are the same as those associated with the numeric criteria in 
EPA's December 2010 rule. For more information on the basis for these 
duration and frequency components, see 75 Fed. Reg. 75776-77.
2. Selection of Target for Numeric Nutrient Criteria
    In evaluating the appropriate endpoint for deriving numeric 
nutrient criteria, EPA first looked at Florida's applicable designated 
uses since, as mentioned in the previous sections, water quality 
criteria must be sufficient to protect the designated uses. CWA 
303(c)(2)(A); 40 CFR 131.11(a)(1). The designated uses established by 
Florida for its streams include Class I (for potable water supply) and 
Class III

[[Page 74994]]

(recreation, propagation and maintenance of a healthy, well-balanced 
population of fish and wildlife). Fla. Admin. Code 62-302.400. EPA next 
looked to Florida's narrative nutrient criterion, which represents 
Florida's determination of what is protective of the Class I and III 
designated uses.\37\ That criterion provides that ``in no case shall 
nutrient concentrations of a body of water be altered so as to cause an 
imbalance of natural populations of aquatic flora and fauna.'' Fla. 
Admin. Code 62-302.530(47)(b). As set out more fully in subsequent 
sections, in deriving the numeric nutrient criteria to protect against 
concentrations of TN and TP that will create an imbalance of natural 
populations of aquatic flora and fauna and, thus, ensure the protection 
of the designated uses in Florida's streams, EPA used the reference 
condition approach.
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    \37\ Florida's narrative nutrient criterion also serves to 
protect their Class II waters for propagation and harvesting of 
shellfish, which will be covered under EPA's forthcoming rulemaking 
efforts for estuarine and coastal waters.
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    Unlike for streams, for Florida's lakes the Agency was able to 
accurately quantify a stressor-response relationship between TN and TP 
concentrations and harmful, adverse effects in those waters. EPA used 
that stressor-response information to derive numeric nutrient criteria, 
promulgated in the December 2010 final rule, to protect designated uses 
for Florida's lakes. EPA did not establish the numeric lake criteria 
exactly at the point where nutrient pollution is demonstrated to 
adversely affect all lakes at all times, as that would not be 
protective of all lakes. Rather, EPA established the numeric lake 
criteria at concentrations that were known to protect against harmful, 
adverse effects by protecting and maintaining the expected trophic 
state \38\ (by meeting protective chlorophyll-a concentrations for 
either oligotrophic or mesotrophic conditions) for the majority of 
lakes. At the same time, EPA allows higher concentrations within a 
given range if there is a positive showing that some higher 
concentrations of TN and TP still maintain the protective chlorophyll-a 
concentrations, and thus still protect the designated uses in a 
particular lake.\39\ The court upheld EPA's numeric nutrient criteria 
for Florida's lakes in its February 18, 2012 Order.
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    \38\ Tropic state describes the nitrogen and phosphorus levels 
and algal state of an aquatic system: Oligotrophic (low nitrogen/
phosphorus and algal productivity), mesotrophic (moderate nitrogen/
phosphorus and algal productivity), and eutrophic (high nitrogen/
phosphorus and algal productivity).
    \39\ Additionally, the SSAC provision at Sec.  131.43(e) is also 
available if it determined that concentrations outside of the range 
are necessary to protect the designated uses in a particular lake.
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    For Florida's streams, as stated in the previous section, EPA 
determined that the scientific data and information available were 
insufficient to establish accurate quantifiable relationships between 
TN and TP concentrations and harmful, adverse effects in streams due to 
confounding factors that affect the chemical and biological responses 
to nutrient pollution in streams, such as shading from canopy and 
stream velocity. Thus, in spite of the substantial data collected over 
many years, EPA could not use the stressor-response approach to 
establish the numeric streams criteria at concentrations that protect 
against harmful adverse effects by protecting and maintaining a given 
biological response at a protective level measured in streams. 
Therefore, EPA relied upon the reference condition approach as 
described in more detail in Section III.C of this preamble to identify 
TN and TP concentrations that protect the designated uses, and above 
which harmful, adverse effects are likely to occur in the majority of 
Florida streams. At the same time, EPA allows alternative criteria be 
set at higher or lower concentrations through the use of the SSAC 
provision, if there is a positive showing that higher or lower 
concentrations of TN and TP are sufficient or necessary to protect the 
designated uses in a particular stream. The following sections set 
forth how EPA determined that the numeric streams criteria in today's 
proposal are set at the appropriate level to protect against a harmful, 
adverse effects due to increased TN and TP concentrations.

C. Reference Condition Approach for Developing Numeric Nutrient 
Criteria for Streams

    The reference condition approach, a long-standing peer-reviewed 
methodology published by EPA, was designed to develop protective 
numeric nutrient criteria where reference conditions can be confidently 
defined.\40\ The reference condition approach, which has been well 
documented, peer reviewed, and developed in a number of different 
contexts,41 42 43 44 45 46 is used to derive numeric 
nutrient criteria that are protective of applicable designated uses by 
identifying TN and TP concentrations occurring in least-disturbed, 
healthy streams that are supporting designated uses. The core 
scientific basis for EPA's use of the reference condition approach to 
derive the proposed numeric nutrient criteria for Florida's streams is 
outlined in EPA's December 2010 final rule \47\ and final December 2010 
rule TSD.\48\ Briefly, EPA screened and evaluated water chemistry data 
from more than 11,000 samples from over 6,000 sites Statewide. EPA also 
evaluated biological data consisting of more than 2,000 samples from 
over 1,100 Florida streams. EPA then selected a reference set of 
streams where the Agency was confident that designated uses are 
protected. Finally, EPA selected an upper percentile of the data 
distribution associated with those reference streams as the stream 
criterion-magnitude. While developing the December 2010 final rule, EPA 
met and consulted with FDEP expert scientific and technical staff on 
numerous occasions as part of an ongoing collaborative process. EPA 
carefully considered and evaluated the technical approaches and 
scientific analysis that FDEP presented as part of its July 2009 draft 
numeric nutrient criteria,\49\ as well as FDEP's numerous

[[Page 74995]]

comments on different aspects of EPA's proposed January 2010 final 
rule.
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    \40\ USEPA. 2000. Nutrient Criteria Technical Guidance Manual: 
Rivers and Streams. EPA-822-B-00-002. 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. U.S. Environmental Protection Agency, Science Advisory 
Board, Washington, DC.
    \41\ 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.
    \42\ 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.
    \43\ 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.
    \44\ 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.
    \45\ U.S. EPA. 2001. Nutrient Criteria Technical Manual: 
Estuarine and Coastal Marine Waters. Office of Water, Washington, 
DC. EPA-822-B-01-003.
    \46\ 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. U.S. Environmental 
Protection Agency, Science Advisory Board, Washington, DC.
    \47\ Final rule can be found at: http://edocket.access.gpo.gov/2010/pdf/2010-29943.pdf or 75 Federal Register 75762 (December 6, 
2010).
    \48\ Final rule TSD can be found at: www.regulations.gov, Docket 
 EPA-HQ-OW-2009-0596.
    \49\ FDEP. 2009. Draft Technical Support Document: Development 
of Numeric Nutrient Criteria for Florida's Lakes and Streams. 
Florida Department of Environmental Protection, Standards and 
Assessment Section. Available electronically at: http://www.dep.state.fl.us/water/wqssp/nutrients/docs/tsd_nutrient_crit.docx. Accessed October 2010.
---------------------------------------------------------------------------

    In addition, the Agency also received and carefully considered 
substantial stakeholder input from 13 public hearings in six Florida 
cities during the 2010 comment period. EPA reviewed and evaluated 
further analysis and information included in the more than 22,000 
comments on the January 2010 proposal and an additional 71 comments on 
the August 2010 supplemental notice and request for comment. Finally, 
in reviewing its 2010 application of the reference condition approach 
for purposes of this proposal, EPA also considered FDEP's current rule, 
along with the technical approaches and scientific analysis supporting 
that rule, submitted to EPA on June 13, 2012.\50\
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    \50\ State of Florida Numeric Nutrient Criteria Development 
Plan, Prepared by: Bureau of Assessment and Restoration Support, 
Division of Environmental Assessment and Restoration, Florida 
Department of Environmental Protection Tallahassee, FL, March 2009; 
Technical Support Document: Development of Numeric Nutrient Criteria 
for Florida Lakes, Spring Vents and Streams. Florida Department of 
Environmental Protection, Standards and Assessment Section, 2012.
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1. Selection of Reference Sites
    This section summarizes how EPA applied the reference condition 
approach in developing the December 2010 rule, including how EPA 
selected the set of reference sites and how it aggregated data 
associated with those stream segments. EPA classified Florida streams 
into five stream regions based on similar geographical and watershed 
characteristics. The proposed numeric streams criteria would apply to 
five separate stream Nutrient Watershed Regions (NWRs): Panhandle West, 
Panhandle East, North Central, West Central and Peninsula (north of 
Lake Okeechobee, including the Caloosahatchee River Watershed to the 
west and the St. Lucie Watershed to the east).
    To derive numeric nutrient criteria for streams, EPA first 
identified biologically healthy sites that exhibited the least amount 
of human disturbance and that were known to support designated uses, 
i.e., support natural populations of aquatic flora and fauna. EPA 
applied several screening factors to ensure these sites reflected 
least-disturbed, biologically healthy conditions. The screening factors 
included landscape development intensity index (LDI) scores less than 
2.0 (an indicator of lower impact surrounding land use), average 
nitrate concentrations less than 0.35 mg/L (an indicator of lower 
anthropogenic nitrogen concentrations), exclusion of waters that are 
identified as water quality-limited for nutrients and/or dissolved 
oxygen on Florida's EPA-approved CWA section 303(d) list, and an FDEP-
derived index of the stream macroinvertebrate community (stream 
condition index, or SCI) where average scores are greater than 40 (an 
indicator of a healthy macroinvertebrate community). The result of this 
rigorous analysis was a set of reference sites 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 sites are supporting designated 
uses and natural populations of flora and fauna, and, as set out more 
fully in Section III.C.2, has confidence that if the TN and TP 
concentrations are attained or maintained at the concentrations that 
are among the highest observed at these sites, then designated uses and 
natural populations of aquatic flora and fauna will be protected in 
other streams. Additionally, as discussed further in Section III.C.3, 
additional lines of evidence from the available scientific data and 
information support EPA's conclusion in that they indicate that 
harmful, adverse effects are likely to occur to natural populations of 
aquatic flora and fauna at levels higher than these concentrations.
    In remanding EPA's streams criteria, the Court preliminarily 
concluded that EPA's technical and scientific approaches in deriving 
streams criteria based on the reference condition approach were 
defensible. Specifically, the Court reasoned: ``Each side criticizes 
the Administrator's implementation of this approach. Thus, for example, 
each side criticizes the Administrator's selection of sample streams. 
The environmental parties criticize the duration and frequency 
components. These are matters of scientific judgment on which the rule 
would survive arbitrary-or-capricious review.'' Order at 63.
2. Selection of Stream Criterion-Magnitude
    After selecting the reference set of streams, EPA then examined the 
statistical distributions of the data associated with stream sites that 
passed all of the screening factors in order to identify an appropriate 
criterion-magnitude to protect designated uses and natural populations 
of aquatic flora and fauna. EPA organized the data (TN and TP values) 
and calculated the geometric mean of the annual geometric mean of TN 
and TP concentrations for each stream segment that contained reference 
sites. EPA used all samples from reference sites within a given stream 
segment in a given year to calculate the annual geometric mean for that 
stream segment. EPA used the geometric mean of these annual geometric 
means for each stream segment so that each stream segment represents 
one average concentration in the distribution of concentrations for 
each NWR. EPA used geometric means for all averages because 
concentrations were log-normally distributed. EPA then identified 
specific statistics, or percentiles, associated with each stream NWR 
reference condition data distribution as the stream criterion-magnitude 
for that region.\51\ Based on the effectiveness of the data quality 
screens in four of five NWRs, EPA has concluded that the 90th 
percentile of annual average concentrations would be protective. EPA 
could not use all of the screening factors outlined in Section III.C.1. 
in order to identify reference sites in the remaining region, the West 
Central Region, because the use of those screens resulted in the 
identification of only one stream segment as a reference site. For this 
reason, EPA utilized only the SCI and 303(d) listed screens to identify 
reference conditions in the West Central NWR, and this approach does 
not rely on a quantitative assessment of potential human disturbance 
through the use of surrounding land cover analysis of stream corridor 
and watershed land development indices. Because of the use of fewer 
data screens to identify reference conditions in that NWR and EPA's 
attendant lower confidence that these sites are least-disturbed 
conditions that support designated uses and natural populations of 
aquatic flora and fauna, EPA has determined the 75th percentile of 
annual average concentrations, rather than the 90th percentile, is the 
protective criterion-magnitude for that region. For the remaining 
stream regions, EPA considers the 90th percentile of the annual average

[[Page 74996]]

concentrations observed in the reference condition distribution as an 
appropriate concentration to specify the criterion-magnitude because 
the Agency is confident that theses least-disturbed sites more closely 
represent minimally-impacted, biologically healthy reference 
conditions, which support the State's Class I and III designated uses.
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    \51\ For the West Central region, where reference sites were 
identified using only the SCI approach, there is less confidence 
that these sites are least-disturbed and represent minimally-
impacted conditions. Unlike in the other NWRs, this approach does 
not rely on a quantitative assessment of potential human disturbance 
through the use of surrounding land cover analysis of stream 
corridor and watershed land development indices, among other things. 
Therefore, because of the lower confidence level, EPA is proposing 
the streams criteria in the West Central region using a more 
conservative percentile of 75% rather than the upper end percentile 
of 90% of the distribution from the SCI sites.
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    However, the Court found that EPA did not provide sufficient 
rationale explaining why it chose the 90th percentile (75th percentile 
in the West Central) of the reference site data distribution as the 
stream criterion-magnitude. That is, EPA did not explain why increasing 
nutrient levels above the upper percentile of annual average 
concentrations measured in reference condition streams would result in 
harmful, adverse effects on natural populations of aquatic flora and 
fauna in Florida's streams. The Court reasoned: ``The Administrator 
apparently concluded only that an increase above this level ordinarily 
causes a change in flora and fauna--not that it causes a harmful 
change. If there is a basis in sound science for disapproving a 
nutrient increase that causes any increase in flora and fauna, not just 
a harmful increase, the Administrator did not cite it. And even if the 
Administrator's conclusion was that an increase in nutrients to a level 
above the 90th percentile ordinarily causes a harmful change in flora 
and fauna, the Administrator again did not cite a sound science basis 
for the conclusion.'' Order at 7.
    For all stream regions, EPA could have selected a criterion-
magnitude at the 75th percentile of the frequency distribution of 
concentrations at reference sites, or any lower percentile of the 
frequency distribution of the general population of a stream class 
(i.e., ``all-streams'' population from impaired to least-impacted), to 
derive the numeric criteria as recommended by EPA's published streams 
criteria guidance.\52\ EPA selected the 90th percentile. EPA found 
support in an EPA nutrient criteria guidance manual that recommends 
percentiles from the 75th to the 95th percentile of the frequency 
distribution of the reference population, where the higher percentile 
values are ``best used to define the criteria when there is great 
confidence that the group of reference waters truly reflects reference 
conditions as opposed, for example, to best available condition.'' \53\
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    \52\ U.S. EPA. 2000b. Nutrient Criteria Technical Guidance 
Manual: Rivers and Streams. EPA-822-B-00-002. U.S. Environmental 
Protection Agency, Office of Water, Washington, DC.
    \53\ U.S. EPA. 2007. Nutrient Criteria Technical Guidance 
Manual: Wetlands. EPA-822-R-07-004. U.S. Environmental Protection 
Agency, Office of Water, Washington, DC.
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    The selection of the 90th percentile reflects EPA's level of 
confidence that these least-disturbed sites more closely represent 
minimally-impacted conditions, while not set at 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 streams 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. For the West Central 
Region, EPA relied on the75th percentile due to the Agency's lower 
level of confidence as discussed in more detail in the previous 
section. By setting the criteria at these concentrations, EPA believes 
the designated uses, i.e., natural populations of aquatic flora and 
fauna, will be protected when these concentrations are attained in the 
majority of the streams in the regions. For those streams that are 
shown to accommodate or require higher or lower concentrations, the 
SSAC provision is provided in EPA's rule as discussed in Section 
III.C.5.
    EPA has concluded, after its reevaluation of the reference 
condition data set and the resulting reference site data distributions 
of annual average TN and TP concentrations that EPA continues to have 
confidence that the upper percentile of annual average nutrient 
concentrations observed in the reference sites will support designated 
uses and natural populations of aquatic flora and fauna. As explained 
in the prior section, based on its evaluation of available scientific 
data and information, EPA used its best professional judgment and 
published guidance to conclude that TN and TP concentrations in excess 
of these values are not likely to protect designated uses and natural 
populations of aquatic flora and fauna. Additionally, as discussed in a 
subsequent section, EPA's review of additional lines of evidence from 
the available scientific data and information, including past 
scientific analyses, new analyses, and the peer-reviewed scientific 
literature, all support the conclusion that harmful, adverse effects on 
natural populations of aquatic flora and fauna from excess nitrogen and 
phosphorus are more likely to occur if concentrations increase above 
the proposed streams criteria set at these upper percentiles of 
reference conditions.
3. Harmful, Adverse Effects Due to Exceedence of EPA's Proposed Streams 
Criteria
    Additional lines of evidence from empirical stressor-response 
analyses and the peer-reviewed scientific literature, which indicate 
that harmful, adverse effects are likely to occur to natural 
populations of aquatic flora and fauna due to exceedances of the 
proposed streams criteria,\54\ support EPA's conclusion that the upper 
percentile of the reference condition data distribution is the 
appropriate nutrient criterion-magnitude for Florida's streams.
---------------------------------------------------------------------------

    \54\ U.S. EPA. 2000. Nutrient Criteria Technical Guidance 
Manual: Rivers and Streams. EPA-822-B-00-002. U.S. Environmental 
Protection Agency, Office of Water, Washington, DC.
---------------------------------------------------------------------------

    In developing this proposal, EPA reviewed the empirical, stressor-
response analyses between nutrients and different biological response 
indicators (e.g., algal biomass, SCI) conducted prior to promulgation 
of the December 2010 final rule, and also reviewed any new analyses. 
The results of these analyses support the Agency's conclusion that 
harmful, adverse effects to natural populations of aquatic flora and 
fauna are likely to occur if TN and TP concentrations increase above 
the proposed streams criteria.\55\
---------------------------------------------------------------------------

    \55\ Technical Support Document for EPA's Proposed Rule for 
Numeric Nutrient Criteria to Protect Florida's Streams and 
Downstream Lakes. U.S. EPA, 2012.
---------------------------------------------------------------------------

    Three technical support documents \56\ in the Agency's original 
rulemaking

[[Page 74997]]

record and the technical support document associated with this proposed 
rule include scientific analyses demonstrating that harmful changes or 
adverse effects are more likely to happen as TN and TP concentrations 
increase above EPA's proposed streams criteria.
---------------------------------------------------------------------------

    \56\ Technical Support Document: Development of Numeric Nutrient 
Criteria for Florida Lakes and Streams. Florida Department of 
Environmental Protection, Standards and Assessment Section, June 
2009; Proposed Methods and Approaches for Developing Numeric 
Nutrient Criteria for Florida's Inland Waters. U.S. EPA 2009; 
Technical Support Document for U.S. EPA's Proposed Rule for Numeric 
Nutrient Criteria for Florida's Inland Surface Fresh Waters. U.S. 
EPA 2010.
---------------------------------------------------------------------------

    The effects of TN and TP on an aquatic ecosystem are well 
understood and documented. There is a substantial and compelling 
scientific basis for the conclusion that excess TN and TP will have 
adverse effects on 
streams.57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 As 
discussed in Section II, excess nitrogen and phosphorus in streams, 
like other aquatic ecosystems, increase vegetative growth (plants and 
algae), and change the assemblage of plant and algal species present in 
the system. Notwithstanding the difficulty associated with identifying 
the TN and TP concentrations that are known to protect against harmful 
effects by protecting and maintaining a given biological response at a 
protective level measured in Florida's streams, the available science 
clearly indicates that adverse responses to nutrient pollution occur.
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    \57\ Biggs, B.J.F. 2000. Eutrophication of streams and rivers: 
Dissolved nutrient-chlorophyll relationships for benthic algae. 
Journal of the North American Benthological Society 19:17-31.
    \58\ Bothwell, M.L. 1985. Phosphorus limitation of lotic 
periphyton growth rates: An intersite comparison using continuous-
flow troughs (Thompson River system, British Columbia). Limnology 
and Oceanography 30:527-542.
    \59\ Bourassa, N., and A. Cattaneo. 1998. Control of periphyton 
biomass in Laurentian streams (Quebec). Journal of the North 
American Benthological Society 17:420-429.
    \60\ Bowling, L.C., and P.D. Baker. 1996. Major cyanobacterial 
bloom in the Barwon-Darling River, Australia, in 1991, and 
underlying limnological conditions. Marine and Freshwater Research 
47:643-657.
    \61\ Cross, W.F., J.B. Wallace, A.D. Rosemond, and S.L. Eggert. 
2006. Whole-system nutrient enrichment increases secondary 
production in a detritus-based ecosystem. Ecology 87:1556-1565.
    \62\ Dodds, W.K., and D.A. Gudder. 1992. The ecology of 
Cladophora. Journal of Phycology 28:415-427.
    \63\ Elwood, J.W., J.D. Newbold, A.F. Trimble, and R.W. Stark. 
1981. The limiting role of phosphorus in a woodland stream 
ecosystem: Effects of P enrichment on leaf decomposition and primary 
producers. Ecology 62:146-158.
    \64\ Francoeur, S.N. 2001. Meta-analysis of lotic nutrient 
amendment experiments: Detecting and quantifying subtle responses. 
Journal of the North American Benthological Society 20:358-368.
    \65\ Moss, B., I. Hooker, H. Balls, and K. Manson. 1989. 
Phytoplankton distribution in a temperate floodplain lake and river 
system. I. Hydrology, nutrient sources and phytoplankton biomass. 
Journal of Plankton Research 11:813-835.
    \66\ Mulholland, P.J. and J.R. Webster. 2010. Nutrient dynamics 
in streams and the role of J-NABS. Journal of the North American 
Benthological Society 29: 100-117.
    \67\ Peterson, B.J., J.E. Hobbie, A.E. Hershey, M.A. Lock, T.E. 
Ford, J.R. Vestal, V.L. McKinley, M.A.J. Hullar, M.C. Miller, R.M. 
Ventullo, and G.S. Volk. 1985. Transformation of a tundra river from 
heterotrophy to autotrophy by addition of phosphorus. Science 
229:1383-1386.
    \68\ Rosemond, A.D., P.J. Mulholland, and J.W. Elwood. 1993. 
Top-down and bottom-up control of stream periphyton: Effects of 
nutrients and herbivores. Ecology 74:1264-1280.
    \69\ Rosemond, A.D., C.M. Pringle, A. Ramirez, and M.J. Paul. 
2001. A test of top-down and bottom-up control in a detritus-based 
food web. Ecology 82:2279-2293.
    \70\ Rosemond, A.D., C.M. Pringle, A. Ramirez, M.J. Paul, and 
J.L. Meyer. 2002. Landscape variation in phosphorus concentration 
and effects on detritus-based tropical streams. Limnology and 
Oceanography 47:278-289.
    \71\ Slavik, K., B.J. Peterson, L.A. Deegan, W.B. Bowden, A.E. 
Hershey, J.E. Hobbie. 2004. Long-term responses of the Kuparuk River 
ecosystem to phosphorus fertilization. Ecology 85:939-954.
---------------------------------------------------------------------------

    For example, excess nitrogen and phosphorus promote the increased 
growth of opportunistic and short-lived plant species that die quickly, 
leaving more dead vegetative material available for consumption by 
lower tropic levels. Excess nitrogen and phosphorus can promote the 
increased growth of less palatable nuisance algae species that result 
in less food available for filter feeders. These negative changes can 
alter the habitat structure by covering the stream or river bed with 
periphyton (attached algae), and/or clogging the water column with 
phytoplankton (floating algae), both of which can adversely affect 
natural or desirable aquatic life. Excess nitrogen and phosphorus can 
also lead to the increased growth of algae that produce toxins that can 
be toxic to fish, invertebrates, and humans. Chemical characteristics 
of the water, such as pH and concentrations of dissolved oxygen (DO), 
can be affected by excess nitrogen and phosphorus, leading to low DO 
conditions and hypoxia that cannot support aquatic life. All of these 
adverse effects change the balance of the natural populations of 
aquatic flora and fauna expected to occur. In turn, each of these 
negative changes can lead to other negative changes in the stream 
community and ecology and, ultimately, to harmful, adverse effects to 
the overall function of the linked aquatic ecosystem and subsequent 
failure to support designated uses.
    In light of this well-established paradigm, EPA reviewed the latest 
peer-reviewed scientific literature and found many nutrient thresholds 
where harmful, adverse effects in streams are coincident with or occur 
above EPA's proposed streams criteria. In these examples, there are 
regional and site-specific factors (e.g., precipitation, temperature, 
flow) that may account for the differences in the nutrient threshold 
concentrations, but, in general, EPA's proposed streams criteria are 
consistent with the range of thresholds of harmful, adverse effects 
documented in the peer-reviewed scientific literature. For example, TN 
and TP concentrations ranging between 0.659-0.714 mg/L and 0.048-0.071 
mg/L, respectively, have been associated with moderate levels of 
productivity, or mesotrophy, in rivers and streams.\72\ Higher 
concentrations of nutrients lead to eutrophy, which is what numeric 
nutrient criteria, in general, are intended to prevent. As another 
example, increases in suspended chlorophyll-a, decreases in water 
clarity, and decreases in macroinvertebrate and fish abundance in 
Wisconsin rivers and streams were observed over a TN and TP range of 
0.5-2.0 mg/L and 0.035-0.150 mg/L, respectively.\73\ Adverse increases 
in productivity (i.e., organic matter supply), also known as 
eutrophication, can negatively alter the metabolism of aquatic systems 
and lead to adverse environmental conditions such as depressed 
dissolved oxygen concentrations that cannot support aquatic life. These 
conditions, in turn, can harm macroinvertebrate and fish communities, 
creating changes to the balance of the natural populations of these 
aquatic fauna. The TN and TP concentrations above which these adverse 
effects are more likely to occur are coincident with EPA's proposed 
streams criteria TN and TP concentrations.
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    \72\ Dodds, W.K. 2006. Eutrophication and trophic state in 
rivers and streams. Limnol. Oceanogr. 51(1):671-680.
    \73\ Robertson, D.M., B.M. Weigel, and D.J. Graczyk. 2008. 
Nutrient concentrations and their relations to the biotic integrity 
of nonwadeable rivers in Wisconsin. U.S. Geological Survey and U.S. 
Department of the Interior professional paper 1754; Robertson, D.M., 
D.J. Graczyk, P.J. Garrison, L. Wang, G. LaLiberte, and R. 
Bannerman. 2006. Nutrient concentrations ant their relations to the 
biotic integrity of wadeable streams in Wisconsin. U.S. Geological 
Survey and U.S. Department of the Interior professional paper 1722.
---------------------------------------------------------------------------

    Many of the thresholds reported in the latest peer-reviewed 
scientific literature vary in comparison to the proposed criteria for 
Florida's streams due to site- and regional-specific factors such as 
climate and stream flow. However, the nutrient concentrations reported 
in the literature demonstrate and confirm that harmful, adverse effects 
occur as TN and TP concentrations increase in streams and are likely to 
occur as concentrations increase above the criteria concentrations that 
EPA has selected for Florida streams. EPA considers the

[[Page 74998]]

association of the TN and TP concentrations with documented harmful, 
adverse effects to be compelling and supportive of this proposed rule. 
For a complete list of comparable nutrient thresholds reported in the 
scientific literature, see ``EPA Proposed Rule TSD for Florida's 
Streams and DPVs for Unimpaired Lakes'' (Chapter 1, Scientific 
Literature).
4. Additional Evidence of Harmful Effects in Florida Streams Above 
EPA's Proposed Criteria
    In addition to reviewing the peer-reviewed scientific literature 
mentioned in the prior section, EPA reviewed analyses conducted by FDEP 
that demonstrated that excess nitrogen and phosphorus adversely affect 
streams. In its technical support document for deriving numeric 
nutrient criteria, FDEP stated: ``The results of the analyses generally 
indicate that many of the biological measures evaluated exhibit a 
statistically significant adverse response to nutrient pollution; 
however, the relationships between the biological response variables 
and nutrient levels were confounded by numerous other factors such as 
color, pH, conductivity, and canopy cover. While DEP believes the 
effect of nutrients on the biological communities is not clear enough 
to be used as the sole basis for establishing numeric nutrient 
criteria, the observed relationships between nutrients and the various 
biological measures demonstrate the need for nutrient criteria to 
prevent adverse biological effects in Florida streams. While the 
analysis in this chapter did not produce numeric thresholds that could 
be used as water quality criteria, the relationships that were 
determined, while relatively weak, do support the values derived using 
the Nutrient Benchmark Approach. Both the analysis of the Rapid 
Periphyton Survey (regarding probability of increased algal thickness) 
and the analysis of the second change point in the stream periphyton 
response to nutrients indicate that the biological response to nutrient 
enrichment will generally occur at levels higher than the values 
generated using the Benchmark Distribution Approach''.\74\
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    \74\ Technical Support Document: Development of Numeric Nutrient 
Criteria for Florida Lakes, Spring Vents and Streams. Florida 
Department of Environmental Protection, Standards and Assessment 
Section, 2012, p. 110-111.
---------------------------------------------------------------------------

    EPA has reviewed the available periphyton data in Florida streams 
and has verified that a harmful, adverse increase in the amount of 
algal coverage (> 6 mm thick over more than 25% of the stream bottom) 
will be substantially more likely as concentrations of TN and TP 
increase above EPA's proposed numeric streams criteria. This adverse 
biological response represents harmful, adverse changes to the natural 
populations of aquatic flora that occur as concentrations increase 
above the protective values in EPA's proposed numeric streams criteria. 
For more information on the likelihood of increases in the amount of 
algal coverage at varying concentrations of TN and TP, see ``EPA 
Proposed Rule TSD for Florida's Streams and DPVs for Unimpaired Lakes'' 
(Chapter 1, Stressor-Response Relationships).
    EPA also reviewed the available stream fauna data, specifically 
FDEP's multi-metric index of stream macroinvertebrates (e.g., insect 
larvae, worms), which FDEP developed as an indicator of stream 
health.\75\ The index, called the stream condition index (SCI), is a 
generic index, indicating the aggregate impact of human disturbance on 
stream macroinvertebrates. It measures the number and diversity of 
various invertebrate taxa (i.e., individuals sharing the same general 
identity) and was not designed to be uniquely responsive to nutrients, 
but nutrients may contribute to adverse impacts. The SCI score for a 
given sample can range between 0 and 100, where 0 represents a highly 
degraded community and 100 represents the highest quality community. 
EPA re-analyzed Florida-specific stream data and found that stream 
macroinvertebrate community index scores predictably decrease below a 
level EPA and FDEP consider biologically healthy as a function of 
increasing TN and TP concentrations.
---------------------------------------------------------------------------

    \75\ Technical Support Document for EPA's Proposed Rule for 
Numeric Nutrient Criteria to Protect Florida's Streams and 
Downstream Lakes. USEPA, 2012.
---------------------------------------------------------------------------

    Furthermore, when ambient TN or TP concentrations were greater than 
EPA's proposed criteria, SCI scores indicated that, on average, faunal 
populations were imbalanced. For example, SCI scores ranged from 30 to 
50 when ambient TP concentrations were equivalent to EPA's proposed TP 
criteria for each of the five stream NWRs. A SCI score of 50 has been 
identified by scientific experts to be associated with the loss of rare 
native taxa and with the replacement of some sensitive or ubiquitous 
taxa by more pollutant tolerant taxa--this is a level where there is 
some negative change in the natural populations of aquatic fauna, but 
is still considered a score that represents a biologically healthy 
condition; whereas a SCI score of 30 has been associated with 
unbalanced distribution of major groups from what is expected--this is 
a level where there is a profound harmful change in the natural 
populations of aquatic fauna.\76\
---------------------------------------------------------------------------

    \76\ Technical Support Document for U.S. EPA's Final Rule for 
Numeric Criteria for Nitrogen/Phosphorus Pollution in Florida's 
Inland Surface Fresh Waters. U.S. EPA 2010, pp. 49-51.
---------------------------------------------------------------------------

    EPA applied the average SCI of 40 as one of many screening factors 
in selecting reference sites that were considered to be biologically 
healthy. EPA believes an average SCI of 40 is a level where there is 
some negative change in the natural populations of aquatic fauna, but 
before profound harmful change has occurred.\77\ Following the court's 
remand of the streams criteria, EPA evaluated data in Florida streams 
and found that when the nutrient concentrations exceed EPA's proposed 
numeric streams criteria, the SCI score is 45-70% more likely to be 
less than 50, meaning that it is more likely that there will be some 
negative change as TN and TP concentrations increase above EPA's 
proposed streams criteria. In addition, when the nutrient 
concentrations exceed EPA's proposed numeric streams criteria, the SCI 
score is 17-34% more likely to be less than 30, meaning that it is more 
likely that there will be profound harmful change. Thus, the 
concentrations of EPA's proposed numeric streams criteria represent 
levels above which harmful change begins to be more likely. This 
adverse biological response represents harmful, adverse changes to the 
natural populations of aquatic fauna that occur at concentrations above 
the protective values in EPA's proposed numeric streams criteria. For 
more information on the likelihood of SCI scores at varying 
concentrations of TN and TP, see ``EPA Proposed Rule TSD for Florida's 
Streams and DPVs for Unimpaired Lakes'' (Chapter 1, Stressor-Response 
Relationships).
---------------------------------------------------------------------------

    \77\ Technical Support Document for U.S. EPA's Final Rule for 
Numeric Criteria for Nitrogen/Phosphorus Pollution in Florida's 
Inland Surface Fresh Waters. U.S. EPA 2010.
---------------------------------------------------------------------------

    When considered together and in light of the conclusions drawn by 
FDEP,\78\ the previous and new analyses all indicate that a predictable 
harmful, adverse change (i.e., increase in TN and TP concentrations 
causing imbalance in natural populations of aquatic flora or fauna) 
would likely occur if levels of TN and TP exceed the proposed streams 
criteria.
---------------------------------------------------------------------------

    \78\ Technical Support Document: Development of Numeric Nutrient 
Criteria for Florida Lakes and Streams. Florida Department of 
Environmental Protection, Standards and Assessment Section, June 
2009, p. 96.

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

[[Page 74999]]

5. EPA's Rule Includes the SSAC Provision and Process To Address Any 
Uncertainties Associated With the Reference Condition Approach
    EPA recognizes the uncertainties associated with setting numeric 
nutrient criteria based on the reference condition approach. The case 
law is clear, however, that in protecting human health and the 
environment, EPA can act in light of scientific uncertainty and choose 
to act proactively. American Iron & Steel Institute, 115 F.3d 979, 
(D.C. Cir. 1997) (``[I]t is within EPA's discretion to decide that in 
the wake of uncertainty, it would be better to give the values a 
conservative bent rather than err on the other side.''). While it was 
appropriate for EPA to act to adopt numeric nutrient criteria for 
streams based on the reference condition approach even in the face of 
some scientific uncertainty, EPA also recognized that site-specific 
water quality conditions may make it appropriate to adopt either more 
or less stringent numeric nutrient criteria for a specific water body 
or set of water bodies. To address those situations, and as discussed 
previously in this proposal, EPA's December 2010 final rule authorized 
and established a specific administrative process for adopting, site-
specific alternative criteria (``SSAC'').

D. Proposed Numeric Criteria for the State of Florida's Streams

    EPA is proposing numeric nutrient criteria for TN and TP in five 
geographically distinct watershed regions of Florida's streams not 
covered by the State of Florida's Rule classified as Class I or III 
waters under Florida law (Section 62-302.400, F.A.C.). The proposed TN 
and TP criteria are listed in Table B-1. The proposed criteria are the 
same criteria published in EPA's final rule signed on November 14, 2010 
and published at 75 FR 75762 (December 6, 2010). For purposes of this 
proposed rule and in response to the Court's February 18, 2012 order, 
EPA is proposing these criteria values and explaining how the proposed 
criteria will ensure the protection of the Florida's Class I and III 
designated uses by avoiding harmful changes in TN and TP concentrations 
that would result in an imbalance of natural populations of aquatic 
flora or fauna. EPA requests comment on its proposed numeric nutrient 
criteria for Florida's streams and supporting rationale.

   Table B-1--EPA's Proposed Numeric Criteria for Florida Streams Not
                 Covered by the State of Florida's Rule
------------------------------------------------------------------------
                                    Instream protection value criteria
    Nutrient watershed region    ---------------------------------------
                                      TN (mg/L) *         TP (mg/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. Andrew 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. John's River Watershed, Nassau Coastal Drainage
  Area, and St. Mary's River Watershed.
* For a given waterbody, the annual geometric mean of TN or TP
  concentrations shall not exceed the applicable criterion concentration
  more than once in a three-year period.

E. Proposed Numeric Criteria To Ensure the Downstream Protection of the 
State of Florida's Unimpaired Lakes

    Similar to the Court's opinion regarding EPA's streams criteria, 
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. Order at 70. Thus, the 
Court invalidated the option for establishing default DPVs to protect 
unimpaired lakes in EPA's final rule and remanded it to the Agency for 
further action. Order at 85. This proposed rule provides three options 
for establishing a default DPV for unimpaired lakes and clarifies that 
the proposed options would ensure the attainment and maintenance of the 
numeric lake criteria so as to prevent harmful effects from occurring 
in a downstream lake.
    EPA is proposing default DPV approaches for TN and TP that would 
provide for the attainment and maintenance of downstream water quality 
standards for Florida's unimpaired lakes pursuant to 40 CFR 131.10(b) 
when modeling approaches are unavailable. For this proposed rule, EPA 
is providing for public comment three default approaches available for 
use when modeling cannot be performed to derive DPVs that ensure the 
attainment and maintenance of the numeric lake criteria that, in turn, 
protect the designated uses in Florida's lakes. The default approaches 
would be applicable to streams that flow into unimpaired lakes, but 
could also be used for streams that flow into impaired lakes. The 
default approaches would supplement EPA's promulgated DPVs for the 
protection of downstream lakes, which are codified at 40 CFR 
131.43(c)(2)(ii), consistent with the February 18, 2012 Court order. 
Order at 85.
    Briefly, EPA's final rule provided that DPVs apply to tributary 
streams at the point of entry to the lake, also referred to as the pour 
point. The final rule specified that where sufficient data and 
information are available, DPVs may be established through application 
of the BATHTUB model. See 40 CFR 131.43(c)(2)(ii)(B). EPA's final rule 
also specifically authorizes FDEP or EPA to

[[Page 75000]]

use a model other than BATHTUB when either FDEP or EPA determines that 
it would be appropriate to use another scientifically defensible 
modeling approach that results in the protection of downstream lakes. 
40 CFR 131.43(c)(2)(ii)(B). A lake-specific DPV derived through such 
modeling provides the most refined DPV for a stream at the pour point. 
Where sufficient information is not available to derive TN and/or TP 
DPVs using water quality modeling and the lake does not attain the 
applicable TN, TP, and/or chlorophyll-a criteria or is un-assessed, 
criteria values for TN and/or TP that apply to that lake are to be used 
as the default DPVs. 40 CFR 131.43(c)(2)(ii)(D). See id. EPA believes 
that this approach, which the Court upheld, is protective because the 
TN and TP concentrations entering the lake are unlikely to need to be 
lower than the criterion concentration necessary to be protective of 
the lake itself.
    In the final rule, water quality modeling was EPA's preferred 
approach for the derivation of DPVs. Water quality modeling is the most 
rigorous and most data-demanding method and results in the most refined 
DPVs. The default methods were intended only for use where there is 
insufficient data to use a model. While using a default option to 
develop DPVs requires less data, it also generally leads to more 
stringent criteria to account for the uncertainties associated with 
these less refined approaches.
    The rule proposed today provides three options for a default DPV 
that would apply in cases when there are insufficient data to use a 
water quality model for any unimpaired lake for which EPA has 
promulgated numeric nutrient criteria. The three default options EPA is 
proposing are not intended to supersede or limit the two approaches EPA 
provided in the final rule, codified at 40 CFR 131.43(c)(2)(ii), which 
were upheld by the Court. Order at pp. 69-70, 85. Rather, the default 
options are intended to provide flexibility in deriving a DPV in the 
situation where there is not sufficient information to develop a DPV 
using a water quality model. Thus, EPA views the proposed DPV options 
as supplemental to EPA's other established approaches for deriving 
DPVs. All three options for default DPVs are designed to ensure that 
the unimpaired lake criteria would be attained and maintained when the 
inflowing stream's TN and TP concentrations meet the DPV at the pour 
point.
    The first proposed default option simply utilizes the downstream 
lake criteria as the DPV applicable at the pour point to the lake. EPA 
refers readers to 40 CFR Sec.  131.43(c)(1) for the applicable TN and 
TP lake criteria, which would serve as the DPV. EPA believes that this 
proposed option is protective because it is unlikely that the TN and TP 
concentrations entering the lake need to be lower than the criterion 
concentration necessary to be protective of the lake itself.
    The second proposed default option uses Florida-specific stream and 
lake data to empirically link the DPV to the attainment and maintenance 
of Florida's lake criteria in each of the three lake classes. This 
option utilizes Florida's extensive stream and lake data to compute a 
linear regression model, which relates the inflowing stream TN and TP 
concentrations to the TN and TP concentrations in the downstream lake. 
EPA developed a linear regression model for each of the three lake 
classes based on EPA's lake dataset provided in the final rule and 
Florida's stream data from its statewide water quality database.\79\
---------------------------------------------------------------------------

    \79\ IWR Run 40.
---------------------------------------------------------------------------

    The linear regression equation is used to predict what the 
inflowing stream's TN and TP concentrations need to be in order for the 
lake concentrations to meet the lake criteria EPA established in the 
December 6, 2010 final rule. EPA's calculated TN and TP DPVs for each 
lake class using this approach are provided in Table C-1. The approach 
is described in further detail in the EPA Proposed Rule TSD for 
Florida's Streams and DPVs for Unimpaired Lakes.
    For this proposed option, in circumstances where additional lake 
and stream data are available, the linear regression equation could be 
updated using this new data and used to calculate default DPVs that are 
reflective of newer, more site-specific information.

   Table C-1--EPA's Proposed DPVs for Each Lake Class Using the Second
                            Default Approach
------------------------------------------------------------------------
                                                       Default option 2
                                                     -------------------
                     Lake class                        TN DPV    TP DPV
                                                       (mg/L)    (mg/L)
------------------------------------------------------------------------
Colored Lakes.......................................      1.59      0.11
Clear, High Alkaline Lakes..........................      1.40      0.09
Clear, Low Alkaline Lakes...........................      0.87      0.06
------------------------------------------------------------------------

    The third proposed default option utilizes stream data that is 
spatially linked to and temporally coincident with the downstream lake 
when it is attaining the applicable lake criteria. This proposed option 
is a reference condition-based DPV approach that is conditioned upon 
the downstream lake attaining all applicable numeric nutrient criteria, 
TN, TP, and chlorophyll-a, including the duration and frequency 
components of the applicable lake criteria. To compute a reference 
condition-based DPV, the period of record during which the downstream 
lake was attaining all applicable criteria must be determined. At a 
minimum, and pursuant to 40 CFR 131.43(c)(1), the lake must not exceed 
any applicable numeric nutrient criteria, which are expressed as annual 
geometric means, more than once in a three-year period. If this 
condition is met, then a DPV for that lake can be computed using TN and 
TP data from the stream discharging into the lake coincident in time 
with the period of record when the lake was attaining all applicable 
numeric nutrient criteria. Because of the hydrologic link between 
streams and lakes, it follows that nitrogen and phosphorus 
concentrations in the stream would be sufficient to meet the lake 
criteria provided that the lake was meeting all applicable numeric 
nutrient criteria. In general, this approach is less refined compared 
to the modeling approach EPA promulgated at 40 CFR 131.43(c)(1)(ii)(B) 
because it does not incorporate the water quality parameters and data 
that would be necessary to derive a site-specific DPV, for either TN or 
TP, using a water quality model such as BATHTUB. Nonetheless, EPA 
believes that the data and information that would support this third 
approach, in the absence of additional data that would support 
modeling, is still sufficient to ensure the protection of the 
downstream lake because of the hydrologic linkage between the stream 
and downstream lake. A DPV calculated under this option may be more 
stringent than a DPV calculated using a water quality model. This 
default approach is 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 Clean Water Act. Higher 
levels of TN and/or TP may be allowed in watersheds where it is 
demonstrated that such higher levels will fully protect the lake's 
water quality standard. To the extent that it is determined that the 
default DPV for a given lake tributary is over protective, applying a 
water quality model as set out in EPA's preferred approach will result 
in a more refined definition of the DPV for that tributary.
    As discussed earlier, the calculation of the DPV using the three 
default

[[Page 75001]]

options requires that the lake criteria be explicitly considered. The 
applicable numeric lake criteria can be found at 40 CFR 131.43(c)(1). 
EPA recognizes that lake criteria may be modified pursuant to the 
modified lake criteria provision at 40 CFR 131.43(c)(1)(ii). Where lake 
criteria are modified in accordance with this provision, the modified 
criteria would be the applicable criteria in any of the three default 
DPV approaches. The duration and frequency components of DPV magnitudes 
computed using the proposed default approaches would be an annual 
geometric mean not to be exceeded more than once over a three-year 
period. These components of the proposed approaches align with the 
duration and frequency of both the numeric lake criteria, codified at 
40 CFR 131.43(c)(1), and the streams criteria which are proposed to be 
codified at 40 CFR 131.43(c)(2).
    As in the final rule, protection of downstream lakes using the 
options described in this proposed rule is accomplished through 
establishment of a DPV. The applicable criteria for streams that flow 
into downstream lakes include both the instream criteria for TN and TP 
and the DPV, which is a concentration or loading value at the point of 
entry of a stream into a downstream lake that ensures the attainment 
and maintenance of the numeric lake criteria. EPA selected the point of 
entry into the lake as the location to measure water quality because 
the lake responds to the input from the pour point, and all 
contributions from the stream network above this point in a watershed 
affect the water quality at the pour point. When a DPV is exceeded at 
the pour point, the waters that collectively comprise the network of 
streams in the watershed above that pour point are considered to not 
attain the DPV for purposes of CWA section 303(d). The State may 
identify these impaired waters as a group rather than individually.
    Contributions of TN and/or TP from sources in stream tributaries 
upstream of the pour point are accountable to the DPV because the water 
quality in the stream tributaries must result in attainment of the DPV 
at the pour point into the lake. The spatial allocation of load within 
the watershed is an important accounting step to ensure that the DPV is 
achieved at the point of entry into the lake. How the watershed load is 
allocated may differ based on watershed characteristics and existing 
sources (e.g., areas that are more susceptible to physical loss of 
nitrogen; location of towns, farms, and dischargers), so long as the 
DPV is met at the point of entry into the downstream lake. Where 
additional information is available, watershed modeling could be used 
to develop allocations that reflect hydrologic variability and other 
water quality considerations. For protection of the downstream lake, 
what is important is an accounting for nutrient pollution loadings on a 
watershed scale that results in meeting the DPV at the point of entry 
into the downstream lake.
    As in the December 6, 2010 final rule, this proposal provides that 
additional DPVs may be established in upstream locations to represent 
sub-allocations of the total allowable loading or concentration. Such 
sub-allocations may be useful where there are differences in 
hydrological conditions and/or sources of TN and/or TP in different 
parts of the watershed. In addition to the explanations provided 
earlier, EPA refers the reader to its technical support document 
associated with the December 6, 2010 final rule for specific 
information supporting how harmful, adverse effects are more likely to 
occur in lakes at TN and TP concentrations above the established 
numeric lake criteria (Chapter 2, Derivation of EPA's Numeric Nutrient 
Criteria for Lakes).
    EPA requests comment on the three proposed default approaches, 
including whether implementation of DPVs calculated using the default 
approaches would ensure the attainment and maintenance of the 
downstream numeric lake criteria in Florida's unimpaired lakes. The 
proposed default DPV approaches and DPVs are aimed at the protection of 
unimpaired lakes. However, EPA recognizes that the second and third 
options may also be appropriate for the protection of impaired lakes 
and offer additional flexibility to the default DPV approach for 
impaired lakes, which is codified at 40 CFR 131.43(c)(2)(ii)(D). EPA 
requests comment on applying the second and third default DPV options 
to impaired lakes as well as unimpaired lakes. In addition, EPA 
requests comments on whether the Agency should promulgate default DPV 
values in addition to default DPV approaches to be used in situations 
when modeling is unavailable.

F. Applicability of Criteria When Final

    EPA proposes that the numeric nutrient criteria for Florida's 
streams not covered by Florida's Rule and the DPVs for unimpaired lakes 
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 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.
    In addition to this proposal, EPA has proposed to stay the December 
6, 2010 final rule \80\ (75 FR 75762) to November 15, 2013 (See http://water.epa.gov/lawsregs/rulesregs/florida_inland.cfm). This date should 
closely coincide with the effective date of this proposed rule, which 
is approximately 60 days following the publication of the final rule 
(i.e., shortly after August 31, 2013).
---------------------------------------------------------------------------

    \80\ Federal Register, Vol. 75, No. 233, 75762, December 6, 
2010. Water Quality Standards for the State of Florida's Lakes and 
Flowing Waters.
---------------------------------------------------------------------------

    For water bodies that Florida has designated as Class I 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.

[[Page 75002]]

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 Federal standards be either not 
finalized or withdrawn?

    Under the CWA, Congress gave states primary responsibility for 
developing and adopting WQS for their navigable waters. (See CWA 
section 303(a)-(c)). EPA is proposing numeric nutrient criteria for 
flowing waters outside the South Florida Region not covered by the 
State of Florida's Rule and DPVs for unimpaired lakes to meet the 
Agency's obligations under the Consent Decree. EPA notes if Florida's 
Rule will not take effect due to subsection 62-302.531(9), F.A.C., EPA 
would expect to finalize the criteria in this proposed rulemaking for 
all flowing waters (i.e., streams) located outside of the South Florida 
Region that are designated as either Class I or Class III. EPA solicits 
comment on this potential outcome. EPA recognizes that Florida has 
exercised the option to adopt and submit to EPA numeric nutrient 
criteria for some of the State's Class I and many of the State's Class 
III waters and EPA has approved those criteria as consistent with CWA 
section 303(c) and implementing regulations at 40 CFR part 131. 
Consistent with CWA section 303(c)(4), EPA does not intend to proceed 
with the final rulemaking for those waters for which EPA has approved 
Florida's criteria, provided that the newly approved State water 
quality standards will be allowed to go into effect, FDEP will be 
allowed to implement them consistent with their Implementation 
Document, and, with respect to numeric DPVs, 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.
    EPA is not obligated under the Consent Decree to promulgate 
regulations setting forth numeric nutrient criteria in all Class I and 
III lakes and flowing waters if the State of Florida submits and EPA 
approves new or revised WQS for these waterbodies. EPA approved 
revisions on November 30, 2012 and is in discussions with Florida 
regarding waters not covered by the State's numeric nutrient criteria.
    Pursuant to 40 CFR 131.21(c), if EPA does finalize this proposed 
rule, the EPA-promulgated WQS would be applicable WQS for purposes of 
the CWA until EPA withdraws the federally-promulgated standard. 
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 when EPA is assured 
that numeric nutrient criteria that fully meet the requirements of 
section 303(c) of the CWA and EPA's implementing regulations at 40 CFR 
part 131 are in effect.
    Among the newly-approved state water quality standards are numeric 
criteria for nutrients that apply to a set of streams, as that term is 
specifically defined in the newly-approved state water quality 
standards. Under the Consent Decree, EPA is relieved of its obligation 
to propose numeric criteria for nutrients after FDEP submits and EPA 
approves new or revised water quality standards. Thus, under normal 
circumstances, EPA would be clearly relieved of its obligation to 
propose numeric criteria for nutrients Florida covered in its newly-
approved state water quality standards. EPA notes that a provision 
included in Florida's Rule, specifically subsection 62-302.531(9), 
F.A.C., casts some doubt as to whether the newly approved state water 
quality standards will go into effect if EPA proposes and promulgates 
numeric nutrient criteria for streams not covered by the newly approved 
State water quality standards. Therefore, it is unclear whether an 
EPA's proposal to ``gap fill'', or establish numeric criteria for 
nutrients for Florida streams that FDEP does not cover in its Rule, 
would trigger 62-302.531(9), F.A.C. and result in Florida's streams 
criteria not taking effect.
    In addition, due to a recent administrative challenge filed in the 
State of Florida Department of Administrative Hearings, there is 
uncertainty as to whether FDEP will be able to implement its newly 
approved state water quality standards consistent with FDEP's 
``Implementation of Florida's Numeric Nutrient Standards'' 
(Implementation Document). Thus, EPA approved portions of Florida's new 
or revised water quality standards subject to the State being able to 
implement them as provided in its Implementation Document. If, as a 
result of legal challenge, FDEP is unable to implement its Rule as 
provided in its Implementation Document, EPA would intend to revisit 
its November 30, 2012 approval of Florida's new or revised water 
quality standards. EPA has therefore reserved its authority to withdraw 
or modify that approval.
    In light of the above, EPA seeks comment on finalizing a rule that 
applies EPA's streams criteria to streams meeting EPA's definition of 
``stream'' that are not covered under Florida's numeric interpretation 
of narrative nutrient criteria at 62-302.531(2)(c), F.A.C. This would 
serve to fill gaps in coverage if Florida's streams criteria are in 
effect, or apply to all streams if Florida's streams criteria are not 
in effect for any reason, including those mentioned above. EPA's 
understanding is that it is obligated to propose numeric criteria in 
streams not covered by 62-302.531(2)(c) F.A.C. under the consent 
decree. EPA acknowledges that it is possible that there may be 
approaches that are similarly protective of designated uses in a subset 
of the uncovered Class III waters and seeks comment on alternatives.
    Finally, as described in EPA's November 30, 2012 approval of 
Florida's new or revised water quality standards, 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, however, 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

[[Page 75003]]

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.

V. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review and Executive 
Order 13563: Improving Regulation and Regulatory Review

    Under Executive Order (EO) 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.

B. Paperwork Reduction Act

    This action does not impose an information collection burden under 
the provisions of the Paperwork Reduction Act, 44 U.S.C. 3501 et seq. 
Burden is defined at 5 CFR 1320.3(b). It 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 WQS program, states must adopt WQS for their waters 
and must submit those WQS to EPA for approval; 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 requirements. EPA also has the authority 
to promulgate WQS in any case where the Administrator determines that a 
new or revised standard is necessary to meet the requirements of the 
Act. These state standards (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 WQS.
    Thus, under the CWA, EPA's promulgation of WQS establishes 
standards that the State 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 proposed rule. In doing so, the State will 
have a number of choices associated with permit writing. 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

    This proposed rule contains no Federal mandates under the 
regulatory provisions of Title II of the Unfunded Mandates Reform Act 
for state, local, or tribal governments or the private sector. The 
State may use these resulting water quality criteria in implementing 
its water quality control programs. This proposed rule does not 
regulate or affect any entity and, 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. Moreover, WQS, 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 WQS 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 will 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 will not alter 
Florida's considerable discretion in implementing these WQS. Further, 
this proposed rule will not preclude Florida from adopting WQS that EPA 
concludes meet the requirements of the CWA, after promulgation of the 
final rule, which would eliminate the need for these Federal standards 
and lead EPA to withdraw them. 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 had extensive communication with the State of Florida to 
discuss EPA's concerns with the State's water quality criteria and 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.
    During its previous rulemaking and development of water quality 
standards for Florida's lakes and flowing waters,

[[Page 75004]]

EPA concluded that the rule \81\ may have tribal implications. 
Ultimately, however, EPA felt that the rule would neither impose 
substantial direct compliance costs on tribal governments, nor preempt 
Tribal law. Therefore, EPA met with the Seminole Tribe on January 19, 
2010 and requested an opportunity to meet with the Miccosukee Tribe to 
discuss EPA's rule, although a meeting was never requested by the 
Tribe.
---------------------------------------------------------------------------

    \81\ 75 FR 75762, December 6, 2010. Water Quality Standards for 
the State of Florida's Lakes and Flowing Waters.
---------------------------------------------------------------------------

    Because this current proposal re-proposes the same numeric nutrient 
criteria with further explanation on how the criteria will ensure the 
protection of the Florida's designated uses by avoiding harmful changes 
in nutrient levels, and provides for the same approaches for 
determining DPVs as in the final rule with some additional flexibility, 
EPA determined that tribal consultation will not be needed. However, 
EPA will specifically solicit additional comment on this proposed rule 
from tribal officials during the public comment period.

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's promulgation of 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 (59 FR 7629, 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 will afford a 
greater level of protection to both human health and the environment if 
these numeric nutrient criteria are promulgated for Class I and Class 
III waters in the State of Florida.

List of Subjects in 40 CFR Part 131

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

    Dated: November 30, 2012.
Lisa P. Jackson,
Administrator.
    For the reasons set out in the preamble, 40 CFR part 131 is 
proposed to be amended as follows:

PART 131--WATER QUALITY STANDARDS

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

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

Subpart D--[Amended]

    2. Section 131.43 is amended by:
    a. Revising (c)(2)(i).
    b. Revising paragraph (c)(2)(ii)(C).
    The revisions read as follows:


Sec.  131.43  Florida.

* * * * *
    (c) * * *
    (2) Criteria for streams.
    (i) The applicable instream protection value (IPV) criteria for 
total nitrogen (TN) and total phosphorus (TP) for streams within each 
respective nutrient watershed region are shown on Table 2.

                                 Table 2
------------------------------------------------------------------------
                                    Instream protection value criteria
    Nutrient watershed region    ---------------------------------------
                                     TN (mg/L) \*\       TP (mg/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. Andrew 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.

[[Page 75005]]

 
\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. John's River Watershed, Nassau Coastal Drainage
  Area, and St. Mary's 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.

    (ii) Criteria for protection of downstream lakes.
    (A) * * *
    (B) * * *
    (C) When the State or EPA has not derived a DPV for a stream 
pursuant to paragraph (c)(2)(ii)(B) of this section, and where the 
downstream lake attains the applicable chlorophyll-a criterion and the 
applicable TP and/or TN criteria, then the DPV for TN and/or TP will be 
determined using any of the following options: For the first option, 
the DPV for TN and/or TP applicable at the pour point to the lake is 
the applicable TN and/or TP criteria for the downstream lake codified 
in 40 CFR 131.43(c)(1), similar to paragraph (c)(2)(ii)(D) of this 
section. For the second option, the DPV for TN and/or TP applicable at 
the pour point of the receiving lake is found in Table 3.

                                 Table 3
------------------------------------------------------------------------
                                                       Default option 2
                                                     -------------------
                     Lake class                        TN DPV    TP DPV
                                                       (mg/L)    (mg/L)
------------------------------------------------------------------------
Colored Lakes.......................................      1.59      0.11
Clear, High Alkaline Lakes..........................      1.40      0.09
Clear, Low Alkaline Lakes...........................      0.87      0.06
------------------------------------------------------------------------

    For the third option, the DPV for TN and/or TP applicable at the 
pour point to the lake is computed using TN and TP data from the stream 
discharging into the lake coincident in time with the period of record 
when the lake was attaining all applicable nutrient criteria pursuant 
to 40 CFR 131.43(c)(1). These default approaches supplement EPA's 
promulgated DPVs for the protection of downstream lakes in paragraphs 
(c)(2)(ii)(B) and (D) of this section.

[FR Doc. 2012-30114 Filed 12-17-12; 8:45 am]
BILLING CODE 6560-50-P