Notice of Intent for the East Locust Creek Watershed Revised Plan, Sullivan County, Missouri, 72621-72622 [2014-28673]

Download as PDF 72621 Notices Federal Register Vol. 79, No. 235 Monday, December 8, 2014 This section of the FEDERAL REGISTER contains documents other than rules or proposed rules that are applicable to the public. Notices of hearings and investigations, committee meetings, agency decisions and rulings, delegations of authority, filing of petitions and applications and agency statements of organization and functions are examples of documents appearing in this section. DEPARTMENT OF AGRICULTURE Natural Resources Conservation Service [Docket No. NRCS–2014–0014] Notice of Intent for the East Locust Creek Watershed Revised Plan, Sullivan County, Missouri Natural Resources Conservation Service, USDA. ACTION: Notice of Intent to Prepare a Supplemental Environmental Impact Statement. AGENCY: Pursuant to Section 102(2)(c) of the National Environmental Policy Act of 1969 (NEPA); as amended (42 U.S.C. 4321 et seq.), the Natural Resources Conservation Service (NRCS), U.S. Department of Agriculture, as lead federal agency, will prepare a Supplemental Environmental Impact Statement (SEIS) for the East Locust Creek Watershed Revised Plan (ELCWRP), Sullivan County, Missouri, involving the proposed construction of a multi-purpose reservoir. The purpose of this supplement is to address changes which have occurred since the NRCS prepared the East Locust Creek Watershed Revised Plan and Environmental Impact Statement in 2006. The SEIS will update the original EIS with more recent relevant environmental information and expand the alternatives analysis beyond those previously considered. The SEIS will evaluate reasonable and practicable alternatives and their expected environmental impacts. ADDRESSES: To be included on the mailing list for review of the SEIS, all requests should be submitted to Mr. Harold Deckerd, USDA-Natural Resources Conservation Service, Parkade Center, Suite 250, 601 Business Loop 70 West, Columbia, Missouri 65203–2585. mstockstill on DSK4VPTVN1PROD with NOTICES SUMMARY: VerDate Sep<11>2014 20:19 Dec 05, 2014 Jkt 235001 Mr. Harold Deckerd, NRCS Missouri State Office, by email: harold.deckerd@ mo.usda.gov, by regular mail (see ADDRESSES), or by telephone: 573–876– 0912. SUPPLEMENTARY INFORMATION: The NRCS in cooperation with the North Central Missouri Regional Water Commission (NCMRWC) and the U.S. Army Corps of Engineers (Corps) will prepare a SEIS for the East Locust Creek Watershed Revised Plan in Sullivan County, Missouri authorized pursuant to the Watershed Protection and Flood Prevention Act, Public Law 83–566, (16 U.S.C. 1001–1008). The NRCS has determined that additional analysis is required and that the purposes of the National Environmental Policy Act would be furthered through the preparation of the SEIS. The Corps will be a cooperating agency in the preparation of the SEIS. The SEIS will consider all reasonable and practicable alternatives to meet the purpose and need for the federal action. The SEIS will assess the potential social, economic, and environmental impacts of the project, and will address federal, state, and local regulatory requirements along with pertinent environmental and socio-economic issues. The SEIS will analyze the direct, indirect, and cumulative effects of the proposed action. The Federal SEIS process begins with the publication of this Notice of Intent. 1. Background: The 79,490-acre East Locust Creek Watershed is located in north-central Missouri approximately 30 miles west of Kirksville in Sullivan County with small portions of the watershed in neighboring Putnam and Linn Counties. East Locust Creek is a tributary to Locust Creek which drains to the Grand River and the Missouri River. The Sullivan and Putnam County Commissions and the Sullivan and Putnam County Soil and Water Conservation Districts initially applied for federal watershed planning assistance in the East Locust Creek Watershed in 1974. Missouri governor Christopher Bond approved their application that same year. The U.S. Soil Conservation Service (later renamed and hereafter referred to as NRCS) collected pre-authorization planning data and analyzed the East Locust Creek Watershed as part of the FOR FURTHER INFORMATION CONTACT: PO 00000 Frm 00001 Fmt 4703 Sfmt 4703 larger Northern Missouri River Tributaries Study. East Locust Creek Watershed planning was authorized in March 1984 and NRCS began planning activities under the authority of the Watershed Protection and Flood Prevention Act of 1954, Public Law 83– 566, as amended (16 U.S.C. 1001–1008). NRCS completed the East Locust Creek Watershed Plan-Environmental Assessment in 1986. The plan recommended one large and 120 small dams to reduce soil erosion and flood damages. A Finding of No Significant Impact (FONSI) was published in the Federal Register on July 17, 1986. Local sponsors signed the Watershed Agreement in November 1986 and assistance for installation was authorized in August 1987. The Missouri Drought Plan (Missouri Dept. of Natural Resources, 2002) places Sullivan County and surrounding counties in a region classified as having ‘‘severe surface and groundwater supply drought vulnerability.’’ Underlying bedrock geology severely limits groundwater quality and availability. Recognizing the regional need for a dependable water supply, the Locust Creek Watershed Board in November 2000 requested NRCS study a potential supplement to the 1986 East Locust Creek Watershed Plan-Environmental Assessment to include a public water supply reservoir. The NCMRWC was formed in 2001 with assistance from the Missouri Department of Natural Resources ‘‘to provide an abundant source of low-cost, pure, quality water for the residents of North Central Missouri.’’ The NCMRWC immediately became a local sponsor of the planning effort. NRCS began planning activities following authorization in July 2003. NRCS issued a Notice of Intent to prepare an Environmental Impact Statement in September of 2004. NRCS completed the East Locust Creek Watershed Revised Plan and Environmental Impact Statement (ELCWRP) in March 2006 and announced a Record of Decision to proceed with installation in September 2006. The ELCWRP found the present water supply systems for the neighboring ten-county region are inadequate and experience pressures from drought conditions. In addition, the ELCWRP documented annual flood damages to crop and pasture land, fences, roads and bridges. The ELCWRP E:\FR\FM\08DEN1.SGM 08DEN1 mstockstill on DSK4VPTVN1PROD with NOTICES 72622 Federal Register / Vol. 79, No. 235 / Monday, December 8, 2014 / Notices also identified the need for additional water-based recreational opportunities in the surrounding area. The project has not been installed because sufficient funding has not been available. Installation of the proposed action will result in temporary and permanent impacts to jurisdictional waters of the United States requiring a Clean Water Act (CWA) Section 404 permit. The Corps has not issued a Section 404 permit for this project. Potential impacts of all reasonable and practicable alternatives will be updated and analyzed in the SEIS in compliance with Section 404(b)(1) of the CWA. 2. Proposed Action: The proposed federal action as presented in the 2006 EIS includes one approximately 2,235acre multiple-purpose reservoir on East Locust Creek, a water intake structure, a raw water line, fish and wildlife habitat enhancement and water-based recreational facilities. The purpose of the proposed federal action is to: Provide approximately 7.0 million gallons per day of raw water supply to meet the projected 50-year usage demand for the ten counties served by the NCMRWC; provide approximately 72,000 annual water-based recreational user-days and provide an approximate 22% reduction in annual flood damages in the 16.3 miles of East Locust Creek floodplain between the reservoir and the confluence with Locust Creek. 3. Alternatives: The SEIS will evaluate environmental impacts of the following alternatives and any other action alternatives identified that may be reasonable and practicable: (1) Creation of a multi-purpose reservoir; (2) a range of reasonable alternatives to meet the overall project purposes and needs; and (3) the no-action alternative. The SEIS will identify the National Economic Development (NED) alternative, which is the alternative with the greatest net economic benefit consistent with protecting the Nation’s environment and document the estimated direct, indirect and cumulative impacts of the proposed action and alternatives on the environment. 4. Scoping: In developing the 2006 ELCWRP, numerous scoping meetings were held to gather public input and keep the community informed on the status of project planning activities. Several community surveys and interviews were conducted to gather information, and periodic news articles were published to update local citizens. Problems identified through the scoping process include: • Inadequate rural water supply in the 10-county Green Hills Region • Annual flood damages to crops, pastures, fences and infrastructure VerDate Sep<11>2014 20:19 Dec 05, 2014 Jkt 235001 • Unmet demand for water-based recreational facilities. NEPA procedures do not require additional public scoping meetings for the development of a SEIS and none are planned at this time. Comments received from Federal, State or local agencies, Native American Tribes, nongovernmental organizations, and interested citizens will be used to assist in the development of the Draft and Final SEIS (See ADDRESSES above to submit comments). 5. Public Involvement: The NRCS invites full public participation to promote open communication and better decision-making. All persons and organizations with an interest in the ELCWRP are urged to comment. Public comments are welcomed and opportunities for public participation include submitting comments to the NRCS: (1) During the development of the Draft SEIS, (2) during the review and comment period upon publishing the Draft SEIS; and (3) for 30 days after publication of the Final SEIS. Distribution of the comments received will be included in the Administrative Record without change and may include any personal information provided unless the commenter indicates that the comment includes information claimed to be confidential business information. 6. Other Environmental Review and Coordination Requirements: The Corps will be a cooperating agency in the preparation of the SEIS. The NRCS as the lead federal agency will continue to coordinate with other agencies and entities throughout the NEPA process including: The NCMRWC, Missouri Department of Natural Resources (Section 401, Historic Preservation and Dam Safety), Missouri Department of Conservation, U.S. Fish and Wildlife Service and USEPA. The Draft SEIS will address project compliance with applicable laws and regulations, including NEPA, CWA, Endangered Species Act, and the National Historic Preservation Act. 7. Permits or Licenses Required: The proposed federal action would require a CWA Section 404 permit from the Corps. The project would also require certification by the State of Missouri, Department of Natural Resources, under Section 401 of the CWA, that the project would not violate state water quality standards. A land disturbance permit issued by the Missouri Department of Natural Resources under Section 402 of the CWA (National Pollutant Discharge Elimination System Permit) would be required. Construction and Safety Permits issued by the Missouri Dam and Reservoir Safety Program would also be required. PO 00000 Frm 00002 Fmt 4703 Sfmt 4703 8. Availability of Draft SEIS: The draft SEIS is estimated to be complete and available for public review in 2016. (This activity is listed in the Catalog of Federal Domestic Assistance under NO. 10.904, Watershed Protection and Flood Prevention, and is subject to the provisions of Executive Order 12372, which requires intergovernmental consultation with State and local officials.) Dated: November 25, 2014. J.R. Flores, State Conservationist, Natural Resources Conservation Service. [FR Doc. 2014–28673 Filed 12–5–14; 8:45 am] BILLING CODE 3410–16–P DEPARTMENT OF AGRICULTURE Rural Housing Service Notice of Request for Extension of a Currently Approved Information Collection Rural Housing Service, USDA. ACTION: Proposed collection; comments requested. AGENCIES: In accordance with the Paperwork Reduction Act of 1995, this notice announces the Rural Housing Service (RHS), intention to request an extension for a currently approved information collection in support of compliance with Civil Rights laws. DATES: Comments on this notice must be received by February 6, 2015 to be assured of consideration. FOR FURTHER INFORMATION CONTACT: Angilla Denton, Equal Opportunity Specialist, Rural Development, Civil Rights Staff, U.S. Department of Agriculture, STOP 0703, 1400 Independence Ave. SW., Washington, DC 20250–0703, Telephone (202) 692– 4109 (voice). SUPPLEMENTARY INFORMATION: Title: 7 CFR 1901–E, Civil Rights Compliance Requirements. OMB Number: 0575–0018. Expiration Date of Approval: February 28, 2015. Type of Request: Extension of a Currently Approved Information Collection. Abstract: The information collection under OMB Number 0575–0018 enables the RHS, Rural Business-Cooperative Service (RBS), and Rural Utilities Service (RHS), to effectively monitor a recipient’s compliance with the civil rights laws, and to determine whether or not service and benefits are being provided to beneficiaries on an equal opportunity basis. SUMMARY: E:\FR\FM\08DEN1.SGM 08DEN1

Agencies

[Federal Register Volume 79, Number 235 (Monday, December 8, 2014)]
[Proposed Rules]
[Pages 72621-72622]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2014-28673]



[[Page 72913]]

Vol. 79

Monday,

No. 235

December 8, 2014

Part IV





Environmental Protection Agency





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40 CFR Part 63





National Emissions Standards for Hazardous Air Pollutants: Primary 
Aluminum Reduction Plants; Proposed Rule

Federal Register / Vol. 79, No. 235 / Monday, December 8, 2014 / 
Proposed Rules

[[Page 72914]]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 63

[EPA-HQ-OAR-2011-0797; FRL-9917-44-OAR]
RIN 2060-AQ92


National Emissions Standards for Hazardous Air Pollutants: 
Primary Aluminum Reduction Plants

AGENCY: Environmental Protection Agency.

ACTION: Supplemental proposed rulemaking.

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SUMMARY: This action supplements our proposed amendments to the 
national emission standards for hazardous air pollutants (NESHAP) for 
the Primary Aluminum Production source category published in the 
Federal Register on December 6, 2011. In that action, the Environmental 
Protection Agency (EPA) proposed amendments based on the initial 
residual risk and technology reviews (RTR) for this source category, 
and also proposed certain emission limits reflecting performance of 
Maximum Achievable Control Technology (MACT). Today's action reflects a 
revised technology review and a revised residual risk analysis for the 
Primary Aluminum Production source category and proposes new and 
revised emission standards based on those analyses, newly obtained 
emissions test data, and comments we received in response to the 2011 
proposal, including certain revisions to the technology-based standards 
reflecting performance of MACT. This action also proposes new 
compliance requirements to meet the revised standards. This action, if 
adopted, will provide improved environmental protection regarding 
potential emissions of hazardous air pollutant (HAP) emissions from 
primary aluminum production facilities.

DATES: Comments. Comments must be received on or before January 22, 
2015. A copy of comments on the information collection provisions 
should be submitted to the Office of Management and Budget (OMB) on or 
before January 7, 2015.
    Public Hearing. If anyone contacts the EPA requesting to speak at a 
public hearing by December 15, 2014, a public hearing will be held on 
December 23, 2014 at the U.S. EPA building at 109 T.W. Alexander Drive, 
Research Triangle Park, NC 27711. If you are interested in requesting a 
public hearing or attending the public hearing, contact Ms. Virginia 
Hunt at (919) 541-0832 or at hunt.virginia@epa.gov. If the EPA holds a 
public hearing, the EPA will keep the record of the hearing open for 30 
days after completion of the hearing to provide an opportunity for 
submission of rebuttal and supplementary information.

ADDRESSES: Comments. Submit your comments, identified by Docket ID No. 
EPA-HQ-OAR-2011-0797, by one of the following methods:
     Federal eRulemaking Portal: http://www.regulations.gov. 
Follow the online instructions for submitting comments.
     Email: A-and-R-docket@epa.gov. Include Attention Docket ID 
No. EPA-HQ-OAR-2011-0797 in the subject line of the message.
     Fax: (202) 566-9744. Attention Docket ID No. EPA-HQ-OAR-
2011-0797.
     Mail: Environmental Protection Agency, EPA Docket Center 
(EPA/DC), Mail Code: 28221T, Attention Docket ID No. EPA-HQ-OAR-2011-
0797, 1200 Pennsylvania Avenue NW., Washington, DC 20460. 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/Courier Delivery: EPA Docket Center, Room 3334, EPA 
WJC West Building, 1301 Constitution Avenue NW., Washington, DC 20004, 
Attention Docket ID No. EPA-HQ-OAR-2011-0797. 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-
2011-0797. The EPA's policy is that all comments received will be 
included in the public docket without change and may be made available 
online at http://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 http://www.regulations.gov Web site 
is an ``anonymous access'' system, which means the 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 the EPA 
without going through http://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, the 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 the EPA cannot read your comment 
due to technical difficulties and cannot contact you for clarification, 
the EPA may not be able to consider your comment. Electronic files 
should not include special characters or any form of encryption and be 
free of any defects or viruses. For additional information about the 
EPA's public docket, visit the EPA Docket Center homepage at: http://
www.epa.gov/dockets.
    Docket. The EPA has established a docket for this rulemaking under 
Docket ID No. EPA-HQ-OAR-2011-0797. All documents in the docket are 
listed in the 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 regulations.gov or in 
hard copy at the EPA Docket Center, Room 3334, EPA WJC West Building, 
1301 Constitution Avenue 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.
    Public Hearing: If anyone contacts the EPA requesting a public 
hearing by December 15, 2014, the public hearing will be held on 
December 23, 2014 at the EPA's campus at 109 T.W. Alexander Drive, 
Research Triangle Park, North Carolina. The hearing will begin at 10:00 
a.m. (Eastern Standard Time) and conclude at 5:00 p.m. (Eastern 
Standard Time). There will be a lunch break from 12:00 p.m. to 1:00 
p.m. Please contact Ms. Virginia Hunt at 919-541-0832 or at 
hunt.virginia@epa.gov to register to speak at the hearing or to inquire 
as to whether or not a hearing will be held. The last day to pre-
register in advance to speak at the hearing will be December 22, 2014. 
Additionally, requests to speak will be taken the day of the hearing at 
the hearing registration desk, although preferences on speaking times 
may not be able to be accommodated. If you require the service of a 
translator or

[[Page 72915]]

special accommodations such as audio description, please let us know at 
the time of registration. If you require an accommodation, we ask that 
you pre-register for the hearing, as we may not be able to arrange such 
accommodations without advance notice. The hearing will provide 
interested parties the opportunity to present data, views or arguments 
concerning the proposed action. The EPA will make every effort to 
accommodate all speakers who arrive and register. Because these hearing 
are being held at U.S. government facilities, individuals planning to 
attend the hearing should be prepared to show valid picture 
identification to the security staff in order to gain access to the 
meeting room. Please note that the REAL ID Act, passed by Congress in 
2005, established new requirements for entering federal facilities. If 
your driver's license is issued by Alaska, American Samoa, Arizona, 
Kentucky, Louisiana, Maine, Massachusetts, Minnesota, Montana, New 
York, Oklahoma or the state of Washington, you must present an 
additional form of identification to enter the federal building. 
Acceptable alternative forms of identification include: Federal 
employee badges, passports, enhanced driver's licenses and military 
identification cards. In addition, you will need to obtain a property 
pass for any personal belongings you bring with you. Upon leaving the 
building, you will be required to return this property pass to the 
security desk. No large signs will be allowed in the building, cameras 
may only be used outside of the building and demonstrations will not be 
allowed on federal property for security reasons. The EPA may ask 
clarifying questions during the oral presentations, but will not 
respond to the presentations at that time. Written statements and 
supporting information submitted during the comment period will be 
considered with the same weight as oral comments and supporting 
information presented at the public hearing.
    Docket: The EPA has established a docket for this rulemaking under 
Docket ID No. EPA-HQ–OAR-2011-0797. All documents in the docket 
are listed in the www.regulations.gov index. Although listed in the 
index, some information is not publicly available, e.g., CBI or other 
information whose disclosure is restricted by statute. Certain other 
material, such as copyrighted material, will be publicly available only 
in hard copy. Publicly available docket materials are available either 
electronically in www.regulations.gov or in hard copy at the EPA Docket 
Center, EPA WJC West Building, 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 Air Docket is (202) 566-1742.

FOR FURTHER INFORMATION CONTACT: For questions about this proposed 
action, contact Mr. David Putney, Sector Policies and Programs Division 
(D243-02), Office of Air Quality Planning and Standards, Environmental 
Protection Agency, Research Triangle Park, NC 27711; telephone (919) 
541-2016; fax number: (919) 541-3207; and email address: 
putney.david@epa.gov. For specific information regarding the risk 
modeling methodology, contact Mr. Jim Hirtz, 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) 541-0881; fax number: (919) 
541-0840; and email address: hirtz.james@epa.gov. For information about 
the applicability of the NESHAP to a particular entity, contact Mr. 
Patrick Yellin, Office of Enforcement and Compliance Assurance, U.S. 
Environmental Protection Agency, EPA WJC West Building, Mail Code 
2227A, 1200 Pennsylvania Avenue NW., Washington, DC 20460; telephone 
number: (202) 564-2970 and email address: yellin.patrick@epa.gov.

SUPPLEMENTARY INFORMATION: 
    Preamble Acronyms and Abbreviations. We use multiple acronyms and 
terms in this preamble. While this list may not be exhaustive, to ease 
the reading of this preamble and for reference purposes, the EPA 
defines the following terms and acronyms here:

As arsenic
ADAF age-dependent adjustment factor
AEGL acute exposure guideline levels
AERMOD air dispersion model used by the HEM-3 model
ATSDR Agency for Toxic Substances and Disease Registry
BLDS bag leak detection system
BTF beyond-the-floor
CAA Clean Air Act
CalEPA California EPA
CBI Confidential Business Information
Cd cadmium
CE Cost Effectiveness
CFR Code of Federal Regulations
COS carbonyl sulfide
Cr chromium
Cr\+3\ trivalent chromium
Cr\+6\ hexavalent chromium
CWPB1 center-worked prebake one
CWPB2 center-worked prebake two
CWPB3 center-worked prebake three
D/Fs polychlorinated dibenzo-p-dioxins and polychlorinated 
dibenzofurans
EF Emission Factors
EJ environmental justice
EPA Environmental Protection Agency
ERPG Emergency Response Planning Guidelines
ERT Electronic Reporting Tool
FR Federal Register
HAP hazardous air pollutants
HEM-3 Human Exposure Model, Version 1.1.0
HF hydrogen fluoride
Hg mercury
HI Hazard Index
HQ Hazard Quotient
HSS horizontal stud Soderberg
IRIS Integrated Risk Information System
km kilometer
LOAEL lowest-observed-adverse-effect level
LOEL lowest-observed-effect level
MACT maximum achievable control technology
MCEM methylene chloride extractable matter
mg/dscm milligrams per dry standard cubic meter
mg/kg-day milligrams per kilogram-day
mg/m\3\ milligrams per cubic meter
MIR maximum individual risk
Mn manganese
MRL Minimal Risk Level
NAAQS National Ambient Air Quality Standards
NAICS North American Industry Classification System
NAS National Academy of Sciences
NATA National Air Toxics Assessment
NEI National Emissions Inventory
NESHAP National Emissions Standards for Hazardous Air Pollutants
Ni nickel
NOAEL no-observed-adverse-effect level
NRC National Research Council
NTTAA National Technology Transfer and Advancement Act
OAQPS Office of Air Quality Planning and Standards
OECA Office of Enforcement and Compliance Assurance
OMB Office of Management and Budget
PAH polycyclic aromatic hydrocarbons
Pb lead
PB-HAP hazardous air pollutants known to be persistent and bio-
accumulative in the environment
PCB polychlorinated biphenyls
PEL probable effect level
PM particulate matter
POM polycyclic organic matter
ppm parts per million
RDL representative method detection level
REL reference exposure level
RFA Regulatory Flexibility Act
RfC reference concentration
RfD reference dose
RTR residual risk and technology review
SAB Science Advisory Board
SBA Small Business Administration
SSM startup, shutdown and malfunction
SWPB side-worked prebake
TF total fluorides
TOSHI target organ-specific hazard index
TPY tons per year

[[Page 72916]]

TRIM.FaTE Total Risk Integrated Methodology.Fate, Transport, and 
Ecological Exposure model
TTN echnology Transfer Network
UF uncertainty factor
[mu]g/dscm micrograms per dry standard cubic meter
[mu]g/m\3\ micrograms per cubic meter
UMRA Unfunded Mandates Reform Act
UPL Upper Prediction Limit
URE unit risk estimate
VCS voluntary consensus standards
VSS1 vertical stud Soderberg one
VSS2 vertical stud Soderberg two

    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?
II. Background Information
    A. What is the statutory authority for this action?
    B. What is this source category and how does the current NESHAP 
regulate its HAP emissions?
    C. What is the history of the Primary Aluminum Production source 
category risk and technology review?
    D. What data collection activities were conducted to support 
this action?
III. Analytical Procedures
    A. For purposes of this supplemental proposal, how did we 
estimate the post-MACT risks posed by the Primary Aluminum 
Production source category?
    B. How did we consider the risk results in making decisions for 
this supplemental proposal?
    C. How did we perform the technology review?
IV. Revised Analytical Results and Proposed Decisions for the 
Primary Aluminum Production Source Category
    A. What actions are we proposing pursuant to CAA sections 
112(d)(2) and 112(d)(3)?
    B. What are the results of the risk assessment and analyses?
    C. What are our proposed decisions regarding risk acceptability, 
ample margin of safety and adverse environmental effects based on 
our revised analyses?
    D. What are the results and proposed decisions based on our 
technology review?
    E. What other actions are we proposing?
    F. What compliance dates are we proposing?
V. Summary of the Revised Cost, Environmental and Economic Impacts
    A. What are the affected sources?
    B. What are the air quality impacts?
    C. What are the cost impacts?
    D. What are the economic impacts?
    E. What are the benefits?
VI. Request for Comments
VII. Submitting Data Corrections
VIII. 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?

    Table 1 of this preamble lists the industrial source category that 
is the subject of this supplemental proposal. Table 1 is not intended 
to be exhaustive but rather to provide a guide for readers regarding 
the entities that this proposed action is likely to affect. The 
proposed standards, once promulgated, will be directly applicable to 
the affected sources. Federal, state, local and tribal government 
entities would not be affected by this proposed action. As defined in 
the ``Initial List of Categories of Sources Under Section 112(c)(1) of 
the Clean Air Act Amendments of 1990'' (see 57 FR 31576, July 16, 
1992), the ``Primary Aluminum Production'' source category is any 
facility which produces primary aluminum by the electrolytic reduction 
process.\1\
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    \1\ U.S. EPA. Documentation for Developing the Initial Source 
Category List--Final Report, EPA/OAQPS, EPA-450/3-91-030, July, 
1992.

    Table 1--NESHAP and Industrial Source Categories Affected by This
                             Proposed Action
------------------------------------------------------------------------
         Source category                  NESHAP          NAICS code \a\
------------------------------------------------------------------------
Primary Aluminum Production......  Primary Aluminum               33131
                                    Reduction Plants.
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\a\ 2012 North American Industry Classification System.

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 action is available on the Internet through EPA's Technology 
Transfer Network (TTN) Web site, a forum for information and technology 
exchange in various areas of air pollution control. Following signature 
by the EPA Administrator, the EPA will post a copy of this proposed 
action at: http://www.epa.gov/ttn/atw/alum/alumpg.html. Following 
publication in the Federal Register, the EPA will post the Federal 
Register version of the proposal and key technical documents at this 
same Web site. Information on the overall RTR program is available at 
the following Web site: http://www.epa.gov/ttn/atw/rrisk/rtrpg.html.

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 comments that includes information claimed 
as CBI, you must submit a copy of the comments that does not contain 
the information claimed as CBI 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 Code of Federal Regulations (CFR) part 2. Send or deliver 
information identified as CBI

[[Page 72917]]

only to the following address: Roberto Morales, OAQPS Document Control 
Officer (C404-02), OAQPS, U.S. Environmental Protection Agency, 
Research Triangle Park, North Carolina 27711, Attention Docket ID No. 
EPA-HQ-OAR-2011-0797.

II. Background Information

A. What is the statutory authority for this action?

    Section 112 of the Clean Air Act (CAA) establishes a two-stage 
regulatory process to address emissions of HAPs from stationary 
sources. In the first stage, after the EPA has identified categories of 
sources emitting one or more of the HAP listed in CAA section 112(b), 
CAA section 112(d) requires us to promulgate technology-based NESHAP 
for those sources. ``Major sources'' are those that emit or have the 
potential to emit 10 tons per year (tpy) or more of a single HAP or 25 
tpy or more of any combination of HAPs. For major sources, the 
technology-based NESHAP must reflect the maximum degree of emission 
reductions of HAPs achievable (after considering cost, energy 
requirements and non-air quality health and environmental impacts) and 
are commonly referred to as MACT standards.
    MACT standards must reflect the maximum degree of emissions 
reduction achievable through the application of measures, processes, 
methods, systems or techniques, including, but not limited to, measures 
that (1) reduce the volume of or eliminate pollutants through process 
changes, substitution of materials or other modifications; (2) enclose 
systems or processes to eliminate emissions; (3) capture or treat 
pollutants when released from a process, stack, storage or fugitive 
emissions point; (4) are design, equipment, work practice or 
operational standards (including requirements for operator training or 
certification); or (5) are a combination of the above. CAA section 
112(d)(2)(A) through (E). The MACT standards may take the form of 
design, equipment, work practice or operational standards where the EPA 
first determines either that (1) a pollutant cannot be emitted through 
a conveyance designed and constructed to emit or capture the pollutant, 
or that any requirement for, or use of, such a conveyance would be 
inconsistent with law; or (2) the application of measurement 
methodology to a particular class of sources is not practicable due to 
technological and economic limitations. CAA section 112(h)(1) and (2).
    The MACT ``floor'' is the minimum control level allowed for MACT 
standards promulgated under CAA section 112(d)(3) and may not be based 
on cost considerations. For new sources, the MACT floor cannot be less 
stringent than the emissions control that is achieved in practice by 
the best-controlled similar source. The MACT floor for existing sources 
can be less stringent than floors for new sources but not 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). In developing MACT 
standards, the EPA must also consider control options that are more 
stringent than the floor. We may establish standards more stringent 
than the floor based on considerations of the cost of achieving the 
emission reductions, any non-air quality health and environmental 
impacts and energy requirements.
    The EPA is then required to review these technology-based standards 
and revise them ``as necessary (taking into account developments in 
practices, processes, and control technologies)'' no less frequently 
than every 8 years. CAA section 112(d)(6). In conducting this review, 
the EPA is not required to recalculate the MACT floor. Natural 
Resources Defense Council (NRDC) v. EPA, 529 F.3d 1077, 1084 (D.C. Cir. 
2008). Association of Battery Recyclers, Inc. v. EPA, 716 F.3d 667, 
672-73 (D.C. Cir. 2013).
    The second stage in standard-setting focuses on reducing any 
remaining (i.e., ``residual'') risk according to CAA section 112(f). 
CAA section 112(f)(1) required that the EPA prepare a report to 
Congress discussing (among other things) methods of calculating the 
risks posed (or potentially posed) by sources after implementation of 
the MACT standards, the public health significance of those risks and 
the EPA's recommendations as to legislation regarding such remaining 
risk. The EPA prepared and submitted the Residual Risk Report to 
Congress, EPA-453/R-99-001 (Risk Report) in March 1999. CAA section 
112(f)(2) then provides that if Congress does not act on any 
recommendation in the Risk Report, the EPA must analyze and address 
residual risk for each category or subcategory of sources 8 years after 
promulgation of such standards pursuant to CAA section 112(d).
    Section 112(f)(2) of the CAA requires the EPA to determine for 
source categories subject to MACT standards whether the emission 
standards provide an ample margin of safety to protect public health. 
Section 112(f)(2)(B) of the CAA expressly preserves the EPA's use of 
the two-step process for developing standards to address any residual 
risk and the agency's interpretation of ``ample margin of safety'' 
developed in the National Emissions Standards for Hazardous Air 
Pollutants: Benzene Emissions from Maleic Anhydride Plants, 
Ethylbenzene/Styrene Plants, Benzene Storage Vessels, Benzene Equipment 
Leaks, and Coke By-Product Recovery Plants (Benzene NESHAP) (54 FR 
38044, September 14, 1989). The EPA notified Congress in the Risk 
Report that the agency intended to use the Benzene NESHAP approach in 
making CAA section 112(f) residual risk determinations (EPA-453/R-99-
001, p. ES-11). The EPA subsequently adopted this approach in its 
residual risk determinations and in a challenge to the risk review for 
the Synthetic Organic Chemical Manufacturing source category, the 
United States Court of Appeals for the District of Columbia Circuit 
upheld as reasonable the EPA's interpretation that CAA section 
112(f)(2) incorporates the approach established in the Benzene NESHAP. 
See NRDC v. EPA, 529 F.3d 1077, 1083 (D.C. Cir. 2008) (``[S]ubsection 
112(f)(2)(B) expressly incorporates the EPA's interpretation of the 
Clean Air Act from the Benzene standard, complete with a citation to 
the Federal Register.''); see also, A Legislative History of the Clean 
Air Act Amendments of 1990, vol. 1, p. 877 (Senate debate on Conference 
Report).
    The first step in the process of evaluating residual risk is the 
determination of acceptable risk. If risks are unacceptable, the EPA 
cannot consider cost in identifying the emissions standards necessary 
to bring risks to an acceptable level. The second step is the 
determination of whether standards must be further revised in order to 
provide an ample margin of safety to protect public health. The ample 
margin of safety is the level at which the standards must be set, 
unless an even more stringent standard is necessary to prevent, taking 
into consideration costs, energy, safety and other relevant factors, an 
adverse environmental effect.
1. Step 1--Determination of Acceptability
    The agency in the Benzene NESHAP concluded that ``the acceptability 
of risk under section 112 is best judged on the basis of a broad set of 
health risk measures and information'' and that the ``judgment on 
acceptability cannot be reduced to any single factor.'' Benzene

[[Page 72918]]

NESHAP at 38046. The determination of what represents an ``acceptable'' 
risk is based on a judgment of ``what risks are acceptable in the world 
in which we live'' (Risk Report at 178, quoting NRDC v. EPA, 824 F. 2d 
1146, 1165 (D.C. Cir. 1987) (en banc) (``Vinyl Chloride''), recognizing 
that our world is not risk-free.
    In the Benzene NESHAP, we stated that ``EPA will generally presume 
that if the risk to [the maximum exposed] individual is no higher than 
approximately one in 10 thousand, that risk level is considered 
acceptable.'' 54 FR 38045, September 14, 1989. We discussed the maximum 
individual lifetime cancer risk (or maximum individual risk (MIR)) as 
being ``the estimated risk that a person living near a plant would have 
if he or she were exposed to the maximum pollutant concentrations for 
70 years.'' Id. We explained that this measure of risk ``is an estimate 
of the upper bound of risk-based on conservative assumptions, such as 
continuous exposure for 24 hours per day for 70 years.'' Id. We 
acknowledged that maximum individual lifetime cancer risk ``does not 
necessarily reflect the true risk, but displays a conservative risk 
level which is an upper-bound that is unlikely to be exceeded.'' Id.
    Understanding that there are both benefits and limitations to using 
the MIR as a metric for determining acceptability, we acknowledged in 
the Benzene NESHAP that ``consideration of maximum individual risk * * 
* must take into account the strengths and weaknesses of this measure 
of risk.'' Id. Consequently, the presumptive risk level of 100-in-1 
million (1-in-10 thousand) provides a benchmark for judging the 
acceptability of maximum individual lifetime cancer risk, but does not 
constitute a rigid line for making that determination. Further, in the 
Benzene NESHAP, we noted that:

``[p]articular attention will also be accorded to the weight of 
evidence presented in the risk assessment of potential 
carcinogenicity or other health effects of a pollutant. While the 
same numerical risk may be estimated for an exposure to a pollutant 
judged to be a known human carcinogen, and to a pollutant considered 
a possible human carcinogen based on limited animal test data, the 
same weight cannot be accorded to both estimates. In considering the 
potential public health effects of the two pollutants, the Agency's 
judgment on acceptability, including the MIR, will be influenced by 
the greater weight of evidence for the known human carcinogen.''

Id. at 38046. The agency also explained in the Benzene NESHAP that:

    ``[i]n establishing a presumption for MIR, rather than a rigid 
line for acceptability, the Agency intends to weigh it with a series 
of other health measures and factors. These include the overall 
incidence of cancer or other serious health effects within the 
exposed population, the numbers of persons exposed within each 
individual lifetime risk range and associated incidence within, 
typically, a 50 km exposure radius around facilities, the science 
policy assumptions and estimation uncertainties associated with the 
risk measures, weight of the scientific evidence for human health 
effects, other quantified or unquantified health effects, effects 
due to co-location of facilities, and co-emission of pollutants.''

    Id. At 38045. In some cases, these health measures and factors 
taken together may provide a more realistic description of the 
magnitude of risk in the exposed population than that provided by 
maximum individual lifetime cancer risk alone.
    As noted earlier, in NRDC v. EPA, the court held that CAA section 
112(f)(2) ``incorporates the EPA's interpretation of the Clean Air Act 
from the Benzene Standard.'' The court further held that Congress' 
incorporation of the Benzene standard applies equally to carcinogens 
and non-carcinogens. 529 F.3d at 1081-82. Accordingly, we also consider 
non-cancer risk metrics in our determination of risk acceptability and 
ample margin of safety.
2. Step 2--Determination of Ample Margin of Safety
    CAA section 112(f)(2) requires the EPA to determine, for source 
categories subject to MACT standards, whether those standards provide 
an ample margin of safety to protect public health. As explained in the 
Benzene NESHAP, ``the second step of the inquiry, determining an `ample 
margin of safety,' again includes consideration of all of the health 
factors, and whether to reduce the risks even further . . . . Beyond 
that information, additional factors relating to the appropriate level 
of control will also be considered, including costs and economic 
impacts of controls, technological feasibility, uncertainties and any 
other relevant factors. Considering all of these factors, the agency 
will establish the standard at a level that provides an ample margin of 
safety to protect the public health, as required by section 112.'' 54 
FR 38046, September 14, 1989.
    According to CAA section 112(f)(2)(A), if the MACT standards for 
HAP ``classified as a known, probable, or possible human carcinogen do 
not reduce lifetime excess cancer risks to the individual most exposed 
to emissions from a source in the category or subcategory to less than 
one in one million,'' the EPA must promulgate residual risk standards 
for the source category (or subcategory), as necessary to provide an 
ample margin of safety to protect public health. In doing so, the EPA 
may adopt standards equal to existing MACT standards if the EPA 
determines that the existing standards (i.e., the MACT standards) are 
sufficiently protective. NRDC v. EPA, 529 F.3d 1077, 1083 (D.C. Cir. 
2008) (``If EPA determines that the existing technology-based standards 
provide an `ample margin of safety,' then the Agency is free to readopt 
those standards during the residual risk rulemaking.'') The EPA must 
also adopt more stringent standards, if necessary, to prevent an 
adverse environmental effect,\2\ but must consider cost, energy, safety 
and other relevant factors in doing so.
---------------------------------------------------------------------------

    \2\ ``Adverse environmental effect'' is defined as any 
significant and widespread adverse effect, which may be reasonably 
anticipated to wildlife, aquatic life or natural resources, 
including adverse impacts on populations of endangered or threatened 
species or significant degradation of environmental qualities over 
broad areas. CAA section 112(a)(7).
---------------------------------------------------------------------------

    The CAA does not specifically define the terms ``individual most 
exposed,'' ``acceptable level'' and ``ample margin of safety.'' In the 
Benzene NESHAP, 54 FR 38044-38045, September 14, 1989, we stated as an 
overall objective:

    In protecting public health with an ample margin of safety under 
section 112, EPA strives to provide maximum feasible protection 
against risks to health from hazardous air pollutants by (1) 
protecting the greatest number of persons possible to an individual 
lifetime risk level no higher than approximately 1-in-1 million and 
(2) limiting to no higher than approximately 1-in-10 thousand [i.e., 
100-in-1 million] the estimated risk that a person living near a 
plant would have if he or she were exposed to the maximum pollutant 
concentrations for 70 years.

    The agency further stated that ``[t]he EPA also considers incidence 
(the number of persons estimated to suffer cancer or other serious 
health effects as a result of exposure to a pollutant) to be an 
important measure of the health risk to the exposed population. 
Incidence measures the extent of health risks to the exposed population 
as a whole, by providing an estimate of the occurrence of cancer or 
other serious health effects in the exposed population.'' Id. at 38045.
    In the ample margin of safety decision process, the agency again 
considers all of the health risks and other health information 
considered in the first step, including the incremental risk reduction 
associated with standards more stringent than the MACT standard or a 
more stringent standard that the EPA

[[Page 72919]]

has determined is necessary to ensure risk is acceptable. In the ample 
margin of safety analysis, the agency considers additional factors, 
including costs and economic impacts of controls, technological 
feasibility, uncertainties and any other relevant factors. Considering 
all of these factors, the agency will establish the standard at a level 
that provides an ample margin of safety to protect the public health, 
as required by CAA section 112(f). 54 FR 38046, September 14, 1989.

B. What is this source category and how does the current NESHAP 
regulate its HAP emissions?

    The NESHAP for Primary Aluminum Reduction Plants were promulgated 
on October 7, 1997 (62 FR 52407), codified at 40 CFR part 63, subpart 
LL (referred to as subpart LL or MACT rule in the remainder of this 
preamble), and amended on November 2, 2005 (70 FR 66285). The MACT rule 
is applicable to facilities with affected sources associated with the 
production of aluminum by electrolytic reduction. These facilities are 
described in the following paragraph and collectively comprise what is 
commonly known as the Primary Aluminum Production source category.
    Aluminum is produced from refined bauxite ore (also known as 
alumina), using an electrolytic reduction process in a series of cells 
called a ``potline.'' The raw materials include alumina, petroleum 
coke, pitch and fluoride salts. According to information available on 
the Web site of The Aluminum Association, Inc. (http://
www.aluminum.org), approximately 40 percent of the aluminum produced in 
the U.S. comes from primary aluminum facilities. The two main potline 
types are prebake (a newer, higher efficiency, lower-emitting 
technology) and Soderberg (an older, lower efficiency, higher-emitting 
technology). There are currently 13 facilities located in the United 
States that are subject to the requirements of this NESHAP: 12 primary 
aluminum production plants and one carbon-only prebake anode production 
facility. These 12 primary aluminum production plants have 
approximately 45 potlines that produce aluminum. Ten primary aluminum 
production plants have a paste production operation, and 10 of the 12 
primary aluminum production plants have anode bake furnaces. Eleven of 
the 12 primary aluminum facilities use prebake potlines; the other 
plant uses Soderberg potlines. Due to a decrease in demand for 
aluminum, four of the facilities are currently idle, including the 
Soderberg facility. The major HAPs emitted by these facilities are 
carbonyl sulfide (COS), hydrogen fluoride (HF), particulate HAP metals 
and polycyclic organic matter (POM), specifically polycyclic aromatic 
hydrocarbons (PAH).
    The standards promulgated in 1997 and 2005 apply to emissions of 
HF, measured using total fluorides (TF) as a surrogate, from all 
potlines and anode bake furnaces and POM (as measured by methylene 
chloride extractables) from Soderberg potlines, anode bake furnaces, 
paste production plants and pitch storage tanks associated with primary 
aluminum production. Affected sources under the rules are each potline, 
each anode bake furnace (except for one that is located at a facility 
that only produces anodes for use off-site), each paste production 
plant and each new pitch storage tank.
    The NESHAP designated seven subcategories of existing potlines 
based primarily on differences in the process operation and 
configuration. The control of primary emissions from the reduction 
process is typically achieved by a dry alumina scrubber (with a 
baghouse to collect the alumina and other particulate matter (PM)). The 
control technology typically used for anode bake furnaces is a dry 
alumina scrubber. A capture system vented to a dry coke scrubber is 
used for control of paste production plants. See Tables 2 and 3 for the 
applicable emission limits established under the 1997 NESHAP and the 
2005 Amendments.

  Table 2--Summary of Current MACT Emission Limits for Existing Sources
             Under the 1997 NESHAP, and the 2005 Amendments
------------------------------------------------------------------------
            Source                  Pollutant          Emission limit
------------------------------------------------------------------------
Potlines \1\
    CWPB1 potlines............  TF...............  0.95 kg/Mg (1.9 lb/
                                                    ton) of aluminum
                                                    produced.
    CWPB2 potlines............  TF...............  1.5 kg/Mg (3.0 lb/
                                                    ton) of aluminum
                                                    produced.
    CWPB3 potlines............  TF...............  1.25 kg/Mg (2.5 lb/
                                                    ton) of aluminum
                                                    produced.
    SWPB potlines.............  TF...............  0.8 kg/Mg (1.6 lb/
                                                    ton) of aluminum
                                                    produced.
    VSS1 potlines.............  TF...............  1.1 kg/Mg (2.2 lb/
                                                    ton) of aluminum
                                                    produced.
                                POM..............  1.2 kg/Mg (2.4 lb/
                                                    ton) of aluminum
                                                    produced.
    VSS2 potlines.............  TF...............  1.35 kg/Mg (2.7 lb/
                                                    ton) of aluminum
                                                    produced.
                                POM..............  2.85 kg/Mg (5.7 lb/
                                                    ton) of aluminum
                                                    produced.
    HSS potlines..............  TF...............  1.35 kg/Mg (2.7 lb/
                                                    ton) of aluminum
                                                    produced.
                                POM..............  2.35 kg/Mg (4.7 lb/
                                                    ton) of aluminum
                                                    produced.
Paste Production..............  POM..............  Install, operate and
                                                    maintain equipment
                                                    for capture of
                                                    emissions and vent
                                                    to a dry coke
                                                    scrubber.
Anode Bake Furnace (collocated  TF...............  0.10 kg/Mg (0.20 lb/
 with a primary aluminum                            ton) of green anode.
 plant).
                                POM..............  0.09 kg/Mg (0.18 lb/
                                                    ton) of green anode.
------------------------------------------------------------------------
\1\CWPB1 = Center-worked prebake potline with the most modern reduction
  cells; includes all center-worked prebake potlines not specifically
  identified as CWPB2 or CWPB3.
CWPB2 = Center-worked prebake potlines located at Alcoa in Rockdale,
  Texas; Kaiser Aluminum in Mead, Washington; Ormet Corporation in
  Hannibal, Ohio; Ravenswood Aluminum in Ravenswood, West Virginia;
  Reynolds Metals in Troutdale, Oregon; and Vanalco Aluminum in
  Vancouver, Washington.
CWPB3 = Center-worked prebake potline that produces very high purity
  aluminum, has wet scrubbers as the primary control system and is
  located at the Century Aluminum primary aluminum plant in Kentucky.
HSS = Horizontal stud Soderberg potline (no facilities remain in the
  U.S.).
SWPB = Side-worked prebake potline.
VSS1 = Vertical stud Soderberg potline (no facilities remain in the
  U.S.).
VSS2 = Vertical stud Soderberg potlines (located at an idle facility
  known as Columbia Falls Aluminum in Columbia Falls, Montana).


[[Page 72920]]


 Table 3--Summary of Current MACT Emission Limits for New Sources Under
                the 1997 NESHAP, and the 2005 Amendments
------------------------------------------------------------------------
            Source                  Pollutant          Emission limit
------------------------------------------------------------------------
All Potlines..................  TF...............  0.6 kg/Mg (1.2 lb/
                                                    ton) of aluminum
                                                    produced.
VSS1, VSS2 and HSS potlines...  POM..............  0.32 kg/Mg (0.63 lb/
                                                    ton) of aluminum
                                                    produced.
Paste Production..............  POM..............  Install, operate and
                                                    maintain equipment
                                                    for capture of
                                                    emissions and vent
                                                    to a dry coke
                                                    scrubber.
Anode Bake Furnace (collocated  TF...............  0.01 kg/Mg (0.020 lb/
 with a primary aluminum                            ton) of green anode.
 plant).
                                POM..............  0.025 kg/Mg (0.05 lb/
                                                    ton) of green anode.
Pitch storage tanks...........  POM..............  Emission control
                                                    system designed and
                                                    operated to reduce
                                                    inlet POM emissions
                                                    by 95 percent or
                                                    greater.
------------------------------------------------------------------------

    The 1997 NESHAP for primary aluminum reduction plants incorporates 
new source performance standards for potroom groups. These emission 
limits are listed in Table 3. The limits for new Soderberg facilities 
apply to any Soderberg facility that adds a new potroom group to an 
existing potline or is associated with a potroom group that meets the 
definition of a modified or reconstructed potroom group. Since these 
POM limits are very stringent, they effectively preclude the operation 
of any new Soderberg potlines. We expect any new potline would need to 
be a prebake potline to comply with the new source limits in the 
NESHAP.
    Compliance with the emission limits in the current rule is 
demonstrated by performance testing which can be addressed individually 
for each affected source or according to emissions averaging 
provisions. Monitoring requirements include monthly measurements of TF 
secondary emissions, quarterly measurement of POM secondary emissions 
and annual measurement of primary emissions, continuous parametric 
monitoring for each emission control device, a monitoring device to 
track daily weight of aluminum produced and daily inspection for 
visible emissions. Recordkeeping for the rule is consistent with the 
General Provisions requirements with the addition of recordkeeping for 
daily production of aluminum, records supporting emissions averaging 
and records documenting the portion of TF measured as PM or gaseous 
form.

C. What is the history of the Primary Aluminum Production source 
category risk and technology review?

    Pursuant to section 112(f)(2) of the CAA, in 2011 we conducted an 
initial evaluation of the residual risk associated with the NESHAP for 
Primary Aluminum Reduction Plants. At that time, we also conducted an 
initial technology review pursuant to section 112(d)(6) of the CAA. 
Finally, we also reviewed the 2005 MACT rule to determine whether other 
amendments were appropriate. Based on the results of that initial RTR, 
and the MACT rule review, we proposed amendments to the NESHAP (also 
known as subpart LL) on December 6, 2011 (76 FR 76260) (referred to as 
the 2011 proposal in the remainder of this FR document). The proposed 
amendments in the 2011 proposal which we are revisiting in today's 
supplemental proposal include the following:
     Proposed emission limits for POM from prebake potlines;
     Amendments to the monitoring, notification, recordkeeping 
and testing requirements; and
     Proposed provisions establishing an affirmative defense to 
civil penalties for violations caused by malfunctions.
    As explained below, we are also proposing provisions which have no 
analogue in the 2011 proposal.
    The comment period for the December 2011 proposal opened on 
December 6, 2011, and ended on February 1, 2012. We received 
significant comments from industry representatives, environmental 
organizations and state regulatory agencies. After reviewing the 
comments, and after consideration of additional data and information 
received since the 2011 proposal, we determined it is appropriate to 
revise some of our analyses and to publish a supplemental proposal. 
After collecting and reviewing additional data, we are proposing 
technology-based emission limits pursuant to CAA sections 112(d)(2) and 
(3) for PM, as a surrogate for particulate HAP metals, for new and 
existing potlines, anode bake furnaces and paste plants. We are also 
proposing revised technology-based emissions limits for POM emissions 
from prebake potlines and amendments to the monitoring, notification, 
recordkeeping and testing requirements to implement these emission 
limits. Pursuant to CAA section 112(f)(2), we are also proposing risk-
based emission standards for POM, nickel (Ni) and arsenic (As) 
emissions from potlines in the VSS2 subcategory and proposing testing 
and monitoring requirements to demonstrate compliance with the 
standards for Ni and As. We are also proposing revisions to the testing 
and compliance requirements for COS emissions.
    In addition, we are withdrawing our 2011 proposal to include an 
affirmative defense in this rule in light of a recent court decision 
vacating an affirmative defense in one of the EPA's CAA section 112(d) 
regulations. NRDC v. EPA, 749 F. 3d 1055 (D.C. Cir. 2014) (vacating 
affirmative defense provisions in CAA section 112(d) rule establishing 
emission standards for Portland cement kilns).
    Today's supplemental proposed rulemaking will allow the public an 
opportunity to review and comment on the revised analyses and revised 
proposed amendments described above.
    However, we also proposed other requirements in the 2011 proposal 
(listed below) for which we have made no revisions to the analyses, are 
not proposing any changes and are not reopening for public comment. 
These are:
     POM standards for existing pitch storage tanks and related 
monitoring, reporting and testing requirements;
     Emissions limits for COS from potlines;
     Elimination of startup, shutdown and malfunction (SSM) 
exemptions; and
     Electronic reporting.
    The comment period for the December 2011 proposal opened on 
December 6, 2011, and ended on February 1, 2012. We will address the 
comments we received during the public comment period for the 2011 
proposal at the time we publish final RTR amendments for the Primary 
Aluminum Production source category based on the 2011 proposal and 
today's supplemental proposal.

[[Page 72921]]

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

    The 2011 risk assessment was based on estimates of PAH emissions 
derived from test measurements conducted in the 1990's on facilities 
that may not have been representative of current operating practices 
and using test methods that were inferior to those currently available. 
In addition, data available to estimate emissions of HAP metals from 
potlines were very limited, and no data were available to estimate HAP 
metals emissions from anode bake furnaces and paste plants. 
Furthermore, no data were available to estimate dioxin/furan (D/F) and 
polychlorinated biphenyl (PCB) emissions from potlines, anode bake 
furnaces and paste plants.
    The proposed emission limits for POM from prebake potlines included 
in the 2011 proposal were based on extremely limited data. Also lacking 
were reliable data on which to base MACT standards for PM (as a 
surrogate for HAP metals) emissions from potlines, anode bake furnaces 
and paste plants.
    Therefore, in March 2013 we sent an information request to the 
primary aluminum companies pursuant to section 114 of the CAA to gather 
additional relevant emissions test data. In response to this request, 
selected facilities provided the following data:
     Additional emission test data for POM emissions from 
prebake potlines;
     Additional emission test data for PM emissions from 
prebake potlines, Soderberg potlines (which have subsequently shut 
down), anode bake furnaces and paste plants;
     Additional emission test data for speciated PAH, speciated 
HAP metals, speciated PCBs and speciated polychlorinated dibenzo-p-
dioxins and polychlorinated dibenzofurans from potlines, anode bake 
furnaces and paste plants.

III. Analytical Procedures

A. For purposes of this supplemental proposal, how did we estimate the 
post-MACT risks posed by the Primary Aluminum Production source 
category?

    The EPA conducted a risk assessment that provides estimates of the 
MIR posed by the HAP emissions from each source in the source category, 
the hazard index (HI) for chronic exposures to HAP with the potential 
to cause noncancer health effects and the hazard quotient (HQ) for 
acute exposures to HAP with the potential to cause noncancer health 
effects. The assessment also provides estimates of the distribution of 
cancer risks within the exposed populations, cancer incidence and an 
evaluation of the potential for adverse environmental effects. The 
eight sections that follow this paragraph describe how we estimated 
emissions and conducted the risk assessment. 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 Primary Aluminum Production Source Category in 
Support of the 2014 Supplemental Proposal. The methods used to assess 
risks (as described in the eight primary steps below) 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; 
\3\ they are also consistent with the key recommendations contained in 
that report.
---------------------------------------------------------------------------

    \3\ 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. How did we estimate actual emissions and identify the emissions 
release characteristics?
    Using the test reports from the 2013 information request we 
calculated annual emission rates of PAHs, D/Fs, PCBs and HAP metals 
from primary and secondary potline exhausts, anode bake furnace 
exhausts and paste plant exhausts. Where no test data were available we 
calculated and applied emission factors (EF) for these pollutants and 
emission points based on average emission rates from similarly operated 
sources to estimate emissions. However, it is important to note that 
only two facilities tested for D/F and PCBs. Furthermore, many of the 
test results for D/Fs and PCBs were below detection limits. More than 
half of the mercury (Hg) emissions tests results were also below 
detection limit. Therefore, there are greater uncertainties regarding 
D/F, PCB and Hg emissions compared to the other HAP. To estimate 
emissions in cases where some, but not all, data were below the 
detection limit, we assumed the undetected emissions were equal to one-
half the detection limit, which is the established approach for dealing 
with non-detects in the EPA's RTR program when developing emissions 
estimates for input to the risk assessments. Subsequently, we developed 
EF based on these limited data to estimate emissions at the other 
facilities. We believe the emissions estimates for D/F and PCBs are 
quite conservative (i.e., more likely to be overestimated rather than 
underestimated) because we assumed undetected emissions were equal to 
one half the detection limit. We note that EPA may, but is not 
obligated to amend MACT standards. In the case of D/F, Hg and PCB, 
where many of the emissions tests were below detection limit, and given 
the uncertainties and limitations of the data (for example, we have 
test data for D/F and PCBs for only one of the 11 prebake facilities), 
the EPA is choosing not to propose standards for these HAP at this 
time.
    We also obtained test data from recent compliance tests for TF and 
estimated HF emissions from primary and secondary potline exhausts and 
anode bake furnace exhausts. We estimated COS emissions as described in 
the 2011 risk assessment. We did not receive any additional test data 
for COS. Thus, the emissions estimates for COS have not changed since 
the 2011 proposal. As noted above, we are not accepting further comment 
on either this analysis or the proposed emission limit for COS.
    We also verified information regarding emissions release 
characteristics such as stack heights, stack gas exit velocities, stack 
temperatures and source locations. In addition to the quality assurance 
(QA) of the source data for the facilities contained in the dataset, we 
also checked the coordinates of every emission source in the dataset 
using tools such as Google Earth. Where coordinates used in the 2011 
risk assessment were found to be incorrect, we identified and corrected 
them. We also performed a QA assessment of the emissions data and 
release characteristics to ensure the data were reliable and that there 
were no outliers. The emissions data and the methods used to estimate 
emissions from all the various emissions sources are described in more 
detail in the technical document: Revised Draft Development of the RTR 
Emissions Dataset for the Primary Aluminum Production Source Category, 
which is available in the docket for this action (Docket ID No. EPA-HQ-
OAR-2011-0797).
2. How did we estimate MACT-allowable emissions?
    The available emissions data in the RTR emissions dataset include 
estimates of the mass of HAP emitted during the specified annual time 
period. In some cases, these ``actual'' emission levels are lower than 
the emission levels required to comply with the current MACT standards. 
The emissions level allowed to be emitted by the MACT standards is 
referred to as the ``MACT-allowable'' emissions level. We discussed the 
use of both MACT-allowable and actual

[[Page 72922]]

emissions in the final Coke Oven Batteries residual risk rule (70 FR 
19998-19999, April 15, 2005) and in the proposed and final Hazardous 
Organic NESHAP residual risk rules (71 FR 34428, June 14, 2006, and 71 
FR 76609, December 21, 2006, respectively). In those actions, we noted 
that assessing the risks at the MACT-allowable level is inherently 
reasonable since these risks reflect the maximum level facilities could 
emit and still comply with national emission standards. We also 
explained that it is reasonable to consider actual emissions, where 
such data are available, in both steps of the risk analysis, in 
accordance with the Benzene NESHAP approach.
    For this supplemental proposal, we evaluated allowable emissions 
based on responses to the information request. We estimated that 
allowable emissions for the currently regulated HAP (i.e., PAHs and HF) 
were generally about 1.5 times higher than the actual emissions. 
Therefore, to calculate allowable emissions of PAHs and HF, we assumed 
that allowable emissions were 1.5 times the actual emissions for all 
facilities except for one idle Soderberg facility (Columbia Falls). For 
Columbia Falls, which has the highest potential for emissions of all 
the facilities, we evaluated site-specific data and estimated that 
allowable emissions for the regulated HAP (i.e., PAHs and HF) were 
about 1.9 times higher than estimated actual emissions when the plant 
is operating. Regarding unregulated HAP, the NESHAP currently includes 
no standards for COS, PCB, D/F and HAP metal emissions. Since there is 
no standard in place for these HAP and, therefore, no defined level of 
``MACT allowable'' emissions levels, we assumed that allowable 
emissions for COS, PCB, D/F and HAP metal emissions were equal to 
estimated actual emissions. Further explanation is provided in the 
technical document: Revised Draft Development of the RTR Emissions 
Dataset for the Primary Aluminum Production Source Category, which is 
available in the docket (Docket ID No. EPA-HQ-OAR-2011-0797).
3. How did we conduct dispersion modeling, determine inhalation 
exposures and estimate individual and population inhalation risks?
    Both long-term and short-term inhalation exposure concentrations 
and health risks from the source category addressed in this proposal 
were estimated using the Human Exposure Model (Community and Sector 
HEM-3 version 1.1.0). The HEM-3 performs three primary risk assessment 
activities: (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,\4\ and (3) estimating 
individual and population-level inhalation risks using the exposure 
estimates and quantitative dose-response information.
---------------------------------------------------------------------------

    \4\ This metric comes from the Benzene NESHAP. See 54 FR 38046.
---------------------------------------------------------------------------

    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.\5\ To perform the dispersion modeling and to 
develop the preliminary risk estimates, HEM-3 draws on three data 
libraries. The first is a library of meteorological data, which is used 
for dispersion calculations. This library includes 1 year (2011) of 
hourly surface and upper air observations for more than 800 
meteorological stations, selected to provide coverage of the United 
States and Puerto Rico. A second library of United States Census Bureau 
census block \6\ internal point locations and populations provides the 
basis of human exposure calculations (U.S. 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://www2.epa.gov/fera/dose-response-assessment-assessing-health-
risks-associated-exposure-hazardous-air-pollutants and are discussed in 
more detail later in this section.
---------------------------------------------------------------------------

    \5\ 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).
    \6\ 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 each HAP 
emitted by each source for which we have emissions data in the source 
category. 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 each of the HAP (in micrograms per cubic meter 
([mu]g/m\3\)) by its unit risk estimate (URE). The URE 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 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.
    In the case of Ni compounds, to provide a health-protective 
estimate of potential cancer risks, we used the IRIS URE value for Ni 
subsulfide in the assessment for the 2011 proposed rule for the Primary 
Aluminum Production source category. Based on past scientific and 
technical considerations, the determination of the percent of Ni 
subsulfide was considered a major factor for estimating the extent and 
magnitude of the risks of cancer due to Ni-containing emissions. Nickel 
speciation information for some of the largest Ni-emitting sources 
(including oil combustion, coal combustion and others) suggested that 
at least 35 percent of total Ni emissions may be soluble compounds and 
that the URE for the mixture of inhaled Ni compounds (based on Ni 
subsulfide, and representative of pure insoluble crystalline Ni) could 
be derived to reflect the assumption that 65 percent of the total mass 
of Ni may be carcinogenic.
    Based on consistent views of major scientific bodies (i.e., 
National Toxicology Program (NTP) in their 12th Report of the 
Carcinogens (ROC),\7\ International Agency for Research on

[[Page 72923]]

Cancer (IARC) \8\ and other international agencies) \9\ that consider 
all Ni compounds to be carcinogenic, we currently consider all Ni 
compounds to have the potential of being carcinogenic to humans. The 
12th Report of the Carcinogens states that the ``combined results of 
epidemiological studies, mechanistic studies, and carcinogenic studies 
in rodents support the concept that Ni compounds generate Ni ions in 
target cells at sites critical for carcinogenesis, thus allowing 
consideration and evaluation of these compounds as a single group.'' 
Although the precise Ni compound (or compounds) responsible for the 
carcinogenic effects in humans is not always clear, studies indicate 
that Ni sulfate and the combinations of Ni sulfides and oxides 
encountered in the Ni refining industries cause cancer in humans (these 
studies are summarized in a review by Grimsrud et al., 2010 \10\). The 
major scientific bodies mentioned above have also recognized that there 
are differences in toxicity and/or carcinogenic potential across the 
different Ni compounds.
---------------------------------------------------------------------------

    \7\ National Toxicology Program (NTP), 2011. Report on 
Carcinogens. 12th ed. Research Triangle Park, NC: US Department of 
Health and Human Services (DHHS), Public Health Service. Available 
online at http://ntp.niehs.nih.gov/ntp/roc/twelfth/roc12.pdf.
    \8\ International Agency for Research on Cancer (IARC), 1990. 
IARC Monographs on the Evaluation of Carcinogenic Risks to Humans. 
Chromium, nickel, and welding. Vol. 49. Lyons, France: International 
Agency for Research on Cancer, World Health Organization Vol. 
49:256.
    \9\ World Health Organization (WHO, 1991) and the European 
Union's Scientific Committee on Health and Environmental Risks 
(SCHER, 2006).
    \10\ Grimsrud TK and Andersen A. Evidence of Carcinogenicity in 
Humans of Water-soluble Nickel Salts. J Occup Med Toxicol 2010, 5:1-
7. Available online at http://www.ossup-med.com/content/5/1/7.
---------------------------------------------------------------------------

    In the inhalation risk assessment for this supplemental proposal, 
we chose to take a conservative approach: we considered all Ni 
compounds to be as carcinogenic as Ni subsulfide and applied the IRIS 
URE for Ni subsulfide without a factor to reflect the assumption that 
100 percent of the total mass of Ni may be as carcinogenic as pure Ni 
subsulfide. However, given that there are two additional URE values 
\11\ derived for exposure to mixtures of Ni compounds, as a group, that 
are 2-3 fold lower than the IRIS URE for Ni subsulfide, the EPA also 
considers it reasonable to use a value that is 50 percent of the IRIS 
URE for Ni subsulfide for providing an estimate of the lower end of the 
plausible range of cancer potency values for different mixtures of Ni 
compounds.
---------------------------------------------------------------------------

    \11\ Two UREs (other than the current IRIS values) have been 
derived for nickel compounds as a group: One developed by the 
California Department of Health Services (http://www.arb.ca.gov/
toxics/id/summary/nickel_tech_b.pdf) and the other by the Texas 
Commission on Environmental Quality (http://www.epa.gov/ttn/atw/
nata1999/99pdfs/healtheffectsinfo.pdf).
---------------------------------------------------------------------------

    The EPA estimated incremental individual lifetime cancer risks 
associated with emissions from the facilities in the source category 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 \12\) emitted 
by the modeled sources. 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, 
September 14, 1989) and the limitations of Gaussian dispersion models, 
including AERMOD.
---------------------------------------------------------------------------

    \12\ 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 SAB in their 2002 peer review of the 
EPA's National Air Toxics Assessment (NATA) titled, 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 a value selected from 
one of several sources. First, the chronic reference level can be the 
EPA reference concentration (RfC) (http://www.epa.gov/riskassessment/
glossary.htm), 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.'' Alternatively, in cases where an RfC from the EPA's IRIS 
database is not available or where the EPA determines that using a 
value other than the RfC is appropriate, the chronic reference level 
can be a value from the following prioritized sources: (1) The Agency 
for Toxic Substances and Disease Registry (ATSDR) Minimum Risk Level 
(MRL) (http://www.atsdr.cdc.gov/mrls/index.asp), which is defined as 
``an estimate of daily human exposure to a hazardous substance that is 
likely to be without an appreciable risk of adverse non-cancer health 
effects) over a specified duration of exposure''; (2) the CalEPA 
Chronic Reference Exposure Level (REL) (http://www.oehha.ca.gov/air/
hot_spots/pdf/HRAguidefinal.pdf), which is defined as ``the 
concentration level (that is expressed in units of micrograms per cubic 
meter ([mu]g/m\3\) for inhalation exposure and in a dose expressed in 
units of milligram per kilogram-day (mg/kg-day) for oral exposures), at 
or below which no adverse health effects are anticipated for a 
specified exposure duration''; or (3), as noted above, a scientifically 
credible dose-response value that has been developed in a manner 
consistent with the EPA guidelines and has undergone a peer review 
process similar to that used by the EPA, in place of or in concert with 
other values.
    POM, a carcinogenic HAP with a mutagenic mode of action, is emitted 
by the facilities in this source category.\13\ For this compound 
group,\14\ the EPA's analysis applies the age-dependent adjustment 
factors (ADAF) described in the EPA's Supplemental Guidance for 
Assessing Susceptibility from Early-Life Exposure to Carcinogens.\15\ 
This adjustment has the effect of increasing the estimated lifetime 
risks for POM by a factor of 1.6. In addition, although primary 
aluminum facilities reported most of their total POM emissions as 
individual compounds, the EPA expresses carcinogenic potency for 
compounds in this group in terms of benzo[a]pyrene equivalence, based 
on evidence that carcinogenic POM has the same mutagenic mechanism of 
action as benzo[a]pyrene. For this reason, the EPA's Science Policy 
Council \16\ recommends applying the Supplemental Guidance to all 
carcinogenic PAH for which risk estimates are based on relative 
potency. Accordingly, we have applied the ADAF to the benzo[a]pyrene 
equivalent portion of all POM mixtures.
---------------------------------------------------------------------------

    \13\ U.S. EPA. Performing risk assessments that include 
carcinogens described in the Supplemental Guidance as having a 
mutagenic mode of action. Science Policy Council Cancer Guidelines 
Implementation Work Group Communication II: Memo from W.H. Farland, 
dated October 4, 2005.
    \14\ See the Risk Assessment for Source Categories document 
available in the docket for a list of HAP with a mutagenic mode of 
action.
    \15\ U.S. EPA. Supplemental Guidance for Assessing Early-Life 
Exposure to Carcinogens. EPA/630/R-03/003F, 2005. http://
www.epa.gov/ttn/atw/childrens_supplement_final.pdf.
    \16\ U.S. EPA. Science Policy Council Cancer Guidelines 
Implementation Workgroup Communication II: Memo from W.H. Farland, 
dated June 14, 2006.
---------------------------------------------------------------------------

    As mentioned above, in order to characterize non-cancer chronic 
effects, and in response to key

[[Page 72924]]

recommendations from the SAB, the EPA selects dose-response values that 
reflect the best available science for all HAP included in RTR risk 
assessments.\17\ More specifically, for a given HAP, the EPA examines 
the availability of inhalation reference values from the sources 
included in our tiered approach (e.g., IRIS first, ATSDR second, CalEPA 
third) and determines which inhalation reference value represents the 
best available science. Thus, as new inhalation reference values become 
available, the EPA will typically evaluate them and determine whether 
they should be given preference over those currently being used in RTR 
risk assessments.
---------------------------------------------------------------------------

    \17\ The SAB peer review of RTR Risk Assessment Methodologies is 
available at: http://yosemite.epa.gov/sab/sabproduct.nsf/
4AB3966E263D943A8525771F00668381/$File/EPA-SAB-10-007-unsigned.pdf.
---------------------------------------------------------------------------

    The EPA also evaluated screening estimates of acute exposures and 
risks for each of the HAP (for which appropriate acute dose-response 
values are available) at the point of highest potential off-site 
exposure for each facility. To do this the EPA estimated the risks when 
both the peak hourly emissions rate and worst-case dispersion 
conditions occur. We also assume that a person is located at the point 
of highest impact during that same time. In accordance with the mandate 
of section 112(f)(2) of the CAA, we use the point of highest off-site 
exposure to assess the potential risk to the maximally exposed 
individual. The acute HQ is the estimated acute exposure divided by the 
acute dose-response value. In each case, the EPA calculated acute HQ 
values using best available, short-term dose-response values. These 
acute dose-response values, which are described below, include the 
acute REL, acute exposure guideline levels (AEGL) and emergency 
response planning guidelines (ERPG) for 1-hour exposure durations. As 
discussed below, we used conservative assumptions for emissions rates, 
meteorology and exposure location.
    As described in the CalEPA's Air Toxics Hot Spots Program Risk 
Assessment Guidelines, Part I, The Determination of Acute Reference 
Exposure Levels for Airborne Toxicants, an acute REL value (http://
www.oehha.ca.gov/air/pdf/acuterel.pdf) is defined as ``the 
concentration level at or below which no adverse health effects are 
anticipated for a specified exposure duration.'' Id. at page 2. Acute 
REL values are based on the most sensitive, relevant, adverse health 
effect reported in the peer-reviewed medical and toxicological 
literature. Acute REL values are designed to protect the most sensitive 
individuals in the population through the inclusion of margins of 
safety. Because margins of safety are incorporated to address data gaps 
and uncertainties, exceeding the REL does not automatically indicate an 
adverse health impact.
    AEGL values were derived in response to recommendations from the 
National Research Council (NRC). As described in Standing Operating 
Procedures (SOP) of the National Advisory Committee on Acute Exposure 
Guideline Levels for Hazardous Substances (http://www.epa.gov/oppt/
aegl/pubs/sop.pdf),\18\ ``the NRC's previous name for acute exposure 
levels--community emergency exposure levels--was replaced by the term 
AEGL to reflect the broad application of these values to planning, 
response, and prevention in the community, the workplace, 
transportation, the military, and the remediation of Superfund sites.'' 
Id. at 2. This document also states that AEGL values ``represent 
threshold exposure limits for the general public and are applicable to 
emergency exposures ranging from 10 minutes to eight hours.'' Id. at 2.
---------------------------------------------------------------------------

    \18\ National Academy of Sciences (NAS), 2001. Standing 
Operating Procedures for Developing Acute Exposure Levels for 
Hazardous Chemicals, page 2.
---------------------------------------------------------------------------

    The document lays out the purpose and objectives of AEGL by stating 
that ``the primary purpose of the AEGL program and the National 
Advisory Committee for Acute Exposure Guideline Levels for Hazardous 
Substances is to develop guideline levels for once-in-a-lifetime, 
short-term exposures to airborne concentrations of acutely toxic, high-
priority chemicals.'' Id. at 21. In detailing the intended application 
of AEGL values, the document states that ``[i]t is anticipated that the 
AEGL values will be used for regulatory and nonregulatory purposes by 
U.S. Federal and state agencies and possibly the international 
community in conjunction with chemical emergency response, planning and 
prevention programs. More specifically, the AEGL values will be used 
for conducting various risk assessments to aid in the development of 
emergency preparedness and prevention plans, as well as real-time 
emergency response actions, for accidental chemical releases at fixed 
facilities and from transport carriers.'' Id. at 31.
    The AEGL-1 value is then specifically defined as ``the airborne 
concentration (expressed as ppm (parts per million) or mg/m\3\ 
(milligrams per cubic meter)) of a substance above which it is 
predicted that the general population, including susceptible 
individuals, could experience notable discomfort, irritation, or 
certain asymptomatic non-sensory effects. However, the effects are not 
disabling and are transient and reversible upon cessation of 
exposure.'' Id. at 3. The document also notes that, ``Airborne 
concentrations below AEGL-1 represent exposure levels that can produce 
mild and progressively increasing but transient and nondisabling odor, 
taste, and sensory irritation or certain asymptomatic, non-sensory 
effects.'' Id. Similarly, the document defines AEGL-2 values as ``the 
airborne concentration (expressed as parts per million or milligrams 
per cubic meter) of a substance above which it is predicted that the 
general population, including susceptible individuals, could experience 
irreversible or other serious, long-lasting adverse health effects or 
an impaired ability to escape.'' Id.
    ERPG values are derived for use in emergency response, as described 
in the American Industrial Hygiene Association's Emergency Response 
Planning (ERP) Committee document titled, ERPGS Procedures and 
Responsibilities (https://www.aiha.org/get-involved/
AIHAGuidelineFoundation/EmergencyResponsePlanningGuidelines/Documents/
ERP-SOPs2006.pdf), which states that, ``Emergency Response Planning 
Guidelines were developed for emergency planning and are intended as 
health based guideline concentrations for single exposures to 
chemicals.'' \19\ Id. at 1. The ERPG-1 value is defined as ``the 
maximum airborne concentration below which it is believed that nearly 
all individuals could be exposed for up to 1 hour without experiencing 
other than mild transient adverse health effects or without perceiving 
a clearly defined, objectionable odor.'' Id. at 2. Similarly, the ERPG-
2 value is defined as ``the maximum airborne concentration below which 
it is believed that nearly all individuals could be exposed for up to 
one hour without experiencing or developing irreversible or other 
serious health effects or symptoms which could impair an individual's 
ability to take protective action.'' Id. at 1.
---------------------------------------------------------------------------

    \19\ ERP Committee Procedures and Responsibilities. November 1, 
2006. American Industrial Hygiene Association.
---------------------------------------------------------------------------

    As can be seen from the definitions above, the AEGL and ERPG values 
include the similarly-defined severity levels 1 and 2. For many 
chemicals, a severity level 1 value AEGL or ERPG has not been developed 
because the types of

[[Page 72925]]

effects for these chemicals are not consistent with the AEGL-1/ERPG-1 
definitions; in these instances, we compare higher severity level AEGL-
2 or ERPG-2 values to our modeled exposure levels to screen for 
potential acute concerns. When AEGL-1/ERPG-1 values are available, they 
are used in our acute risk assessments.
    Acute REL values for 1-hour exposure durations are typically lower 
than their corresponding AEGL-1 and ERPG-1 values. Even though their 
definitions are slightly different, AEGL-1 values are often the same as 
the corresponding ERPG-1 values, and AEGL-2 values are often equal to 
ERPG-2 values. Maximum HQ values from our acute screening risk 
assessments typically result when basing them on the acute REL value 
for a particular pollutant. In cases where our maximum acute HQ value 
exceeds 1, we also report the HQ value based on the next highest acute 
dose-response value (usually the AEGL-1 and/or the ERPG-1 value).
    To develop screening estimates of acute exposures in the absence of 
hourly emissions data, generally, we first develop estimates of maximum 
hourly emissions rates by multiplying the average actual annual hourly 
emissions rates by a default factor to cover routinely variable 
emissions. We choose the factor to use partially based on process 
knowledge and engineering judgment reflecting, where appropriate, 
circumstances of the particular source category at issue. The factor 
chosen also reflects a Texas study of short-term emissions variability, 
which showed that most peak emission events in a heavily-industrialized 
four-county area (Harris, Galveston, Chambers and Brazoria Counties, 
Texas) were less than twice the annual average hourly emissions rate. 
The highest peak emissions event was 74 times the annual average hourly 
emissions rate, and the 99th percentile ratio of peak hourly emissions 
rate to the annual average hourly emissions rate was 9.\20\ Considering 
this analysis, to account for more than 99 percent of the peak hourly 
emissions, we apply a conservative screening multiplication factor of 
10 to the average annual hourly emissions rate in our acute exposure 
screening assessments as our default approach. However, we use a factor 
other than 10 if we have information that indicates that a different 
factor is appropriate for a particular source category.
---------------------------------------------------------------------------

    \20\ See http://www.tceq.state.tx.us/compliance/field_ops/eer/
index.html or the docket to access the source of these data.
---------------------------------------------------------------------------

    For the Primary Aluminum Production source category, information 
was available to determine process-specific factors. The processes in 
this source category are typically equipped with controls which will 
not allow startup of the emission source until the associated control 
device is operating and will automatically shut down the emission 
source if the associated controls malfunction. Further, some processes, 
for example, the potlines, operate continuously so there are no 
significant spikes in emissions. We, thus, believe emissions from the 
potlines are relatively consistent over time with minimal fluctuation. 
However, we realize that emissions vary over time. Furthermore, as 
described above, we estimate the maximum allowable emissions for this 
source category are about 1.5 times higher than the average long-term 
actual emissions for these sources. Therefore, we assume that hourly 
emissions rates from potlines could occasionally increase by a factor 
of up to 1.5 times the average hourly emissions, which, for the reasons 
stated above, we believe is a valid multiplier to estimate maximum 
acute emissions from potlines. Other processes, for example paste 
production and anode baking, may have specific cycles, with peak 
emissions occurring for a part of that cycle. We assume these peak 
emissions could be as high as 2 times the average emissions for paste 
plants and bake furnaces. As discussed in sections II.D and III.A.1 of 
this preamble, above, we collected data regarding the emissions from 
these processes. Those emissions data represent emissions during 
periods of normal operations (as opposed to during periods of peak 
emissions).
    Therefore, based on the modes of operation and other factors 
described above, we applied an acute emissions multiplier of 1.5 to all 
potline emissions for input to the acute risk assessment, and for paste 
production and anode baking we applied an acute emissions multiplier of 
2. We regard these factors as conservative (i.e., they are designed not 
to underestimate variability). Even with data available to develop 
process-specific factors, our assessment of acute risk reflects 
conservative assumptions, in particular in its assumptions that every 
potline operates at the same hour and that every potline has emissions 
1.5 times higher than the average at the same hour, that this is the 
same hour as the worst-case dispersion conditions, and that a person is 
at the location of maximum concentration during that hour. This results 
in a conservative exposure scenario.
    As part of our acute risk assessment process, for cases where acute 
HQ values from the screening step were less than or equal to 1 for 
modeled HAPs (even under the conservative assumptions of the screening 
analysis), acute impacts were deemed negligible and no further analysis 
was performed for these HAPs. In cases where an acute HQ from the 
screening step was greater than 1, for some modeled HAPs additional 
site-specific data were considered to develop a more refined estimate 
of the potential for acute impacts of concern. These refinements are 
discussed more fully in the Residual Risk Assessment for the Primary 
Aluminum Production Source Category in Support of the 2014 Supplemental 
Proposal, which is available in the docket for this action (Docket ID 
No. EPA-HQ-OAR-2011-0797). Ideally, we would prefer to have continuous 
measurements over time to see how the emissions vary by each hour over 
an entire year. Having a frequency distribution of hourly emissions 
rates over a year would allow us to perform a probabilistic analysis to 
estimate potential threshold exceedances and their frequency of 
occurrence. Such an evaluation could include a more complete 
statistical treatment of the key parameters and elements adopted in 
this screening analysis. Recognizing that this level of data is rarely 
available, we instead rely on the multiplier approach.
    As noted above, the agency may choose to refine the acute screen by 
also assessing the exposure that may occur at a centroid of census 
block. For this source category we first used conservative assumptions 
for emissions rates, meteorology and exposure location for our acute 
analysis. We then refined the acute assessment by also estimating the 
HQ for As at centroids of census blocks.
    To better characterize the potential health risks associated with 
estimated acute exposures to HAP, and in response to a key 
recommendation from the SAB's peer review of the EPA's RTR risk 
assessment methodologies,\21\ we generally examine a wider range of 
available acute health metrics (e.g., RELs, AEGLs) than we do for our 
chronic risk assessments. This is in response to the SAB's 
acknowledgement that there are generally more data gaps and 
inconsistencies in acute reference values than there are in chronic 
reference values. In some cases, when Reference Value Arrays \22\ for 
HAP have

[[Page 72926]]

been developed, we consider additional acute values (i.e., occupational 
and international values) to provide a more complete risk 
characterization.
---------------------------------------------------------------------------

    \21\ The SAB peer review of RTR Risk Assessment Methodologies is 
available at: http://yosemite.epa.gov/sab/sabproduct.nsf/
4AB3966E263D943A8525771F00668381/$File/EPA-SAB-10-007-unsigned.pdf.
    \22\ U.S. EPA. (2009) Chapter 2.9 Chemical Specific Reference 
Values for Formaldehyde in Graphical Arrays of Chemical-Specific 
Health Effect Reference Values for Inhalation Exposures (Final 
Report). U.S. Environmental Protection Agency, Washington, DC, EPA/
600/R-09/061, and available online at http://cfpub.epa.gov/ncea/cfm/
recordisplay.cfm?deid=211003.
---------------------------------------------------------------------------

4. How did we conduct the multipathway exposure and risk screening?
    The EPA conducted a screening analysis examining the potential for 
significant human health risks due to exposures via routes other than 
inhalation (i.e., ingestion). We first determined whether any sources 
in the source category emitted any HAP known to be persistent and 
bioaccumulative in the environment (PB-HAP). The PB-HAP compounds or 
compound classes are identified for the screening from the EPA's Air 
Toxics Risk Assessment Library (available at http://www2.epa.gov/fera/
risk-assessment-and-modeling-air-toxics-risk-assessment-reference-
library).
    For the Primary Aluminum Production source category, we identified 
emissions of cadmium (Cd) compounds, D/F, POM, divalent Hg compounds 
and HF. However, as we explained in section III.A.1 of this preamble, 
many of the emissions tests for mercury and D/F were below detection 
limit or detection limit limited. Nevertheless, we estimated emissions 
of these HAP based on the conservative assumption that undetected 
emissions were equal to one half the detection limit. Therefore, we 
consider the estimates for D/F and Hg to be conservative (i.e., more 
likely to be overestimated rather than underestimated).
    Because one or more of the PB-HAP are emitted by at least one 
facility in the Primary Aluminum Production source category, we 
proceeded to the next step of the evaluation. In this step, we 
determined whether the facility-specific emissions rates of the emitted 
PB-HAP were large enough to create the potential for significant non-
inhalation human health risks under reasonable worst-case conditions. 
To facilitate this step, we developed emissions rate screening levels 
for several PB-HAP using a hypothetical upper-end screening exposure 
scenario developed for use in conjunction with the EPA's Total Risk 
Integrated Methodology.Fate, Transport, and Ecological Exposure 
(TRIM.FaTE) model. The PB-HAP with emissions rate screening levels are: 
Cd, lead, D/F, Hg compounds and POM. We conducted a sensitivity 
analysis on the screening scenario to ensure that its key design 
parameters would represent the upper end of the range of possible 
values, such that it would represent a conservative, but not impossible 
scenario. The facility-specific emissions rates of these PB-HAP were 
compared to the emission rate screening levels for these PB-HAP to 
assess the potential for significant human health risks via non-
inhalation pathways. We call this application of the TRIM.FaTE model 
the Tier 1 TRIM-screen or Tier 1 screen.
    For the purpose of developing emissions rates for our Tier 1 TRIM-
screen, we derived emission levels for these PB-HAP (other than lead 
(Pb) compounds) at which the maximum excess lifetime cancer risk would 
be 1-in-1 million (i.e., for D/F and POM) or, for HAP that cause non-
cancer health effects (i.e., Cd compounds and Hg compounds), the 
maximum HQ would be 1. If the emissions rate of any PB-HAP included in 
the Tier 1 screen exceeds the Tier 1 screening emissions rate for any 
facility, we conduct a second screen, which we call the Tier 2 TRIM-
screen or Tier 2 screen.
    In the Tier 2 screen, the location of each facility that exceeded 
the Tier 1 emission rate is used to refine the assumptions associated 
with the environmental scenario while maintaining the exposure scenario 
assumptions. A key assumption that is part of the Tier 1 screen is that 
a lake is located near the facility; we confirm the existence of lakes 
near the facility as part of the Tier 2 screen. We then adjust the 
risk-based Tier 1 screening level for each PB-HAP for each facility 
based on an understanding of how exposure concentrations estimated for 
the screening scenarios for the subsistence fisher and the subsistence 
farmer change with meteorology and environmental assumptions.
    PB-HAP emissions that do not exceed these new Tier 2 screening 
levels are considered to pose no unacceptable risks. When facilities 
exceed the Tier 2 screening levels, it does not mean that multipathway 
impacts are significant, only that we cannot rule out that possibility 
based on the results of the screen.
    If the PB-HAP emissions for a facility exceed the Tier 2 screening 
emissions rate, and data are available, we may decide to conduct a more 
refined Tier 3 multipathway assessment. There are several analyses that 
can be included in a Tier 3 screen depending upon the extent of 
refinement warranted, including validating that the lake is fishable 
and considering plume-rise to estimate emissions lost above the mixing 
layer. If the Tier 3 screen is exceeded, the EPA may further refine the 
assessment. For this source category, we conducted 3 Tier 3 screening 
assessments at Alcoa (Ferndale, WA), Alumax (Goose Creek, SC) and 
Reynolds Metals (Massena, NY). The Reynolds Metals facility is a 
Soderberg facility which was operating at the time we sent out the 
information request and when we collected the emissions data and 
initiated the modeling assessment. However, recently this facility 
permanently shut down all their Soderberg potline operations. It is our 
understanding that this facility will either convert to a prebake 
facility or remain permanently shut down. A detailed discussion of the 
approach for this multipathway risk assessment can be found in Appendix 
9 (Technical Support Document: Human Health Multipathway Residual Risk 
Screening Assessment for the Primary Aluminum Production Source 
Category) of the risk assessment document.
    In evaluating the potential multipathway risk from emissions of Pb 
compounds, rather than developing a screening emissions rate for them, 
we compared maximum estimated chronic inhalation exposures with the 
level of the current National Ambient Air Quality Standard (NAAQS) for 
Pb.\23\ Values below the level of the primary (health-based) Pb NAAQS 
were considered to have a low potential for multipathway risk.
---------------------------------------------------------------------------

    \23\ In doing so, the EPA notes that the legal standard for a 
primary NAAQS--that a standard is requisite to protect public health 
and provide an adequate margin of safety (CAA section 109(b))--
differs from the CAA section 112(f) standard (requiring among other 
things that the standard provide an ``ample margin of safety''). 
However, the lead NAAQS is a reasonable measure of determining risk 
acceptability (i.e., the first step of the Benzene NESHAP analysis) 
since it is designed to protect the most susceptible group in the 
human population--children, including children living near major 
lead emitting sources. 73 FR 67002/3; 73 FR 67000/3; 73 FR 67005/1. 
In addition, applying the level of the primary lead NAAQS at the 
risk acceptability step is conservative, since the primary lead 
NAAQS reflects an adequate margin of safety.
---------------------------------------------------------------------------

    For further information on the multipathway analysis approach, see 
the Residual Risk Assessment for the Primary Aluminum Production Source 
Category in Support of the 2014 Supplemental Proposal, which is 
available in the docket for this action (Docket ID No. EPA-HQ-OAR-2011-
0797).
5. How did we assess risks considering the revised emissions control 
options?
    In addition to assessing baseline inhalation risks and potential 
multipathway risks, we also estimated risks considering the emission

[[Page 72927]]

reductions that would be achieved by the control options under 
consideration in this supplemental proposal (i.e., emission reductions 
reflecting the proposed standards reflecting MACT). In these cases, the 
expected emission reductions were applied to the specific HAP and 
emission points in the RTR emissions dataset to develop corresponding 
estimates of risk that would exist after implementation of the proposed 
amendments in today's action.
6. How did we conduct the environmental risk screening assessment?
a. Adverse Environmental Effect
    The EPA conducts a screening assessment to examine the potential 
for adverse environmental effects as required under section 
112(f)(2)(A) of the CAA. Section 112(a)(7) of the CAA defines ``adverse 
environmental effect'' as ``any significant and widespread adverse 
effect, which may reasonably be anticipated, to wildlife, aquatic life, 
or other natural resources, including adverse impacts on populations of 
endangered or threatened species or significant degradation of 
environmental quality over broad areas.''
b. Environmental HAP
    The EPA focuses on seven HAP, which we refer to as ``environmental 
HAP,'' in its screening analysis: Five PB-HAP and two acid gases. The 
five PB-HAP are Cd, D/F, POM, Hg (both inorganic Hg and methylmercury) 
and Pb compounds. The two acid gases are hydrogen chloride (HCl) and 
HF. We have no data indicating primary aluminum plants emit HCl. 
Therefore, our analysis for this source category does not reflect HCl 
emissions. The rationale for including the remaining six HAP in the 
environmental risk screening analysis is presented below.
    The HAP that persist and bioaccumulate are of particular 
environmental concern because they accumulate in the soil, sediment and 
water. The PB-HAP are taken up, through sediment, soil, water and/or 
ingestion of other organisms, by plants or animals (e.g., small fish) 
at the bottom of the food chain. As larger and larger predators consume 
these organisms, concentrations of the PB-HAP in the animal tissues 
increase as does the potential for adverse effects. The five PB-HAP we 
evaluate as part of our screening analysis account for 99.8 percent of 
all PB-HAP emissions nationally from stationary sources (on a mass 
basis from the 2005 National Emissions Inventory).
    In addition to accounting for almost all of the mass of PB-HAP 
emitted, we note that the TRIM.FaTE model that we use to evaluate 
multipathway risk allows us to estimate concentrations of Cd compounds, 
D/F, POM and Hg in soil, sediment and water. For Pb compounds, we 
currently do not have the ability to calculate these concentrations 
using the TRIM.FaTE model. Therefore, to evaluate the potential for 
adverse environmental effects from Pb compounds, we compare the 
estimated HEM-3 modeled exposures from the source category emissions of 
Pb with the level of the secondary NAAQS for Pb.\24\ We consider values 
below the level of the secondary Pb NAAQS as unlikely to cause adverse 
environmental effects.
---------------------------------------------------------------------------

    \24\ The secondary lead NAAQS is a reasonable measure of 
determining whether there is an adverse environmental effect since 
it was established considering ``effects on soils, water, crops, 
vegetation, man-made materials, animals, wildlife, weather, 
visibility and climate, damage to and deterioration of property, and 
hazards to transportation, as well as effects on economic values and 
on personal comfort and well-being.''
---------------------------------------------------------------------------

    Due to its well-documented potential to cause direct damage to 
terrestrial plants, we include the acid gas HF emitted by primary 
aluminum sources, in the environmental screening analysis. In addition 
to the potential to cause direct damage to plants, high concentrations 
of HF in the air have been linked to fluorosis in livestock. Air 
concentrations of these HAP are already calculated as part of the human 
multipathway exposure and risk screening analysis using the HEM3-AERMOD 
air dispersion model, and we are able to use the air dispersion 
modeling results to estimate the potential for an adverse environmental 
effect.
    The EPA acknowledges that other HAP beyond the seven HAP discussed 
above may have the potential to cause adverse environmental effects. 
Therefore, the EPA may include other relevant HAP in its environmental 
risk screening in the future, as modeling science and resources allow. 
The EPA invites comment on the extent to which other HAP emitted by the 
source category may cause adverse environmental effects. Such 
information should include references to peer-reviewed ecological 
effects benchmarks that are of sufficient quality for making regulatory 
decisions, as well as information on the presence of organisms located 
near facilities within the source category that such benchmarks 
indicate could be adversely affected.
c. Ecological Assessment Endpoints and Benchmarks for PB-HAP
    An important consideration in the development of the EPA's 
screening methodology is the selection of ecological assessment 
endpoints and benchmarks. Ecological assessment endpoints are defined 
by the ecological entity (e.g., aquatic communities including fish and 
plankton) and its attributes (e.g., frequency of mortality). Ecological 
assessment endpoints can be established for organisms, populations, 
communities or assemblages and ecosystems.
    For PB-HAP (other than Pb compounds), we evaluated the following 
community-level ecological assessment endpoints to screen for organisms 
directly exposed to HAP in soils, sediment and water:
     Local terrestrial communities (i.e., soil invertebrates, 
plants) and populations of small birds and mammals that consume soil 
invertebrates exposed to PB-HAP in the surface soil;
     Local benthic (i.e., bottom sediment dwelling insects, 
amphipods, isopods and crayfish) communities exposed to PB-HAP in 
sediment in nearby water bodies; and
     Local aquatic (water-column) communities (including fish 
and plankton) exposed to PB-HAP in nearby surface waters.
    For PB-HAP (other than Pb compounds), we also evaluated the 
following population-level ecological assessment endpoint to screen for 
indirect HAP exposures of top consumers via the bioaccumulation of HAP 
in food chains:
     Piscivorous (i.e., fish-eating) wildlife consuming PB-HAP-
contaminated fish from nearby water bodies.
    For Cd compounds, D/F, POM and Hg, we identified the available 
ecological benchmarks for each assessment endpoint. An ecological 
benchmark represents a concentration of HAP (e.g., 0.77 ug of HAP per 
liter of water) that has been linked to a particular environmental 
effect level through scientific study. For PB-HAP we identified, where 
possible, ecological benchmarks at the following effect levels:
     Probable effect levels (PEL): Level above which adverse 
effects are expected to occur frequently;
     Lowest-observed-adverse-effect level (LOAEL): The lowest 
exposure level tested at which there are biologically significant 
increases in frequency or severity of adverse effects; and

[[Page 72928]]

     No-observed-adverse-effect levels (NOAEL): The highest 
exposure level tested at which there are no biologically significant 
increases in the frequency or severity of adverse effect.
    We established a hierarchy of preferred benchmark sources to allow 
selection of benchmarks for each environmental HAP at each ecological 
assessment endpoint. In general, the EPA sources that are used at a 
programmatic level (e.g., Office of Water, Superfund Program) were used 
in the analysis, if available. If not, the EPA benchmarks used in 
regional programs (e.g., Superfund) were used. If benchmarks were not 
available at a programmatic or regional level, we used benchmarks 
developed by other federal agencies (e.g., National Oceanic and 
Atmospheric Administration (NOAA)) or state agencies.
    Benchmarks for all effect levels are not available for all PB-HAP 
and assessment endpoints. In cases where multiple effect levels were 
available for a particular PB-HAP and assessment endpoint, we use all 
of the available effect levels to help us to determine whether 
ecological risks exist and, if so, whether the risks could be 
considered significant and widespread.
d. Ecological Assessment Endpoints and Benchmarks for Acid Gases
    The environmental screening analysis also evaluated potential 
damage and reduced productivity of plants due to direct exposure to 
acid gases in the air. For acid gases, we evaluated the following 
ecological assessment endpoint:
     Local terrestrial plant communities with foliage exposed 
to acidic gaseous HAP in the air.
    The selection of ecological benchmarks for the effects of acid 
gases on plants followed the same approach as for PB-HAP (i.e., we 
examine all of the available chronic benchmarks). For HCl, the EPA 
identified chronic benchmark concentrations. We note that the benchmark 
for chronic HCl exposure to plants is greater than the reference 
concentration for chronic inhalation exposure for human health. This 
means that where the EPA includes regulatory requirements to prevent an 
exceedance of the reference concentration for human health, additional 
analyses for adverse environmental effects of HCl would not be 
necessary.
    For HF, the EPA identified chronic benchmark concentrations for 
plants and evaluated chronic exposures to plants in the screening 
analysis. High concentrations of HF in the air have also been linked to 
fluorosis in livestock. However, the HF concentrations at which 
fluorosis in livestock occur are higher than those at which plant 
damage begins. Therefore, the benchmarks for plants are protective of 
both plants and livestock.
e. Screening Methodology
    For the environmental risk screening analysis, the EPA first 
determined whether any facilities in the Primary Aluminum Production 
source category emitted any of the seven environmental HAP. For the 
Primary Aluminum Production source category, we identified emissions of 
five of the PB-HAP (Cd, Hg, Pb, D/F and POM) and one acid gas (HF).
    Because one or more of the seven environmental HAP evaluated are 
emitted by the facilities in the source category, we proceeded to the 
second step of the evaluation.
f. PB-HAP Methodology
    For Cd, Hg, POM and D/F, the environmental screening analysis 
consists of two tiers, while Pb compounds are analyzed differently as 
discussed earlier. However, as we explained in section III.A.1 above, 
there are greater uncertainties in the emissions estimates for Hg or D/
F because of the limitations in the available data and because a large 
portion of emissions tests results were below the detection limit for 
those HAP. Nevertheless, to be conservative (i.e., more likely to 
overestimate risks rather than underestimate risks), we have included 
emissions estimates of Hg and D/F in the PB-HAP risk screen based on 
conservative assumptions (i.e., emissions of one half the detection 
limit were assumed for those tests where no pollutants were detected).
    In the first tier, we determined whether the maximum facility-
specific emission rates of each of the emitted environmental HAP were 
large enough to create the potential for adverse environmental effects 
under reasonable worst-case environmental conditions. These are the 
same environmental conditions used in the human multipathway exposure 
and risk screening analysis.
    To facilitate this step, TRIM.FaTE was run for each PB-HAP under 
hypothetical environmental conditions designed to provide 
conservatively high HAP concentrations. The model was set to maximize 
runoff from terrestrial parcels into the modeled lake, which in turn, 
maximized the chemical concentrations in the water, the sediments and 
the fish. The resulting media concentrations were then used to back-
calculate a screening level emission rate that corresponded to the 
relevant exposure benchmark concentration value for each assessment 
endpoint. To assess emissions from a facility, the reported emission 
rate for each PB-HAP was compared to the screening level emission rate 
for that PB-HAP for each assessment endpoint. If emissions from a 
facility do not exceed the Tier 1 screening level, the facility 
``passes'' the screen, and, therefore, is not evaluated further under 
the screening approach. If emissions from a facility exceed the Tier 1 
screening level, we evaluate the facility further in Tier 2.
    In Tier 2 of the environmental screening analysis, the emission 
rate screening levels are adjusted to account for local meteorology and 
the actual location of lakes in the vicinity of facilities that did not 
pass the Tier 1 screen. The modeling domain for each facility in the 
Tier 2 analysis consists of eight octants. Each octant contains 5 
modeled soil concentrations at various distances from the facility (5 
soil concentrations x 8 octants = total of 40 soil concentrations per 
facility) and one lake with modeled concentrations for water, sediment 
and fish tissue. In the Tier 2 environmental risk screening analysis, 
the 40 soil concentration points are averaged to obtain an average soil 
concentration for each facility for each PB-HAP. For the water, 
sediment and fish tissue concentrations, the highest value for each 
facility for each pollutant is used. If emission concentrations from a 
facility do not exceed the Tier 2 screening level, the facility passes 
the screen, and is typically not evaluated further. If emissions from a 
facility exceed the Tier 2 screening level, the facility does not pass 
the screen and, therefore, may have the potential to cause adverse 
environmental effects. Such facilities are evaluated further to 
investigate factors such as the magnitude and characteristics of the 
area of exceedance.
g. Acid Gas Methodology
    The environmental screening analysis evaluates the potential 
phytotoxicity and reduced productivity of plants due to chronic 
exposure to HF (we have no data regarding HCl emissions from primary 
aluminum facilities and, therefore, HCl was not analyzed). The 
environmental risk screening methodology for HF is a single-tier screen 
that compares the average off-site ambient air concentration over the 
modeling domain to ecological benchmarks for each of the acid gases. 
Because air concentrations are compared directly to the ecological 
benchmarks, emission-based screening levels are not calculated for HF 
as they

[[Page 72929]]

are in the ecological risk screening methodology for PB-HAPs.
    For purposes of ecological risk screening, the EPA identifies a 
potential for adverse environmental effects to plant communities from 
exposure to acid gases when the average concentration of the HAP around 
a facility exceeds the LOAEL ecological benchmark. In such cases, we 
further investigate factors such as the magnitude and characteristics 
of the area of exceedance (e.g., land use of exceedance area, size of 
exceedance area) to determine if there is an adverse environmental 
effect.
    For further information on the environmental screening analysis 
approach, see the Residual Risk Assessment for the Primary Aluminum 
Production Source Category in Support of the 2014 Supplemental 
Proposal, which is available in the docket for this action (Docket ID 
No. EPA-HQ-OAR-2011-0797).
7. How did we conduct facility-wide assessments?
    To put the source category risks in context, we typically examine 
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, we examine the HAP emissions not only from the 
source category of interest, but also emissions of HAP from all other 
emissions sources at the facility for which we have data. 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. 
The Residual Risk Assessment for the Primary Aluminum Production Source 
Category in Support of the 2014 Supplemental Proposal, available 
through the docket for this action, provides the methodology and 
results of the facility-wide analyses, including all facility-wide 
risks.
8. How did we consider uncertainties in risk assessment?
    In the Benzene NESHAP, we concluded that risk estimation 
uncertainty should be considered in our decision-making under the ample 
margin of safety framework. Uncertainty and the potential for bias are 
inherent in all risk assessments, including those performed for this 
proposal. Although uncertainty exists, we believe that our approach, 
which used conservative tools and assumptions, ensures that our 
decisions are health protective and environmentally protective. A brief 
discussion of the uncertainties in the RTR emissions dataset, 
dispersion modeling, inhalation exposure estimates and dose-response 
relationships follows below. A more thorough discussion of these 
uncertainties is included in the Revised Draft Development of the RTR 
Emissions Dataset for the Primary Aluminum Production Source Category, 
and the Residual Risk Assessment for the Primary Aluminum Production 
Source Category in Support of the 2014 Supplemental Proposal, which is 
available in the docket for this action (Docket ID No. EPA-HQ-OAR-2011-
0797).
a. Uncertainties in the RTR Emissions Dataset
    Although the development of the RTR emissions dataset involved QA/
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 datasets are accurate, errors in emission estimates and other 
factors. The emission estimates considered in this analysis generally 
are annual totals for certain years, and they do not reflect short-term 
fluctuations during the course of a year or variations from year to 
year. The estimates of peak hourly emission rates for the acute effects 
screening assessment were based on an emission adjustment factor for 
each emission process group and applied to the average annual hourly 
emission rates, which are intended to account for emission fluctuations 
due to normal facility operations.
    As described above and in the Revised Draft Development of the RTR 
Emissions Dataset for the Primary Aluminum Production Source Category, 
we gathered a substantial amount of emissions test data from currently 
operating facilities (plus test data from a then-operating, now closed 
Soderberg facility). Required testing under the CAA section 114 request 
included measurements of HAP metal emissions from primary and secondary 
potline exhausts at seven facilities, as well as measurements of HAP 
metal emissions from three anode bake furnace exhausts and three paste 
plant exhausts. We also received additional POM emissions data from 
eight facilities. Furthermore, we received speciated PAH, PCB and D/F 
emissions data from primary and secondary exhausts of two potlines (one 
Soderberg potline and one prebake potline), as well as exhausts from 
one anode bake furnace and one paste plant. We used these data to 
estimate emissions from emission points for which we had no emissions 
test data. Also, there is additional uncertainty concerning the 
estimated emissions of Hg and D/F since, as discussed in sections 
III.A.1 and IV.A of this preamble, a substantial portion of the 
emissions test results for those HAP were reported as below laboratory 
detection limits. Finally, we received hexavalent chromium (Cr\+6\) 
emissions stack test data from primary and secondary potline exhausts 
at two facilities and an anode bake furnace and a paste plant at one 
facility. We used the average results from these tests to apportion 
emissions of Cr\+6\ and trivalent chromium (Cr\+3\) for the remaining 
facilities that did not test. Therefore, there are some uncertainties 
regarding the split between Cr\+6\ and Cr\+3\ for these remaining 
facilities. Nevertheless, we believe the test data we used are 
representative. Thus, the uncertainties are not significant. 
Furthermore, since we used the average results of the available tests, 
the values we used as input for the risk assessment are equally likely 
to be overestimates or underestimates of the actual speciated 
emissions.
b. Uncertainties in Dispersion Modeling
    We recognize there is uncertainty in ambient concentration 
estimates associated with any model, including the EPA's recommended 
regulatory dispersion model, AERMOD. In using a model to estimate 
ambient pollutant concentrations, the user chooses certain options to 
apply. For RTR assessments, we select some model options that have the 
potential to overestimate ambient air concentrations (e.g., not 
including plume depletion or pollutant transformation). We select other 
model options that have the potential to underestimate ambient impacts 
(e.g., not including building downwash). Other options that we select 
have the potential to either under- or overestimate ambient levels 
(e.g., meteorology and receptor locations). On balance, considering the 
directional nature of the uncertainties commonly present in ambient 
concentrations estimated by dispersion models, the approach we apply in 
the RTR assessments should yield unbiased estimates of ambient HAP 
concentrations.
c. Uncertainties in Inhalation Exposure
    The EPA did not include the effects of human mobility on exposures 
in the assessment. Specifically, short-term mobility and long-term 
mobility between census blocks in the modeling

[[Page 72930]]

domain were not considered.\25\ The approach of not considering short 
or long-term population mobility does not bias the estimate of the 
theoretical MIR (by definition), 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., 1-in-10 thousand 
or 1-in-1 million).
---------------------------------------------------------------------------

    \25\ 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. We reduce this uncertainty by analyzing 
large census blocks near facilities using aerial imagery and adjusting 
the location of the block centroid to better represent the population 
in the block, as well as adding additional receptor locations where the 
block population is not well represented by a single location.
    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 emission 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 
domestic 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 the unlikely scenario where a facility 
maintains, or even increases, its emissions levels over a period of 
more than 70 years, residents live beyond 70 years at the same 
location, and the residents spend most of their days at that location, 
then the cancer inhalation risks could potentially be underestimated. 
However, annual cancer incidence estimates from exposures to emissions 
from these sources would not be affected by the length of time an 
emissions source operates.
    The exposure estimates used in these analyses assume chronic 
exposures to ambient (outdoor) 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, 
indoor levels are typically lower. This factor has the potential to 
result in an overestimate of 25 to 30 percent of exposures.\26\
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    \26\ 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 the EPA 
conducts as part of the risk review under section 112(f) of the CAA 
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 the presence of humans at the location of the 
maximum concentration. In the acute screening assessment that we 
conduct under the RTR program, we assume that peak emissions from the 
source category and worst-case meteorological conditions co-occur, 
thus, resulting in maximum ambient concentrations. These two events are 
unlikely to occur at the same time, making these assumptions 
conservative. We then include the additional assumption that a person 
is located at this point during this same time period. For the primary 
aluminum source category, these assumptions would tend to be 
conservative worst-case actual exposures as it is unlikely that a 
person would be located at the point of maximum exposure during the 
time when peak emissions and worst-case meteorological conditions occur 
simultaneously.
    For the primary aluminum source category, we refined the acute 
exposure assessment by estimating the HQ at a centroid of a census 
block. This reduces the uncertainty in the assessment because we are 
evaluating the potential for exposures to occur at locations where 
people could actually live, rather than at the point of maximum off-
site concentration.
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 Guidelines for Carcinogen Risk Assessment 
(EPA/630/P-03/001B, March 2005); 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'' (Guidelines for Carcinogen Risk Assessment, 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 Assessment for the Primary Aluminum Production Source Category in 
Support of the November 2014 Proposal, which is available in the docket 
for this action (Docket ID No. EPA-HQ-OAR-2011-0797).
    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).\27\ In some circumstances, the true risk could be as 
low as zero; however, in other circumstances the risk could be greater. 
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

[[Page 72931]]

limitations for other uses (e.g., priority-setting or expected benefits 
analysis).
---------------------------------------------------------------------------

    \27\ IRIS glossary (http://ofmpub.epa.gov/sor_internet/registry/
termreg/searchandretrieve/glossariesandkeywordlists/
search.do?details=&glossaryName=IRIS%20Glossary).
---------------------------------------------------------------------------

    Chronic non-cancer 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,\28\ e.g., factors of 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.
---------------------------------------------------------------------------

    \28\ 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 the 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.
    Many of the UF used to account for variability and uncertainty in 
the development of acute reference values are quite similar to those 
developed for chronic durations, but they more often use individual UF 
values that may be less than 10. The UF are applied based on chemical-
specific or health effect-specific information (e.g., simple irritation 
effects do not vary appreciably between human individuals, hence a 
value of 3 is typically used), or based on the purpose for the 
reference value (see the following paragraph). The UF applied in acute 
reference value derivation include: (1) Heterogeneity among humans; (2) 
uncertainty in extrapolating from animals to humans; (3) uncertainty in 
lowest observed adverse effect (exposure) level to no observed adverse 
effect (exposure) level adjustments; and (4) uncertainty in accounting 
for an incomplete database on toxic effects of potential concern. 
Additional adjustments are often applied to account for uncertainty in 
extrapolation from observations at one exposure duration (e.g., 4 
hours) to derive an acute reference value at another exposure duration 
(e.g., 1 hour).
    Not all acute reference values are developed for the same purpose 
and care must be taken when interpreting the results of an acute 
assessment of human health effects relative to the reference value or 
values being exceeded. Where relevant to the estimated exposures, the 
lack of short-term dose-response values at different levels of severity 
should be factored into the risk characterization as potential 
uncertainties.
    Although every effort is made to identify appropriate human health 
effect dose-response assessment values for all pollutants emitted by 
the sources in this risk assessment, some HAP emitted by this source 
category are lacking dose-response assessments. Accordingly, these 
pollutants cannot be included in the quantitative risk assessment, 
which could result in quantitative estimates understating HAP risk.
    To help to alleviate this potential underestimate, where we 
conclude similarity with a HAP for which a dose-response assessment 
value is available, we use that value as a surrogate for the assessment 
of the HAP for which no value is available. To the extent use of 
surrogates indicates appreciable risk, we may identify a need to 
increase priority for new IRIS assessment of that substance. We 
additionally note that, generally speaking, HAP of greatest concern due 
to environmental exposures and hazard are those for which dose-response 
assessments have been performed, reducing the likelihood of 
understating risk.
e. Uncertainties in the Multipathway Assessment
    For each source category, we generally rely on site-specific levels 
of PB-HAP emissions to determine whether a refined assessment of the 
impacts from multipathway exposures is necessary. This determination is 
based on the results of a three-tiered screening analysis that relies 
on the outputs from models that estimate environmental pollutant 
concentrations and human exposures for four PB-HAP. Two important types 
of uncertainty associated with the use of these models in RTR risk 
assessments and inherent to any assessment that relies on environmental 
modeling are model uncertainty and input uncertainty.\29\
---------------------------------------------------------------------------

    \29\ In the context of this discussion, the term ``uncertainty'' 
as it pertains to exposure and risk encompasses both variability in 
the range of expected inputs and screening results due to existing 
spatial, temporal and other factors, as well as uncertainty in being 
able to accurately estimate the true result.
---------------------------------------------------------------------------

    Model uncertainty concerns whether the selected models are 
appropriate for the assessment being conducted and whether they 
adequately represent the actual processes that might occur for that 
situation. An example of model uncertainty is the question of whether 
the model adequately describes the movement of a pollutant through the 
soil. This type of uncertainty is difficult to quantify. However, based 
on feedback received from previous EPA SAB reviews and other reviews, 
we are confident that the models used in the screen are appropriate and 
state-of-the-art for the multipathway risk assessments conducted in 
support of RTR.
    Input uncertainty is concerned with how accurately the models have 
been configured and parameterized for the assessment at hand. For Tier 
1 of the multipathway screen, we configured the models to avoid 
underestimating exposure and risk. This was

[[Page 72932]]

accomplished by selecting upper-end values from nationally-
representative datasets for the more influential parameters in the 
environmental model, including selection and spatial configuration of 
the area of interest, lake location and size, meteorology, surface 
water and soil characteristics and structure of the aquatic food web. 
We also assume an ingestion exposure scenario and values for human 
exposure factors that represent reasonable maximum exposures. The 
multipathway screens include some hypothetical elements, namely the 
hypothetical farmer and fisher scenarios. It is important to note that 
even though EPA conducted a multipathway assessment based on these 
scenarios, no data exist to verify the existence of either the farmer 
or fisher scenario outlined above.
    In Tier 2 of the multipathway assessment, we refine the model 
inputs to account for meteorological patterns in the vicinity of the 
facility versus using upper-end national values and we identify the 
actual location of lakes near the facility rather than the default lake 
location that we apply in Tier 1. By refining the screening approach in 
Tier 2 to account for local geographical and meteorological data, we 
decrease the likelihood that concentrations in environmental media are 
overestimated, thereby increasing the usefulness of the screen. The 
assumptions and the associated uncertainties regarding the selected 
ingestion exposure scenario are the same for Tier 1 and Tier 2.
    For both Tiers 1 and 2 of the multipathway assessment, our approach 
to addressing model input uncertainty is generally cautious. We choose 
model inputs from the upper end of the range of possible values for the 
influential parameters used in the models, and we assume that the 
exposed individual exhibits ingestion behavior that would lead to a 
high total exposure. This approach reduces the likelihood of not 
identifying high risks for adverse impacts.
    Despite the uncertainties, when individual pollutants or facilities 
do screen out, we are confident that the potential for adverse 
multipathway impacts on human health is very low. On the other hand, 
when individual pollutants or facilities do not screen out, it does not 
mean that multipathway impacts are significant, only that we cannot 
rule out that possibility and that a refined multipathway analysis for 
the site might be necessary to obtain a more accurate risk 
characterization for the source category. For further information on 
uncertainties and the Tier 1 and 2 screening methods, refer to the risk 
document Appendix 5, Technical Support Document for TRIM-Based 
Multipathway Tiered Screening Methodology for RTR.
    We completed a Tier 3 multipathway screen for this supplemental 
proposal. This assessment contains less uncertainty compared to the 
Tier 1 and Tier 2 screens. The Tier 3 screen improves the lake 
characterization used in the Tier 2 analysis and improves the screen by 
adjusting for emissions lost to the upper air sink through plume-rise 
calculations. The Tier 3 screen reduces uncertainty through improved 
lake evaluations used in the Tier 2 screen and by calculating the 
amount of mass lost to the upper air sink through plume rise. 
Nevertheless, some uncertainties also exist here. The Tier 3 
multipathway screen and related uncertainties are described in detail 
in section 4 of the Residual Risk Assessment for the Primary Aluminum 
Production Source Category in Support of the 2014 Supplemental 
Proposal, which is available in the docket for this action (Docket ID 
No. EPA-HQ-OAR-2011-0797).
f. Uncertainties in the Environmental Risk Screening Assessment
    For each source category, we generally rely on site-specific levels 
of environmental HAP emissions to perform an environmental screening 
assessment. The environmental screening assessment is based on the 
outputs from models that estimate environmental HAP concentrations. The 
same models, specifically the TRIM.FaTE multipathway model and the 
AERMOD air dispersion model, are used to estimate environmental HAP 
concentrations for both the human multipathway screening analysis and 
for the environmental screening analysis. Therefore, both screening 
assessments have similar modeling uncertainties.
    Two important types of uncertainty associated with the use of these 
models in RTR environmental screening assessments--and inherent to any 
assessment that relies on environmental modeling--are model uncertainty 
and input uncertainty.\30\
---------------------------------------------------------------------------

    \30\ In the context of this discussion, the term 
``uncertainty,'' as it pertains to exposure and risk assessment, 
encompasses both variability in the range of expected inputs and 
screening results due to existing spatial, temporal and other 
factors, as well as uncertainty in being able to accurately estimate 
the true result.
---------------------------------------------------------------------------

    Model uncertainty concerns whether the selected models are 
appropriate for the assessment being conducted and whether they 
adequately represent the movement and accumulation of environmental HAP 
emissions in the environment. For example, does the model adequately 
describe the movement of a pollutant through the soil? This type of 
uncertainty is difficult to quantify. However, based on feedback 
received from previous EPA SAB reviews and other reviews, we are 
confident that the models used in the screen are appropriate and state-
of-the-art for the environmental risk assessments conducted in support 
of our RTR analyses.
    Input uncertainty is concerned with how accurately the models have 
been configured and parameterized for the assessment at hand. For Tier 
1 of the environmental screen for PB-HAP, we configured the models to 
avoid underestimating exposure and risk to reduce the likelihood that 
the results indicate the risks are lower than they actually are. This 
was accomplished by selecting upper-end values from nationally-
representative datasets for the more influential parameters in the 
environmental model, including selection and spatial configuration of 
the area of interest, the location and size of any bodies of water, 
meteorology, surface water and soil characteristics and structure of 
the aquatic food web. In Tier 1, we used the maximum facility-specific 
emissions for the PB-HAP (other than Pb compounds, which were evaluated 
by comparison to the secondary Pb NAAQS) that were included in the 
environmental screening assessment and each of the media when comparing 
to ecological benchmarks. This is consistent with the conservative 
design of Tier 1 of the screen. In Tier 2 of the environmental 
screening analysis for PB-HAP, we refine the model inputs to account 
for meteorological patterns in the vicinity of the facility versus 
using upper-end national values, and we identify the locations of water 
bodies near the facility location. By refining the screening approach 
in Tier 2 to account for local geographical and meteorological data, we 
decrease the likelihood that concentrations in environmental media are 
overestimated, thereby increasing the usefulness of the screen. To 
better represent widespread impacts, the modeled soil concentrations 
are averaged in Tier 2 to obtain one average soil concentration value 
for each facility and for each PB-HAP. For PB-HAP concentrations in 
water, sediment and fish tissue, the highest value for each facility 
for each pollutant is used.
    For the environmental screening assessment for acid gases, we 
employ a single-tiered approach. We use the modeled air concentrations 
and compare those with ecological benchmarks.

[[Page 72933]]

    For both Tiers 1 and 2 of the environmental screening assessment, 
our approach to addressing model input uncertainty is generally 
cautious. We choose model inputs from the upper end of the range of 
possible values for the influential parameters used in the models, and 
we assume that the exposed individual exhibits ingestion behavior that 
would lead to a high total exposure. This approach reduces the 
likelihood of not identifying potential risks for adverse environmental 
impacts.
    Uncertainty also exists in the ecological benchmarks for the 
environmental risk screening analysis. We established a hierarchy of 
preferred benchmark sources to allow selection of benchmarks for each 
environmental HAP at each ecological assessment endpoint. In general, 
EPA benchmarks used at a programmatic level (e.g., Office of Water, 
Superfund Program) were used if available. If not, we used EPA 
benchmarks used in regional programs (e.g., Superfund Program). If 
benchmarks were not available at a programmatic or regional level, we 
used benchmarks developed by other agencies (e.g., NOAA) or by state 
agencies.
    In all cases (except for Pb compounds, which were evaluated through 
a comparison to the NAAQS for Pb and its compounds), we searched for 
benchmarks at the following three effect levels, as described in 
section III.A.6 of this preamble:
    1. A no-effect level (i.e., NOAEL).
    2. Threshold-effect level (i.e., LOAEL).
    3. Probable effect level (i.e., PEL).
    For some ecological assessment endpoint/environmental HAP 
combinations, we could identify benchmarks for all three effect levels, 
but for most, we could not. In one case, where different agencies 
derived significantly different numbers to represent a threshold for 
effect, we included both. In several cases, only a single benchmark was 
available. In cases where multiple effect levels were available for a 
particular PB-HAP and assessment endpoint, we used all of the available 
effect levels to help us to determine whether risk exists and if the 
risks could be considered significant and widespread.
    The EPA evaluates the following seven HAP in the environmental risk 
screening assessment: Cd, D/F, POM, Hg (both inorganic Hg and 
methylmercury), Pb compounds, HCl \31\ and HF, where applicable. These 
seven HAP represent pollutants that can cause adverse impacts for 
plants and animals either through direct exposure to HAP in the air or 
through exposure to HAP that is deposited from the air onto soils and 
surface waters. These seven HAP also represent those HAP for which we 
can conduct a meaningful environmental risk screening assessment. For 
other HAP not included in our screening assessment, the model has not 
been parameterized such that it can be used for that purpose. In some 
cases, depending on the HAP, we may not have appropriate multipathway 
models that allow us to predict the concentration of that pollutant. 
The EPA acknowledges that other HAP beyond the seven HAP that we are 
evaluating may have the potential to cause adverse environmental 
effects and, therefore, the EPA may evaluate other relevant HAP in the 
future, as modeling science and resources allow.
---------------------------------------------------------------------------

    \31\ As noted above, we have no data regarding HCl emissions 
from primary aluminum plants so the EPA did not evaluate HCl in this 
screening assessment for this proposal.
---------------------------------------------------------------------------

    Further information on uncertainties and the Tier 1 and 2 screening 
methods is provided in Appendix 5 of the document ``Technical Support 
Document for TRIM-Based Multipathway Tiered Screening Methodology for 
RTR: Summary of Approach and Evaluation.'' Also, see the Residual Risk 
Assessment for the Primary Aluminum Production Source Category in 
Support of the 2014 Supplemental Proposal, available in the docket for 
this action (Docket ID No. EPA-HQ-OAR-2011-0797).

B. How did we consider the risk results in making decisions for this 
supplemental proposal?

    As discussed in section II.A of this preamble, in evaluating and 
developing standards under CAA section 112(f)(2), we apply a two-step 
process to address residual risk. In the first step, the EPA determines 
whether risks are acceptable. This determination ``considers all health 
information, including risk estimation uncertainty, and includes a 
presumptive limit on maximum individual lifetime [cancer] risk (MIR) 
\32\ of approximately [1-in-10 thousand] [i.e., 100-in-1 million].'' 54 
FR 38045, September 14, 1989. If risks are unacceptable, the EPA must 
determine the emissions standards necessary to bring risks to an 
acceptable level without considering costs. In the second step of the 
process, the EPA considers whether the emissions standards provide an 
ample margin of safety ``in consideration of all health information, 
including the number of persons at risk levels higher than 
approximately 1-in-1 million, as well as other relevant factors, 
including costs and economic impacts, technological feasibility, and 
other factors relevant to each particular decision.'' Id. The EPA must 
promulgate emission standards necessary to provide an ample margin of 
safety.
---------------------------------------------------------------------------

    \32\ Although defined as ``maximum individual risk,'' MIR refers 
only to cancer risk. MIR, one metric for assessing cancer risk, is 
the estimated risk were an individual exposed to the maxi
========================================================================
Notices
                                                Federal Register
________________________________________________________________________

This section of the FEDERAL REGISTER contains documents other than rules 
or proposed rules that are applicable to the public. Notices of hearings 
and investigations, committee meetings, agency decisions and rulings, 
delegations of authority, filing of petitions and applications and agency 
statements of organization and functions are examples of documents 
appearing in this section.

========================================================================


Federal Register / Vol. 79, No. 235 / Monday, December 8, 2014 / 
Notices

[[Page 72621]]



DEPARTMENT OF AGRICULTURE

Natural Resources Conservation Service

[Docket No. NRCS-2014-0014]


Notice of Intent for the East Locust Creek Watershed Revised 
Plan, Sullivan County, Missouri

AGENCY: Natural Resources Conservation Service, USDA.

ACTION: Notice of Intent to Prepare a Supplemental Environmental Impact 
Statement.

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

SUMMARY: Pursuant to Section 102(2)(c) of the National Environmental 
Policy Act of 1969 (NEPA); as amended (42 U.S.C. 4321 et seq.), the 
Natural Resources Conservation Service (NRCS), U.S. Department of 
Agriculture, as lead federal agency, will prepare a Supplemental 
Environmental Impact Statement (SEIS) for the East Locust Creek 
Watershed Revised Plan (ELCWRP), Sullivan County, Missouri, involving 
the proposed construction of a multi-purpose reservoir. The purpose of 
this supplement is to address changes which have occurred since the 
NRCS prepared the East Locust Creek Watershed Revised Plan and 
Environmental Impact Statement in 2006. The SEIS will update the 
original EIS with more recent relevant environmental information and 
expand the alternatives analysis beyond those previously considered. 
The SEIS will evaluate reasonable and practicable alternatives and 
their expected environmental impacts.

ADDRESSES: To be included on the mailing list for review of the SEIS, 
all requests should be submitted to Mr. Harold Deckerd, USDA-Natural 
Resources Conservation Service, Parkade Center, Suite 250, 601 Business 
Loop 70 West, Columbia, Missouri 65203-2585.

FOR FURTHER INFORMATION CONTACT: Mr. Harold Deckerd, NRCS Missouri 
State Office, by email: harold.deckerd@mo.usda.gov, by regular mail 
(see ADDRESSES), or by telephone: 573-876-0912.

SUPPLEMENTARY INFORMATION: The NRCS in cooperation with the North 
Central Missouri Regional Water Commission (NCMRWC) and the U.S. Army 
Corps of Engineers (Corps) will prepare a SEIS for the East Locust 
Creek Watershed Revised Plan in Sullivan County, Missouri authorized 
pursuant to the Watershed Protection and Flood Prevention Act, Public 
Law 83-566, (16 U.S.C. 1001-1008). The NRCS has determined that 
additional analysis is required and that the purposes of the National 
Environmental Policy Act would be furthered through the preparation of 
the SEIS. The Corps will be a cooperating agency in the preparation of 
the SEIS. The SEIS will consider all reasonable and practicable 
alternatives to meet the purpose and need for the federal action. The 
SEIS will assess the potential social, economic, and environmental 
impacts of the project, and will address federal, state, and local 
regulatory requirements along with pertinent environmental and socio-
economic issues. The SEIS will analyze the direct, indirect, and 
cumulative effects of the proposed action. The Federal SEIS process 
begins with the publication of this Notice of Intent.
    1. Background: The 79,490-acre East Locust Creek Watershed is 
located in north-central Missouri approximately 30 miles west of 
Kirksville in Sullivan County with small portions of the watershed in 
neighboring Putnam and Linn Counties. East Locust Creek is a tributary 
to Locust Creek which drains to the Grand River and the Missouri River.
    The Sullivan and Putnam County Commissions and the Sullivan and 
Putnam County Soil and Water Conservation Districts initially applied 
for federal watershed planning assistance in the East Locust Creek 
Watershed in 1974. Missouri governor Christopher Bond approved their 
application that same year. The U.S. Soil Conservation Service (later 
renamed and hereafter referred to as NRCS) collected pre-authorization 
planning data and analyzed the East Locust Creek Watershed as part of 
the larger Northern Missouri River Tributaries Study. East Locust Creek 
Watershed planning was authorized in March 1984 and NRCS began planning 
activities under the authority of the Watershed Protection and Flood 
Prevention Act of 1954, Public Law 83-566, as amended (16 U.S.C. 1001-
1008). NRCS completed the East Locust Creek Watershed Plan-
Environmental Assessment in 1986. The plan recommended one large and 
120 small dams to reduce soil erosion and flood damages. A Finding of 
No Significant Impact (FONSI) was published in the Federal Register on 
July 17, 1986. Local sponsors signed the Watershed Agreement in 
November 1986 and assistance for installation was authorized in August 
1987.
    The Missouri Drought Plan (Missouri Dept. of Natural Resources, 
2002) places Sullivan County and surrounding counties in a region 
classified as having ``severe surface and groundwater supply drought 
vulnerability.'' Underlying bedrock geology severely limits groundwater 
quality and availability. Recognizing the regional need for a 
dependable water supply, the Locust Creek Watershed Board in November 
2000 requested NRCS study a potential supplement to the 1986 East 
Locust Creek Watershed Plan-Environmental Assessment to include a 
public water supply reservoir. The NCMRWC was formed in 2001 with 
assistance from the Missouri Department of Natural Resources ``to 
provide an abundant source of low-cost, pure, quality water for the 
residents of North Central Missouri.'' The NCMRWC immediately became a 
local sponsor of the planning effort. NRCS began planning activities 
following authorization in July 2003. NRCS issued a Notice of Intent to 
prepare an Environmental Impact Statement in September of 2004. NRCS 
completed the East Locust Creek Watershed Revised Plan and 
Environmental Impact Statement (ELCWRP) in March 2006 and announced a 
Record of Decision to proceed with installation in September 2006. The 
ELCWRP found the present water supply systems for the neighboring ten-
county region are inadequate and experience pressures from drought 
conditions. In addition, the ELCWRP documented annual flood damages to 
crop and pasture land, fences, roads and bridges. The ELCWRP

[[Page 72622]]

also identified the need for additional water-based recreational 
opportunities in the surrounding area. The project has not been 
installed because sufficient funding has not been available. 
Installation of the proposed action will result in temporary and 
permanent impacts to jurisdictional waters of the United States 
requiring a Clean Water Act (CWA) Section 404 permit. The Corps has not 
issued a Section 404 permit for this project. Potential impacts of all 
reasonable and practicable alternatives will be updated and analyzed in 
the SEIS in compliance with Section 404(b)(1) of the CWA.
    2. Proposed Action: The proposed federal action as presented in the 
2006 EIS includes one approximately 2,235-acre multiple-purpose 
reservoir on East Locust Creek, a water intake structure, a raw water 
line, fish and wildlife habitat enhancement and water-based 
recreational facilities. The purpose of the proposed federal action is 
to: Provide approximately 7.0 million gallons per day of raw water 
supply to meet the projected 50-year usage demand for the ten counties 
served by the NCMRWC; provide approximately 72,000 annual water-based 
recreational user-days and provide an approximate 22% reduction in 
annual flood damages in the 16.3 miles of East Locust Creek floodplain 
between the reservoir and the confluence with Locust Creek.
    3. Alternatives: The SEIS will evaluate environmental impacts of 
the following alternatives and any other action alternatives identified 
that may be reasonable and practicable: (1) Creation of a multi-purpose 
reservoir; (2) a range of reasonable alternatives to meet the overall 
project purposes and needs; and (3) the no-action alternative. The SEIS 
will identify the National Economic Development (NED) alternative, 
which is the alternative with the greatest net economic benefit 
consistent with protecting the Nation's environment and document the 
estimated direct, indirect and cumulative impacts of the proposed 
action and alternatives on the environment.
    4. Scoping: In developing the 2006 ELCWRP, numerous scoping 
meetings were held to gather public input and keep the community 
informed on the status of project planning activities. Several 
community surveys and interviews were conducted to gather information, 
and periodic news articles were published to update local citizens. 
Problems identified through the scoping process include:
     Inadequate rural water supply in the 10-county Green Hills 
Region
     Annual flood damages to crops, pastures, fences and 
infrastructure
     Unmet demand for water-based recreational facilities.
    NEPA procedures do not require additional public scoping meetings 
for the development of a SEIS and none are planned at this time. 
Comments received from Federal, State or local agencies, Native 
American Tribes, non-governmental organizations, and interested 
citizens will be used to assist in the development of the Draft and 
Final SEIS (See ADDRESSES above to submit comments).
    5. Public Involvement: The NRCS invites full public participation 
to promote open communication and better decision-making. All persons 
and organizations with an interest in the ELCWRP are urged to comment. 
Public comments are welcomed and opportunities for public participation 
include submitting comments to the NRCS: (1) During the development of 
the Draft SEIS, (2) during the review and comment period upon 
publishing the Draft SEIS; and (3) for 30 days after publication of the 
Final SEIS. Distribution of the comments received will be included in 
the Administrative Record without change and may include any personal 
information provided unless the commenter indicates that the comment 
includes information claimed to be confidential business information.
    6. Other Environmental Review and Coordination Requirements: The 
Corps will be a cooperating agency in the preparation of the SEIS. The 
NRCS as the lead federal agency will continue to coordinate with other 
agencies and entities throughout the NEPA process including: The 
NCMRWC, Missouri Department of Natural Resources (Section 401, Historic 
Preservation and Dam Safety), Missouri Department of Conservation, U.S. 
Fish and Wildlife Service and USEPA. The Draft SEIS will address 
project compliance with applicable laws and regulations, including 
NEPA, CWA, Endangered Species Act, and the National Historic 
Preservation Act.
    7. Permits or Licenses Required: The proposed federal action would 
require a CWA Section 404 permit from the Corps. The project would also 
require certification by the State of Missouri, Department of Natural 
Resources, under Section 401 of the CWA, that the project would not 
violate state water quality standards. A land disturbance permit issued 
by the Missouri Department of Natural Resources under Section 402 of 
the CWA (National Pollutant Discharge Elimination System Permit) would 
be required. Construction and Safety Permits issued by the Missouri Dam 
and Reservoir Safety Program would also be required.
    8. Availability of Draft SEIS: The draft SEIS is estimated to be 
complete and available for public review in 2016.

(This activity is listed in the Catalog of Federal Domestic 
Assistance under NO. 10.904, Watershed Protection and Flood 
Prevention, and is subject to the provisions of Executive Order 
12372, which requires intergovernmental consultation with State and 
local officials.)

    Dated: November 25, 2014.
J.R. Flores,
State Conservationist, Natural Resources Conservation Service.
[FR Doc. 2014-28673 Filed 12-5-14; 8:45 am]
BILLING CODE 3410-16-P