[Federal Register Volume 77, Number 26 (Wednesday, February 8, 2012)]
[Proposed Rules]
[Pages 6627-6656]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-2434]



[[Page 6627]]

Vol. 77

Wednesday,

No. 26

February 8, 2012

Part II





Environmental Protection Agency





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40 CFR Part 63





National Emission Standards for Hazardous Air Pollutant Emissions: Hard 
and Decorative Chromium Electroplating and Chromium Anodizing Tanks; 
and Steel Pickling-HCl Process Facilities and Hydrochloric Acid 
Regeneration Plants; Proposed Rule

Federal Register / Vol. 77, No. 26 / Wednesday, February 8, 2012 / 
Proposed Rules

[[Page 6628]]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 63

[EPA-HQ-OAR-2010-0600; FRL-9626-7]
RIN 2060-AQ60


National Emission Standards for Hazardous Air Pollutant 
Emissions: Hard and Decorative Chromium Electroplating and Chromium 
Anodizing Tanks; and Steel Pickling-HCl Process Facilities and 
Hydrochloric Acid Regeneration Plants

AGENCY: Environmental Protection Agency (EPA).

ACTION: Supplemental notice of proposed rulemaking.

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SUMMARY: This action supplements our proposed amendments to National 
Emission Standards for Hazardous Air Pollutant Emissions for Hard and 
Decorative Chromium Electroplating and Chromium Anodizing Tanks; and 
Steel Pickling-HCl Process Facilities and Hydrochloric Acid 
Regeneration Plants, which were published on October 21, 2010 (75 FR 
65068, October 21, 2010). In that action, EPA proposed amendments to 
these NESHAP under section 112(d)(6) and (f)(2) of the Clean Air Act. 
Specifically, this action presents a new technology review and a new 
residual risk analysis for chromium electroplating and anodizing 
facilities and proposes revisions to the NESHAP based on those reviews. 
This action also proposes to remove an alternative compliance method 
for Steel Pickling hydrochloric acid regeneration plants. Finally, this 
action proposes to incorporate electronic reporting requirements into 
both NESHAP.

DATES: Comments must be received on or before March 26, 2012. Under the 
Paperwork Reduction Act, comments on the information collection 
provisions are best assured of having full effect if the Office of 
Management and Budget (OMB) receives a copy of your comments on or 
before March 9, 2012.
    Public Hearing. If anyone contacts the EPA requesting to speak at a 
public hearing by February 21, 2012, a public hearing will be held on 
February 23, 2012.

ADDRESSES: You may submit comments, identified by Docket ID No. EPA-HQ-
OAR-2010-0600, by one of the following methods:
     Federal eRulemaking Portal: www.regulations.gov: Follow 
the instructions for submitting comments.
     Email: a-and-r-docket@epa.gov. Include Docket ID No. EPA-
HQ-OAR-2010-0600 in the subject line of the message.
     Fax: (202) 566-9744. Attention Docket ID No. EPA-HQ-OAR-
2010-0600.
     Mail: U.S. Postal Service, send comments to: EPA Docket 
Center, EPA West (Air Docket), Attention Docket ID No. EPA-HQ-OAR-2010-
0600, U.S. Environmental Protection Agency, Mailcode: 2822T, 1200 
Pennsylvania Ave. NW., Washington, DC 20460. Please include a total of 
two copies. In addition, please mail a copy of your comments on the 
information collection provisions to the Office of Information and 
Regulatory Affairs, Office of Management and Budget (OMB), Attn: Desk 
Officer for EPA, 725 17th Street NW., Washington, DC 20503.
     Hand Delivery: U.S. Environmental Protection Agency, EPA 
West (Air Docket), Room 3334, 1301 Constitution Ave. NW., Washington, 
DC 20004. Attention Docket ID No. EPA-HQ-OAR-2010-0600. 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-OAR-
2010-0600. EPA's policy is that all comments received will be included 
in the public docket without change and may be made available online at 
www.regulations.gov, including any personal information provided, 
unless the comment includes information claimed to be confidential 
business information (CBI) or other information whose disclosure is 
restricted by statute. Do not submit information that you consider to 
be CBI or otherwise protected through www.regulations.gov or email. The 
www.regulations.gov Web site is an ``anonymous access'' system, which 
means EPA will not know your identity or contact information unless you 
provide it in the body of your comment. If you send an email comment 
directly to EPA without going through www.regulations.gov, your email 
address will be automatically captured and included as part of the 
comment that is placed in the public docket and made available on the 
Internet. 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. The EPA has established a docket for this rulemaking under 
Docket ID No. EPA-HQ-OAR-2010-0600. 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, is not placed on the Internet 
and 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 the EPA Docket Center, EPA West, 
Room 3334, 1301 Constitution Ave. NW., Washington, DC. 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, and the telephone number for the EPA 
Docket Center is (202) 566-1742.

FOR FURTHER INFORMATION CONTACT: For questions about this proposed 
action, contact Mr. Phil Mulrine, Sector Policies and Programs Division 
(D243-02), Office of Air Quality Planning and Standards, U.S. 
Environmental Protection Agency, Research Triangle Park, NC 27711, 
telephone (919) 541-5289; fax number: (919) 541-3207; and email 
address: mulrine.phil@epa.gov. For specific information regarding the 
risk modeling methodology, contact Mr. Mark Morris, Health and 
Environmental Impacts Division (C539-02), Office of Air Quality 
Planning and Standards, U.S. Environmental Protection Agency, Research 
Triangle Park, NC 27711; telephone number: (919) 541-5416; fax number: 
(919) 541-0840; and email address: morris.mark@epa.gov.

SUPPLEMENTARY INFORMATION:
    Organization of this Document. The information in this preamble is 
organized as follows:

I. General Information
    A. Does this action apply to me?
    B. Where can I get a copy of this document and other related 
information?
    C. What should I consider as I prepare my comments for the EPA?
    D. When would a public hearing occur?
II. Background Information
    A. Overview of the Chromium Electroplating and Chromium 
Anodizing Source Categories
    B. What is the history of the chromium electroplating and 
chromium anodizing risk and technology reviews?
    C. Overview of the steel pickling source category

[[Page 6629]]

    D. What is the history of the Steel Pickling Risk and Technology 
Review?
    E. What data collection activities were conducted to support 
this action?
III. Analyses Performed
    A. How did we perform the technology review?
    B. For purposes of this supplemental proposal, how did we 
estimate the risk posed by each of the three chromium electroplating 
source categories?
IV. Analytical Results and Proposed Decisions for the Three Chromium 
Electroplating Source Categories
    A. What are the results and proposed decisions based on our 
technology review?
    B. What are the results of the risk assessment?
    C. What are our proposed decisions regarding risk acceptability 
and ample margin of safety?
    D. Compliance Dates
V. What action are we proposing for the steel pickling source 
category?
    A. Elimination of an Alternative Compliance Option
    B. Compliance Dates
VI. What other actions are we proposing?
    A. Electronic Reporting
VII. Summary of Cost, Environmental, and Economic Impacts
    A. What are the affected sources?
    B. What are the emission reductions?
    C. What are the cost impacts?
    D. What are the economic impacts?
    E. What are the benefits?
VIII. Request for Comments
IX. 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 Risks and Safety Risks
    H. Executive Order 13211: Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use
    I. National Technology Transfer and Advancement Act
    J. Executive Order 12898: Federal Actions To Address 
Environmental Justice in Minority Populations and Low-Income 
Populations

I. General Information

A. Does this action apply to me?

    The regulated industrial source categories that are the subject of 
this proposal are listed in Table 1 to this preamble. Table 1 is not 
intended to be exhaustive, but rather provides a guide for readers 
regarding entities likely to be affected by the proposed action for the 
source categories listed. These standards, and any changes considered 
in this rulemaking, would be directly applicable to sources as a 
federal program. Thus, federal, state, local, and tribal government 
entities are not affected by this proposed action. Table 1 shows the 
regulated categories affected by this proposed action.

                Table 1--NESHAP and Industrial Source Categories Affected by This Proposed Action
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NESHAP and source category                                                              NAICS code     MACT code
                                                                                               \1\           \2\
----------------------------------------------------------------------------------------------------------------
Chromium Electroplating NESHAP, Subpart N....  Chromium Anodizing Tanks.............        332813          1607
                                               Decorative Chromium Electroplating...        332813          1610
                                               Hard Chromium Electroplating.........        332813          1615
-------------------------------------------------------------------------------------              -------------
Steel Pickling--HCl Process Facilities And Hydrochloric Acid Regeneration Plants        3311, 3312          0310
 NESHAP, Subpart CCC
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\1\ North American Industry Classification System.
\2\ Maximum Achievable Control Technology.

B. Where can I get a copy of this document and other related 
information?

    In addition to being available in the docket, an electronic copy of 
this proposal will also be available on the World Wide Web (WWW) 
through the Technology Transfer Network (TTN). Following signature by 
the EPA Administrator, a copy of this proposed action will be posted on 
the TTN's policy and guidance page for newly proposed or promulgated 
rules at the following address: http://www.epa.gov/ttn/atw/rrisk/rtrpg.html. The TTN provides information and technology exchange in 
various areas of air pollution control.
    Additional information is available on the residual risk and 
technology review (RTR) web page at http://www.epa.gov/ttn/atw/rrisk/rtrpg.html. This information includes source category descriptions and 
detailed emissions and other data that were used as inputs to the risk 
assessments.

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

    Submitting CBI. Do not submit information containing CBI to the EPA 
through http://www.regulations.gov or email. Clearly mark the part or 
all of the information that you claim to be CBI. For CBI information on 
a disk or CD-ROM that you mail to the EPA, mark the outside of the disk 
or CD-ROM as CBI and then identify electronically within the disk or 
CD-ROM the specific information that is claimed as CBI. In addition to 
one complete version of the comment that includes information claimed 
as CBI, a copy of the comment that does not contain the information 
claimed as CBI must be submitted for inclusion in the public docket. If 
you submit a CD-ROM or disk that does not contain CBI, mark the outside 
of the disk or CD-ROM clearly that it does not contain CBI. Information 
not marked as CBI will be included in the public docket and the EPA's 
electronic public docket without prior notice. Information marked as 
CBI will not be disclosed except in accordance with procedures set 
forth in 40 CFR part 2. Send or deliver information identified as CBI 
only to the following address: Roberto Morales, OAQPS Document Control 
Officer (C404-02), Office of Air Quality Planning and Standards, U.S. 
Environmental Protection Agency, Research Triangle Park, North Carolina 
27711, Attention Docket ID Number EPA-HQ-OAR-2010-0600.

D. When would a public hearing occur?

    If a public hearing is held, it will be held at 10:00 a.m. on 
February 23, 2012 and will be held at a location to be determined. 
Persons interested in presenting oral testimony at the hearing should 
contact Mr. Phil Mulrine, Office of Air Quality Planning and Standards, 
Sector Policies and Programs Division (D243-02), U.S. Environmental 
Protection Agency, Research Triangle Park, NC 27711, telephone (919) 
541-5289; fax number: (919) 541-3207; email address: 
mulrine.phil@epa.gov.

[[Page 6630]]

II. Background Information

A. Overview of the Chromium Electroplating and Chromium Anodizing 
Source Categories

    The Chromium Electroplating NESHAP regulates emissions of chromium 
compounds from three source categories: hard chromium electroplating, 
decorative chromium electroplating, and chromium anodizing. The NESHAP 
apply to both major sources and area sources. The NESHAP were 
promulgated on January 25, 1995 (60 FR 4963) and codified at 40 CFR 
part 63, subpart N. We proposed amendments to the NESHAP on June 5, 
2002 (67 FR 38810) to address issues related to changes in control 
technology, monitoring and implementation. The amendments were 
promulgated on July 19, 2004 (69 FR 42885).
1. Hard Chromium Electroplating
    The Hard Chromium Electroplating source category consists of 
facilities that plate base metals with a relatively thick layer of 
chromium using an electrolytic process. Hard chromium electroplating 
provides a finish that is resistant to wear, abrasion, heat, and 
corrosion. These facilities plate large cylinders and industrial rolls 
used in construction equipment and printing presses, hydraulic 
cylinders and rods, zinc die castings, plastic molds, engine 
components, and marine hardware.
    The NESHAP distinguishes between large hard chromium electroplating 
facilities and small hard chromium electroplating facilities. Large 
hard chromium electroplating facilities are defined as any such 
facility with a cumulative annual rectifier capacity equal to or 
greater than 60 million ampere-hours per year (amp-hr/yr). Small hard 
chromium electroplating facilities are defined as any facility with a 
cumulative annual rectifier capacity less than 60 million amp-hr/yr. 
The NESHAP requires all affected tanks located at large hard chromium 
electroplating facilities to meet an emissions limit of 0.015 
milligrams per dry standard cubic meter (mg/dscm). Alternatively, large 
hard chromium facilities also can comply with the NESHAP by maintaining 
the surface tension limits in affected tanks equal to or less than 45 
dynes per centimeter (dynes/cm), if measured using a stalagmometer, or 
35 dynes/cm, if measured using a tensiometer.
    The Chromium Electroplating NESHAP requires affected tanks at 
existing small hard chromium electroplating facilities to meet an 
emissions limit of 0.030 mg/dscm and affected tanks at new small hard 
chromium electroplating facilities to meet a limit of 0.015 mg/dscm. 
Alternatively, these sources have the option of complying with surface 
tension limits equal to or less than 45 dynes per centimeter (dynes/
cm), if measured using a stalagmometer, or 35 dynes/cm, if measured 
using a tensiometer. Under the current NESHAP, any small hard chromium 
electroplating tank for which construction or reconstruction was 
commenced on or before December 16, 1993 (i.e., the proposal date for 
the original NESHAP) is subject to the existing source standards and 
any small hard chromium electroplating tank constructed or 
reconstructed after December 16, 1993 is subject to new source 
standards.
    We estimate that there currently are approximately 230 large hard 
chromium electroplating facilities and 450 small hard chromium 
electroplating facilities in operation. Of the 450 small hard chromium 
electroplating facilities, we estimate that 150 of these facilities 
have one or more tanks that are subject to the new source standards, 
and the affected sources at the other 300 facilities are subject to the 
existing source standards.
2. Decorative Chromium Electroplating
    The Decorative Chromium Electroplating source category consists of 
facilities that plate base materials such as brass, steel, aluminum, or 
plastic with layers of copper and nickel, followed by a relatively thin 
layer of chromium to provide a bright, tarnish- and wear-resistant 
surface. Decorative chromium electroplating is used for items such as 
automotive trim, metal furniture, bicycles, hand tools, and plumbing 
fixtures. We estimate that there currently are approximately 590 
decorative chromium electroplating plants in operation. The NESHAP 
requires all existing and new decorative chromium electroplating 
sources to meet an emissions limit of 0.01 mg/dscm, or meet the surface 
tension limits of 45 dynes/cm, if measured using a stalagmometer, or 35 
dynes/cm, if measured using a tensiometer.
3. Chromium Anodizing
    The Chromium Anodizing source category consists of facilities that 
use chromic acid to form an oxide layer on aluminum to provide 
resistance to corrosion. The chromium anodizing process is used to coat 
aircraft parts (such as wings and landing gears) as well as 
architectural structures that are subject to high stress and corrosive 
conditions. We estimate that there currently are about 180 chromium 
anodizing plants in operation. The NESHAP requires all existing and new 
chromium anodizing sources to meet an emissions limit of 0.01 mg/dscm, 
or meet the surface tension limits of 45 dynes/cm, if measured using a 
stalagmometer, or 35 dynes/cm, if measured using a tensiometer.

B. What is the history of the chromium electroplating and chromium 
anodizing risk and technology reviews?

    Pursuant to section 112(f)(2) of the CAA, we evaluated the residual 
risk associated with the NESHAP in 2010. At that time, we also 
conducted a technology review, as required by section 112(d)(6). Based 
on the results of our initial residual risk and technology reviews, we 
proposed on October 21, 2010 (75 FR 65071) that the risks due to HAP 
emissions from these source categories were acceptable and that no 
additional controls were necessary to provide an ample margin of safety 
to protect public health because we had not identified additional 
controls that would reduce risk at reasonable costs. Thus, we did not 
propose to revise the NESHAP under 112(f)(2). However, as explained in 
that proposal publication, we were concerned about the potential cancer 
risks due to emissions from this category and asked for additional 
information and comments on this issue.
    As a result of our technology review in 2010, we proposed the 
following amendments to the NESHAP to:
     Incorporate several housekeeping practices into 40 CFR 
63.342(f);
     phase out the use of wetting agent fume suppressants 
(WAFS) based on perfluorooctyl sulfonates (PFOS);
     revise the startup, shutdown, and malfunction provisions 
(SSM) in the rule;
     revise the monitoring and testing requirements; and,
     make a few technical corrections to the NESHAP.
    The comment period for the October 21, 2010 proposal ended on 
December 6, 2010, and we are not re-opening the comment period on those 
issues. However, we will address the comments we received during the 
October 21, 2010 to December 6, 2010 public comment period at the time 
we take final action.

C. Overview of the Steel Pickling Source Category

    Steel pickling is a treatment process in which the heavy oxide 
crust or mill scale that develops on the steel surface during hot 
forming or heat treating is removed chemically in a bath of aqueous 
acid solution. Pickling is a process applied to metallic substances 
that removes surface impurities, stains,

[[Page 6631]]

or crusts to prepare the metal for subsequent plating (e.g., with 
chromium) or other treatment, such as galvanization or painting. An 
acid regeneration plant is defined in the rule as the equipment and 
processes that regenerate fresh hydrochloric acid pickling solution 
from spent pickle liquor using a thermal treatment process. The HAP 
emission points from the steel pickling process include steel pickling 
baths, steel pickling sprays, and tank vents. The HAP emission point 
from acid regeneration plants is the spray roaster.
    We estimate that there are approximately 80 facilities subject to 
the MACT standards that are currently performing steel pickling and/or 
acid regeneration. Many of these facilities are located adjacent to 
integrated iron and steel manufacturing plants or electric arc furnace 
steelmaking facilities (minimills) that produce steel from scrap. 
Facilities that regenerate HCl may or may not be located at steel 
pickling operations.

D. What is the history of the steel pickling risk and technology 
review?

    Pursuant to section 112(f)(2) of the CAA, we evaluated the residual 
risk associated with the NESHAP in 2010. We also conducted a technology 
review, as required by section 112(d)(6) of the CAA. Based on the 
results of our residual risk assessment, we proposed on October 21, 
2010 that the risks were acceptable and that there were no additional 
cost effective controls to reduce risk further and that the NESHAP 
provides an ample margin of safety to protect public health and 
prevented an adverse environmental effect. In that notice, we also 
proposed no changes based on the technology review because we did not 
identify any new, feasible technologies that warranted changes to the 
NESHAP. We are not taking comment on these proposed determinations.

E. What data collection activities were conducted to support this 
action?

1. Chromium Electroplating and Chromium Anodizing Source Categories
    Several commenters expressed concern that the data set used in the 
risk assessment that was relied on for the October 2010 proposal was 
not based on actual data from an adequate number of facilities and was 
not representative of the current chromium electroplating industry. In 
response to these comments, we contacted 28 State and local air 
pollution control agencies to request information on the industry. The 
requested information included facility data (name, location, number of 
employees), process type, tank design and operating parameters, annual 
hours of operation, emission control technology, control device 
operating parameters, emission test data, and other available 
supporting documents, such as emission inventory reports and operating 
permits. Agencies were asked to provide data on the 5 to 10 facilities 
that were likely to have the highest risk based on either chromium 
emissions or close proximity to sensitive receptors, and any additional 
facilities for which the data were readily available. The agencies were 
also asked to review the list of facilities we had in our Chromium 
Electroplating Database and update the list to the extent that they had 
more recent information on plant closings, new plants, or changes in 
processes.
    We received the most current data available from a total of 24 
agencies. We supplemented the data provided by the agencies with 
additional information we obtained from operating permits and other 
information downloaded from State Web sites. We also received some data 
from an industry organization (i.e., the National Association for 
Surface Finishing, located in Washington, DC). The updated data set 
included information on 346 plants. After eliminating redundancies in 
the data and deleting data for facilities that were no longer in 
operation or no longer performing chromium electroplating or anodizing, 
the new data set included annual emissions for 301 plants currently in 
operation. Of these, approximately 128 plants were located in 
California, and 173 plants were located in other States. Finally, we 
performed a quality control check of plant geographic coordinates and 
updated the coordinates for approximately 400 plants, focusing on those 
plants most likely to have high emissions.
    We believe the current data set to be significantly better than the 
data set we relied on for the 2010 proposal for a number of reasons. 
The current data set provides improved emissions estimates for many 
facilities, based on actual emissions test data; provides actual 
emissions data for a larger number of facilities than had been modeled 
for the 2010 proposal; includes an updated plant list that accounts for 
facilities that have opened recently and eliminates nearly 200 plants 
that have recently closed or have stopped performing chromium 
electroplating; includes more plant-specific data on numbers and types 
of electroplating tanks, types of emissions controls, and control 
system operating parameters; and corrected geographic locations 
(latitudes, longitudes) for hundreds of chromium electroplating and 
anodizing facilities.
    For the October 21, 2010, proposal we used the actual emissions 
data available at the time, which covered far fewer plants, and, in 
many cases, were based on general emission factors and other data not 
specific to the plant in question. To fill in data gaps for the October 
2010 proposal, we relied on plant capacity, process design, process 
operating, and control device data collected during the development of 
the original MACT standard in the early 1990's to develop a series of 
model plants for each process (hard chromium electroplating, decorative 
chromium electroplating, and chromium anodizing). We used theoretical 
emissions estimates for the model plants to represent actual facilities 
in operation. As we have collected much more data on actual emissions 
from facilities currently in operation, we now realize that the 
emission estimates based on pre-MACT data used for the October proposal 
significantly overestimated emissions. In addition, we modeled all of 
the unknown facilities (i.e., the facilities where we did not know the 
type of plating) using the hard chromium electroplating emission factor 
developed from the model plants. Since hard chromium electroplating 
facilities have the highest emissions among the three source categories 
this resulted in very conservative estimates of emissions for those 
unknown sources.
    The list of plants in our current data set much better reflects the 
current status of the industry. First, it better reflects the status 
because we have greatly improved the locations of several hundred 
plants, which is critical in assessing risk. Second, the emissions data 
in the current data set better reflect actual emissions from facilities 
currently in operation because it reflects emission levels since 
implementation of the NESHAP.
    In addition, having more accurate data on such things as the 
emission controls in use, the number of affected electroplating and 
anodizing tanks, tank operating parameters, facility types, stack 
parameters (such as exhaust flow rates), and other information allowed 
us to better estimate current nationwide emissions and the cost and 
environmental impacts associated with the control options. More details 
on the data collection activities for this supplemental proposal are 
provided in the technical document ``Information on Chromium 
Electroplating Facilities Collected from State and Local Agencies from 
January to March 2011,'' which is available in the docket for this 
action.

[[Page 6632]]

Additional details on the industry data collected are provided in the 
technical document ``Profile of Chromium Electroplating Processes and 
Emissions,'' which is available in the docket for this action.
2. Steel Pickling Source Category
    We had sufficient emissions data for this source category at the 
time of the October 21, 2010 proposal for the risk analysis. 
Nevertheless, subsequent to the close of the comment period, we 
gathered more data and information regarding the status of facility 
processes and controls, and we further evaluated the MACT rule to 
determine if any updates or corrections would be appropriate.

III. Analyses Performed

A. How did we perform the technology review?

    For our October 2010 proposal, we performed several activities for 
purposes of evaluating developments in practices, processes, and 
control technologies for the chromium electroplating source categories: 
(1) We reviewed comments received on the proposed 2002 amendments to 
the Chromium Electroplating NESHAP (67 FR 38810, June 5, 2002) to 
determine whether they identified any developments that warranted 
further consideration; (2) we reviewed the supporting documentation for 
the 2007 amendments to California's Airborne Toxic Control Measure 
(ATCM) for Chromium Plating and Chromium Anodizing Facilities; and (3) 
we searched the RACT/BACT/LAER Clearinghouse (RBLC) and the Internet to 
identify other practices, processes, or control technologies that could 
be applied to chromium electroplating.
    The October 21, 2010 proposal of the Chromium Electroplating NESHAP 
identified four developments in practices, processes, and control 
technologies that were considered for the technology review: emission 
elimination devices, high efficiency particulate air (HEPA) filters, 
wetting agent fume suppressants (WAFS), and housekeeping practices. 
These technologies and practices are described in detail in the October 
2010 proposal. Furthermore, our initial analyses, findings, and 
conclusions regarding these developments are discussed in the preamble 
to the October 2010 proposal. The following paragraphs describe 
additional analyses that were performed for today's supplemental 
proposal.
1. Emissions Limits
    a. Large Hard Chromium Electroplating. Most large hard chromium 
facilities currently have one or more add-on control devices such as 
packed bed scrubbers (PBS), composite mesh pad (CMP) scrubbers, mesh 
pad mist eliminators (MPMEs), high efficiency scrubbers, or HEPA 
filters. Some facilities use add-on controls plus WAFS to limit 
emissions. However, some facilities control their emissions using only 
WAFS and have no add-on control device.
    To evaluate how effective the emission control technologies 
currently used on existing large hard chromium electroplating sources 
are in reducing emissions and meeting the emissions limit, we compiled 
the available data on emission concentration (mg/dscm) we collected 
from the 24 State and local agencies and ranked the data from lowest to 
highest. We have data from 75 tanks located at 38 facilities. We then 
reviewed the data to better understand where existing sources operated 
with respect to the emissions limit. That is, we looked at the number 
of sources that operated at or below various emission levels, including 
75 percent of the emissions limit, 50 percent of the emissions limit, 
and 40 percent of the emissions limit.
    The data indicate that most of these sources operate well below the 
0.015 mg/dscm emissions limit. For example, approximately 88 percent of 
existing sources operate at less than 75 percent of the emissions limit 
(i.e., below 0.011 mg/dscm); 72 percent of sources operate at less than 
50 percent of the emissions limit (i.e., below 0.0075 mg/dscm); and 
about 67 percent of existing large hard chromium electroplating sources 
achieve emissions below 0.006 mg/dscm. We then considered several 
options for reducing the emissions and weighed the costs and emissions 
reductions associated with each option. Further discussion of these 
options and the proposed decisions are presented in section IV below.
    For purpose of addressing new large chromium electroplating 
facilities, we considered the feasibility of a more stringent emissions 
limit. Specifically, we examined what emission level could be met using 
available add-on control devices (such as with a CMP, MPME, or high 
efficiency scrubber) or a combination of add-on controls (such as a CMP 
plus a HEPA filter or an MPME plus a HEPA filter) and the emissions 
concentrations that could be achieved by using a combination of add-on 
control technology and WAFS. The results of this analysis and the 
proposed decisions are described in section IV below.
    b. Small Hard Chromium Electroplating. For small hard chromium 
electroplating facilities, we performed the same type of analyses 
described in the previous section for large hard chromium 
electroplating. In terms of emissions limits, the NESHAP distinguishes 
between existing facilities, which are subject to an emissions limit of 
0.030 mg/dscm, and new facilities, which are subject to an emissions 
limit of 0.015 mg/dscm. We compiled and ranked the available data, 
which also indicate that the large majority of sources operate well 
below the current emissions limits. We have data on emissions 
concentrations for 73 tanks at 56 facilities located in States other 
than California which were used for this ranking. We estimate that 
there are a total of 414 small hard chromium plants located in States 
other than California. We estimate that there are a total of 450 plants 
nationwide, with about 36 plants located in California. We considered 
different options for reducing the emissions limits. We also considered 
removing the existing distinction between existing and new, as they are 
currently defined in the NESHAP, because many of the ``new'' facilities 
have been in operation for more than 17 years and we were considering 
proposing a more stringent new source standard for all sources. We 
evaluated the impacts, in terms of costs and emissions reductions, that 
would result for various potential proposed emissions limits at or 
below 0.015 mg/dscm. We did not evaluate potential limits greater than 
0.015 mg/dscm since about one-third of the currently operating small 
hard chromium sources are already subject to an emissions limit of 
0.015 mg/dscm. Specifically, we considered two main options: (1) 
Propose that all small hard chromium electroplating facilities 
currently in operation meet an emissions limit of 0.015 mg/dscm, and 
(2) propose that all small hard chromium electroplating facilities 
currently in operation meet an emissions limit of 0.010 mg/dscm. The 
results of this analysis and the proposed decisions are described in 
section IV below.
    We also considered revising the definition of new small hard 
chromium electroplating facilities, based on the proposal date for this 
action, and requiring those facilities to meet a more stringent 
emissions limit. The results of this analysis and the proposed 
decisions are described in section IV below.
    c. Decorative Chromium Electroplating. For decorative chromium 
electroplating, we intended to perform

[[Page 6633]]

analyses similar to that performed for hard chromium electroplating. 
However, the data set for decorative chromium electroplating was much 
smaller (e.g., 20 data points for decorative chromium electroplating 
vs. 75 data points for large hard chromium), and we did not think the 
data were adequate for considering several different emissions 
reductions options. The primary reason for the smaller data set is that 
the most commonly used method for controlling emissions from decorative 
chromium electroplating is adding WAFS to the electroplating tank bath. 
Since sources that use WAFS and comply with the surface tension limits 
are not required to conduct an emission test, there are limited test 
data available.
    However, we did rank the available data on existing sources in the 
decorative chromium electroplating source category by emissions level 
to determine the typical level of emissions performance and range of 
performance among those sources to determine options for revising these 
limits. All the facilities for which we have data have emissions 
concentrations less than 0.007 mg/dscm (i.e., at least 30 percent below 
the applicable emissions limit of 0.010 mg/dscm). Further discussion of 
this analysis and the proposed decisions for existing and new 
decorative chromium electroplating sources are presented in section IV 
below.
    d. Chromium Anodizing. In the case of chromium anodizing, we had 
only a single data point (0.0016 mg/dscm), which is significantly below 
the current emissions limit of 0.010 mg/dscm. However, we concluded 
that the data on decorative chromium electroplating was relevant to 
determining the feasible options for chromium anodizing. For one, many 
chromium anodizing sources (approximately 50 percent) are controlled 
using only WAFS. It was for this reason that the current NESHAP 
specifies the same emissions limits of 0.010 mg/dscm for both chromium 
anodizing and decorative chromium electroplating sources. In addition, 
chromium anodizing plants are comparable to decorative chromium 
electroplating plants with respect to the relative magnitude of 
chromium emissions. Finally, the feasibility and options for 
controlling emissions from chromium anodizing are similar to those for 
decorative chromium. Further discussion of this analysis and the 
proposed decisions for existing and new chromium anodizing sources are 
presented in section IV below.
2. Surface Tension Limits
    The NESHAP provides that affected sources must either meet an 
emissions limit specified in the NESHAP or must maintain the surface 
tension in chromium electroplating or chromium anodizing tanks below 
one of two specified surface tension limits, depending on the type of 
instrument used to measure surface tension. Despite the fact that the 
emissions limits for the three chromium electroplating source 
categories differ, the surface tension limits in the current NESHAP are 
the same for all three source categories and are the same for existing 
and new sources, as follows: if a stalagmometer is used to measure 
surface tension, the surface tension limit is 45 dynes/cm, and, if a 
tensiometer is used, the surface tension limit is 35 dynes/cm. The 
available data, which are described in detail in the technical document 
``Development of Revised Surface Tension Limits for Chromium 
Electroplating and Anodizing Tanks Controlled with Wetting Agent Fume 
Suppressants,'' which is available in the docket, indicate that 
maintaining the surface tension below these limits ensures that 
emissions are below 0.01 mg/dscm, which is the most stringent limit 
currently in the NESHAP.
    As part of the information collection described in section II.E of 
this preamble, we obtained test data for several decorative and hard 
chromium electroplating sources controlled using only WAFS. These data 
on surface tension and emission concentration were evaluated to 
determine the relationship between emissions and surface tension. We 
analyzed these data to evaluate the feasibility of requiring lower 
surface tension limits and the corresponding emissions levels. Further 
details of this analysis and the results, and the proposed decisions 
based on this analysis, are presented below in section IV.A.

B. For purposes of this supplemental proposal, how did we estimate the 
risk posed by each of the three chromium electroplating source 
categories?

    The EPA conducted a risk assessment that provided estimates of the 
maximum individual risk (MIR) posed by HAP emissions from sources in 
the source category and the hazard index (HI) for chronic exposures to 
HAP with the potential to cause noncancer health effects. The 
assessment also provided estimates of the distribution of cancer risks 
within the exposed populations, cancer incidence, and an evaluation of 
the potential for adverse environmental effects for each source 
category. The docket for this rulemaking contains the following 
document which provides more information on the risk assessment inputs 
and models: Residual Risk Assessment for the Chromic Acid Anodizing, 
Decorative Chromium Electroplating, and Hard Chromium Electroplating 
Source Categories. The methods used to assess risks are consistent with 
those peer-reviewed by a panel of the EPA's Science Advisory Board 
(SAB) in 2009 and described in their peer review report issued in 2010 
\1\; they are also consistent with the key recommendations contained in 
that report.
---------------------------------------------------------------------------

    \1\ U.S. EPA SAB. Risk and Technology Review (RTR) Risk 
Assessment Methodologies: For Review by the EPA's Science Advisory 
Board with Case Studies--MACT I Petroleum Refining Sources and 
Portland Cement Manufacturing, May 2010.
---------------------------------------------------------------------------

1. Estimating Actual Emissions
    As explained previously, the revised data set for the Chromium 
Electroplating NESHAP source categories includes significantly improved 
emissions data for many more plants than the data set used for the 
October 2010 proposal. However, to assess nationwide residual risk, it 
was still necessary to estimate emissions for much of the industry. 
Rather than estimate those emissions using the model plant approach 
used for the October 2010 proposal, we used a Monte Carlo procedure to 
simulate actual emissions for those plants for which actual emissions 
data were not available. The simulation model used the pool of 
available data on actual emissions concentrations, exhaust flow rates, 
and annual operating hours for each process type (hard chromium 
electroplating, decorative chromium electroplating, and chromium 
anodizing). Actual emissions data (lbs/yr) were fitted to a Weibull 
distribution and emissions for plants for which emissions were unknown 
were simulated using the actual data for each plant type. Because 
process-specific data were used to simulate emissions for each 
facility, it was necessary to identify the process type for each of the 
plants. Although the process type was known for many plants, it was 
unknown for a large number of other plants. By scaling up the data on 
known plants, and using other available data on the industry, the 
profile of the current chromium electroplating industry was estimated 
in terms of the number of each type of plant.
    One of the primary goals in simulating actual annual emissions was 
to develop a data set of emissions estimates that best represents 
chromium electroplating plants operating in the U.S. For this reason, a 
distinction was made between chromium electroplating plants located in 
California and plants located elsewhere (i.e., the non-

[[Page 6634]]

California plants). Because chromium electroplating plants located in 
California are subject to emissions limits that are significantly more 
stringent than the limits specified in the NESHAP, they typically use 
multiple emissions controls, including HEPA filters in many cases, to 
reduce emissions. Thus, emissions for California plants are not 
representative of emissions for non-California plants. For this reason, 
the data on California plants were not included in the data set used to 
simulate emissions for plants located in other States. However, the 
data on actual emissions from plants located in California were used to 
estimate emissions for other plants in California. Thus, we did not 
exclude the California data from the overall analysis; we treated the 
data from plants in California differently. (Additional details on the 
emissions data for the California plants are provided below.) Based on 
the total numbers of plants nationwide, plant types were randomly 
assigned to each of the unknown plants, while ensuring that the total 
numbers of each type of plants nationwide were preserved. After 
assigning plant types, emissions for each plant was simulated 5,000 
times using only the data for that specific type of plant (e.g., only 
data for small hard chromium electroplating plants were used to 
simulate emissions for a small hard chromium electroplating plant). 
Once all 5,000 simulations were completed, the mean of the simulated 
values for each plant was determined and that value was used to 
populate the risk modeling file on actual emissions.
    Taking into account all of the new emissions data collected 
following the public comment period for the October 2010 proposal, plus 
the good quality emissions data collected previously, the data set 
included emissions estimates for a total of 301 plants. Of these, 
approximately 128 plants were located in California, and 173 plants 
were located in other States. A review of the data indicated that 
emissions for the California plants were significantly lower than 
emissions for the non-California plants. For example, emissions from 
the large hard chromium electroplating plants in California averaged 
0.027 lbs/yr, whereas the average for the non-California large hard 
chromium plants was 2.62 lbs/yr. For small hard chromium 
electroplating, the California plants averaged 0.0095 lbs/yr and the 
non-California plants averaged 0.56 lbs/yr. For decorative chromium 
electroplating, the average emissions were 0.00042 lbs/yr (California) 
and 0.55 lbs/yr (non-California). For chromium anodizing, the average 
emissions were 0.00035 lbs/yr (California) and 0.46 lbs/yr (non-
California). These results clearly indicated that the data for plants 
in California were not representative of plants located outside of 
California. For this reason, all subsequent analyses related to 
estimating emissions for plants located outside of California were 
performed using only data for non-California plants.
    For the California plants we used the emissions estimates as 
reported. For all the plants outside of California, we used actual 
emissions estimates if they were available. For the other plants we 
used the simulation model described above to estimate emissions.
    Overall, we believe that the resulting emissions simulated by the 
model are much more representative of actual emissions on average and 
also are more representative of the variability of emissions from plant 
to plant. Additional details on the simulation approach can be found in 
the emissions technical document ``Simulation of Actual and Allowable 
Emissions for Chromium Electroplating Facilities,'' which is available 
in the docket for this rulemaking.
2. Estimating MACT-Allowable Emissions
    To estimate allowable annual emissions (e.g., lbs/yr) for those 
plants for which actual emissions concentration data were available, we 
calculated the allowable annual emissions using the MACT emissions 
limit. In other words, we scaled up actual annual emissions for those 
plants using the ratio of the emissions concentration (measured during 
the performance test) to the MACT limit. For example, if the measured 
concentration for a large hard chromium plant was 0.0075 mg/dscm, which 
is one-half of the 0.015 mg/dscm emissions limit, we scaled up annual 
emissions by a factor or 2. For those plants for which we did not have 
actual emissions data, we used the same emissions simulation approach 
used to estimate actual emissions, as described previously. That is, 
data for California plants were excluded from the analysis; process 
types were assigned to each plant for which the process was unknown, 
while ensuring that the total number of each type of plant matched the 
estimated numbers of plants nationwide; and a Monte Carlo simulation 
model was developed using the pool of available data on emissions 
concentrations, exhaust flow rates, and annual operating hours for each 
process type to simulate allowable emissions for each plant. However, 
instead of using the actual emissions concentration data in the 
simulation model, we used the corresponding MACT emissions limit. Thus, 
we calculated the allowable emissions by using the pool of available 
data on exhaust flow rates and annual operating hours for each process 
type and assumed each source had emissions concentrations equal to the 
MACT emissions limit (i.e., we assumed they were emitting at the 
maximum level allowed by the MACT standard). For example, to estimate 
the allowable emissions for a large hard chromium electroplating plant, 
data on large hard chromium plant exhaust flow rates and annual 
operating hours were used, along with an emissions concentration of 
0.015 mg/dscm, which is the emissions limit specified in the NESHAP for 
large hard chromium electroplating plants. As was used for calculating 
actual emissions estimates, 5,000 simulations were performed for each 
plant, and the average of simulated values was used to represent 
allowable emissions for the plant. Additional details on the simulation 
approach can be found in the emissions technical document ``Simulation 
of Actual and Allowable Emissions for Chromium Electroplating 
Facilities,'' which is available in the docket for this rulemaking.
3. Conducting Dispersion Modeling, Determining Inhalation Exposures, 
and Estimating Individual and Population Inhalation Risks
    Both long-term and short-term inhalation exposure concentrations 
and health risks from the three chromium electroplating source 
categories were estimated using the Human Exposure Model (HEM-3). The 
HEM-3 performs three of the primary risk assessment activities listed 
above: (1) Conducting dispersion modeling to estimate the 
concentrations of HAP in ambient air, (2) estimating long-term and 
short-term inhalation exposures to individuals residing within 50 
kilometers (km) of the modeled sources, and (3) estimating individual 
and population-level inhalation risks using the exposure estimates and 
quantitative dose-response information.
    The air dispersion model used by the HEM-3 model (AERMOD) is one of 
the EPA's preferred models for assessing pollutant concentrations from 
industrial facilities.\2\ To perform the dispersion modeling and to 
develop the preliminary risk estimates, HEM-3

[[Page 6635]]

draws on three data libraries. The first is a library of meteorological 
data, which is used for dispersion calculations. This library includes 
1 year of hourly surface and upper air observations for approximately 
200 meteorological stations, selected to provide coverage of the United 
States and Puerto Rico. A second library, of United States Census 
Bureau census block \3\ internal point locations and populations, 
provides the basis of human exposure calculations (Census, 2010). In 
addition, for each census block, the census library includes the 
elevation and controlling hill height, which are also used in 
dispersion calculations. A third library of pollutant unit risk factors 
and other health benchmarks is used to estimate health risks. These 
risk factors and health benchmarks are the latest values recommended by 
the EPA for HAP and other toxic air pollutants. These values are 
available at http://www.epa.gov/ttn/atw/toxsource/summary.html and are 
discussed in more detail later in this section.
---------------------------------------------------------------------------

    \2\ U.S. EPA. Revision to the Guideline on Air Quality Models: 
Adoption of a Preferred General Purpose (Flat and Complex Terrain) 
Dispersion Model and Other Revisions (70 FR 68218, November 9, 
2005).
    \3\ A census block is the smallest geographic area for which 
census statistics are tabulated.
---------------------------------------------------------------------------

    In developing the risk assessment for chronic exposures, we used 
the estimated annual average ambient air concentrations of chromium 
emitted by each source. The air concentrations at each nearby census 
block centroid were used as a surrogate for the chronic inhalation 
exposure concentration for all the people who reside in that census 
block. We calculated the MIR for each facility as the cancer risk 
associated with a continuous lifetime (24 hours per day, 7 days per 
week, and 52 weeks per year for a 70-year period) exposure to the 
maximum concentration at the centroid of inhabited census blocks. 
Individual cancer risks were calculated by multiplying the estimated 
lifetime exposure to the ambient concentration of chromium (in 
micrograms per cubic meter ([mu]g/m\3\)) by its unit risk estimate 
(URE), which is an upper bound estimate of an individual's probability 
of contracting cancer over a lifetime of exposure to a concentration of 
1 microgram of the pollutant per cubic meter of air. For residual risk 
assessments, we generally use URE values from the EPA's Integrated Risk 
Information System (IRIS). For carcinogenic pollutants without the EPA 
IRIS values, we look to other reputable sources of cancer dose-response 
values, often using California EPA (CalEPA) URE values, where 
available. In cases where new, scientifically credible dose response 
values have been developed in a manner consistent with the EPA 
guidelines and have undergone a peer review process similar to that 
used by the EPA, we may use such dose-response values in place of, or 
in addition to, other values, if appropriate.
    Incremental individual lifetime cancer risks were estimated as the 
sum of the risks for each of the carcinogenic HAP (including those 
classified as carcinogenic to humans, likely to be carcinogenic to 
humans, and suggestive evidence of carcinogenic potential \4\) emitted 
by the modeled source. Cancer incidence and the distribution of 
individual cancer risks for the population within 50 km of the sources 
were also estimated for the source category as part of this assessment 
by summing individual risks. A distance of 50 km is consistent with 
both the analysis supporting the 1989 Benzene NESHAP (54 FR 38044) and 
the limitations of Gaussian dispersion models, including AERMOD.
---------------------------------------------------------------------------

    \4\ These classifications also coincide with the terms ``known 
carcinogen, probable carcinogen, and possible carcinogen,'' 
respectively, which are the terms advocated in the EPA's previous 
Guidelines for Carcinogen Risk Assessment, published in 1986 (51 FR 
33992, September 24, 1986). Summing the risks of these individual 
compounds to obtain the cumulative cancer risks is an approach that 
was recommended by the EPA's Science Advisory Board (SAB) in their 
2002 peer review of EPA's National Air Toxics Assessment (NATA) 
entitled, NATA--Evaluating the National-scale Air Toxics Assessment 
1996 Data--an SAB Advisory, available at: http://yosemite.epa.gov/
sab/sabproduct.nsf/214C6E915BB04E14852570CA007A682C/$File/
ecadv02001.pdf.
---------------------------------------------------------------------------

    To assess the risk of non-cancer health effects from chronic 
exposures, we summed the HQ for each of the HAP that affects a common 
target organ system to obtain the HI for that target organ system (or 
target organ-specific HI, TOSHI). The HQ is the estimated exposure 
divided by the chronic reference value, which is either the EPA 
reference concentration (RfC), defined as ``an estimate (with 
uncertainty spanning perhaps an order of magnitude) of a continuous 
inhalation exposure to the human population (including sensitive 
subgroups) that is likely to be without an appreciable risk of 
deleterious effects during a lifetime,'' or, in cases where an RfC from 
the EPA's IRIS database is not available, the EPA will utilize the 
following prioritized sources for our chronic dose-response values: (1) 
The Agency for Toxic Substances and Disease Registry Minimum Risk 
Level, which is defined as ``an estimate of daily human exposure to a 
substance that is likely to be without an appreciable risk of adverse 
effects (other than cancer) over a specified duration of exposure''; 
(2) the CalEPA Chronic Reference Exposure Level (REL), which is defined 
as ``the concentration level at or below which no adverse health 
effects are anticipated for a specified exposure duration''; and (3), 
as noted above, in cases where scientifically credible dose-response 
values have been developed in a manner consistent with the EPA 
guidelines and have undergone a peer review process similar to that 
used by the EPA, we may use those dose-response values in place of or 
in concert with other values.
4. Conducting Multipathway Exposure and Risk Screening
    As explained in the October 2010 proposal, chromium electroplating 
facilities do not emit any of the 14 PB-HAP compounds or compound 
classes identified for the multipathway screening in the EPA's Air 
Toxics Risk Assessment Library (available at http://www.epa.gov/ttn/fera/risk_atra_vol1.html). Because none of these PB-HAP are emitted 
by sources in the chromium electroplating source categories, we 
concluded at the time of the proposal that there is low potential for 
significant non-inhalation human or environmental risks for these 
source categories. The data we received since proposal continues to 
indicate that chromium electroplating sources do not emit any of those 
14 PB-HAP compounds or compound classes.
5. Conducting Other Analyses: Facility-Wide Risk Assessments and 
Demographic Analyses
a. Facility-Wide Risk
    To put the source category risks in context, we examined the risks 
from the entire ``facility,'' where the facility includes all HAP-
emitting operations within a contiguous area and under common control. 
In other words, for each facility that includes one or more sources 
from a source category under review, we examined the HAP emissions not 
only from that source category, but also emissions of HAP from all 
other emission sources at the facility. The emissions data for 
generating these ``facility-wide'' risks were obtained from the 2005 
NEI. We analyzed risks due to the inhalation of HAP that are emitted 
``facility-wide'' for the populations residing within 50 km of each 
facility, consistent with the methods used for the source category 
analysis described above. For these facility-wide risk analyses, the 
modeled source category risks were compared to the facility-wide risks 
to determine the portion of facility-wide risks that could be 
attributed to each of the three chromium electroplating source 
categories. We specifically examined the facility that was associated 
with the

[[Page 6636]]

highest estimate of risk and determined the percentage of that risk 
attributable to the source category of interest. The risk documentation 
available through the docket for this action provides all facility-wide 
risks and the percentage of source category contribution for the three 
chromium electroplating source categories.
    The methodology and results of the facility-wide analyses for each 
source category are included in the residual risk documentation as 
referenced in section IV of this preamble, which is available in the 
docket for this action.
b. Demographic Analysis
    To examine the potential for any environmental justice (EJ) issues 
that might be associated with these source categories, we performed 
demographic analyses of the at-risk populations for two of the three 
chromium electroplating categories. We performed these analyses for 
only these two source categories because the chromium anodizing source 
category is not associated with significant populations with estimated 
cancer risks above 1 in a million. For the hard and decorative chromium 
electroplating source categories, we evaluated the percentages of 
different social, demographic and economic groups within the 
populations living near the facilities who were estimated to be 
subjected to cancer risks greater than 1 in a million due to HAP 
emissions from chromium electroplating. We compared the percentages of 
these demographic groups to the total percentages of those demographic 
groups nationwide. The methodology and results of the demographic 
analyses are included in the technical reports: ``Risk and Technology 
Review--Analysis of Socio-Economic Factors for Populations Living Near 
Hard Chromium Electroplating Facilities''; and ``Risk and Technology 
Review--Analysis of Socio-Economic Factors for Populations Living Near 
Decorative Chromium Electroplating Facilities.'' These reports are 
available in the docket for this action.
6. Considering Uncertainties in Risk Assessment
    Uncertainty and the potential for bias are inherent in all risk 
assessments, including those performed for the source category 
addressed in this supplemental proposal. Although uncertainty exists, 
we believe that our approach, which used conservative tools and 
assumptions, ensures that our decisions are health-protective. A brief 
discussion of the uncertainties in the emissions data set, dispersion 
modeling, inhalation exposure estimates and dose-response relationships 
follows below. A more thorough discussion of these uncertainties is 
included in the risk assessment documentation available in the docket 
for this action.
a. Uncertainties in the Emissions Data Set
    Although the development of the RTR data sets involved quality 
assurance/quality control processes, the accuracy of emissions values 
will vary depending on the source of the data, the degree to which data 
are incomplete or missing, the degree to which assumptions made to 
complete the data sets are inaccurate, errors in estimating emissions 
values, and other factors.
    The emission estimates considered in this analysis generally are 
annual totals for certain years that do not reflect short-term 
fluctuations during the course of a year or variations from year to 
year. Additionally, although we believe that we have good data for 
hundreds of facilities in these source categories in our RTR data set, 
our data set does not include data for many other existing facilities.
    To simulate emissions estimates for plants for which we did not 
have actual emissions estimates, separate data sets were compiled for 
each process type: large hard chromium electroplating, small hard 
chromium electroplating, decorative chromium electroplating, and 
chromium anodizing. The data sets included combinations of actual data 
on emissions concentrations, exhaust flow rates, annual operating 
hours, and hourly emission rates. In addition, assumptions were used to 
fill in some of the data gaps. For example, if, for a specific 
facility, data on all parameters except exhaust flow rate were known, 
the exhaust flow rate was estimated using average flow rate data for 
other plants of similar process (e.g., large hard chromium 
electroplating). A similar procedure was used to estimate annual 
operating hours if all data except for annual operating hours were 
known. The relative sizes of the data sets used to simulate emissions 
also introduce various levels of uncertainty in the simulations: the 
smaller the data set, the greater the variability in the analysis, and 
the greater the uncertainty in the emissions estimates. For example, 
the data set for chromium anodizing was the smallest and, therefore, is 
expected to have the highest level of uncertainty; the data set for 
large hard chromium electroplating was the largest and is expected to 
have the lowest degree of uncertainty in the emissions simulations.
    Moreover, even after collecting the additional information, we 
still had many sources in our data set for which we did not know the 
type of facility (e.g., hard chromium electroplating, decorative 
chromium electroplating, or chromium anodizing). To assign source types 
to these unknown sources for the model input file, we first determined 
the percent of each of the type of sources among the sources for which 
we have data, then we assumed that the remaining unknown sources (those 
for which we did not know the source type) would comprise the same 
percentages for each type. Finally, we randomly assigned a source type 
to each unknown plant based on these percentages. For further details 
on these data, the simulation approach, and the associated 
uncertainties, see the technical document ``Simulation of Actual and 
Allowable Emissions for Chromium Electroplating Facilities,'' which is 
available in the docket.
    In terms of speciation, it was assumed that emissions from all 
chromium electroplating sources consisted of 98 percent hexavalent 
chromium and 2 percent trivalent chromium. The actual speciation of 
chromium in exhaust streams may vary slightly from source to source. 
However, historical data indicate that emissions from chromium 
electroplating sources are almost entirely comprised of hexavalent 
chromium, and the 98%/2% assumed speciation was believed to be 
representative of sources on average.
b. Uncertainties in Dispersion Modeling
    While the analysis employed the EPA's recommended regulatory 
dispersion model, AERMOD, we recognize that there is uncertainty in 
ambient concentration estimates associated with any model, including 
AERMOD. In circumstances where we had to choose between various model 
options, where possible, model options (e.g., rural/urban, plume 
depletion, chemistry) were selected to provide an overestimate of 
ambient air concentrations of the HAP rather than underestimates. 
However, because of practicality and data limitation reasons, some 
factors (e.g., meteorology, building downwash) have the potential in 
some situations to overestimate or underestimate ambient impacts. For 
example, meteorological data were taken from a single year (1991) and 
facility locations can be a significant distance from the site where 
these data were taken.
c. Uncertainties in Inhalation Exposure
    The effects of human mobility on exposures were not included in the

[[Page 6637]]

assessment. Specifically, short-term mobility and long-term mobility 
between census blocks in the modeling domain were not considered.\5\ 
The assumption of not considering short or long-term population 
mobility does not bias the estimate of the theoretical MIR, nor does it 
affect the estimate of cancer incidence because the total population 
number remains the same. It does, however, affect the shape of the 
distribution of individual risks across the affected population, 
shifting it toward higher estimated individual risks at the upper end 
and reducing the number of people estimated to be at lower risks, 
thereby increasing the estimated number of people at specific high risk 
levels (e.g., one in 10,000 or one in one million).
---------------------------------------------------------------------------

    \5\ Short-term mobility is movement from one micro-environment 
to another over the course of hours or days. Long-term mobility is 
movement from one residence to another over the course of a 
lifetime.
---------------------------------------------------------------------------

    In addition, the assessment predicted the chronic exposures at the 
centroid of each populated census block as surrogates for the exposure 
concentrations for all people living in that block. Using the census 
block centroid to predict chronic exposures tends to over-predict 
exposures for people in the census block who live farther from the 
facility and under-predict exposures for people in the census block who 
live closer to the facility. Thus, using the census block centroid to 
predict chronic exposures may lead to a potential understatement or 
overstatement of the true maximum impact, but is an unbiased estimate 
of average risk and incidence.
    The assessment evaluates the cancer inhalation risks associated 
with pollutant exposures over a 70-year period, which is the assumed 
lifetime of an individual. In reality, both the length of time that 
modeled emissions sources at facilities actually operate (i.e., more or 
less than 70 years), and the domestic growth or decline of the modeled 
industry (i.e., the increase or decrease in the number or size of 
United States facilities), will influence the future risks posed by a 
given source or source category. Depending on the characteristics of 
the industry, these factors will, in most cases, result in an 
overestimate both in individual risk levels and in the total estimated 
number of cancer cases. However, in rare cases, where a facility 
maintains or increases its emissions levels beyond 70 years, residents 
live beyond 70 years at the same location, and the residents spend most 
of their days at that location, then the risks could potentially be 
underestimated. Annual cancer incidence estimates from exposures to 
emissions from these sources would not be affected by uncertainty in 
the length of time emissions sources operate.
    The exposure estimates used in these analyses assume chronic 
exposures to ambient levels of pollutants. Because most people spend 
the majority of their time indoors, actual exposures may not be as 
high, depending on the characteristics of the pollutants modeled. For 
many of the HAP, indoor levels are roughly equivalent to ambient 
levels, but for very reactive pollutants or larger particles, these 
levels are typically lower. This factor has the potential to result in 
an overstatement of 25 to 30 percent of exposures.\6\
---------------------------------------------------------------------------

    \6\ U.S. EPA. National-Scale Air Toxics Assessment for 1996. 
(EPA 453/R-01-003; January 2001; page 85.)
---------------------------------------------------------------------------

    In addition to the uncertainties highlighted above, there are 
several factors specific to the acute exposure assessment that should 
be highlighted. The accuracy of an acute inhalation exposure assessment 
depends on the simultaneous occurrence of independent factors that may 
vary greatly, such as hourly emissions rates, meteorology, and human 
activity patterns. In this assessment, we assume that individuals 
remain for 1 hour at the point of maximum ambient concentration as 
determined by the co-occurrence of peak emissions and worst-case 
meteorological conditions. These assumptions would tend to be worst-
case actual exposures as it is unlikely that a person would be located 
at the point of maximum exposure during the time of worst-case impact.
d. Uncertainties in Dose-Response Relationships
    There are uncertainties inherent in the development of the dose-
response values used in our risk assessments for cancer effects from 
chronic exposures and non-cancer effects from both chronic and acute 
exposures. Some uncertainties may be considered quantitatively, and 
others generally are expressed in qualitative terms. We note as a 
preface to this discussion a point on dose-response uncertainty that is 
brought out in the EPA's 2005 Cancer Guidelines; namely, that ``the 
primary goal of EPA actions is protection of human health; accordingly, 
as an Agency policy, risk assessment procedures, including default 
options that are used in the absence of scientific data to the 
contrary, should be health protective'' (EPA 2005 Cancer Guidelines, 
pages 1-7). This is the approach followed here, as summarized in the 
next several paragraphs. A complete detailed discussion of 
uncertainties and variability in dose-response relationships is given 
in the residual risk documentation which is available in the docket for 
this action.
    Cancer URE values used in our risk assessments are those that have 
been developed to generally provide an upper bound estimate of risk. 
That is, they represent a ``plausible upper limit to the true value of 
a quantity'' (although this is usually not a true statistical 
confidence limit).\7\ In some circumstances, the true risk could be as 
low as zero; however, in other circumstances the risk could be 
greater.\8\ When developing an upper bound estimate of risk and to 
provide risk values that do not underestimate risk, health-protective 
default approaches are generally used. To err on the side of ensuring 
adequate health protection, the EPA typically uses the upper bound 
estimates rather than lower bound or central tendency estimates in our 
risk assessments, an approach that may have limitations for other uses 
(e.g., priority-setting or expected benefits analysis).
---------------------------------------------------------------------------

    \7\ IRIS glossary (http://www.epa.gov/NCEA/iris/help_gloss.htm).
    \8\ An exception to this is the URE for benzene, which is 
considered to cover a range of values, each end of which is 
considered to be equally plausible, and which is based on maximum 
likelihood estimates.
---------------------------------------------------------------------------

    Chronic non-cancer reference concentration (RfC) and reference dose 
(RfD) values represent chronic exposure levels that are intended to be 
health-protective levels. Specifically, these values provide an 
estimate (with uncertainty spanning perhaps an order of magnitude) of a 
continuous inhalation exposure (RfC) or a daily oral exposure (RfD) to 
the human population (including sensitive subgroups) that is likely to 
be without an appreciable risk of deleterious effects during a 
lifetime. To derive values that are intended to be ``without 
appreciable risk,'' the methodology relies upon an uncertainty factor 
(UF) approach, (U.S. EPA, 1993, 1994) which considers uncertainty, 
variability and gaps in the available data. The UF are applied to 
derive reference values that are intended to protect against 
appreciable risk of deleterious effects. The UF are commonly default 
values,\9\ e.g., factors of

[[Page 6638]]

10 or 3, used in the absence of compound-specific data; where data are 
available, UF may also be developed using compound-specific 
information. When data are limited, more assumptions are needed and 
more UF are used. Thus, there may be a greater tendency to overestimate 
risk in the sense that further study might support development of 
reference values that are higher (i.e., less potent) because fewer 
default assumptions are needed. However, for some pollutants, it is 
possible that risks may be underestimated.
---------------------------------------------------------------------------

    \9\ According to the NRC report, Science and Judgment in Risk 
Assessment (NRC, 1994) ``[Default] options are generic approaches, 
based on general scientific knowledge and policy judgment, that are 
applied to various elements of the risk assessment process when the 
correct scientific model is unknown or uncertain.'' The 1983 NRC 
report, Risk Assessment in the Federal Government: Managing the 
Process, defined default option as ``the option chosen on the basis 
of risk assessment policy that appears to be the best choice in the 
absence of data to the contrary'' (NRC, 1983a, p. 63). Therefore, 
default options are not rules that bind the Agency; rather, the 
Agency may depart from them in evaluating the risks posed by a 
specific substance when it believes this to be appropriate. In 
keeping with EPA's goal of protecting public health and the 
environment, default assumptions are used to ensure that risk to 
chemicals is not underestimated (although defaults are not intended 
to overtly overestimate risk). See EPA, 2004, An Examination of EPA 
Risk Assessment Principles and Practices, EPA/100/B-04/001 available 
at: http://www.epa.gov/osa/pdfs/ratf-final.pdf.
---------------------------------------------------------------------------

    While collectively termed ``UF,'' these factors account for a 
number of different quantitative considerations when using observed 
animal (usually rodent) or human toxicity data in the development of 
the RfC. The UF are intended to account for: (1) Variation in 
susceptibility among the members of the human population (i.e., inter-
individual variability); (2) uncertainty in extrapolating from 
experimental animal data to humans (i.e., interspecies differences); 
(3) uncertainty in extrapolating from data obtained in a study with 
less-than-lifetime exposure (i.e., extrapolating from sub-chronic to 
chronic exposure); (4) uncertainty in extrapolating the observed data 
to obtain an estimate of the exposure associated with no adverse 
effects; and (5) uncertainty when the database is incomplete or there 
are problems with the applicability of available studies.

IV. Analytical Results and Proposed Decisions for the Three Chromium 
Electroplating Source Categories

A. What are the results and proposed decisions based on our technology 
review?

1. Emissions Limits for Large Hard Chromium Electroplating
    a. Emissions Limits for Existing Large Hard Chromium Sources. As 
mentioned above, the available data from 75 tanks located at 38 
facilities outside of California indicate that approximately 88 percent 
of existing large hard chromium electroplating sources located outside 
of California have emissions levels that are less than 75 percent of 
the current emissions limit (i.e., below 0.011 mg/dscm); 72 percent of 
these sources emit at less than 50 percent of the emissions limit 
(i.e., below 0.0075 mg/dscm); and about 60 percent of these sources 
achieve emissions below 0.006 mg/dscm. There are an additional 17 
facilities located in California, which on average have considerably 
lower emissions compared to plants in other States. These findings 
demonstrate that the add-on emission control technologies and/or the 
fume suppressants used by the majority of facilities in this source 
category are very effective in reducing chromium emissions and that 
most facilities have emissions well below the current limit.
    We considered three options to lower the emissions limit. Table 2 
summarizes the emissions, costs, and cost effectiveness for these 
options, which are described further in the following paragraphs.

      Table 2--Summary of Options Considered for Potential Revised Emissions Limits for Large Hard Chromium
                                            Electroplating Facilities
----------------------------------------------------------------------------------------------------------------
                                   Number of       Emissions                                          Cost
            Option                  plants        reductions,   Capital costs,    Annualized    effectiveness, $/
                                   affected         lbs/yr             $          costs, $/yr          lb
----------------------------------------------------------------------------------------------------------------
Reduce emissions limit to                   41             121      $1,821,000      $2,196,000           $18,100
 0.011 mg/dscm................
Reduce emissions limit to                   76             169       2,847,000       4,182,000            24,700
 0.0075 mg/dscm...............
Reduce emissions limit to                   97             180       3,414,000       5,368,000            29,900
 0.006 mg/dscm................
----------------------------------------------------------------------------------------------------------------

    The first option considered was to propose that large hard chromium 
electroplating plants meet an emissions limit of 0.011 mg/dscm, which 
is equivalent to a 25 percent reduction of the current emission limit. 
The second option evaluated was a limit of 0.006 mg/dscm since this is 
the level that would be equivalent to the concentration that can be 
achieved (based on the 99 percent upper tolerance limit) when WAFS are 
used to control emissions and the surface tension in the affected 
chromium electroplating tank is maintained at the level of the proposed 
revised surface tension limits (described in section IV.A.5). Finally, 
as a third option, we selected an emissions limit of 0.0075 mg/dscm for 
large hard chromium electroplating plants to provide an intermediate 
option that is more stringent than the first option of 0.011 mg/dscm, 
but less stringent than the second option of 0.006 mg/dscm.
    As noted above, we considered the option of lowering the current 
emissions limit by 25 percent, which would result in a limit of 0.011 
mg/dscm. Under this option, we estimate that 26 plants (11 percent of 
the total plants nationwide) would need to reduce emissions to comply 
with this option because they have emissions above 0.011 mg/dscm. We 
also assume that an additional 15 plants (6 percent) that have 
emissions close to this level (i.e., have emissions concentrations 
greater than 0.009 mg/dscm) would likely need to make adjustments and 
reduce emissions to ensure continuous compliance with a limit of 0.011 
mg/dscm. Therefore, overall we estimate that 41 of the existing large 
hard chromium facilities (about 18 percent of the total) would reduce 
emissions in order to ensure compliance with a new emissions limit of 
0.011 mg/dscm. We assume that most of these 41 facilities would achieve 
these extra reductions with the addition of fume suppressants. The 
available data, which are described in the technical document 
``Development of Revised Surface Tension Limits for Chromium 
Electroplating and Anodizing Tanks Controlled with Wetting Agent Fume 
Suppressants,'' indicate that about 15 percent of sources in the large 
hard chromium electroplating industry outside of California use fume 
suppressants to supplement the level of control achieved by an add-on 
control device; for facilities located in California the percentage is 
even higher. However, we also assume that some facilities would need to 
install new add-on control devices or retrofit their existing controls 
to meet the proposed limit. The only costs for the other 192 facilities 
(82

[[Page 6639]]

percent of the total) would be testing and/or monitoring costs.
    Based on this analysis, we estimate that the total estimated 
capital costs for all large hard chromium electroplating sources to 
comply with this option (i.e., a limit of 0.011 mg/dscm) and conduct 
the necessary testing and monitoring would be $1.8 million and the 
average capital costs per facility across all facilities would be 
$8,300. The estimated range of capital costs per plant would be from $0 
to $180,000. The total annualized costs would be an estimated $2.2 
million, which includes the costs for controls (WAFS and add-on 
controls) plus testing. The average annual cost per facility across all 
facilities would be about $10,000. The annualized costs per facility 
range from $0 to $55,000. We estimate that these requirements would 
reduce emissions of chromium (mainly hexavalent chromium) by 121 pounds 
per year (lbs/yr), and that the cost-effectiveness would be $18,100 per 
pound. The cost estimates for the WAFS accounts for the potential for 
slightly higher costs for non-PFOS WAFS compared to PFOS-based WAFS and 
includes a conservative assumption that the costs for non-PFOS WAFS 
will be 15 percent higher than the costs for PFOS-based WAFS. The use 
of non-PFOS WAFS to limit surface tension is described further in 
section IV.A.5 below. More information about the estimates of costs and 
reductions and how they were derived are provided in the technical 
support document ``Procedures for Determining Control Costs and Cost 
Effectiveness for Chromium Electroplating Supplemental Proposal'', 
which is available in the docket for this action.
    Another option considered was to lower the current emissions limit 
by 50 percent, which would result in a limit of 0.0075 mg/dscm. Under 
this option, and using a similar assumption (as that used above) that 
facilities with emissions close to this level (i.e., with emissions 
greater than 0.006) would make adjustments and reduce emissions to 
ensure compliance with the revised limit, we estimate that 76 of the 
existing large hard chromium facilities (about 33 percent of the total) 
would reduce emissions in order to ensure compliance with an emissions 
limit of 0.0075 mg/dscm. This would include the approximately 28 
percent of sources not currently meeting this limit, as well as sources 
(approximately 5 percent) that are currently measuring close to this 
limit and that would likely need to make adjustments to ensure 
continuous compliance with a limit of 0.0075 mg/dscm. We assume that 
most of these 76 facilities would achieve these extra reductions with 
the addition of fume suppressants. However, we also assume that some 
facilities would need to install new add-on control devices or retrofit 
their existing controls to meet the limit.
    Based on this analysis, we estimate that the total estimated 
capital costs for all large hard chromium electroplating sources to 
comply with this second option (i.e., a limit of 0.0075 mg/dscm) and 
conduct the necessary testing and monitoring would be about $2.8 
million, and the average capital costs per facility across all 
facilities would be about $12,000. The total annualized costs are 
estimated to be about $4.2 million, and the estimated average annual 
cost per facility across all facilities would be about $19,000. We 
estimate that these requirements would reduce emissions by 169 lbs/yr, 
and that the cost-effectiveness would be about $24,700 per pound. 
Moreover, the incremental cost-effectiveness (i.e., the increased costs 
per pound that result from increasing the level of stringency from 
option 1 to option 2) is estimated to be about $41,800 per pound. This 
option would also result in more facilities needing to install or 
retrofit add-on controls and would have more significant impacts on 
small businesses compared to the first option discussed above.
    We also considered the option of lowering the limit by 60 percent, 
which would result in a limit of 0.006 mg/dscm. The option of reducing 
the emissions limit to 0.006 mg/dscm was evaluated because that 
concentration is equivalent to the concentration that can be achieved 
when WAFS are used to control emissions and the surface tension in the 
affected chromium electroplating tank is maintained at levels 
consistent with the surface tension limits that are being proposed in 
this action (as described in section IV.A.5). However, the number of 
facilities affected, the cost-effectiveness, and incremental cost-
effectiveness were significantly higher than the estimated costs and 
impacts for the two options presented above (as shown in Table 2), and 
would result in greater economic impacts to small businesses.
    We made the decision to consider more stringent emissions limits 
than the limit in the current NESHAP primarily because the revised data 
set indicated that most facilities were operating well below the 
current emissions limit. This indicated that more stringent emissions 
limits could be implemented without significant economic burden to the 
industry.
    After considering the three options described above for reducing 
the emissions limit and after weighing the costs and emissions 
reductions associated with each option, we are proposing to reduce the 
emissions limit for affected tanks located at existing large hard 
chromium electroplating facilities to 0.011 mg/dscm. We conclude this 
emissions limit would achieve significant reductions in emissions at a 
reasonable cost. This option results in reductions from about 18 
percent of the facilities. We project that these facilities would 
generally be the higher emitting facilities since they would be the 
facilities with emissions concentrations at the upper end (above 0.009 
mg/dscm) compared to other facilities; therefore, this lower limit will 
achieve significant reductions. We did not choose the other options for 
a number of reasons, including the following: those options would pose 
greater economic burden, would be less cost effective, would have 
significantly higher incremental cost-effectiveness, would have higher 
total annualized costs and higher average costs per facility, would 
impact substantially more facilities, and would result in greater 
impacts to a greater number of small businesses.
    Nevertheless, as an alternative to meeting the proposed emissions 
limits, we are proposing to allow existing large hard chromium 
electroplating facilities to meet the surface tension limits that are 
also being proposed in this action. The proposed surface tension limits 
would be 40 dynes/cm, if measured using a stalagmometer, and 33 dynes/
cm, if measured using a tensiometer. Section IV.A.5 of this preamble 
discusses the analyses performed and the basis for these proposed 
surface tension limits. As described in section IV.A.5 of this 
preamble, we conclude that maintaining surface tension at this level 
would reflect a level of emissions that is lower than the emissions 
limit (of 0.011 mg/dscm) proposed above.
    b. Compliance Testing and Monitoring. To demonstrate compliance, we 
are proposing that each facility would need to provide a new or 
previous performance stack emissions test that is representative of 
current operations and current controls and is conducted at the exit of 
the control device to show they are in compliance with the emissions 
limit. Or, as an alternative, facilities could demonstrate compliance 
with the MACT standard by monitoring surface tension and demonstrate 
that they maintain the surface tension below the proposed limits of 40 
dynes/cm, if measured with

[[Page 6640]]

a stalagmometer, and 33 dynes/cm, if measured with a tensiometer.
    c. Estimated Costs and Impacts for Existing Large Hard Chromium 
Facilities for the Proposed Option. We estimate that 41 of the existing 
large hard chromium facilities (about 18 percent of the total) would 
reduce emissions in order to ensure compliance with a new emissions 
limit of 0.011 mg/dscm. This would include the approximately 11 percent 
not currently meeting this limit, as well as sources (approximately 6 
percent) that are currently measuring close to this limit and that 
would likely need to make adjustments to ensure continuous compliance 
with the proposed 0.011 mg/dscm level. We assume that most of these 41 
facilities would achieve these extra reductions with the addition of 
fume suppressants. However, we also assume that some facilities would 
need to install new add-on control devices or retrofit their existing 
controls to meet the limit. We estimate that 27 plants would be 
required only to conduct performance tests; and the remaining plants 
would not be required to test or add additional controls.
    Based on this analysis, we estimate that the total estimated 
capital costs for all large hard chromium electroplating sources to 
comply with the revised limits and conduct the necessary testing and 
monitoring is estimated to be $1.8 million and the average capital 
costs per facility across all facilities are $8,300. The total 
annualized costs are estimated to be $2.2 million, and the average 
annual cost per facility across all facilities is estimated to $10,000. 
The range for annualized costs per facility range from $0 to $57,000. 
These costs include the costs for controls (WAFS and add-on controls) 
plus testing. We estimate these requirements will reduce chromium 
emissions (mainly hexavalent chromium) by 121 pounds per year, and that 
the cost-effectiveness would be $18,100 per pound. We conclude that 
these costs (e.g., total capital and annualized costs, and the costs 
per plant) and the cost effectiveness are reasonable, particularly 
since hexavalent chromium is a known human carcinogen.
    d. Emissions Limits for New Large Hard Chromium Sources. We also 
considered options for a more stringent emissions limit for new 
sources. In doing so, we recognized the need to re-define ``new 
source'' to help clarify which facilities would be subject to the new 
source standards being proposed in this action. For purposes of the 
revisions to the NESHAP being proposed, a new facility would be one 
that commences construction or reconstruction after February 8, 2012. 
All other sources are considered existing facilities for purposes of 
these proposed amendments.
    In evaluating options for a more stringent emissions limit for new 
large hard chromium electroplating facilities, we considered the 
emissions concentrations that could be achieved using available add-on 
control devices (such as with a CMP, MPME or high efficiency scrubber) 
or a combination of add-on controls (such as a CMP plus a HEPA filter 
or an MPME plus a HEPA filter) and the emissions concentrations that 
could be achieved using WAFS. To analyze the level of emissions that 
can be achieved with add-on controls, we evaluated available data on 
the emissions concentrations that are achieved by existing hard 
chromium electroplating facilities that have various add-on controls or 
combinations of controls. Based on our analysis, we conclude that the 
best available control technology configurations, such as CMP plus a 
HEPA filter, a MPME plus a HEPA filter, or a high efficiency scrubber, 
can achieve emissions concentrations of approximately 0.003 mg/dscm or 
lower. We also considered the costs associated with each of these types 
of control configurations. We estimate that the capital cost to install 
a CMP plus a HEPA filter for a new large hard chromium source is about 
$306,400 and that the annualized costs would be $109,300/yr. We also 
estimate that the capital and annualized costs for the other comparable 
control technology configurations would be no greater than these. We 
conclude that these costs are reasonable for new sources that choose 
one of these combinations of add-on controls to minimize emissions.
    Nevertheless, as discussed in section IV.A.5 of this preamble, 
maintaining affected tanks below the proposed surface tension limits, 
which would be a cost-effective compliance option for new large hard 
chromium sources, would limit chromium emissions concentrations to less 
than 0.006 mg/dscm. The combination of add-on controls described above 
(e.g., CMP plus HEPA filter or an MPME plus HEPA filter or a high 
efficiency scrubber) can reliably achieve emissions of 0.003 mg/dscm or 
lower at a reasonable cost for those new sources that choose to use 
these add-on controls to comply with the NESHAP instead of WAFS. The 
available data indicate that all existing hard chromium electroplating 
sources that use these add-on controls (e.g., CMP plus HEPA filter or 
an MPME plus HEPA filter) achieve emissions of 0.003 mg/dscm or lower, 
well below 0.006 mg/dscm. Moreover, based on the data that we have, 60 
percent of all existing large hard chromium facilities already achieve 
emissions below 0.006 regardless of the type of controls they use. For 
example, many facilities that only have a CMP alone (without the HEPA 
filter) have emissions below 0.006 mg/dscm. Therefore, we conclude that 
some new facilities may be able to achieve emissions below 0.006 mg/
dscm with only a CMP, which would be lower costs than those costs 
mentioned above for the combination of controls. Taking into account an 
allowance for variability in emission testing and control device 
performance for those sources that comply using add-on controls, and to 
provide new facilities the flexibility to use WAFS to minimize 
emissions to comply with the emissions limit as an alternative to add-
on controls, we are proposing an emissions limit of 0.006 mg/dscm for 
new sources. That is, we are proposing to require affected tanks at new 
large hard chromium electroplating facilities to meet an emissions 
limit of 0.006 mg/dscm.
    Today's action would also allow new large hard chromium 
electroplating sources the option of meeting the proposed surface 
tension limits (40 dynes/cm by stalagmometer and 33 dynes/cm by 
tensiometer) as an alternative to the proposed emissions limit of 0.006 
mg/dscm.
2. Emissions Limits for Small Hard Chromium Electroplating
    a. Emissions Limits for Small Hard Chromium Sources. As we did for 
large hard chromium electroplating, described above to evaluate 
possible options to reduce the emissions limits, we compiled and ranked 
the available data, which indicate that more than 80 percent of the 
currently operating small hard chromium electroplating sources have 
emissions concentrations below the current emissions limit for new 
small hard chromium electroplating sources (i.e., 0.015 mg/dscm). We 
have such data for 73 tanks at 56 facilities located in States other 
than California. We estimate that there are a total of 450 small hard 
chromium plants in the U.S., with 36 of those plants located in 
California and 414 plants located in other States. The plants located 
in California have considerably lower emissions on average compared to 
plants in other States. We evaluated three possible options for a more 
stringent standard for these small hard chromium electroplating 
sources, considering the costs and emissions reductions that would be 
achieved under each of these options. Table 3 summarizes the emissions 
reductions,

[[Page 6641]]

costs, and cost effectiveness associated with these options.

      Table 3--Summary of Options Considered for Potential Revised Emissions Limits for Small Hard Chromium
                                            Electroplating Facilities
----------------------------------------------------------------------------------------------------------------
                                                   Emissions                                          Cost
            Option                 Numer of       reductions,       Capital       Annualized     effectiveness,
                                    plants          lbs/yr         costs, $       costs, $/yr         $/lb
----------------------------------------------------------------------------------------------------------------
Reduce emissions limit to 0.015 mg/dscm
----------------------------------------------------------------------------------------------------------------
Existing Small Hard Chromium..              85              41      $1,445,000        $652,000           $15,800
----------------------------------------------------------------------------------------------------------------
Reduce emissions limit to 0.010 mg/dscm
----------------------------------------------------------------------------------------------------------------
Existing Small Hard Chromium..             140              64       2,447,000       1,225,000            19,200
New * Small Hard Chromium.....              34               7         571,000         243,000            36,000
----------------------------------------------------------------------------------------------------------------
Reduce emissions limit to 0.006 mg/dscm
----------------------------------------------------------------------------------------------------------------
Existing Small Hard Chromium..             171              81       3,161,000       1,585,000            19,700
New * Small Hard Chromium.....              80              35       1,268,000         653,000            18,800
----------------------------------------------------------------------------------------------------------------
* The term ``new'' as used in this table refers to sources subject to the new source limit in the current NESHAP
  (i.e., sources that were constructed or reconstructed after December 16, 1993).

    The first option evaluated was to require existing small hard 
chromium electroplating plants to meet the emissions limit currently 
required for new small hard chromium electroplating plant (i.e., 0.015 
mg/dscm). As described above, the current NESHAP (promulgated in 1995), 
includes a limit of 0.03 for existing sources and a limit of 0.015 for 
new sources (those constructed or reconstructed after December 16, 
1993). We decided that it was appropriate to evaluate this option since 
many small hard chromium plants (those constructed or reconstructed 
since December 16, 1993) are already subject to this limit and because 
the vast majority of currently operating small hard chromium plants are 
achieving emissions at or below this level.
    We also considered a more stringent option of proposing a limit of 
0.006 mg/dscm for the same reason described previously for large hard 
chromium electroplating. That is, an emissions limit of 0.006 mg/dscm 
would be equivalent to the concentration that can be achieved when WAFS 
are used to control emissions and the surface tension in the affected 
chromium electroplating tank is maintained by the revised limits that 
are being proposed in this action.
    Finally, as a third option, we evaluated a possible emissions limit 
of 0.010 mg/dscm for small hard chromium electroplating plants to 
provide an intermediate option that is more stringent than the first 
option of 0.015 mg/dscm, but less stringent than the second option of 
0.006 mg/dscm. These options are described in more detail in the 
following paragraphs.
    As noted above, the first option we considered was to propose that 
all currently operating small hard chromium facilities meet the new 
source limit in the current NESHAP (i.e., 0.015 mg/dscm). Under this 
option, we estimate that 55 plants (12 percent of the total small hard 
chromium plants nationwide) would need to reduce emissions to comply 
with this option because they have emissions at or above 0.015 mg/dscm. 
We also assume that an additional 30 plants (7 percent) that have 
emissions close to this level (i.e., have emissions concentrations 
greater than 0.012 mg/dscm) would likely need to make adjustments and 
reduce emissions to ensure continuous compliance with a limit of 0.015 
mg/dscm. Under this option we estimate that 85 small hard chromium 
facilities (about 19 percent of the total) would reduce emissions. We 
assume that most of these 85 facilities would achieve these extra 
reductions with the addition of fume suppressants. However, we also 
assume that some facilities would need to install new add-on control 
devices or retrofit their existing controls to meet the limit.
    The total estimated capital costs for all small hard chromium 
electroplating sources to comply with this option and conduct the 
necessary testing and monitoring would be $1.45 million, and the 
average capital costs per facility across all facilities would be 
$5,300. The total annualized costs are estimated to be $650,000, and 
the average annual cost per facility across all facilities is $2,400. 
These costs include the costs for controls (WAFS and add-on controls) 
plus testing. The annualized costs per facility are estimated to range 
from $0 to $22,000 per year. We estimate that this option would reduce 
chromium emissions by 41.3 pounds per year, and that the cost-
effectiveness would be $15,800 per pound. More information about the 
estimates of costs and reductions and how they were derived are 
provided in the technical document ``Procedures for Determining Control 
Costs and Cost Effectiveness for Chromium Electroplating Supplemental 
Proposal'', which is available in the docket for this action.
    Another option evaluated was to lower the limit for existing and 
new sources to 0.01 mg/dscm. Under this option we estimate that 174 
small hard chromium facilities (about 39 percent of the total) would 
need to reduce emissions. We assume that most of these 174 facilities 
would achieve these extra reductions with the addition of fume 
suppressants. However, we also assume that several facilities would 
need to install new add-on control devices or retrofit their existing 
controls to meet the limit.
    The total estimated capital costs for all small hard chromium 
electroplating sources to comply with this option and conduct the 
necessary testing and monitoring would be $3.02 million and the average 
capital costs per facility across all facilities would be $17,400. The 
total annualized costs are estimated to be about $1.47 million, and the 
average annual cost per facility across all facilities would be about 
$8,400. We estimate that this option would reduce emissions by 71 
pounds per year, and that the cost-effectiveness would be about $20,700 
per pound. Moreover, the incremental cost-effectiveness (i.e., the 
increased costs per pound that result

[[Page 6642]]

from increasing the level of stringency from option 1 to option 2) is 
estimated to be about $27,000 per pound. This option would also result 
in more facilities needing to install or retrofit add-on controls and 
would have more significant impacts on small businesses compared to 
option 1.
    We also considered the more stringent option of lowering the limit 
to 0.006 mg/dscm, which would be consistent with the emissions that can 
be achieved using WAFS and maintaining the surface tension below the 
limit being proposed in this action. However, the number of facilities 
affected, the cost-effectiveness, and incremental cost-effectiveness 
were significantly higher than the estimated costs and impacts for the 
two options presented above (as indicated in Table 3), and would result 
in greater economic impacts to small businesses.
    After considering the impacts of these three options, we are 
proposing to reduce the emissions limit for existing small hard 
chromium electroplating sources to 0.015 mg/dscm, which is equal to the 
MACT limit we established for new small hard chromium electroplating 
sources when we first promulgated the NESHAP (60 FR 4963, January 25, 
1995).
    As an alternative to meeting the proposed emissions limits, we are 
proposing to allow existing small hard chromium electroplating 
facilities to meet the surface tension limits that are also being 
proposed in this action. The proposed surface tension limits would be 
40 dynes/cm, if measured using a stalagmometer, and 33 dynes/cm, if 
measured using a tensiometer. Section IV.A.5 of this preamble discusses 
the analyses performed and the basis for these proposed surface tension 
limits. As described in section IV.A.5 of this preamble, we conclude 
that maintaining surface tension at this level would reflect a level of 
emissions that is lower than the emissions limit (of 0.015 mg/dscm) 
proposed above.
    b. Compliance Testing and Monitoring. To demonstrate compliance, we 
are proposing that each facility would need to provide a new or 
previous performance stack emissions test that is representative of 
current operations and current controls and is conducted at the exit of 
the control device to show they are in compliance with the emissions 
limit. Or, as an alternative, facilities can demonstrate compliance 
with the MACT standard by monitoring surface tension and demonstrate 
that they maintain the surface tension below the proposed limits of 40 
dynes/cm, if measured with a stalagmometer, and 33 dynes/cm, if 
measured with a tensiometer.
    c. Estimated Costs and Impacts for Small Hard Chromium Facilities.
    We estimate that 85 small hard chromium facilities (about 19 
percent of the total) would reduce emissions to ensure compliance with 
the proposed limit. We assume that most of these 85 facilities would 
achieve these extra reductions with the addition of fume suppressants. 
However, we also assume that some facilities would need to install new 
add-on control devices or retrofit their existing controls to meet the 
limit. We estimate that 26 plants would be required only to conduct 
performance tests; and the remaining plants would not be required to 
test or add additional controls.
    The total estimated capital costs for all small hard chromium 
electroplating sources to comply with the proposed revised limits and 
conduct the necessary testing and monitoring is estimated to be $1.45 
million and the average capital costs per facility are $5,300. The 
total annualized costs are estimated to be $650,000, and the average 
annual cost per facility is $2,400. We estimate that these requirements 
will reduce chromium emissions by 41.3 pounds per year, and that the 
cost-effectiveness would be $15,800 per pound. We conclude that these 
costs (e.g., total capital and annualized costs, and the costs per 
plant) and the cost effectiveness are reasonable, particularly since 
hexavalent chromium is a known human carcinogen.
    d. Emissions Limits for New Small Hard Chromium Sources.
    For new small hard chromium facilities, we considered options for a 
more stringent emissions limit based on the same type of analysis 
described above for large hard chromium electroplating sources. As is 
the case for large hard chromium electroplating, we are also proposing 
to re-define new source as those sources, the construction or 
reconstruction of which commenced after February 8, 2012.
    For the reasons described previously (in section IV.A.1.d) for 
large hard chromium electroplating facilities, we are proposing to 
require new small hard chromium electroplating facilities, to limit 
emissions from affected tanks to 0.006 mg/dscm. Those reasons include 
the findings that add-on controls (such as a CMP plus HEPA filter) or 
WAFS can achieve this level of emissions at new hard chromium sources 
for a reasonable cost. We estimate that installing a combination of CMP 
with HEPA filter on a new small hard chromium electroplating source 
would result in capital costs of $127,000 and annualized costs of 
$45,000 per year. Furthermore, we believe that sources could meet this 
level with other control configurations or with WAFS alone for lower 
costs. We conclude that any new source should be able to achieve this 
level of performance with typical add-on control devices or with use of 
WAFS.
    Today's action would also allow new small hard chromium 
electroplating sources the option of meeting the proposed surface 
tension limits (40 dynes/cm by stalagmometer and 33 dynes/cm by 
tensiometer) as an alternative to the proposed emissions limit of 0.006 
mg/dscm.
3. Decorative Chromium Electroplating
    a. Emissions Limits for Existing and New Sources. As described 
above, the current emissions limit for decorative chromium 
electroplating is 0.010 mg/dscm. We reviewed the available data on 
existing sources in the decorative chromium electroplating source 
category to determine the typical level of emissions performance and 
range of performance among those sources to assess options for revising 
the current limit. We also reviewed the available data on surface 
tension levels and the relationship of surface tension to emissions 
concentrations since most decorative chromium electroplating tanks rely 
primarily or entirely on WAFS to limit emissions. WAFS are the most 
common method for limiting emissions from these facilities.
    With regard to emissions concentration data, we have data from 20 
tanks at 17 facilities. Based on these data, the emissions 
concentrations from these 20 tanks are all less than 0.007. The highest 
value is 0.0066 mg/dscm. Two of these tanks (about 11 percent) have 
emissions between 0.006 to 0.0066. All the other tanks in this data set 
(about 89 percent) have emissions concentrations below 0.006 mg/dscm. 
Some tanks have emissions much lower than 0.006 mg/dscm.
    With regard to our analysis of surface tension and its relationship 
with emissions concentrations, as described in section IV.A.5 below 
(and in more details in the ``Development of Revised Surface Tension 
Limits for Chromium Electroplating and Anodizing Tanks Controlled with 
Wetting Agent Fume Suppressants,'' which is available in the docket for 
this action), we conclude that maintaining surface tension to 40 dynes/
cm (as measured by a stalagmometer) and 33 dynes/cm (as measured with a 
tensiometer) in decorative chromium electroplating baths would maintain 
emissions below 0.006 mg/dscm.

[[Page 6643]]

    After reviewing these data and evaluating various regulatory 
options, we are proposing to lower the limit for existing decorative 
electroplating tanks to 0.007 mg/dscm, which would be a 30 percent 
reduction from the current limit of 0.01 mg/dscm. Our general approach 
to choosing this option was similar to that explained previously for 
hard chromium electroplating. On the one hand, the available data 
indicate that most decorative chromium electroplating sources have 
emissions well below the current emissions limit of 0.010 mg/dscm. As 
noted above, all sources in our data set have emissions concentrations 
below 0.007 mg/dscm. Thus, we concluded that a more stringent limit 
could achieve reductions in emissions, particularly in terms of 
allowable emissions, without imposing a significant burden on the 
industry. On the other hand, the large majority of decorative chromium 
electroplating tanks are controlled with WAFS, and the available 
surface tension data indicate that emissions from these source are in 
the range of 0.004 to 0.006 mg/dscm (as described further in section 
IV.A.5). We considered this concentration range as a lower bound to 
what could reasonably be required. Therefore, we decided to select an 
option between 0.006 and 0.01 mg/dscm for further evaluation. 
Subsequently, we chose to evaluate 0.007 mg/dscm for this thorough 
evaluation since this is the upper end of the emissions levels for 
sources in our data set.
    Although all facilities in our data set that use an add-on control 
device have emissions below 0.007 mg/dscm, we realize that some sources 
(an estimated 8 facilities) currently have emissions relatively close 
to this limit and therefore would likely need to make adjustments and 
achieve reductions to ensure continuous compliance with the proposed 
0.007 mg/dscm level. Based on the available emissions concentration 
data, we estimate that about 8 facilities may need to reduce emissions 
to ensure compliance with this limit. (See the technical support 
document ``Procedures for Determining Control Costs and Cost 
Effectiveness for Chromium Electroplating Supplemental Proposal'' which 
is available in the docket for more details). However, it is important 
to note that sources would have the choice to comply with the standard 
either by demonstrating emissions are less than 0.007 mg/dscm (with a 
stack test), or by maintaining surface tension below 40 dynes/cm (as 
measured by a stalagmometer) or 33 dynes/cm (as measured with the 
tensiometer), as described further in section IV.A.5 below. We believe 
that most of the decorative chromium facilities would choose this 
surface tension compliance approach.
    Nevertheless, we estimate that by lowering the limit to 0.007 mg/
dscm (and recognizing that plants would have the option to demonstrate 
compliance by meeting the surface tension limits), the total capital 
costs for all decorative chromium electroplating facilities to comply 
with this option and to conduct all the necessary testing and 
monitoring would be $183,000, and the average capital costs per 
facility would be $400. The total annualized costs are estimated to be 
$189,000, and the average annual cost per facility is $390. We estimate 
that this option would reduce emissions by 39 pounds per year, and that 
the cost-effectiveness would be $4,800 per pound.
    We also considered other options, but we concluded that proposing a 
limit of 0.007 was the most appropriate option. Therefore, we are 
proposing an emissions limit of 0.007 mg/dscm for existing decorative 
chromium electroplating sources. We conclude that this lower proposed 
limit would likely require no costs for add-on controls for these 
sources since all facilities for which we have data are already 
performing below this level with their current controls and that all 
the other facilities (that may need to achieve reductions) will do so 
by adding fume suppressants rather than installing add-on controls or 
retrofitting their existing controls.
    This limit of 0.007 mg/dscm would apply to any affected decorative 
chromium electroplating source that is controlled with an add-on 
emission control device and chooses to demonstrate compliance with a 
stack emissions test.
    As an alternative to meeting the proposed emissions limit, we are 
proposing to allow existing decorative chromium electroplating 
facilities to meet the surface tension limits that are also being 
proposed in this action. The proposed surface tension limits would be 
40 dynes/cm, if measured using a stalagmometer, and 33 dynes/cm, if 
measured using a tensiometer. Section IV.A.5 of this preamble discusses 
the analyses performed and the basis for these proposed surface tension 
limits. As described in section IV.A.5 of this preamble, we conclude 
that maintaining surface tension at this level would reflect a level of 
emissions that is lower than the emissions limit (of 0.007 mg/dscm) 
proposed above.
    With regard to new sources, we are proposing to require new 
decorative chromium electroplating tanks meet an emissions limit of 
0.006 mg/dscm, consistent with the proposed new source limit for hard 
chromium electroplating sources. As explained previously, the available 
data indicate that chromium electroplating plants that use WAFS to 
control emissions and maintain the surface tension below the proposed 
limits would meet an emissions concentration of 0.006 mg/dscm. 
Furthermore, the data used to develop these revised surface tension 
limits indicate that WAFS are equally effective in controlling 
emissions from hard chromium electroplating tanks and from decorative 
chromium electroplating tanks. In addition, the available data indicate 
that over 80 percent of existing decorative chromium electroplating 
plants with add-on controls already meet this proposed new source 
emissions limit. Therefore, new facilities should be able to achieve 
this level of emissions at relatively low costs by using WAFS or with 
the type of add-on control devices used by existing facilities in this 
source category. As an alternative, we are proposing that new sources 
can demonstrate compliance with the MACT standards by maintaining 
surface tension limits of 40 dynes/cm, if measured by stalagmometer, 
and 33 dynes/cm, if measured by tensiometer.
    As is the case for hard chromium electroplating, today's action 
would re-define new sources to clarify which emissions limits would 
apply to a specific facility.
    b. Compliance Testing and Monitoring.
    To demonstrate compliance, we are proposing that each decorative 
chromium electroplating source that uses an add-on control device to 
control emissions from affected tanks and chooses to comply with the 
proposed emissions limit, rather than the surface tension limits, would 
need to provide a new or previous performance stack emissions test that 
is representative of current operations and current controls and is 
conducted at the exit of the control device to show they are in 
compliance with the emissions limit. Facilities that elect the 
alternative option to comply with the surface tension limits would be 
required to monitor surface tension, as currently required by the 
NESHAP.
    c. Costs and Impacts for Decorative Chromium Electroplating.
    The total estimated capital costs for all decorative chromium 
electroplating facilities to comply with these proposed revised 
standards (i.e., lower surface tension limits or lower emissions 
limits) and to conduct all the necessary testing and monitoring is 
estimated to be

[[Page 6644]]

$183,000, and the average capital costs per facility are $400. The 
total annualized costs are estimated to be $189,000, and the average 
annual cost per facility across all facilities is $390. The range for 
annualized costs per facility are from $0 to $4,200. We estimate that 
these requirements will reduce emissions by 39 pounds per year, and 
that the cost-effectiveness would be $4,800 per pound.
4. Chromium Anodizing
    a. Emissions Limits for Existing and New Chromium Anodizing 
Sources. As discussed in section III.B.1.d. of this preamble, although 
we did not have the data to perform a detailed analysis of options for 
chromium anodizing sources, there is a basis for concluding that the 
same emissions limits being proposed for decorative chromium 
electroplating would also be appropriate for chromium anodizing 
sources. In terms of relative magnitude of emissions, the types of 
emission controls commonly used, and the emissions limits in the 
current NESHAP, these two source categories are similar. With regard to 
emissions levels, based on the available data, the average emissions 
from chromium anodizing plants are about 20 percent lower than the 
average emissions from decorative electroplating plants, with an 
average of about 0.46 pounds per year per facility for anodizing plants 
and 0.57 pounds per year per plant for decorative chromium 
electroplating. With regard to controls, the majority of chromium 
anodizing and decorative chromium electroplating plants rely partly or 
entirely on WAFS to limit emissions. Moreover, the tank sizes are 
similar, with an average of about 1,020 gallons per tank for decorative 
chromium electroplating plants and 1,380 gallons per tank for chromium 
anodizing plants. Overall, we conclude that chromium anodizing plants 
should be able to limit emissions just as effectively and to the same 
level as the decorative plants, primarily using WAFS, for about the 
same costs. Consequently, we are proposing the same emissions limits 
for new and existing chromium anodizing sources as are being proposed 
for decorative chromium electroplating sources. That is, we are 
proposing that existing chromium anodizing sources would have to meet 
an emissions limit of 0.007 mg/dscm, and new sources would have to meet 
an emissions limit of 0.006 mg/dscm. Sources would also have the option 
of meeting the proposed surface tension limits as an alternative to 
meeting the proposed emissions limits. As is the case for hard chromium 
electroplating, today's action would re-define new sources to clarify 
which emissions limits would apply to a specific facility. 
Nevertheless, since we have very limited data on chromium anodizing 
plants, we specifically request comments on these proposed limits and 
we seek data and information on emissions from these chromium anodizing 
sources, including emissions test results, emissions concentration 
data, mass rate emissions (e.g., lbs per year), flow rates, and other 
emissions release information.
    b. Compliance Testing and Monitoring. To demonstrate compliance, we 
are proposing that each chromium anodizing facility that uses an add-on 
control device to control emissions from affected tanks and chooses to 
comply with the proposed emissions limit, rather than the surface 
tension limits, would need to provide a new or previous performance 
stack emissions test that is representative of current operations and 
current controls and is conducted at the exit of the control device to 
show they are in compliance with the emissions limit. Facilities that 
elect the alternative option to comply with the surface tension limits 
would be required to monitor surface tension, as currently required by 
the NESHAP.
    c. Costs and Impacts for Chromic Acid Anodizing.
    To meet the proposed lower emissions limits and/or the lower 
surface tension limits, we conservatively assume that about 50 percent 
of facilities will need to use additional WAFS, which would result in 
increased annualized costs. Since emissions are already quite low for 
these facilities, we assume that no facilities will need to install 
add-on controls to meet the lower limits. Therefore, the only capital 
costs will be costs for testing.
    The total estimated capital costs for all chromic acid anodizing 
facilities to comply with the revised limits, which is completely for 
testing and monitoring, is estimated to be $245,000 and the average 
capital costs per facility are $1,700. The total annualized costs, 
which include costs for WAFS and annualized costs for testing and 
monitoring, are estimated to be $54,000 and the average annual cost per 
facility across all facilities is $370. The range for annualized costs 
per facility are from $0 to $2,600. We estimate that these requirements 
will reduce emissions by 6 pounds per year, and that the cost-
effectiveness would be $9,100 per pound. More information about the 
estimates of costs and reductions and how they were derived are 
provided in the technical support document ``Procedures for Determining 
Control Costs and Cost Effectiveness for Chromium Electroplating 
Supplemental Proposal,'' which is available in the docket for this 
action.
5. Surface Tension Limits
    As described in section III.A.2 of this preamble, the available 
data on surface tension and emission concentration were evaluated in 
terms of upper tolerance limits (UTLs) to help us better understand the 
relationship between surface tension and emissions. As a first step, we 
categorized the data according to the type of instrument used 
(stalagmometer or tensiometer). We discarded any data for which we 
could not identify the measurement instrument.
    We analyzed the data for the purpose of developing tolerance limits 
that could be used to establish emissions concentrations for specified 
surface tension values. Statistical tolerance limits are limits within 
which a stated proportion of the population is expected to lie. The UTL 
represents the value below which it can be expected that the specified 
percentage of the measurements would fall for the specified level of 
confidence in repeated sampling. For example, the 95 percent UTL with 
99 percent confidence level is the value for which we can conclude with 
99 percent certainty or confidence that at least 95 percent of the data 
points lie below. We used this UTL approach in our analysis at these 
percent values (i.e., the 95 percent UTL with 99 percent confidence 
level).
    To determine the UTL for various surface tension limits, we divided 
the surface tension data into intervals that had enough data points to 
calculate the mean and standard deviation. Separate data sets and 
intervals were determined for surface tension measurements using 
stalagmometers and for measurements using tensiometers. We then applied 
a statistical procedure to develop UTLs for each surface tension 
interval. We evaluated the results to determine appropriate intervals 
(i.e., surface tension limits) that would be achievable from a process 
operating perspective and would achieve significant reductions in 
chromium emissions. We used these surface tension limits as the basis 
for our proposed decisions regarding surface tension. These proposed 
decisions are described previously in sections IV.A.1 through IV.A.4. 
The results of the UTL analysis indicate that maintaining the surface 
tension below 40 dynes/cm, as measured using a stalagmometer, would 
limit emissions to no more than 0.0055 mg/dscm; and maintaining the 
surface

[[Page 6645]]

tension below 32.5 dynes/cm, as measured using a tensiometer, would 
limit emissions to no more than 0.0047 mg/dscm. Recognizing that these 
instruments measure surface tension in integer increments, we rounded 
the tensiometer limit to 33 dynes/cm and concluded that maintaining 
these two surface tension limits (40 dynes/cm by stalagmometer and 33 
dynes/cm by tensiometer) in chromium electroplating and anodizing baths 
would maintain emissions below 0.006 mg/dscm. Additional details on the 
analysis of the surface tension data can be found in the technical 
memorandum, ``Development of Revised Surface Tension Limits for 
Chromium Electroplating and Anodizing Tanks Controlled with Wetting 
Agent Fume Suppressants,'' which is available in the docket for this 
action.
    Based on available data, many facilities that currently use WAFS 
already achieve surface tensions well below these levels (i.e., 40 
dynes/cm and 33 dynes/cm), and based on available information, we 
conclude that other facilities can easily achieve these levels with a 
relatively small increase in the use of fume suppressants. Therefore, 
as an alternative to meeting the proposed emissions limits, we are 
proposing to allow new and existing sources in all three source 
categories (hard chromium electroplating, decorative chromium 
electroplating, and chromium anodizing) that use WAFS to comply with 
the NESHAP to meet these proposed lower surface tension limits (40 
dynes/cm as measured with a stalagmometer and 33 dynes/cm as measured 
with a tensiometer).
    As mentioned above, in the October 21, 2010 Federal Register notice 
(75 FR 65068), we proposed phasing out the use of wetting agent fume 
suppressants (WAFS) that contain perfluorooctyl sulfonates (PFOS). 
Based on available information, we continue to believe that non-PFOS 
WAFS are available that can effectively limit surface tension for about 
the same costs as PFOS-based WAFS, and that these non-PFOS WAFS can 
achieve surface tension levels below the proposed surface tension 
limits (described above).\10,11\ However, to be conservative, we have 
assumed that the costs for non-PFOS WAFS will be 15 percent higher than 
the PFOS based WAFS and these additional costs have been included in 
the costs presented in today's notice. More information about the cost 
estimates for WAFS and how they were derived are provided in the 
technical support document ``Procedures for Determining Control Costs 
and Cost Effectiveness for Chromium Electroplating Supplemental 
Proposal,'' which is available in the docket for this action.
---------------------------------------------------------------------------

    \10\ Barlowe, G. and Patton, N., 2011. ``Non-PFOS, Permanent 
Mist Suppressants for Hard Chromium Plating, Decorative Chromium 
Plating and Chromic Etch Applications''. March 1, 2011.
    \11\ Danish, EPA. 2011. Substitution of PFOS for use in non-
decorative hard chrome plating. Pia Brunn Poulsen, Lars K. Gram and 
Allan Astrup Jensen. Danish Environmental Protection Agency. 
Environmental Project No. 1371 2011.
---------------------------------------------------------------------------

    We are not re-opening the comment period on the proposed phase out 
of the use of PFOS-based WAFS. However, we are soliciting comment and 
data on whether the proposed surface tension limits can be met through 
the use of non-PFOS WAFS. We seek data and information on the type of 
WAFS used, what surface tensions have been achieved, what hexavalent 
chromium emissions reductions have been achieved, fume suppressant 
costs, and detailed information related to the feasibility of using 
different types of WAFS.

B. What are the results of the risk assessment?

1. Inhalation Risk Assessment Results
    Table 4 provides an overall summary of the inhalation risk 
assessment results for the source category.

                                    Table 4--Chromium Electroplating and Anodizing Inhalation Risk Assessment Results
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                  Maximum individual                                 Maximum chronic non-
                                                                   cancer risk (in 1                     Annual        cancer TOSHI \4\
                                                   Number of         million) \2\         Population     cancer   -------------------------- Maximum off-
                 Source category                   facilities -------------------------- at risk  >=   incidence                              site acute
                                                      \1\         Actual     Allowable      1-in-1     (cases per     Actual     Allowable    non-cancer
                                                                emissions    emissions   million \3\   year) \3\    emissions    emissions        HQ
                                                                  level        level                                  level        level
--------------------------------------------------------------------------------------------------------------------------------------------------------
Hard Chromium Electro-plating...................          699           20           50      130,000         0.05         0.02         0.04       \5\ NA
Decorative Chromium Electro-plating.............          577           10           70       43,000         0.02        0.008         0.06       \5\ NA
Chromic acid Anodizing..........................          179            5           60        5,000        0.003        0.004         0.05       \5\ NA
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Number of facilities evaluated in the risk analysis.
\2\ Maximum individual excess lifetime cancer risk.
\3\ Based on actual emissions.
\4\ Maximum TOSHI. The target organ with the highest TOSHI for these source categories is the respiratory system.
\5\ NA = Not applicable. There are no HAP with acute dose-response benchmark values, so no acute HQ were calculated for these source categories.

    As shown in Table 4, the results of the inhalation risk assessment 
for the hard chromium electroplating source category indicate the 
maximum lifetime individual cancer risk could be up to 20-in-1 million 
based on actual emission levels of hexavalent chromium, and the maximum 
chronic noncancer TOSHI value could be up to 0.02. The total estimated 
national cancer incidence from these facilities, based on actual 
emission levels, is 0.05 excess cancer cases per year, or one case in 
every 20 years. In addition, we note that approximately 1,100 people 
are estimated to have cancer risks greater than 10 in one million, and 
approximately 130,000 people are estimated to have risks greater than 
1-in-1 million based on estimates of actual emissions. Based on 
allowable emission levels, the maximum lifetime individual cancer risk 
could be up to 50-in-1 million, and the maximum chronic noncancer TOSHI 
value could be up to 0.04. Hexavalent chromium, which is a known human 
carcinogen, is the only HAP emitted by these sources and the HAP 
driving all these risks.
    The results of the inhalation risk assessment for the decorative 
chromium electroplating source category indicate the maximum lifetime 
individual cancer risk could be up to 10-in-1 million based on actual 
emission levels, and the maximum chronic noncancer TOSHI value could be 
up to 0.008. The total estimated national cancer incidence from these 
facilities, based on actual emission levels, is 0.02 excess cancer 
cases per year, or one case in every 50 years. In addition, we note 
that approximately 100 people are estimated to have cancer risks 
greater than 10 in

[[Page 6646]]

one million, and approximately 43,000 people are estimated to have 
risks greater than 1-in-1 million based on estimates of actual 
emissions. Based on allowable emission levels, the maximum lifetime 
individual cancer risk could be up to 70-in-1 million, and the maximum 
chronic noncancer TOSHI value could be up to 0.06.
    The results of the inhalation risk assessment for the chromic acid 
anodizing source category indicate the maximum lifetime individual 
cancer risk could be up to 5-in-1 million based on actual emission 
levels, and the maximum chronic noncancer TOSHI value could be up to 
0.004. The total estimated national cancer incidence from these 
facilities, based on actual emission levels, is 0.003 excess cancer 
cases per year, or one case in every 333 years. In addition, we note 
that no people are estimated to have cancer risks greater than 10-in-1 
million, and approximately 5,000 people are estimated to have risks 
greater than 1-in-1 million. Based on allowable emission levels, the 
maximum lifetime individual cancer risk could be up to 60-in-1 million, 
and the maximum chronic noncancer TOSHI value could be up to 0.05.
    The cancer risk estimates for all of the chromium electroplating 
source categories, especially those based on actual emissions, are 
considerably different compared to the results that were presented in 
the initial RTR proposal on October 21, 2010, (75 FR 65071). The risks 
due to the estimates of actual emissions presented above are 
considerably lower than those presented in the October 21, 2010 
proposal FR Notice for hard chromium and decorative chromium plants. 
However, the risks due to actual emissions for chrome anodizing are 
about the same as the October 2010 proposal. The revised estimate of 
risks based on allowable emissions presented above are lower for hard 
chromium, about the same for decorative, and considerably higher for 
anodizing plants compared to the October 2010 proposal. The main reason 
for the difference is that we have significantly improved data on 
emissions and facility characteristics for this supplemental proposal, 
and we used a different methodology to estimate emissions for 
facilities for which we had incomplete data. This improved data set is 
described further in section II.E of this preamble, and the methodology 
is described in section III.B.
    For all three source categories, there were no reported emissions 
of PB-HAP, and chromium emissions are not known to have any associated 
adverse environmental impacts; therefore, we conclude there is low 
potential for human health multipathway risks or adverse environmental 
impacts. Also, because there are no HAP with acute dose-response 
benchmark values, no acute HQ were calculated for these source 
categories, and we believe that the potential for acute effects is low.
2. Facility-Wide Risk Assessment Results
    Table 5 displays the results of the facility-wide risk assessment. 
This assessment was conducted based on actual emission levels. For 
detailed facility-specific results, see Appendix 5 of the ``Residual 
Risk Assessment for the Chromic Acid Anodizing, Decorative Chromium 
Electroplating, and Hard Chromium Electroplating Source Categories'' 
which is available in the docket for this rulemaking.

              Table 5--Chromium Electroplating and Anodizing Facility-Wide Risk Assessment Results
----------------------------------------------------------------------------------------------------------------
                                                                             Decorative
                  Source category                       Hard chromium         chromium       Chromium  anodizing
                                                       electroplating      electroplating
----------------------------------------------------------------------------------------------------------------
Number of facilities analyzed......................                 699                 577                179
----------------------------------------------------------------------------------------------------------------
                                                  Cancer Risk:
----------------------------------------------------------------------------------------------------------------
Estimated maximum facility-wide individual cancer                    70                  80                 10
 risk (in 1 million)...............................
Number of facilities with estimated facility-wide                     0                   0                  0
 individual cancer risk of 100-in-1 million or more
Number of facilities at which the source category                     0                   0                  0
 contributes 50 percent or more to the facility-
 wide individual cancer risks of 100-in-1 million
 or more...........................................
Number of facilities at which the source category                   195                  98                 31
 contributes 50 percent or more to the facility-
 wide individual cancer risk of 1-in-1 million or
 more..............................................
----------------------------------------------------------------------------------------------------------------
                                             Chronic Noncancer Risk:
----------------------------------------------------------------------------------------------------------------
Maximum facility-wide chronic noncancer TOSHI......                   2                   7                  0.1
Number of facilities with facility-wide maximum                       1                   2                  0
 noncancer TOSHI greater than 1....................
Number of facilities at which the source category                     0                   0                  0
 contributes 50 percent or more to the facility-
 wide maximum noncancer TOSHI of 1 or more.........
----------------------------------------------------------------------------------------------------------------

    The facility-wide MIR from all HAP emissions at a facility that 
contains sources subject to the hard chromium electroplating MACT 
standards is estimated to be 70-in-1 million, based on actual 
emissions. Of the 699 facilities included in this analysis, none have a 
facility-wide MIR of 100-in-1 million or greater. There are 206 
facilities with facility-wide MIR of 1-in-1 million or greater, of 
which 195 have hard chromium electroplating operations that contribute 
greater than 50 percent to the facility-wide risks. The facility-wide 
maximum individual chronic noncancer TOSHI value is estimated to be 2, 
based on actual emissions, and there is 1 facility with a facility-wide 
maximum individual chronic noncancer TOSHI value greater than 1. Hard 
chromium electroplating operations do not contribute greater than 50 
percent to the facility-wide maximum chronic noncancer TOSHI value at 
any facility.
    The facility-wide MIR from all HAP emissions at a facility that 
contains sources subject to the decorative chromium electroplating MACT 
standards is estimated to be 80-in-1 million, based on actual 
emissions. Of the 577 facilities included in this analysis, none have a 
facility-wide MIR of 100-in-1 million or greater. There are 121 
facilities with a facility-wide MIR of 1-in-1 million or greater, of 
which 98 have decorative chromium

[[Page 6647]]

electroplating operations that contribute greater than 50 percent to 
the facility-wide risks. The facility-wide maximum individual chronic 
noncancer TOSHI value is estimated to be 7, based on actual emissions, 
and there are 2 facilities with facility-wide maximum individual 
chronic noncancer TOSHI values greater than one. Decorative chromium 
electroplating operations do not contribute greater than 50 percent to 
the facility-wide maximum chronic noncancer TOSHI value at any 
facility.
    The facility-wide MIR from all HAP emissions at a facility that 
contains sources subject to the chromium anodizing MACT standards is 
estimated to be 10-in-1 million, based on actual emissions. Of the 179 
facilities included in this analysis, none have a facility-wide MIR of 
100-in-1 million or greater. There are 35 facilities with a facility-
wide MIR of 1-in-1 million or greater, of which 31 have chromium 
anodizing operations that contribute greater than 50 percent to the 
facility-wide risks. The facility-wide maximum individual chronic 
noncancer TOSHI value is estimated to be 0.1.
3. Demographic Analysis Results
    To examine the potential for any environmental justice (EJ) issues 
that might be associated with these source categories, we performed 
demographic analyses of the at-risk populations (i.e., the population 
with estimated lifetime cancer risks greater than or equal to 1-in-1 
million due to emissions from chromium electroplaters) for two of the 
three chromium electroplating categories. The results of the 
demographic analyses are summarized in Table 6. These results, for 
various demographic groups, are based on the estimated risks from 
actual emissions levels for the population living within 50 km of the 
facilities.

             Table 6--Hard and Decorative Chromium Electroplating Demographic Risk Analysis Results
----------------------------------------------------------------------------------------------------------------
                                                                                                   Decorative
                                                             Nationwide       Hard chromium         chromium
                                                                              electroplating     electroplating
----------------------------------------------------------------------------------------------------------------
                                                         .................    Population with cancer risk at or
                                                                                    above 1-in-1 Million
                                                                           -------------------------------------
Total Population.......................................        312,900,000            131,000             43,000
----------------------------------------------------------------------------------------------------------------
                                                 Race by Percent
----------------------------------------------------------------------------------------------------------------
White..................................................                 72                 59                 48
All Other Races........................................                 28                 41                 52
----------------------------------------------------------------------------------------------------------------
                                                 Race by Percent
----------------------------------------------------------------------------------------------------------------
White..................................................                 72                 59                 48
African American.......................................                 13                 21                 21
Native American........................................                1.1                0.8                0.8
Other and Multiracial..................................                 14                 20                 30
----------------------------------------------------------------------------------------------------------------
                                              Ethnicity by Percent
----------------------------------------------------------------------------------------------------------------
Hispanic...............................................                 17                 34                 26
Non-Hispanic...........................................                 83                 66                 74
----------------------------------------------------------------------------------------------------------------
                                                Income by Percent
----------------------------------------------------------------------------------------------------------------
Below Poverty Level....................................                 14                 21                 24
Above Poverty Level....................................                 86                 79                 76
----------------------------------------------------------------------------------------------------------------
                                              Education by Percent
----------------------------------------------------------------------------------------------------------------
Over 25 and without High School Diploma................                 10                 27                 24
Over 25 and with a High School Diploma.................                 90                 73                 76
----------------------------------------------------------------------------------------------------------------

    For hard chromium electroplating, the results indicate that there 
are approximately 131,000 people exposed to a cancer risk at or above 
1-in-1 million due to emissions from the source category. For several 
demographic groups, the percentage of such groups in the at-risk 
population are higher than their respective nationwide percentages, 
including the African American, Other and Multiracial, Hispanic, Below 
the Poverty Level, and Over 25 without a High School Diploma 
demographic groups. These results indicate that these demographic 
groups carry the potential to be disproportionately exposed to 
emissions and risks from this source category. These groups therefore 
stand to benefit the most from the emission reductions achieved by this 
proposed rulemaking.
    For decorative chromium electroplating, the results indicate that 
there are approximately 43,000 people exposed to a cancer risk at or 
above 1-in-1 million due to emissions from the source category. The 
percentages of the at-risk population in several demographic groups are 
higher than their respective nationwide percentages, including the 
African American, Other and Multiracial, Hispanic, Below the Poverty 
Level, and the Over 25 without a High School Diploma demographic 
groups. These results indicate that these demographic groups carry the 
potential to be disproportionately exposed to emissions and risks from 
this source category. These groups therefore stand to benefit the most 
from the emission reductions achieved by this proposed rulemaking.

[[Page 6648]]

C. What are our proposed decisions regarding risk acceptability and 
ample margin of safety?

1. Risk Acceptability
    As noted in the preamble of the October 2010 proposal (75 FR 
65068), we weigh all health risk factors in our risk acceptability 
determination, including the MIR, the numbers of persons in various 
cancer and noncancer risk ranges, cancer incidence, the maximum 
noncancer HI, the maximum acute noncancer hazard, the extent of 
noncancer risks, the potential for adverse environmental effects, and 
risk estimation uncertainties (54 FR 38044, September 14, 1989).
    For each of the three source categories, the risk analysis we 
performed indicates that the cancer risk to the individual most exposed 
due to actual emissions is well below 100-in-1 million (an MIR of 100-
in-1 million is generally considered the upper limit of acceptable 
risk), and that the cancer incidence is less than 0.05 cases per year 
(about 1 case in every 20 years). These risks are due to hexavalent 
chromium emissions. Hexavalent chromium is classified as a known human 
carcinogen by U.S. EPA. While the potential cancer risks due to 
allowable emissions from each of the three chromium electroplating 
categories are higher, they are also less than 100-in-1 million (with 
the highest estimated MIR of 70-in-1 million for the decorative 
chromium electroplating category based on allowable emissions). 
Specifically, for hard chromium electroplating, the MIR due to actual 
emissions is estimated to be 20-in-1 million, and the cancer incidence 
is estimated to be 0.05 cases per year. The MIR due to allowable 
emissions from hard chromium electroplating facilities is estimated to 
be 50-in-1 million, and the cancer incidence is estimated to be 0.2. 
For decorative chromium electroplating, the MIR due to actual emissions 
is estimated to be 10-in-1 million, and the cancer incidence is 
estimated to be 0.02 cases per year. The MIR due to allowable emissions 
from decorative chromium facilities is estimated to be 70-in-1 million, 
and the cancer incidence is estimated to be 0.08. For chromium 
anodizing, the MIR due to actual emissions is estimated to be 5-in-1 
million, and the cancer incidence is estimated to be 0.003 cases per 
year. The MIR due to allowable emissions from chromium anodizing 
facilities is estimated to be 60-in-1 million, and the cancer incidence 
is estimated to be 0.08.
    Our analysis also indicates that chronic noncancer health risks, 
potential acute impacts of concern, multipathway health risks and 
environmental risks are all negligible due to both actual and allowable 
emissions for all three source categories.
    Although the cancer risks are due to emissions of a known human 
carcinogen (hexavalent chromium), since the cancer MIRs due to actual 
emissions are well below 100-in-1 million, and because a number of the 
other risk metrics do not indicate high risk concerns, we are proposing 
to determine that the risks due to HAP emissions from each of the three 
source categories are acceptable.
    We note that the results of our demographic analyses (which are 
presented above) for hard and decorative chromium electroplating 
indicate that certain minority groups and low-income populations may be 
disproportionately exposed to emissions from these categories and to 
any risks that may result due to these emissions because the 
communities most proximate to facilities within these categories have a 
higher proportion of these groups than the national demographic 
profile. We note that we did not identify any vulnerability or 
susceptibility to risks particular to minority and low income 
populations from pollutants emitted from this source category. The 
Agency has determined that the existing NESHAP for these source 
categories provides an acceptable level of risk for all proximate 
populations, including minority and low-income populations.
2. Ample Margin of Safety Analysis
    We next considered whether the existing MACT standard provides an 
ample margin of safety (AMOS). Under the ample margin of safety 
analysis, we evaluate the cost and feasibility of available control 
technologies and other measures (including the controls, measures, and 
costs reviewed under the technology review) that could be applied in 
each of the three source categories to further reduce the risks (or 
potential risks) due to emissions of HAP identified in our risk 
assessment, along with all of the health risks and other health 
information considered in the risk acceptability determination 
described above.
    Based on the fact that we have determined the risks due to actual 
and allowable emissions associated with each of the three categories of 
sources subject to the Chromium Electroplating NESHAP to be acceptable, 
and after evaluating the costs and feasibility of possible options to 
reduce emissions in our technology review, we are proposing that the 
same emission and surface tension limits that we are proposing under 
section 112(d)(6) of the Clean Air Act, which are discussed previously 
in section IV.A of this preamble, will reduce health risks and provide 
an ample margin of safety to protect public health. As described below, 
these proposed actions will reduce the modeled estimated maximum 
individual cancer risks and the modeled population cancer risks for the 
three source categories. Specifically, under Section 112(f) of the 
Clean Air Act, we are proposing the following amendments to the NESHAP:
     Existing large hard chromium electroplating facilities 
would be required to meet an emissions limit of 0.011 mg/dscm or a 
surface tension limit of 40 dynes/cm, if measured by stalagmometer, or 
33 dynes/cm, if measured by tensiometer;
     New large hard chromium electroplating facilities would be 
required to meet an emissions limit of 0.006 mg/dscm or a surface 
tension limit of 40 dynes/cm, if measured by stalagmometer, or 33 
dynes/cm, if measured by tensiometer;
     Existing small hard chromium electroplating facilities 
would be required to meet an emissions limit of 0.015 mg/dscm or a 
surface tension limit of 40 dynes/cm, if measured by stalagmometer, or 
33 dynes/cm, if measured by tensiometer;
     New small hard chromium electroplating facilities would be 
required to meet an emissions limit of 0.006 mg/dscm or a surface 
tension limit of 40 dynes/cm, if measured by stalagmometer, or 33 
dynes/cm, if measured by tensiometer;
     Existing decorative chromium electroplating and chromium 
anodizing facilities would be required to meet an emissions limit of 
0.007 mg/dscm or a surface tension limit of 40 dynes/cm, if measured by 
stalagmometer, or 33 dynes/cm, if measured by tensiometer;
     New decorative chromium electroplating and chromium 
anodizing facilities would be required to meet an emissions limit of 
0.006 mg/dscm or a surface tension limit of 40 dynes/cm, if measured by 
stalagmometer, or 33 dynes/cm, if measured by tensiometer.
    These proposed amendments to the NESHAP would reduce the cancer 
risks due to emissions of hexavalent chromium from this industry for 
all populations, including minority and low-income populations. 
Specifically, we estimate that the MIR based on actual emissions for 
each of these categories would be reduced by 25 to 50 percent, and the 
MIR based on allowable emissions would also be reduced by 25 to 50 
percent. Cancer incidence and the number of people

[[Page 6649]]

exposed to risks greater than 1-in-1 million would also be reduced 
significantly, by about 25 to 50 percent each.
    As described above, we estimate that the total estimated capital 
costs for all existing large hard chromium electroplating sources to 
comply with the proposed revised limits and conduct the necessary 
testing and monitoring would be $1.8 million. The total annualized 
costs are estimated to be $2.2 million. We estimate that these proposed 
requirements would reduce chromium emissions by 121 pounds per year, 
and that the cost-effectiveness would be $18,100 per pound.
    The total estimated capital costs for all existing small hard 
chromium electroplating sources to comply with the proposed revised 
limits and conduct the necessary testing and monitoring is estimated to 
be $1.45 million. The total annualized costs are estimated to be 
$652,000. We estimate that these proposed requirements would reduce 
chromium emissions by 41 pounds per year, and that the cost-
effectiveness would be $15,800 per pound.
    The total estimated capital costs for all existing decorative 
chromium electroplating facilities to comply with these proposed 
revised standards (i.e., lower surface tension limits or lower 
emissions limits) and to conduct all the necessary testing and 
monitoring is estimated to be $183,000. The total annualized costs are 
estimated to be $189,000. We estimate that these proposed requirements 
would reduce emissions by 39 pounds per year, and that the cost-
effectiveness would be $4,800 per pound.
    The total estimated capital costs for all existing chromic acid 
anodizing facilities to comply with the proposed revised limits and 
conduct the necessary testing and monitoring is estimated to be 
$245,000. The total annualized costs are estimated to be $54,000. We 
estimate that these proposed requirements would reduce emissions by 6 
pounds per year, and that the cost-effectiveness would be $9,100 per 
pound.
    We conclude that the costs for all four categories or subcategories 
described above are reasonable given the risk reductions that will be 
achieved.
    Based on all the above information, we propose that the NESHAP as 
revised with these proposed requirements will provide an ample margin 
of safety to protect public health by lowering emission levels and 
reducing cancer risk for all populations, including minority and low-
income populations.

D. Compliance Dates

    We are proposing to require existing facilities to comply with the 
proposed revised emissions limits or revised surface tension 
requirements no later than 2 years after the date of publication of the 
final rule. We believe this much time is needed for facilities to 
determine if they meet the proposed emissions limits, which would 
likely require conducting an emissions test. Scheduling a compliance 
test, conducting the test, and receiving the results, could take as 
much as 4 to 6 months. At that time, affected facilities that do not 
meet the proposed emissions limit would have to perform an engineering 
analysis to determine the control options, decide on what additional 
controls are needed, send out a tender notice, evaluate the bids 
received, and contract the installation and testing of the new 
equipment. Since most chromium electroplating facilities do not have 
in-house engineering expertise, they would likely have to hire 
consultants to perform all of the above work, and that would add to the 
time required.
    We are proposing that all new facilities (newly constructed or 
reconstructed) must comply with the proposed revised emissions limits 
or surface tension requirements upon startup. We are proposing to 
require compliance with the electronic reporting requirements, which 
are discussed in section VII below, upon promulgation of the final 
rule.

V. What action are we proposing for the steel pickling source category?

A. Elimination of an Alternative Compliance Option

    As a result of the review of the NESHAP, we are proposing the 
elimination of language in the NESHAP that allows HCl regeneration 
facilities to establish an alternative chlorine concentration standard 
for existing acid regeneration plants. The NESHAP currently allows the 
owner or operator to request approval for a source-specific standard 
based on the maximum design temperature and minimum excess air that 
allows production of iron oxide of acceptable quality if the source is 
unable to meet the otherwise applicable emissions limit for chlorine 
(Cl2) of 6 parts per million by volume (ppmv) (40 CFR 
subpart CCC). Upon review of this provision, we believe that it does 
not meet the requirements in section 112(d)(2) and (3) of the CAA. MACT 
standards for existing sources cannot be less stringent than the 
average emissions limitation achieved by the best-performing 12 percent 
of existing sources in the category or subcategory (or the best-
performing five sources for categories or subcategories with fewer than 
30 sources). This is referred to as the ``MACT floor.'' The promulgated 
standard in 40 CFR part 63, Sec.  63.1157(b)(2), subpart CCC, was 
established in compliance with EPA's obligation to promulgate a 
standard representing the MACT floor. We do not have authority to allow 
a source to seek an alternative standard if such a source is unable to 
meet a standard which reflects the MACT floor level of control. 
Therefore, we are proposing to amend the NESHAP by removing the 
language in Sec.  63.1157(b)(2) that currently allows a source-specific 
standard for sources that demonstrate they are unable to meet the 
applicable standard and removing the methods for establishing a source-
specific standard under Sec.  63.1161(c)(2) of the NESHAP. This action 
is being proposed under section 112(d)(2) and (3) of the CAA to ensure 
that the NESHAP is consistent with requirements of that section.
    In addition to fulfilling the statutory requirements of Sections 
112(d)(2) and (3), we note that this proposed action also will reduce 
the emissions of chlorine and HCl from this source category, resulting 
in a reduction of the Hazard Index (HI) from 2 due to HCl (that was 
presented in the October 21, 2010 proposal) to an HI of less than one. 
The one facility that posed the HI of 2 (in the October 21, 2010 
proposal) will need to improve controls and reduce emissions by more 
than a factor of 2 to comply with this proposed action.

B. Compliance Dates

    We are proposing that the amendments to Sec.  63.1157(b)(2) and 
Sec.  63.1161(c)(2) of the NESHAP would be effective upon promulgation 
of the final rule.

VI. What other actions are we proposing?

A. Electronic Reporting

    EPA must have performance test data to conduct effective reviews of 
CAA sections 112 and 129 standards, as well as for many other purposes 
including compliance determinations, emission factor development, and 
annual emission rate determinations. In conducting these required 
reviews, EPA has found it ineffective and time consuming, not only for 
us, but also for regulatory agencies and source owners and operators, 
to locate, collect, and submit performance test data because of varied 
locations for data storage and varied data storage methods. In recent 
years, though, stack testing firms have

[[Page 6650]]

typically collected performance test data in electronic format, making 
it possible to move to an electronic data submittal system that would 
increase the ease and efficiency of data submittal and improve data 
accessibility.
    Through this proposal, EPA is presenting a step to increase the 
ease and efficiency of data submittal and improve data accessibility. 
Specifically, EPA is proposing that owners and operators of facilities 
in the Hard and Decorative Chromium Electroplating and Chromium 
Anodizing source categories and the Steel Pickling--HCl Process 
Facilities and Hydrochloric Acid Regeneration Plants source categories 
submit electronic copies of required performance test reports to EPA's 
WebFIRE database. The WebFIRE database was constructed to store 
performance test data for use in developing emission factors. A 
description of the WebFIRE database is available at http://cfpub.epa.gov/oarweb/index.cfm?action=fire.main.
    As proposed above, data entry would be through an electronic 
emissions test report structure called the Electronic Reporting Tool 
(ERT). The ERT would generate an electronic report which would be 
submitted using the Compliance and Emissions Data Reporting Interface 
(CEDRI). The submitted report would be transmitted through EPA's 
Central Data Exchange (CDX) network for storage in the WebFIRE database 
making submittal of data very straightforward and easy. A description 
of the ERT can be found at http://www.epa.gov/ttn/chief/ert/index.html 
and CEDRI can be accessed through the CDX Web site (www.epa.gov/cdx).
    The proposal to submit performance test data electronically to EPA 
would apply only to those performance tests conducted using test 
methods that will be supported by the ERT. The ERT contains a specific 
electronic data entry form for most of the commonly used EPA reference 
methods. A listing of the pollutants and test methods supported by the 
ERT is available at http://www.epa.gov/ttn/chief/ert/index.html. We 
believe that industry would benefit from this proposed approach to 
electronic data submittal. Having these data, EPA would be able to 
develop improved emission factors, make fewer information requests, and 
promulgate better regulations.
    One major advantage of the proposed submittal of performance test 
data through the ERT is a standardized method to compile and store much 
of the documentation required to be reported by this rule. Another 
advantage is that the ERT clearly states what testing information would 
be required. Another important proposed benefit of submitting these 
data to EPA at the time the source test is conducted is that it should 
substantially reduce the effort involved in data collection activities 
in the future. When EPA has performance test data in hand, there will 
likely be fewer or less substantial data collection requests in 
conjunction with prospective required residual risk assessments or 
technology reviews. This would result in a reduced burden on both 
affected facilities (in terms of reduced manpower to respond to data 
collection requests) and EPA (in terms of preparing and distributing 
data collection requests and assessing the results).
    State, local, and tribal agencies could also benefit from more 
streamlined and accurate review of electronic data submitted to them. 
The ERT would allow for an electronic review process rather than a 
manual data assessment making review and evaluation of the source 
provided data and calculations easier and more efficient. Finally, 
another benefit of the proposed data submittal to WebFIRE 
electronically is that these data would greatly improve the overall 
quality of existing and new emissions factors by supplementing the pool 
of emissions test data for establishing emissions factors and by 
ensuring that the factors are more representative of current industry 
operational procedures. A common complaint heard from industry and 
regulators is that emission factors are outdated or not representative 
of a particular source category. With timely receipt and incorporation 
of data from most performance tests, EPA would be able to ensure that 
emission factors, when updated, represent the most current range of 
operational practices. In summary, in addition to supporting regulation 
development, control strategy development, and other air pollution 
control activities, having an electronic database populated with 
performance test data would save industry, state, local, tribal 
agencies, and EPA significant time, money, and effort while also 
improving the quality of emission inventories and, as a result, air 
quality regulations.

VII. Summary of Cost, Environmental, and Economic Impacts

A. What are the affected sources?

1. Chromium Electroplating and Chromium Anodizing
    For the proposed amendments to the Chromium Electroplating NESHAP, 
the affected sources are each hard chromium electroplating tank, each 
decorative chromium electroplating tank, and each chromium anodizing 
tank located at a facility that performs hard chromium electroplating, 
decorative chromium electroplating, or chromium anodizing.
2. Steel Pickling
    For the proposed amendments to the Steel Pickling NESHAP, the 
affected sources are hydrochloric acid regeneration plants that are 
major sources of HAP.

B. What are the emission reductions?

1. Chromium Electroplating and Chromium Anodizing
    Overall, the proposed amendments to the Chromium Electroplating 
NESHAP would reduce nationwide emissions of chromium compounds by an 
estimated 208 pounds per year (lbs/yr) from the current levels of 1,140 
lbs/yr down to 930 lbs/yr. For large hard chromium electroplating, the 
proposed amendments would reduce chromium compound emissions by about 
121 lbs/yr from 561 lbs/yr down to 440 pounds. For small hard chromium 
electroplating, the proposed amendments would reduce chromium compound 
emissions by an estimated 41 lbs/yr from 240 lbs/yr to 199 lbs/yr. For 
decorative chromium electroplating, the proposed amendments would 
reduce chromium compound emissions by an estimated 40 lbs/yr from 280 
lbs/yr down to 240 lbs/yr. For chromium anodizing, the proposed 
amendments would reduce chromium compound emissions by about 6 lbs/yr 
from 66 lbs/yr down to 60 lbs/yr. The proposed amendments would have 
negligible impacts on secondary emissions because the additional 
control equipment that would be required would not significantly impact 
energy use by the affected facilities.
2. Steel Pickling
    We estimate that the proposed amendment to remove the alternative 
compliance provision for hydrochloric acid regeneration facilities 
would reduce emissions of chlorine by 15 tpy.

C. What are the cost impacts?

1. Chromium Electroplating and Chromium Anodizing
    We estimate that these proposed amendments would achieve 208 pounds 
reductions in hexavalent chromium emissions, and that the total capital 
and total annualized cost for the proposed amendments would be $3.7 
million and $3.1 million/yr, respectively. The overall cost 
effectiveness would be $14,900 per pound of hexavalent

[[Page 6651]]

chromium emissions reductions. A summary of the estimated costs and 
reductions of hexavalent chromium emissions are shown in Table 7.

    Table 7--Summary of the Estimated Costs, Reductions, and Cost Effectiveness for Proposed Requirements for
                             Chromium Electroplating and Anodizing Source Categories
----------------------------------------------------------------------------------------------------------------
                                                            Annualized costs
                                            Capital costs   (controls + WAFS      Emissions           Cost
     Source category or subcategory       (controls + WAFS   + all testing),  reductions (lbs/  effectiveness ($/
                                           + all testing)         $/yr               yr)               lb)
----------------------------------------------------------------------------------------------------------------
Large Hard Chromium Electroplating......        $1,821,000        $2,195,000               121           $18,100
Small Hard Chromium Electroplating......         1,445,000           653,000                41            15,800
Decorative Chromium Electroplating......           183,000           189,000                39             4,800
Chromic Acid Anodizing..................           245,000            54,000                 6             9,100
                                         -----------------------------------------------------------------------
    Total...............................         3,694,000         3,090,000               208            14,900
----------------------------------------------------------------------------------------------------------------

2. Steel Pickling
    For HCl acid regeneration plants, we estimate that the capital cost 
for the proposed amendments would be between $100,000 and $200,000, 
depending on whether the existing equipment can be upgraded or will 
need to be replaced. The annualized cost are estimated to be between 
$11,419 and $22,837 per year. The estimated cost effectiveness would be 
$761 to $1,522 per ton of HAP (mainly chlorine and HCl).

D. What are the economic impacts?

1. Chromium Electroplating and Chromium Anodizing
    EPA performed a screening analysis for impacts on all affected 
small entities by comparing compliance costs to average sales revenues 
by employment size category.\12\ This is known as the cost-to-revenue 
or cost-to-sales ratio, or the ``sales test.'' The ``sales test'' is 
the impact methodology EPA primarily employs in analyzing small entity 
impacts as opposed to a ``profits test,'' in which annualized 
compliance costs are calculated as a share of profits. The sales test 
is frequently used because revenues or sales data are commonly 
available for entities impacted by EPA regulations, and profits data 
normally made available are often not the true profit earned by firms 
because of accounting and tax considerations. The use of a ``sales 
test'' for estimating small business impacts for a rulemaking is 
consistent with guidance offered by EPA on compliance with SBREFA \13\ 
and is consistent with guidance published by the U.S. SBA's Office of 
Advocacy that suggests that cost as a percentage of total revenues is a 
metric for evaluating cost increases on small entities in relation to 
increases on large entities (U.S. SBA, 2010).\14\
---------------------------------------------------------------------------

    \12\ http://www.census.gov/econ/susb/data/susb2002.html.
    \13\ The SBREFA compliance guidance to EPA rulewriters regarding 
the types of small business analysis that should be considered can 
be found at: http://www.epa.gov/sbrefa/documents/Guidance-RegFlexAct.pdf. See Table 2 on page 36 for guidance on 
interpretations of the magnitude of the cost-to-sales numbers.
    \14\ U.S. SBA, Office of Advocacy. A Guide for Government 
Agencies, How to Comply with the Regulatory Flexibility Act, 
Implementing the President's Small Business Agenda and Executive 
Order 13272, June 2010.
---------------------------------------------------------------------------

    Based on the analysis, we estimate that approximately 96 percent of 
all affected facilities have a cost-to-sales ratio of less than 1 
percent. In addition, for approximately 1 percent of all affected 
facilities, or 9 facilities with fewer than 20 employees, the potential 
for cost-to-sales impacts may be between 3 and 8 percent. All of these 
facilities are in the hard chromium electroplating category, with 2 of 
the facilities in the small hard chromium electroplating category and 7 
in the large hard chromium electroplating category. For these 
categories, because the average sales receipts used for the analysis 
may understate sales for some facilities and because these facilities 
are likely to be able to pass cost increases through to their 
customers, we do not anticipate the regulatory proposal to result in 
firm closures, significant price increases, or substantial profit loss. 
We conclude that this proposal will not have a significant economic 
impact on a substantial number of small entities. More information and 
details of this analysis are provided in the technical document 
``Economic Impact Analysis for Risk and Technology Review: Chromium 
Electroplating,'' which is available in the docket for this proposed 
rule.
2. Steel Pickling
    Because only one of the approximately 100 facilities incurs any 
cost for controls and that cost is estimated to be less than 1 percent 
of sales, no significant price or productivity impacts are anticipated.

E. What are the benefits?

1. Chromium Electroplating and Chromium Anodizing
    The estimated reductions in chromium emissions that will be 
achieved by this proposed rule will provide benefits to public health. 
The proposed limits will result in significant reductions in the actual 
and allowable emissions of hexavalent chromium therefore will reduce 
the actual and potential cancer risks due to emissions of chromium from 
this source category.
2. Steel Pickling
    The estimated reductions in hydrogen chloride and chlorine 
emissions that will result from this proposed action will provide 
benefits to public health. The proposed limits will result in 
reductions in the potential for noncancer health effects due to 
emissions of these HAP.

VIII. Request for Comments

    We are soliciting comments on all aspects of this proposed action. 
All comments received during the comment period will be considered. In 
EPA's strive to continue to promote sustainability in our protection of 
human health and the environment, we request comment on sustainability 
related to the types of fume suppressants and surfactants, depending on 
their chemical properties, which may have more or less potential for 
negative health and environmental impacts beyond the air emissions 
addressed by this supplemental proposal. In addition to general 
comments on this proposed action, we are also soliciting additional 
information and data (e.g., on emissions, emissions concentrations 
results from stack emissions tests, flow rates, facility parameters, 
facility types, controls, test reports, etc.) that may help to reduce 
the uncertainties inherent in the risk assessments and any additional 
data that would inform the other analyses

[[Page 6652]]

described in this preamble (such as the analyses of the costs and 
reductions that would result from the proposed requirements). Because 
our current data set includes test results for only one chromium 
anodizing tank, we specifically request additional performance test 
data for chromium anodizing sources, including emissions concentration, 
exhaust flow rates, rectifier output, and control device type. Finally, 
we are requesting additional information on the costs and feasibility 
of using WAFS that do not contain PFOS to meet the proposed surface 
tension limits. Such data should include supporting documentation in 
sufficient detail to allow characterization of the quality and 
representativeness of the data or information. We are not re-opening 
the public comment period for the actions proposed in the October 21, 
2010 notice.

IX. 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 12866 (58 FR 51735, October 4, 1993), this 
action is a significant regulatory action because it raises novel legal 
and policy issues. 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

    The information collection requirements in this rule have been 
submitted for approval to OMB under the Paperwork Reduction Act, 44 
U.S.C. 3501, et seq.
    We are not proposing any new paperwork requirements to the Steel 
Pickling--HCl Process Facilities and Hydrochloric Acid Regeneration 
Plants MACT standards. Revisions and burden associated with amendments 
to the Hard and Decorative Chromium Electroplating and Chromium 
Anodizing Tanks are discussed in the following paragraphs. The OMB has 
previously approved the information collection requirements contained 
in the existing regulation being amended with this proposed rule (i.e., 
40 CFR part 63, subparts N and CCC) under the provisions of the 
Paperwork Reduction Act, 44 U.S.C. 3501, et seq. The OMB control 
numbers for EPA's regulations in 40 CFR are listed in 40 CFR part 9. 
Burden is defined at 5 CFR 1320.3(b).
    The ICR document prepared by EPA for the amendments to the Hard and 
Decorative Chromium Electroplating and Chromium Anodizing Tanks NESHAP 
has been assigned EPA ICR number 1611.08. Burden changes associated 
with these amendments would result from the emission testing 
requirements and compliance demonstrations being proposed with today's 
action. The estimated average burden per response is 9 hours; the 
frequency of response is one-time for all respondents that must comply 
with the rule's reporting requirements and the estimated average number 
of likely respondents per year is 485. The cost burden to respondents 
resulting from the collection of information includes the total capital 
cost annualized over the equipment's expected useful life ($100,958), a 
total operation and maintenance component ($0 per year), and a labor 
cost component (about $152,116 per year).
    An agency may not conduct or sponsor, and a person is not required 
to respond to a collection of information unless it displays a 
currently valid OMB control number.
    To comment on the Agency's need for this information, the accuracy 
of the provided burden estimates, and any suggested methods for 
minimizing respondent burden, EPA has established a public docket for 
this rule, which includes these ICR, under Docket ID number EPA-HQ-OAR-
2010-0600. Submit any comments related to the ICR to EPA and OMB. See 
ADDRESSES section at the beginning of this notice for where to submit 
comments to EPA. Send comments to OMB at the Office of Information and 
Regulatory Affairs, Office of Management and Budget, 725 17th Street 
NW., Washington, DC 20503, Attention: Desk Office for EPA. Since OMB is 
required to make a decision concerning the ICR between 30 and 60 days 
after February 8, 2012, a comment to OMB is best assured of having its 
full effect if OMB receives it by March 9, 2012. The final rule will 
respond to any OMB or public comments on the information collection 
requirements contained in this proposal.

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 a 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 today's proposed rule on 
small entities, small entity is defined as: (1) A small business that 
is a small industrial entity 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 which is independently owned and operated and is not 
dominant in its field.
    After considering the economic impact of this supplemental proposed 
rule on small entities, I certify that this action will not have a 
significant economic impact on a substantial number of small entities. 
This proposed rule would impose more stringent emissions limits and 
lower surface tension requirements. These new proposed requirements and 
restrictions to the hard and decorative chromium electroplating and 
chromium anodizing tanks MACT standard will impact small entities, but 
those impacts have been estimated to be nominal. The proposed emissions 
limits reflect the level of performance currently being achieved by 
most facilities, and many facilities currently have emissions that are 
far below the proposed limits. With regard to the remaining facilities 
(those that will need to achieve emissions reductions), most of these 
facilities can achieve the proposed limits at low costs (e.g., by using 
additional fume suppressants).
    The EPA's analysis estimated that 96 percent of the affected 
entities will have an annualized cost of less than 1 percent of sales. 
In addition, approximately 1 percent of affected entities, or 9 
facilities with fewer than 20 employees, may have cost-to-sales ratios 
between 3 to 8 percent. All of these facilities are in the hard 
chromium electroplating category, with 2 of the facilities in the small 
hard chromium electroplating category and 7 in the large hard chromium 
electroplating category.
    Since our analysis indicates that a small subset of facilities 
(about 1 percent) may have cost-to-sales ratios greater than 3 percent, 
we have conducted additional economic impact analyses on this small 
subset of facilities to better understand the potential economic 
impacts for these facilities. The additional analyses indicate the 
estimates of costs-to-sales ratios in the initial analyses are more 
likely to be

[[Page 6653]]

overstated rather than understated because the additional analyses 
indicate that sales are typically higher for these sources than the 
average value used in the initial analysis.
    Moreover, because of the nature of the market, these facilities are 
likely to be able to pass cost increases through to their customers. As 
such, we do not anticipate the proposal to result in firm closures, or 
substantial profit loss. More information and details of this analysis 
are provided in the technical document ``Economic Impact Analysis for 
Risk and Technology Review: Chromium Electroplating,'' which is 
available in the docket for this proposed rule.
    Although this proposed rule will not have a significant economic 
impact on a substantial number of small entities, EPA nonetheless has 
tried to reduce the impact of this rule on small entities. We continue 
to be interested in the potential impacts of the proposed rule on small 
entities and welcome comments on issues related to such impacts.

D. Unfunded Mandates Reform Act

    This proposed rule does not contain a Federal mandate under the 
provisions of Title II of the Unfunded Mandates Reform Act of 1995 
(UMRA), 2 U.S.C. 1531-1538 for state, local, or tribal governments or 
the private sector. The proposed rule would not result in expenditures 
of $100 million or more for State, local, and tribal governments, in 
aggregate, or the private sector in any 1 year. The proposed rule 
imposes no enforceable duties on any State, local, or tribal 
governments or the private sector. Thus, this proposed rule is not 
subject to the requirements of sections 202 or 205 of the UMRA.
    This proposed rule is also not subject to the requirements of 
section 203 of UMRA because it contains no regulatory requirements that 
might significantly or uniquely affect small governments. This action 
contains no requirements that apply to such governments nor does it 
impose obligations upon them.

E. Executive Order 13132: Federalism

    This proposed rule 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. None of the facilities subject 
to this action are owned or operated by State governments, and, because 
no new requirements are being promulgated, nothing in this proposal 
will supersede State regulations. Thus, Executive Order 13132 does not 
apply to this proposed rule.
    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

    This proposed rule will not have tribal implications, as specified 
in Executive Order 13175 (65 FR 67249, November 9, 2000). It will not 
have substantial direct effect on tribal governments, on the 
relationship between the Federal government and Indian tribes, or on 
the distribution of power and responsibilities between the Federal 
government and Indian tribes, as specified in Executive Order 13175. 
Thus, Executive Order 13175 does not apply to this action.
    EPA specifically solicits additional comment on this proposed 
action from tribal officials.

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

    This proposed rule is not subject to Executive Order 13045 (62 FR 
19885, April 23, 1997) because it is not economically significant as 
defined in Executive Order 12866, and because the Agency does not 
believe the environmental health or safety risks addressed by this 
action present a disproportionate risk to children. This action would 
not relax the control measures on existing regulated sources. 
Nevertheless, this proposed action would result in reductions in cancer 
risks due to chromium emissions for people of all ages, including 
children. The EPA's risk assessments (included in the docket for this 
proposed rule) demonstrate that these regulations, with the amendments 
being proposed in today's action, will be health protective.
    The public is invited to submit comments or identify peer-reviewed 
studies and data that assess effects of early life exposure to 
hexavalent chromium.

H. Executive Order 13211: Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use

    This action is not a ``significant energy action'' as defined under 
Executive Order 13211 (66 FR 28355 (May 22, 2001)), because it is not 
likely to have significant adverse effect on the supply, distribution, 
or use of energy. This action will not create any new requirements for 
sources in the energy supply, distribution, or use sectors.

I. National Technology Transfer and Advancement Act

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

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

    Executive Order 12898 (59 FR 7629, February 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.
    The EPA has determined that this proposed rule will not have 
disproportionately high and adverse human health or environmental 
effects on minority or low-income populations because it maintains or 
increases the level of environmental protection for all affected 
populations without having any disproportionately high and adverse 
human health or environmental effects on any population, including any 
minority low-income, or indigenous populations. Further, the EPA is 
proposing that, after implementation of the provisions of this rule, 
the public health of all demographic groups will be protected with an 
ample margin of safety.
    To examine the potential for any environmental justice issues that 
might be associated with two of the source categories associated with 
today's

[[Page 6654]]

proposed rule (Hard Chromium Electroplaters and Decorative Chromium 
Electroplaters), we evaluated the percentages of various social, 
demographic, and economic groups within the at-risk populations living 
near the facilities where these source categories are located and 
compared them to national averages. We did not conduct this type of 
analysis for the chromic acid anodizing or steel pickling categories 
because the numbers of people subjected to cancer risks greater than 1-
in-1 million due to HAP emissions from these source categories were 
quite low. The development of demographic analyses to inform the 
consideration of environmental justice issues in EPA rulemakings is an 
evolving process. The EPA offers the demographic analyses in this 
rulemaking as examples of how such analyses might be developed to 
inform such consideration, and invites public comment on the approaches 
used and the interpretations made from the results, with the hope that 
this will support the refinement and improve utility of such analyses 
for future rulemakings.
    Our analysis of the demographics of the population with estimated 
risks greater than 1-in-1 million indicates potential disparities in 
risks between demographic groups, including the African American, Other 
and Multiracial, Hispanic, Below the Poverty Level, and the Over 25 
without a High School Diploma groups. These groups stand to benefit the 
most from the emission reductions achieved by this proposed rulemaking.
    EPA defines ``Environmental Justice'' to include meaningful 
involvement of all people regardless of race, color, national origin, 
or income with respect to the development, implementation, and 
enforcement of environmental laws, regulations, and policies. To 
promote meaningful involvement, after the rule is proposed, EPA will be 
conducting a webinar to inform the public about the rule and to outline 
how to submit written comments to the docket. Further stakeholder and 
public input is expected through public comment and follow-up meetings 
with interested stakeholders.

List of Subjects in 40 CFR Part 63

    Environmental protection, Air pollution control, Reporting and 
recordkeeping requirements, Volatile organic compounds.

    Dated: January 27, 2012.
Lisa P. Jackson,
Administrator.
    For the reasons stated in the preamble, part 63 of title 40, 
chapter I, of the Code of Federal Regulations is proposed to be amended 
as follows:

PART 63--[AMENDED]

    1. The authority citation for part 63 continues to read as follows:

    Authority: 42 U.S.C. 7401, et seq.

Subpart N--[Amended]

    2. Section 63.341 is amended by adding, in alphabetical order in 
paragraph (a), definitions for existing affected source and new 
affected source.


Sec.  63.341  Definitions and nomenclature.

    (a) * * *
    Existing affected source means an affected hard chromium 
electroplating tank, decorative chromium electroplating tank, or 
chromium anodizing tank, the construction or reconstruction of which 
commenced on or before February 8, 2012.
* * * * *
    New affected source means an affected hard chromium electroplating 
tank, decorative chromium electroplating tank, or chromium anodizing 
tank, the construction or reconstruction of which commenced after 
February 8, 2012.
* * * * *
    3. Section 63.342 is amended by:
    a. Revising paragraphs (c)(1)(i), (c)(1)(ii), and (c)(1)(iii);
    b. Adding paragraph (c)(1)(iv);
    c. Revising paragraphs (c)(2)(i), (c)(2)(ii), and (c)(2)(iii);
    d. Adding paragraph (c)(2)(vi);
    e. Revising paragraphs (d)(1) and (d)(2); and
    f. Adding paragraph (d)(3) to read as follows:


Sec.  63.342  Standards.

* * * * *
    (c)(1) * * *
    (i) Not allowing the concentration of total chromium in the exhaust 
gas stream discharged to the atmosphere to exceed 0.011 milligrams of 
total chromium per dry standard cubic meter (mg/dscm) of ventilation 
air (4.8 x 10-6 grains per dry standard cubic foot (gr/
dscf)) for all open surface hard chromium electroplating tanks that are 
existing affected sources and are located at large hard chromium 
electroplating facilities; or
    (ii) Not allowing the concentration of total chromium in the 
exhaust gas stream discharged to the atmosphere to exceed 0.015 mg/dscm 
(6.6 x 10-6 gr/dscf) for all open surface hard chromium 
electroplating tanks that are existing affected sources and are located 
at small, hard chromium electroplating facilities; or
    (iii) If a chemical fume suppressant containing a wetting agent is 
used, not allowing the surface tension of the electroplating or 
anodizing bath contained within the affected tank to exceed 40 dynes 
per centimeter (dynes/cm) (2.8 x 10-3 pound-force per foot 
(lbf/ft)), as measured by a stalagmometer, or 33 dynes/cm (2.3 x 
10-3 lbf/ft), as measured by a tensiometer at any time 
during tank operation; or
    (iv) Not allowing the concentration of total chromium in the 
exhaust gas stream discharged to the atmosphere to exceed 0.006 mg/dscm 
of ventilation air (2.6 x 10-6 gr/dscf) for all open surface 
hard chromium electroplating tanks that are new affected sources.
* * * * *
    (2) * * *
    (i) Not allowing the concentration of total chromium in the exhaust 
gas stream discharged to the atmosphere to exceed 0.011 mg/dscm of 
ventilation air (4.8 x 10-6 gr/dscf) for all enclosed hard 
chromium electroplating tanks that are existing affected sources and 
are located at large hard chromium electroplating facilities; or
    (ii) Not allowing the concentration of total chromium in the 
exhaust gas stream discharged to the atmosphere to exceed 0.015 mg/dscm 
(6.6 x 10-6 gr/dscf) for all enclosed hard chromium 
electroplating tanks that are existing affected sources and are located 
at small, hard chromium electroplating facilities; or
    (iii) If a chemical fume suppressant containing a wetting agent is 
used, not allowing the surface tension of the electroplating or 
anodizing bath contained within the affected tank to exceed 40 dynes/cm 
(2.8 x 10-3 lbf/ft), as measured by a stalagmometer, or 33 
dynes/cm (2.3 x 10-3 lbf/ft), as measured by a tensiometer 
at any time during tank operation; or
* * * * *
    (vi) Not allowing the concentration of total chromium in the 
exhaust gas stream discharged to the atmosphere to exceed 0.006 mg/dscm 
of ventilation air (2.6 x 10-6 gr/dscf) for all enclosed 
hard chromium electroplating tanks that are new affected sources.
* * * * *
    (d) Standards for decorative chromium electroplating tanks using a 
chromic acid bath and chromium anodizing tanks. During tank operation,

[[Page 6655]]

each owner or operator of an existing, new, or reconstructed affected 
source shall control chromium emissions discharged to the atmosphere 
from that affected source by either:
    (1) Not allowing the concentration of total chromium in the exhaust 
gas stream discharged to the atmosphere to exceed 0.007 mg/dscm (3.1 x 
10-6 gr/dscf) for all existing decorative chromium 
electroplating tanks using a chromic acid bath and all existing 
chromium anodizing tanks; or
    (2) Not allowing the concentration of total chromium in the exhaust 
gas stream discharged to the atmosphere to exceed 0.006 mg/dscm (2.6 x 
10-6 gr/dscf) for all new or reconstructed decorative 
chromium electroplating tanks using a chromic acid bath and all new or 
reconstructed chromium anodizing tanks;
    (3) If a chemical fume suppressant containing a wetting agent is 
used, not allowing the surface tension of the electroplating or 
anodizing bath contained within the affected tank to exceed 40 dynes/cm 
(2.8 x 10-3 lbf/ft), as measured by a stalagmometer or 33 
dynes/cm (2.3 x 10-3 lbf/ft), as measured by a tensiometer 
at any time during tank operation, for all existing, new, or 
reconstructed decorative chromium electroplating tanks using a chromic 
acid bath and all existing, new, or reconstructed chromium anodizing 
tanks.
* * * * *
    4. Section 63.343 is amended by:
    a. Revising paragraphs (a)(1), (a)(2), and (a)(4);
    b. Revising paragraph (b)(1); and
    c. Revising paragraphs (c)(1)(ii), (c)(2)(ii), (c)(4)(ii), 
(c)(5)(i), (c)(5)(ii), and (c)(6)(ii) to read as follows:


Sec.  63.343  Compliance provisions.

    (a)(1) The owner or operator of an existing affected source shall 
comply with the emission limitations in Sec.  63.342 no later than 
[DATE 2 YEARS AFTER PUBLICATION OF FINAL RULE IN Federal Register].
    (2) The owner or operator of a new or reconstructed affected source 
that has an initial startup after [DATE OF PUBLICATION OF FINAL RULE IN 
THE Federal Register], shall comply immediately upon startup of the 
source.
* * * * *
    (4) The owner or operator of a new area source (i.e., an area 
source for which construction or reconstruction was commenced after 
February 8, 2012) that increases actual or potential emissions of 
hazardous air pollutants such that the area source becomes a major 
source must comply with the provisions for new major sources, 
immediately upon becoming a major source.
* * * * *
    (b) Methods to demonstrate initial compliance. (1) Except as 
provided in paragraphs (b)(2) and (b)(3) of this section, an owner or 
operator of an affected source subject to the requirements of this 
subpart is required to conduct an initial performance test as required 
under Sec.  63.7, using the procedures and test methods listed in 
Sec. Sec.  63.7 and 63.344.
* * * * *
    (c) * * *
    (1) * * *
    (ii) On and after the date on which the initial performance test is 
required to be completed under Sec.  63.7, the owner or operator of an 
affected source, or group of affected sources under common control, 
shall monitor and record the pressure drop across the composite mesh-
pad system once each day that any affected source is operating. To be 
in compliance with the standards, the composite mesh-pad system shall 
be operated within 2 inches of water column of the pressure 
drop value established during the initial performance test, or shall be 
operated within the range of compliant values for pressure drop 
established during multiple performance tests.
* * * * *
    (2) * * *
    (ii) On and after the date on which the initial performance test is 
required to be completed under Sec.  63.7, the owner or operator of an 
affected source, or group of affected sources under common control, 
shall monitor and record the velocity pressure at the inlet to the 
packed-bed system and the pressure drop across the scrubber system once 
each day that any affected source is operating. To be in compliance 
with the standards, the scrubber system shall be operated within 10 percent of the velocity pressure value established during the 
initial performance test, and within 1 inch of water column 
of the pressure drop value established during the initial performance 
test, or within the range of compliant operating parameter values 
established during multiple performance tests.
* * * * *
    (4) * * *
    (ii) On and after the date on which the initial performance test is 
required to be completed under Sec.  63.7, the owner or operator of an 
affected source, or group of affected sources under common control, 
shall monitor and record the pressure drop across the fiber-bed mist 
eliminator, and the control device installed upstream of the fiber bed 
to prevent plugging, once each day that any affected source is 
operating. To be in compliance with the standards, the fiber-bed mist 
eliminator and the upstream control device shall be operated within 
1 inch of water column of the pressure drop value 
established during the initial performance test, or shall be operated 
within the range of compliant values for pressure drop established 
during multiple performance tests.
* * * * *
    (5) Wetting agent-type or combination wetting agent-type/foam 
blanket fume suppressants. (i) During the initial performance test, the 
owner or operator of an affected source complying with the emission 
limitations in Sec.  63.342 through the use of a wetting agent in the 
electroplating or anodizing bath shall determine the outlet chromium 
concentration using the procedures in Sec.  63.344(c). The owner or 
operator shall establish as the site-specific operating parameter the 
surface tension of the bath using Method 306B, appendix A of this part, 
setting the maximum value that corresponds to compliance with the 
applicable emission limitation. In lieu of establishing the maximum 
surface tension during the performance test, the owner or operator may 
accept 40 dynes/cm, as measured by a stalagmometer, or 33 dynes/cm, as 
measured by a tensiometer, as the maximum surface tension value that 
corresponds to compliance with the applicable emission limitation. 
However, the owner or operator is exempt from conducting a performance 
test only if the criteria of paragraph (b)(2) of this section are met.
    (ii) On and after the date on which the initial performance test is 
required to be completed under Sec.  63.7, the owner or operator of an 
affected source shall monitor the surface tension of the electroplating 
or anodizing bath. Operation of the affected source at a surface 
tension greater than the value established during the performance test, 
or greater than 40 dynes/cm, as measured by a stalagmometer, or 33 
dynes/cm, as measured by a tensiometer, if the owner or operator is 
using this value in accordance with paragraph (c)(5)(i) of this 
section, shall constitute noncompliance with the standards. The surface 
tension shall be monitored according to the following schedule:
* * * * *
    (6) * * *
    (ii) On and after the date on which the initial performance test is 
required to be completed under Sec.  63.7, the owner or

[[Page 6656]]

operator of an affected source shall monitor the foam blanket thickness 
of the electroplating or anodizing bath. Operation of the affected 
source at a foam blanket thickness less than the value established 
during the performance test, or less than 2.54 cm (1 inch) if the owner 
or operator is using this value in accordance with paragraph (c)(6)(i) 
of this section, shall constitute noncompliance with the standards. The 
foam blanket thickness shall be measured according to the following 
schedule:
* * * * *
    5. Section 63.344 is amended by:
    a. Adding paragraphs (b)(1)(v) through (b)(1)(viii); and
    b. Deleting paragraph (b)(2); to read as follows:


Sec.  63.344  Performance test requirements and test methods.

* * * * *
    (b)(1) * * *
    (v) The performance test was conducted after January 25, 1995;
    (vi) As of [DATE OF PUBLICATION OF FINAL RULE IN Federal Register], 
the source was using the same emissions controls that were used during 
the compliance test; and
    (vii) As of [INSERT DATE OF PUBLICATION OF FINAL RULE IN Federal 
Register], the source was operating under conditions that are 
representative of the conditions under which the source was operating 
during the compliance test; and
    (viii) Based on approval from the permitting authority.
* * * * *
    6. Section 63.347 is amended by adding paragraph (f)(3) to read as 
follows:


Sec.  63.347  Reporting requirements.

* * * * *
    (f)(3)(i) Within 90 days after the date of completing each 
performance test (defined in Sec.  63.2) as required by this subpart, 
you must submit the results of the performance tests required by this 
subpart to EPA's WebFIRE database by using the Compliance and Emissions 
Data Reporting Interface (CEDRI) that is accessed through EPA's Central 
Data Exchange (CDX) (www.epa.gov/cdx). Performance test data must be 
submitted in the file format generated through use of EPA's Electronic 
Reporting Tool (ERT) (see http://www.epa.gov/ttn/chief/ert/index.html). 
Only data collected using test methods on the ERT Web site are subject 
to this requirement for submitting reports electronically to WebFIRE. 
Owners or operators who claim that some of the information being 
submitted for performance tests is confidential business information 
(CBI) must submit a complete ERT file including information claimed to 
be CBI on a compact disk or other commonly used electronic storage 
media (including, but not limited to, flash drives) to EPA. The 
electronic media must be clearly marked as CBI and mailed to U.S. EPA/
OAPQS/CORE CBI Office, Attention: WebFIRE Administrator, MD C404-02, 
4930 Old Page Rd., Durham, NC 27703. The same ERT file with the CBI 
omitted must be submitted to EPA via CDX as described earlier in this 
paragraph. At the discretion of the delegated authority, you must also 
submit these reports, including the confidential business information, 
to the delegated authority in the format specified by the delegated 
authority.
    (ii) All reports required by this subpart not subject to the 
requirements in paragraphs (3)(i) of this section must be sent to the 
Administrator at the appropriate address listed in Sec.  63.13. The 
Administrator or the delegated authority may request a report in any 
form suitable for the specific case (e.g., by commonly used electronic 
media such as Excel spreadsheet, on CD or hard copy). The Administrator 
retains the right to require submittal of reports subject to paragraph 
(3)(i) of this section in paper format.
* * * * *

Subpart CCC--[Amended]

    7. Section 63.1157 is amended by revising (b)(2) to read as 
follows:


Sec.  63.1157  Emission standards for existing sources.

* * * * *
    (b) * * *
    (2) In addition to the requirement of paragraph (b)(1) of this 
section, no owner or operator of an existing plant shall cause or allow 
to be discharged into the atmosphere from the affected plant any gases 
that contain chlorine (Cl2) in a concentration in excess of 
6 ppmv.
* * * * *


Sec.  63.1161  [Amended]

    8. Section 63.1161 is amended by deleting paragraph (c)(2).
    9. Section 63.1164 is amended by revising (a) to read as follows:


Sec.  63.1164  Reporting requirements.

    (a) Reporting results of performance tests. As required by Sec.  
63.10(d)(2) of subpart A of this part, the owner or operator of an 
affected source shall report the results of any performance test 
required by this paragraph to EPA's WebFIRE database by using the 
Compliance and Emissions Data Reporting Interface (CEDRI) that is 
accessed through EPA's Central Data Exchange (CDX) (www.epa.gov/cdx). 
Performance test data shall be submitted in the file format generated 
through use of EPA's Electronic Reporting Tool (ERT) (see http://www.epa.gov/ttn/chief/ert/index.html). Only data collected using test 
methods listed on the ERT Web site are subject to this requirement for 
submitting reports electronically to WebFIRE. Owners or operators who 
claim that some of the performance test information being submitted is 
confidential business information (CBI) shall submit a complete ERT 
file including information claimed to be CBI on a compact disk or other 
commonly used electronic storage media (including, but not limited to, 
flash drives) by registered letter to EPA and the same ERT file with 
the CBI omitted to EPA via CDX as described earlier in this paragraph. 
The compact disk shall be clearly marked as CBI and mailed to U.S. EPA/
OAPQS/CORE CBI Office, Attention: WebFIRE Administrator, MD C404-02, 
4930 Old Page Rd., Durham, NC 27703. At the discretion of the delegated 
authority, owners or operators shall also submit these reports to the 
delegated authority in the format specified by the delegated authority.
* * * * *

Appendix A--[Amended]

    10. Appendix A to part 63, Method 306-B is amended revising 
paragraph 11.2.1.3 to read as follows:

    METHOD 306B--SURFACE TENSION MEASUREMENT FOR TANKS USED AT 
CHROMIUM ELECTROPLATING AND CHROMIUM ANODIZING FACILITIES
* * * * *
    11.0 Analytical Procedure
* * * * *
    11.2.1.3 If a measurement of the surface tension of the solution 
is above the 40 dynes per centimeter limit, as measured using a 
stalagmometer, or above the 33 dynes per centimeter limit, as 
measured using a tensiometer, or above an alternate surface tension 
limit established during the performance test, the time interval 
shall revert back to the original monitoring schedule of once every 
4 hours. A subsequent decrease in frequency would then be allowed 
according to Section 11.2.1.
* * * * *

[FR Doc. 2012-2434 Filed 2-7-12; 8:45 am]
BILLING CODE 6560-50-P