National Emission Standards for Hazardous Air Pollutants From the Pulp and Paper Industry

Federal RegisterDec 27, 2011

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 63

[EPA-HQ-OAR-2007-0544; FRL-9609-8]

RIN 2060-AQ41

National Emission Standards for Hazardous Air Pollutants From the Pulp and Paper Industry

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Proposed rule.

SUMMARY:

The EPA is proposing amendments to the national emission standards for hazardous air pollutants for the pulp and paper industry to address the results of the residual risk and technology review that the EPA is required to conduct under sections 112(d)(6) and (f)(2) of the Clean Air Act. These proposed amendments include revisions to the kraft pulping process condensates standards; a requirement for 5-year repeat emissions testing for selected process equipment; revisions to provisions addressing periods of startup, shutdown and malfunction; additional test methods for measuring methanol; and technical and editorial changes.

DATES:

Comments.

Comments must be received on or before February 27, 2012. Under the Paperwork Reduction Act, comments on the information collection provisions are best assured of having full effect if the Office of Management and Budget receives a copy of your comments on or before January 26, 2012.

Public Hearing.

If anyone contacts the EPA requesting to speak at a public hearing by January 6, 2012, a public hearing will be held on January 11, 2012.

ADDRESSES:

Submit your comments, identified by Docket ID Number EPA-HQ-OAR-2007-0544, by one of the following methods:

•

Federal eRulemaking Portal: http://www.regulations.gov.

Follow the online instructions for submitting comments.

•

Agency Web site: http://www.epa.gov/oar/docket.html.

Follow the instructions for submitting comments on the EPA Air and Radiation Docket Web site.

•

Email: a-and-r-docket@epa.gov.

Include EPA-HQ-OAR-2007-0544 in the subject line of the message.

•

Fax:

Fax your comments to: (202) 566-9744, Attention Docket ID Number EPA-HQ-OAR-2007-0544.

•

Mail:

Send your comments to: EPA Docket Center (EPA/DC), Environmental Protection Agency, Mailcode: 2822T, 1200 Pennsylvania Ave. NW., Washington, DC 20460, Attention: Docket ID Number EPA-HQ-OAR-2007-0544. Please include a total of two copies. In addition, please mail a copy of your comments on the information collection provisions to the Office of Information and Regulatory Affairs, Office of Management and Budget (OMB), Attn: Desk Officer for EPA, 725 17th Street NW., Washington, DC 20503.

•

Hand Delivery or Courier:

In person or by courier, deliver comments to the EPA Docket Center, EPA West (Air Docket), Room 3334, 1301 Constitution Ave. NW., Washington, DC 20460, Attention: Docket ID Number EPA-HQ-OAR-2007-0544. Such deliveries are only accepted during the Docket's normal hours of operation (8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays), and special arrangements should be made for deliveries of boxed information. Please include two copies.

Instructions.

Direct your comments to Docket ID Number EPA-HQ-OAR-2007-0544. The EPA 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 or other information whose disclosure is restricted by statute. Do not submit information that you consider to be confidential business information or otherwise protected through

http://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 avoid the use of special characters, any form of encryption and be free of any defects or viruses. For additional information about the EPA public docket, visit the EPA Docket Center homepage at

http://www.epa.gov/epahome/dockets.htm.

Docket.

The EPA has established a docket for this rulemaking under Docket ID Number EPA-HQ-OAR-2007-0544. All documents in the docket are listed in the

http://www.regulations.gov

index. Although listed in the index, some information is not publicly available (

e.g.,

confidential business information 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

http://www.regulations.gov

or in hard copy at the EPA Docket Center, EPA West, Room 3334, 1301 Constitution Ave., NW., Washington, DC. The Public Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. The telephone number for the Public Reading Room is (202) 566-1744, and the telephone number for the EPA Docket Center is (202) 566-1742.

Public Hearing.

If a public hearing is held, it will begin at 10 a.m. on January 11, 2012 and will be held at the EPA campus in Research Triangle Park, North Carolina, or at an alternate facility nearby. Persons interested in presenting oral testimony or inquiring as to whether a public hearing is to be held should contact Ms. Joan Rogers, Office of Air Quality Planning and Standards, Sector Policies and Programs Division, Natural Resources Group (E143-03), U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711; telephone number: (919) 541-4487.

FOR FURTHER INFORMATION CONTACT:

For questions about this proposed action, contact Mr. John Bradfield, Office of Air Quality Planning and Standards, (E143-03), Environmental Protection Agency, Research Triangle Park, North Carolina 27711; telephone number: (919) 541-3062; fax number: (919) 541-3470; and email address:

bradfield.john@epa.gov.

For specific information regarding the risk modeling methodology, contact Mr. James Hirtz, Health and Environmental Impacts Division (C539-02), Office of Air Quality Planning and Standards, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 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 national emission standards for hazardous air pollutants to a particular entity, contact the appropriate person listed in Table 1 to this preamble.

Table 1—List of EPA Contacts for the NESHAP Addressed in This Proposed Action

NESHAP for:

OECA Contact

OAQPS Contacts

Pulp and Paper

Sara Ayres (202) 564-5391

ayres.sara@epa.gov.

John Bradfield (919) 541-3062

bradfield.john@epa.gov.

EPA's Office of Enforcement and Compliance Assurance.

EPA's Office of Air Quality Planning and Standards.

SUPPLEMENTARY INFORMATION:

Preamble Acronyms and Abbreviations

Several acronyms and terms used to describe industrial processes, data inventories and risk modeling are included in this preamble. While this may not be an exhaustive list, to ease the reading of this preamble and for reference purposes, the following terms and acronyms are defined here:

ACGIH American Conference of Governmental Industrial Hygienists

ADAF Age-Dependent Adjustment Factors

AEGL Acute Exposure Guideline Levels

AERMOD Air dispersion model used by the HEM-3 model

ASME American Society of Mechanical Engineers

ATSDR Agency for Toxic Substances and Disease Registry

BACT Best Available Control Technology

BBDR Biologically-Based Dose-Response

CAA Clean Air Act

CalEPA California Environmental Protection Agency

CBI Confidential Business Information

CCA Clean Condensate Alternative

CD ROM Compact Disk Read Only Memory

CDX Central Data Exchange

CEEL Community Emergency Exposure Levels

CEMS Continuous Emissions Monitoring System

CFR Code of Federal Regulations

CIIT Chemical Industry Institute of Toxicology

EIA Economic Impact Analysis

EJ Environmental Justice

EPA Environmental Protection Agency

ERPG Emergency Response Planning Guidelines

ERT Electronic Reporting Tool

ft Feet

Cubic Feet

FTE Full-Time Equivalents

HAP Hazardous Air Pollutants

HEM-3 Human Exposure Model version 3

HI Hazard Index

HON Hazardous Organic National Emissions Standards for Hazardous Air Pollutants

HQ Hazard Quotient

hr Hour

HVLC High Volume Low Concentration

ICR Information Collection Request

IRIS Integrated Risk Information System

ISIS Industrial Sectors Integrated Solution Model

km Kilometer

LAER Lowest Achievable Emission Rate

lb Pounds

LVHC Low Volume High Concentration

Cubic Meters

MACT Maximum Achievable Control Technology

MACT Code Code within the NEI used to identify processes included in a source category

MEK Methyl Ethyl Ketone

mg Milligrams

MIR Maximum Individual Risk

MRL Minimal Risk Level

NAC/AEGL National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances

NAICS North American Industry Classification System

NAS National Academy of Sciences

NATA National Air Toxics Assessment

NCASI National Council for Air and Stream Improvement

NEI National Emissions Inventory

NESHAP National Emissions Standards for Hazardous Air Pollutants

NIOSH National Institutes for Occupational Safety and Health

NRC National Research Council

NSPS New Source Performance Standard

NTTAA National Technology Transfer and Advancement Act of 1995

O&M Operation and Maintenance

OAQPS EPA's Office of Air Quality Planning and Standards

ODTP Oven-Dried Tons of Pulp

OECA EPA's Office of Enforcement and Compliance Assurance

OMB Office of Management and Budget

PB-HAP Hazardous air pollutants known to be persistent and bio-accumulative in the environment

POM Polycyclic Organic Matter

ppm Parts Per Million

ppmw Parts Per Million by Weight

PRA Paperwork Reduction Act

QA Quality Assurance

QC Quality Control

RACT Reasonably Available Control Technology

RBLC RACT/BACT/LAER Clearinghouse

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

SCC Source Classification Code

Sec Second

SISNOSE Significant Impact on a Substantial Number of Small Entities

SOP Standard Operating Procedures

SSM Startup, Shutdown, and Malfunction

TOSHI Target Organ-Specific Hazard Index

TPY Tons Per Year

TRI Toxics Release Inventory

TRIM Total Risk Integrated Modeling System

TRIM.FaTE Fate, Transport and Environmental Exposure module of EPA's Total Risk Integrated Modeling System

TTN Technology Transfer Network

UF Uncertainty Factor

UMRA Unfunded Mandates Reform Act of 1995

URE Unit Risk Estimate

VCS Voluntary Consensus Standards

VOC Volatile Organic Compound

WWW Worldwide Web

μg Micrograms

Organization of This Document

The information in this preamble is organized as follows:

I. General Information

A. What is the statutory authority for this action?

B. Does this action apply to me?

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

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

II. Background

A. What is this source category and how did the MACT standard regulate its HAP emissions?

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

III. Analyses Performed

A. How did we estimate risks posed by the source category?

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

C. How did we perform the technology review?

D. What other issues are we addressing in this proposal?

IV. Analytical Results and Proposed Decisions

A. What are the results of the risk assessments?

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

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

D. What other actions are we proposing?

E. Compliance Dates

V. Summary of 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. What is the statutory authority for this action?

Section 112 of the CAA establishes a two-stage regulatory process to address emissions of HAP 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) calls for us to promulgate NESHAP for those sources. “Major sources” are those that emit or have the potential to emit 10 tpy or more of a single HAP or 25 tpy or more of any combination of HAP. For major sources, these technology-based standards must reflect the maximum degree of emissions reductions of HAP achievable (after considering cost, energy requirements and nonair quality health and environmental impacts) and are commonly referred to as MACT standards.

Maximum achievable control technology standards must require the maximum degree of emissions reduction through the application of measures, processes, methods, systems or techniques, including, but not limited to, measures that: (A) Reduce the volume of or eliminate pollutants through process changes, substitution of materials or other modifications; (B) enclose systems or processes to eliminate emissions; (C) capture or treat pollutants when released from a process, stack, storage or fugitive emissions point; (D) are design, equipment, work practice or operational standards (including requirements for operator training or certification); or (E) are a combination of the above (CAA section 112(d)(2)(A)-(E)). The MACT standards may take the form of design, equipment, work practice or operational standards where the EPA first determines either that: (A) A pollutant cannot be emitted through a conveyance designed and constructed to emit or capture the pollutants, or that any requirement for, or use of, such a conveyance would be inconsistent with law; or (B) the application of measurement methodology to a particular class of sources is not practicable due to technological and economic limitations (CAA sections 112(h)(1)-(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 emission control that is achieved in practice by the best-controlled similar source. The MACT floors for existing sources can be less stringent than floors for new sources, but they cannot be less stringent than the average emissions limitation achieved by the best-performing 12 percent of existing sources in the category or subcategory (or the best-performing five sources for categories or subcategories with fewer than 30 sources). In developing MACT standards, we must also consider control options that are more stringent than the floor. We may establish standards more stringent than the floor based on the consideration of the cost of achieving the emissions reductions, any nonair quality health and environmental impacts and energy requirements.

The EPA is then required to review these technology-based standards and to revise them “as necessary (taking into account developments in practices, processes, and control technologies)” no less frequently than every 8 years, under CAA section 112(d)(6). In conducting this review, the EPA is not obliged to completely recalculate the prior MACT determination and, in particular, is not obligated to recalculate the MACT floors.

NRDC

EPA,

529 F.3d 1077, 1084 (DC Cir., 2008).

The second stage in standard-setting focuses on reducing any remaining “residual” risk according to CAA section 112(f). This provision requires, first, 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 this report (

Residual Risk Report to Congress,

EPA-453/R-99-001) in March 1999. Congress did not act in response to the report, thereby triggering the EPA's obligation under CAA section 112(f)(2) to analyze and address residual risk.

Section 112(f)(2) of the CAA requires us to determine, for source categories subject to certain MACT standards, whether those emissions standards provide an ample margin of safety to protect public health. If the MACT standards apply to a source category emitting a HAP that is “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 (CAA section 112(f)(2)(A)). This requirement is procedural. It mandates that the EPA establish CAA section 112(f) residual risk standards if certain risk thresholds are not satisfied but does not determine the level of those standards.

NRDC

EPA,

529 F. 3d at 1083. The second sentence of CAA section 112(f)(2) sets out the substantive requirements for residual risk standards: Protection of public health with an ample margin of safety based on the EPA's interpretation of this standard in effect at the time of the CAA amendments.

Id.

This refers to the Benzene NESHAP, described in the next paragraph. The EPA may adopt residual risk standards equal to existing MACT standards (or to standards adopted after the technology review required by CAA section 112(d)(6)) if the EPA determines that the existing standards are sufficiently protective, even if (for example) excess cancer risks to a most exposed individual are not reduced to less than 1 in 1 million.

Id.

at 1083, (“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”). Section 112(f)(2) of the CAA further authorizes the EPA to adopt more stringent standards, if necessary, “to prevent, taking into consideration costs, energy, safety and other relevant factors, an adverse environmental effect.”

“Adverse environmental effect” is defined in CAA section 112(a)(7) 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.

As just noted, CAA section 112(f)(2) expressly preserves our use of the two-step process for developing standards to address any residual risk and our

interpretation of “ample margin of safety” developed in the

National Emission 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 first step in this process is the determination of acceptable risk. The second step provides for an ample margin of safety to protect public health, which is the level at which the standards are set (unless a more stringent standard is required to prevent, taking into consideration costs, energy, safety and other relevant factors, an adverse environmental effect).

The terms “individual most exposed,” “acceptable level,” and “ample margin of safety” are not specifically defined in the CAA. However, CAA section 112(f)(2)(B) preserves the EPA's interpretation set out in the Benzene NESHAP, and the Court in

NRDC

EPA

concluded that the EPA's interpretation of CAA section 112(f)(2) is a reasonable one. See

NRDC

EPA,

529 F.3d at 1083 (D. C. Cir. 2008), which says “[S]ubsection 112(f)(2)(B) expressly incorporates 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,

volume 1, p. 877 (Senate debate on Conference Report). We also notified Congress in the

Residual Risk Report to Congress

that we intended to use the Benzene NESHAP approach in making CAA section 112(f) residual risk determinations (EPA-453/R-99-001, p. ES-11).

In the Benzene NESHAP, we stated as an overall objective:

* * * in protecting public health with an ample margin of safety, we strive 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 facility would have if he or she were exposed to the maximum pollutant concentrations for 70 years.

The agency also stated that, “The 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.” The agency went on to conclude that “estimated incidence would be weighed along with other health risk information in judging acceptability.” As explained more fully in our

Residual Risk Report to Congress,

the EPA does not define “rigid line[s] of acceptability,” but rather considers broad objectives to be weighed with a series of other health measures and factors (EPA-453/R-99-001, p. ES-11). 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” (

Residual Risk Report to Congress,

p. 178, quoting the D.C. Circuit's en banc

Vinyl Chloride

decision at 824 F.2d 1165) 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 1 in 10 thousand, that risk level is considered acceptable.” 54 FR 38045. We discussed the maximum individual lifetime cancer risk 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 acknowledge 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 maximum individual lifetime cancer risk as a metric for determining acceptability, we acknowledged in the 1989 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.

Id.

Further, in the Benzene NESHAP, we noted that, “Particular 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 1989 Benzene NESHAP the following: “In establishing a presumption for MIR [maximum individual cancer risk], 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.

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 explained in the Benzene NESHAP, “[e]ven though the risks judged “acceptable” by the EPA in the first step of the

Vinyl Chloride

inquiry are already low, 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.”

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EPA,

529 F.3d 1077, 1082 (D.C. Cir. 2008), the Court of Appeals held that section 112(f)(2) “incorporates EPA's `interpretation' of the Clean Air Act from the Benzene Standard, and the text of this provision draws no distinction between carcinogens and non-carcinogens.” Additionally, the

Court held there is nothing on the face of the statute that limits the agency's section 112(f) assessment of risk to carcinogens.

Id.

at 1081-82. In the

NRDC

case, the petitioners argued, among other things, that section 112(f)(2)(B) applied only to non-carcinogens. The D.C. Circuit rejected this position, holding that the text of that provision “draws no distinction between carcinogens and non-carcinogens,” I

d.,

and that Congress' incorporation of the Benzene standard applies equally to carcinogens and non-carcinogens.

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. 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 CAA section 112(f). 54 FR 38046.

B. Does this action apply to me?

The regulated industrial source category that is the subject of this proposal is listed in Table 2 of this preamble. Table 2 of this preamble is not intended to be exhaustive, but rather provides a guide for readers regarding the entities likely to be affected by this proposed action. This standard, and any changes considered in this rulemaking, would be directly applicable to affected sources. Federal, state, local and tribal government entities are not affected by this proposed action. As defined in the Source Category Listing Report published by the EPA in 1992, the pulp and paper production source category includes any facility engaged in the production of pulp and/or paper. This category includes, but is not limited to, integrated mills (where pulp and paper or paperboard are manufactured on-site), non-integrated mills (where either pulp or paper/paperboard are manufactured on-site, but not both), and secondary fiber mills (where waste paper is used as the primary raw material). Examples of pulping methods include kraft, soda, sulfite, semi-chemical and mechanical.

Table 2—NESHAP and Industrial Source Categories Affected By This Proposed Action

Source category

NESHAP

NAICS code

MACT code

Pulp and Paper

322

1626-1

North American Industry Classification System.

Maximum Achievable Control Technology.

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

In addition to being available in the docket, an electronic copy of this proposal will also be available on the WWW through the EPA's TNN. Following signature by the EPA Administrator, a copy of this proposed action will be posted on the TTN's policy and guidance page for newly proposed or promulgated rules at the following address:

http://www.epa.gov/ttn/atw/rrisk/rtrpg.html.

The TTN provides information and technology exchange in various areas of air pollution control.

Additional information is available on the RTR Web page at

http://www.epa.gov/ttn/atw/rrisk/rtrpg.html.

This information includes source category descriptions and detailed emissions estimates and other data that were used as inputs to the risk assessments.

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

Submitting CBI.

Do not submit information containing CBI to the EPA through

http://www.regulations.gov

or email. Clearly mark the part or all of the information that you claim to be CBI. For CBI information on a disk or CD ROM that you mail to the EPA, mark the outside of the disk or CD ROM as CBI and then identify electronically within the disk or CD ROM the specific information that is claimed as CBI. In addition to one complete version of the comment that includes information claimed as CBI, a copy of the comment that does not contain the information claimed as CBI must be submitted for inclusion in the public docket. If you submit a CD ROM or disk that does not contain CBI, mark the outside of the disk or CD ROM clearly that it does not contain CBI. Information not marked as CBI will be included in the public docket and the EPA's electronic public docket without prior notice. Information marked as CBI will not be disclosed except in accordance with procedures set forth in 40 CFR part 2. Send or deliver information identified as CBI only to the following address: Roberto Morales, OAQPS Document Control Officer (C404-02), Office of Air Quality Planning and Standards, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, Attention Docket ID Number EPA-HQ-OAR-2007-0544.

II. Background

A. What is this source category and how did the MACT standard regulate its HAP emissions?

The pulp and paper production source category includes any facility engaged in the production of pulp and/or paper. This category includes, but is not limited to, integrated mills (where pulp and paper or paperboard are manufactured on-site), non-integrated mills (where paper/paperboard or pulp are manufactured, but not both), and secondary fiber mills (where waste paper is used as the primary raw material). The pulp and paper production process includes operations such as pulping, bleaching, chemical recovery and papermaking. Different pulping processes are used, including chemical processes (kraft, soda, sulfite and semi-chemical) and mechanical, secondary fiber or non-wood processes.

The NESHAP from the pulp and paper Industry (or MACT rule) was promulgated on April 15, 1998 (63 FR 18504) and codified at 40 CFR part 63, subpart S. As promulgated in 1998, the subpart S MACT standard applies to major sources of HAP emissions from the pulp production areas (

e.g.,

pulping system vents, pulping process condensates) at chemical, mechanical, secondary fiber and non-wood pulp mills; bleaching operations; and papermaking systems. A separate NESHAP (40 CFR part 63, subpart MM) applicable to chemical recovery processes at kraft, soda, sulfite and stand-alone semi-chemical pulp mills was promulgated on January 12, 2001 (66 FR 3180). However, only subpart S is undergoing the RTR that is the subject of this proposal.

This is the first in a series of rules being developed for the pulp and paper

industrial sector. This proposal includes both a risk assessment and a technology review of the emission sources in subpart S, as well as a risk assessment of the whole facility. The whole facility risk assessment includes emissions from the other sources in the pulp and paper industrial sector: boilers covered under subpart DDDDD, chemical recovery systems covered under subpart MM, various sources covered under the NSPS for kraft pulp mills (40 CFR part 60, subpart BB), and other applicable MACT emission sources. In the future, we will also conduct a RTR for the subpart MM category, as well as a review of the kraft pulp mills NSPS, subpart BB. When we conduct the RTR for the subpart MM rule, subpart S emission sources will be included in the facilitywide risk assessment.

According to results of the EPA's 2011 pulp and paper ICR, there are a total of 171 major sources in the United States including:

• 111 major sources that carry out chemical wood pulping (kraft, sulfite, soda or semi-chemical);

• 33 major sources that carry out mechanical, groundwood, secondary fiber and non-wood pulping (without chemical wood pulping);

• 94 major sources that perform bleaching; and

• 156 major sources that manufacture paper or paperboard products.

Facilities in the category perform at least one of several pulp and papermaking operations (

e.g.,

chemical pulping, bleaching and papermaking; pulping and unbleached papermaking;

etc.

Subpart S includes numerical emission limits for pulping system vents, pulping process condensates and bleaching system vents. The control systems used by most mills to meet the subpart S emission limits are as follows:

• Pulping system vents—thermal oxidizers, power boilers, lime kilns and recovery furnaces.

• Pulping process condensates—steam strippers, biological treatment and recycling to pulping equipment that is controlled by the pulping vent standards.

• Bleaching system vents—caustic scrubbers (for chlorinated HAPs, other than chloroform) and process modifications to eliminate the use of chlorine and hypochlorite.

Facilities that only purchase pre-consumer paper or paperboard stock products and convert them into other products (

i.e.,

converting operations) are not part of the subpart S source category and are not affected by today's action.

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

In February 2011, the EPA issued an ICR, pursuant to CAA section 114, to United States pulp and paper manufacturers to gather information needed to conduct the regulatory reviews required under CAA sections 112(d)(6) and (f)(2). The ICR was divided into three parts, with each part due on a different date. Part I requested available information regarding subpart S process equipment, control devices, pulp and paper production, bleaching and other aspects of facility operations, to support the subpart S technology review and a later review of the kraft pulp mills NSPS under 40 CFR part 60, subpart BB. Part II requested updated inventory data for all pulp and paper emission sources, to support the residual risk assessment for the pulp and paper sector (including subparts S and MM) and to both supplement and update the NEI for the source category. Part III requested available information on subpart MM chemical recovery combustion equipment, control devices,

etc.,

to support a later subpart MM technology review (which will include a source category and a facilitywide risk assessment) and a subpart BB NSPS review. Responses to all three parts of the ICR have been received and data from the first two parts of the ICR have been compiled. The response rate for the subpart S ICR was 100 percent.

Part II of the ICR will be available for download on the RTR Web page at:

http://www.epa.gov/ttn/atw/rrisk/rtrpg.html.

III. Analyses Performed

In this section, we describe the analyses performed to support the proposed decisions for the RTR for this source category.

A. How did we estimate risks posed by the source category?

The EPA conducted risk assessments that provided estimates of (1) the MIR posed by the HAP emissions from the 171 pulp and paper mills in the source category, (2) the distribution of cancer and noncancer risks within the exposed populations, (3) the total cancer incidence, (4) estimates of the maximum TOSHI for chronic exposures to HAP with the potential to cause chronic noncancer health effects, (5) worst-case screening estimates of HQ for acute exposures to HAP with the potential to cause noncancer health effects, and (6) an evaluation of the potential for adverse environmental effects. The risk assessments consisted of seven primary steps, as discussed below.

The methods used to assess risks (as described in the seven primary steps below) are consistent with those peer-reviewed by a panel of the EPA's SAB in 2009 and described in their peer review report issued in 2010; they are also consistent with the key recommendations contained in that report.

The docket for this rulemaking contains the following document which provides more information on the risk assessment inputs and models:

Draft Residual Risk Assessment for Pulp and Paper Source Category.

A27DE2.

1. Establishing the Nature and Magnitude of Actual Emissions and Identifying the Emissions Release Characteristics

As discussed in section II.B of this preamble, we used data from Part II of the pulp and paper ICR as the basis for the risk assessment. Part II of the ICR, which concluded in June 2011, targeted facilities that are major sources of HAP emissions and involved an update of pre-populated NEI data spreadsheets (or creation of new NEI datasets). The NEI is a database that contains information about sources that emit criteria air pollutants, their precursors and HAP. The NEI database includes estimates of actual annual air pollutant emissions from point and volume sources; emission release characteristic data such as emission release height, temperature, diameter, velocity and flow rate; and location latitude/longitude coordinates.

The actual annual emissions data in the NEI database were based on data from actual emissions tests and estimates of actual emissions (based on emission factors) provided by subpart S sources surveyed in Part II of the ICR. We received a comprehensive set of emissions test data and emissions estimates that enabled us to conduct risk modeling of detectable HAP emissions for all major source facilities in the pulp and paper category.

Two substantial QA efforts were conducted on the Part II data in order to create the modeling files needed for the residual risk assessment, which included: (1) QA of the updated inventory spreadsheets submitted by each mill prior to import into the compiled database; and (2) QA and standardization of the compiled database.

We reviewed the NEI datasets to ensure that the major pulp and paper processes and pollutants were included and properly identified, to ensure that emissions from the various processes were allocated to the correct source category (

e.g.,

MACT code 1626-1), and to identify emissions and other data anomalies that could affect risk

estimates. We also standardized the various codes (

e.g.,

SCCs, pollutant codes), eliminated duplicate records and checked geographic coordinates. We reviewed emissions release parameters for data gaps and errors, assigned the proper default parameters where necessary, segregated the emission points into logical emission process groups and ensured that fugitive release dimensions were specified or given default values where necessary. We made changes based on available information, including updated information voluntarily submitted by pulp and paper mills.

For more information, see the memorandum in the docket titled,

Inputs to the Pulp and Paper Industry October 2011 Residual Risk Modeling.

We assigned emissions process groups to distinguish between processes with related SCCs. For mills with VOC emissions data but no HAP emissions data, we developed HAP-to-VOC ratios to estimate HAP emissions, using HAP and VOC emission factors provided by NCASI.

However, as noted above, most emissions factors were based on actual tests or actual tests conducted at similar sources (see NCASI Technical Bulletin No. 973).

Additionally, the largest HAP emission compound in the category, methanol, at approximately 86 percent of the HAP in the category, is required to be quantified in each compliance test referenced in the standard. Consequently, the greatest proportion of HAP emissions at each facility are based on emission factors derived from actual source specific tests.

Ibid.

A. Someshwar, NCASI. Compilation of “Air Toxic” and Total Hydrocarbon Emissions Data for Pulp and Paper Mill Sources—A Second Update. Technical Bulletin No. 973. February 2010.

For purposes of risk modeling, we reviewed emissions data for chromium, mercury, POM and glycol ether in order to properly speciate emissions. Chromium emissions were speciated as hexavalent chromium (chromium VI) and trivalent chromium (chromium III).

Mercury emissions were speciated as particulate divalent mercury, gaseous divalent mercury and elemental gaseous mercury.

Total POM emissions were speciated differently for each emission unit type (

e.g.,

gas- or oil-fired paper machine dryers) based on the most common POM compounds emitted from that unit (

e.g.,

phenanthrene, fluorene, pyrene, fluoranthene and/or 2-methylnaphthalene). We speciated all total glycol ether records as 1,2-dimethoxyethane, since this pollutant represents 99 percent of all emissions reported under the glycol ether compounds category from pulp and paper emission sources.

Acrolein emissions were removed from the subpart S modeling file due to uncertainty in the emissions estimates.

For more information, see the memorandum in the docket titled,

Inputs to the Pulp and Paper Industry October 2011 Residual Risk Modeling.

Ibid.

In addition, we reviewed facilitywide data included in the NEI dataset from the EPA's TRI to ensure that combustion-related dioxin/furan emissions were apportioned to the proper MACT code (0107 or 1626-2). As expected, there were no dioxin/furan emissions data for subpart S sources (MACT code 1626-1).

Ibid.

A27DE2.

The Part II NEI emissions dataset for the pulp and paper (subpart S) source category shows 45,000 tpy of total HAP emissions from the 171 mills in the dataset. Methanol, acetaldehyde, cresol/cresylic acid (mixed isomers), phenol, chloroform, formaldehyde, hydrochloric acid, biphenyl, hexachloroethane, xylenes, propionaldehyde and 1,2,4-trichlorobenzene account for the majority of the HAP emissions reported for pulp and paper production (approximately 43,900 tpy, or 97 percent). The remaining 3 percent of the HAP, reported in lesser quantities, include acetophenone, benzene, cumene, carbon disulfide, chlorine, methyl isobutyl ketone, methylene chloride (dichloromethane), naphthalene, styrene, tetrachloroethylene (perchloroethylene), toluene, trichloroethylene and 56 others. Methanol, which accounts for about 86 percent of the total HAP mass emissions, is the HAP emitted by the largest number of facilities, with methanol reported for 166 out of 171 mills in the dataset (or 97 percent). Emissions of the following PB-HAP were identified in the emissions inventory for the pulp and paper (subpart S) source category: cadmium compounds, lead compounds, mercury compounds and POM. As a standard practice in conducting risk assessments for source categories, the EPA conducts a two-step process: (1) Are PB-HAPs being emitted; and (2) are they being released above screening thresholds? If these releases are significantly above the screening thresholds and the EPA has detailed information on the releases and the site, a complete multipathway analysis of the site will be conducted to estimate pathway risks for the source category. Further information about the analysis performed for this category follows in section III.B.4 of this preamble.

2. Establishing the Relationship Between Actual Emissions and MACT-Allowable Emissions Levels

The available emissions data in the Part II NEI emissions dataset include estimates of the mass of HAP actually emitted during the 2009 time period covered under the survey. These “actual” emissions levels are often lower than the emissions levels that a facility might be allowed to emit and still comply with the MACT standards. The emissions levels allowed to be emitted by the MACT standards are referred to as the “MACT-allowable” emissions levels. These represent the highest emissions levels that could be emitted by the facility without violating the MACT standards.

We discussed the use of both MACT-allowable and actual emissions in the final Coke Oven Batteries residual risk rule (70 FR 19998-19999, April 15, 2005) and in the proposed and final HON residual risk rules (71 FR 34428, June 14, 2006, and 71 FR 76609, December 21, 2006, respectively). In those previous actions, we noted that assessing the risks at the MACT-allowable level is inherently reasonable since these risks reflect the maximum level at which sources could emit while still complying with the MACT standards. However, 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 (54 FR 38044, September 14, 1989). It is reasonable to consider actual emissions because sources typically seek to perform better than required by emissions standards to provide an operational cushion to accommodate the variability in manufacturing processes and control device performance. Facilities' actual emissions may also be significantly lower than MACT-allowable emissions for other reasons such as state requirements, better performance of control devices than required by the MACT standards or reduced production.

As described earlier in this section, actual emissions were based on the Part II NEI emissions dataset. To estimate emissions at the MACT-allowable level, we developed a ratio of MACT-allowable to actual emissions for each source type for the facilities in the source category. This ratio is based on the level of control required by the subpart S MACT standards compared to the level of reported actual emissions and available information from the Part I survey on the level of control achieved by the emissions controls in use. For example, if survey data indicated that

an emission point type was being controlled by 92 percent, while the MACT standard required only 87 percent control, we would estimate that MACT-allowable emissions from that emission point type could be as much as 1.6 times higher (13 percent allowable emissions compared with 8 percent actually emitted), and the ratio of MACT-allowable to actual would be 1.6:1 for this emission point type.

Ibid.

After developing these ratios for each emission point type in this source category, we next applied these ratios on an emission process unit basis to the Part II actual emissions data to obtain risk estimates based on MACT-allowable emissions.

Ibid.

3. Conducting Dispersion Modeling, Determining Inhalation Exposures and Estimating Individual and Population Inhalation Risks

Both long-term and short-term inhalation exposure concentrations and health risks from the source category addressed in this proposal were estimated using the HEM-3 human exposure model. The HEM-3 performs three of the primary risk assessment activities listed above: (1) Conducting dispersion modeling to estimate the concentrations of HAP in ambient air, (2) estimating long-term and short-term inhalation exposures to individuals residing within 50 km of the modeled sources, and (3) estimating individual and population-level inhalation risks using the exposure estimates and quantitative dose-response information.

The dispersion model used by HEM-3 is AERMOD, which is one of the EPA's preferred models for assessing pollutant concentrations from industrial facilities.

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 of hourly surface and upper air observations for 130 meteorological stations, selected to provide coverage of the United States and Puerto Rico. A second library of United States Census Bureau census block

internal point locations and populations provides the basis of human exposure calculations based on the year 2000 U.S. Census. In addition, for each census block, the census library includes the elevation and controlling hill height which are also used in dispersion calculations. A third library of pollutant unit risk factors and other health benchmarks is used to estimate health risks. These risk factors and health benchmarks are the latest values recommended by the EPA for HAP and other toxic air pollutants. These values are available at

http://www.epa.gov/ttn/atw/toxsource/summary.html

and are discussed in more detail later in this section.

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).

A census block is generally 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 concentration of each of the 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 primarily used as a surrogate for the chronic inhalation exposure concentration for all the people who reside in that census block. There were two exceptions to this. In those cases where we identified census block centroids which were located on-site, these centroids were re-assigned to a nearby residential location. In those cases where nearby census blocks were abnormally large, additional residential receptors were placed within those census blocks at observable residences to ensure an adequate representation of chronic risks to the nearby residences. 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 an inhabited census block. 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) by its URE, which is an upper bound estimate of an individual's probability of contracting cancer over a lifetime of exposure to a concentration of 1 microgram of the pollutant per cubic meter of air. In general, for residual risk assessments, we use URE values from the EPA's IRIS.

For carcinogenic pollutants without the EPA IRIS values, we look to other reputable sources of cancer dose-response values, often using CalEPA URE values, where available. In cases where new, scientifically credible dose-response values have been developed in a manner consistent with 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.

The IRIS information is available at

http://www.epa.gov/IRIS

In 2004, the EPA determined that the CIIT cancer dose-response value for formaldehyde (5.5 × 10

−9

per μg/m

) was based on better science than the IRIS dose-response value (1.3 × 10

−5

per μg/m

), and we switched from using the IRIS value to the CIIT value in risk assessments supporting regulatory actions. Based on subsequent published research, however, the EPA changed its determination regarding the CIIT model, and, in 2010, the EPA returned to using the 1991 IRIS value. The NAS completed its review of the EPA's draft assessment in April of 2011 (

http://www.nap.edu/catalog.php?record id=13142

), and the EPA has been working on revising the formaldehyde assessment. The EPA will follow the NAS Report recommendations and will present results obtained by implementing the BBDR model for formaldehyde. The EPA will compare these estimates with those currently presented in the External Review draft of the assessment and will discuss their strengths and weaknesses. As recommended by the NAS committee, appropriate sensitivity and uncertainty analyses will be an integral component of implementing the BBDR model. The draft IRIS assessment will be revised in response to the NAS peer review and public comments and the final assessment will be posted on the IRIS database. In the interim, we will present findings using the 1991 IRIS value as a primary estimate and may also consider other information as the science evolves.

We note here that POM, a carcinogenic HAP with a mutagenic mode of action, is emitted by some of the facilities in this category.

For this compound,

the ADAF described in the EPA's

Supplemental Guidance for Assessing Susceptibility from Early-Life Exposure to Carcinogens

were applied. This adjustment has the effect of increasing the estimated lifetime risks for this pollutant by a factor of 1.6. In addition, although only a small fraction

of the total POM emissions were not reported 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 does benzo[a]pyrene. For this reason, the EPA's Science Policy Council

recommends applying the

Supplemental Guidance

to all carcinogenic polycyclic aromatic hydrocarbons 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.

U.S. EPA, 2006. 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 June 14, 2006.

See the

Risk Assessment for Source Categories

document available in the docket for a list of HAP with a mutagenic mode of action.

U.S. EPA, 2005.

Supplemental Guidance for Assessing Early-Life Exposure to Carcinogens.

EPA/630/R-03/003F.

http://www.epa.gov/ttn/atw/childrens_supplement_final.pdf

U.S. EPA, 2006.

Science Policy Council Cancer Guidelines Implementation Workgroup Communication II:

Memo from W.H. Farland, dated June 14, 2006.

Incremental individual lifetime cancer risks associated with emissions from the source category were estimated as the sum of the risks for each of the carcinogenic HAP (including those classified as carcinogenic to humans, likely to be carcinogenic to humans and suggestive evidence of carcinogenic potential

) emitted by the modeled source. Cancer incidence and the distribution of individual cancer risks for the population within 50 km of the source were also estimated for the source category as part of these assessments by summing individual risks. A distance of 50 km is consistent with both the analysis supporting the 1989 Benzene NESHAP (54 FR 38044) and the limitations of Gaussian dispersion models, including AERMOD.

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 EPA's 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 risk of noncancer 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 TOSHI). The HQ is the estimated exposure divided by the chronic reference value, which is either the EPA RfC, defined as “an estimate (with uncertainty spanning perhaps an order of magnitude) of a continuous inhalation exposure to the human population (including sensitive subgroups) that is likely to be without an appreciable risk of deleterious effects during a lifetime,” or, in cases where a RfC is not available, the ATSDR chronic MRL or the CalEPA Chronic REL. The REL is defined as “the concentration level at or below which no adverse health effects are anticipated for a specified exposure duration.” As noted above, in cases where new, scientifically credible dose-response values have been developed in a manner consistent with EPA guidelines and have undergone a peer review process similar to that used by the EPA, we may use those dose-response values in place of or, in addition to, other values.

Worst-case screening estimates of acute exposures and risks were also evaluated for each of the HAP at the point of highest offsite exposure for each facility (

i.e.,

not just the census block centroids) assuming that a person was located at this spot at a time when both the peak (hourly) emission rate and hourly dispersion conditions occurred. In general, acute HQ values were calculated using best available, short-term dose-response value. These acute dose-response values include REL, AEGL and ERPG for 1-hour exposure durations. As discussed below, we used conservative assumptions for emission rates, meteorology and exposure location for our acute analysis.

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.” Reference exposure level values are based on the most sensitive, relevant, adverse health effect reported in the medical and toxicological literature. Reference exposure level values are designed to protect the most sensitive individuals in the population by the inclusion of margins of safety. Since margins of safety are incorporated to address data gaps and uncertainties, exceeding the REL does not automatically indicate an adverse health impact.

Acute Exposure Guideline Levels were derived in response to recommendations from the 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/opptintr/aegl/pubs/sop.pdf

“the NRC's previous name for acute exposure levels—CEEL—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.” 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 8 hours.” The document lays out the purpose and objectives of AEGL by stating (page 21) that “the primary purpose of the AEGL program and the NAC/AEGL Committee is to develop guideline levels for once-in-a-lifetime, short-term exposures to airborne concentrations of acutely toxic, high-priority chemicals.” In detailing the intended application of AEGL values, the document states (page 31) that “[i]t is anticipated that the AEGL values will be used for regulatory and nonregulatory purposes by United States 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.”

NAS, 2001.

Standing Operating Procedures for Developing Acute Exposure Levels for Hazardous Chemicals,

page 2.

The AEGL-1 value is then specifically defined as “the airborne concentration of a substance above which it is predicted that the general population, including susceptible individuals, could experience notable discomfort, irritation, or certain asymptomatic nonsensory effects. However, the effects are not disabling and are transient and reversible upon cessation of exposure.” The document also notes (page 3) 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, nonsensory effects.” Similarly, the document defines AEGL-2 values as “the airborne concentration (expressed as ppm or mg/m

) 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.”

Emergency Response Planning Guidelines values are derived for use in emergency response, as described in the American Industrial Hygiene

Association's document titled,

Emergency Response Planning Guidelines (ERPG) Procedures and Responsibilities

(

http://www.aiha.org/1documents/committees/ERPSOPs2006.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.”

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.” 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 1 hour without experiencing or developing irreversible or other serious health effects or symptoms which could impair an individual's ability to take protective action.”

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; in these instances, higher severity level AEGL-2 or ERPG-2 values are compared to our modeled exposure levels to screen for potential acute concerns.

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 threshold (usually the AEGL-1 and/or the ERPG-1 value).

To develop screening estimates of acute exposures, we first developed estimates of maximum hourly emission rates by multiplying the average actual annual hourly emission rates by a factor to cover routinely variable emissions. An acute multiplication factor of 1.6 was used for papermaking equipment (

e.g.,

paper machines, stock preparation, repulping) based on a paper machine peak-to-mean analysis. Similarly, a peak-to-mean multiplier of 2 was used for pulp and paper wastewater treatment units based on analysis of data from pulp and paper primary clarifiers and aerated stabilization basins. Peak-to-mean multipliers ranging from 1 to 3.1 were developed for other types of pulp and paper equipment based on the routine annual emissions data and peak hourly emissions data obtained from Part II survey data.

More information supporting the use of these factors for Pulp and Paper production is presented in the memorandum,

Inputs to the Pulp and Paper Industry October 2011 Residual Risk Modeling,

which is available in the docket for this action.

In cases where all acute HQ values from the screening step were less than or equal to 1, acute impacts were deemed negligible and no further analysis was performed. In the cases where an acute HQ from the screening step was greater than 1, additional site-specific data were considered to develop a more refined estimate of the potential for acute impacts of concern. The data refinements included using site-specific facility layouts, as available, to distinguish facility property from an area where the public could access and be exposed. These refinements are discussed in the draft risk assessment documents, which are available in the docket for this source category. 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 emission 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. However, we recognize that having this level of data is rare, and hence our use of the multiplier approach.

4. Multipathway Exposure and Risk Screening

The potential for significant human health risks due to exposures via routes other than inhalation (

i.e.,

multipathway exposures) and the potential for adverse environmental impacts were evaluated in a three-step process. In the first step, we determined whether any facilities emitted any HAP known to be persistent and bio-accumulative in the environment (PB-HAP). There are 14 PB-HAP compounds or compound classes identified for this screening in the EPA's

Air Toxics Risk Assessment Library

(available at

http://www.epa.gov/ttn/fera/risk_atra_vol1.html

). They are cadmium compounds, chlordane, chlorinated dibenzodioxins and furans, dichlorodiphenyldichloroethylene, heptachlor, hexachlorobenzene, hexachlorocyclohexane, lead compounds, mercury compounds, methoxychlor, polychlorinated biphenyls, POM, toxaphene and trifluralin. Emissions of four different PB-HAP were identified in the Part II NEI emissions dataset for the pulp and paper (subpart S) source category: cadmium compounds, lead compounds, mercury compounds and POM. These four compounds plus chlorinated dibenzodioxins and furans were identified in the NEI dataset for the entire mill, which includes sources inside and outside the subpart S category (

e.g.,

boilers, chemical recovery combustion sources). In the second step of the screening process, we determined whether the facility-specific emission rates of each of the emitted PB-HAP were large enough to create the potential for significant non-inhalation human health or environmental risks. To facilitate this step, we have developed emission rate thresholds for each PB-HAP using a hypothetical screening exposure scenario developed for use in conjunction with the TRIM.FaTE model. The hypothetical screening scenario was subjected to a sensitivity analysis to ensure that its key design parameters were established such that environmental media concentrations were not underestimated (

i.e.,

to minimize the occurrence of false negatives or results that suggest that risks might be acceptable when, in fact, actual risks are high), and to also minimize the occurrence of false positives for human health endpoints. We call this application of the TRIM.FaTE model TRIM-Screen. The facility specific emission rates of each of the PB-HAP in each source category were compared to the emission threshold values for each of the PB-HAP identified in the source category datasets.

For all of the facilities in the source category addressed in this proposal, all of the PB-HAP emission rates were less than the emission threshold values, except for one facility with POM emissions as benzo(a)pyrene that exceeded the screening emission rate by a factor of 2. For POM, exceeding the screening emission rate relates to a potential for creating a cancer risk in excess of 1 in a million. In performing the screening for potential multipathway exposures and risks of

concern, we determined that emissions of POM were not significant enough to pose multipathway impacts of concern for human health or the environment. If the emission rates of the PB-HAP had been determined to be significant, the source category would have been further evaluated for potential non-inhalation risks and adverse environmental effects in a third step through site-specific refined assessments using the EPA's TRIM.FaTE model.

For further information on the multipathway analysis approach, see the residual risk documentation as referenced in section IV.A of this preamble.

5. Assessing Risks Considering Emissions Control Options

This rulemaking does not require the installation of any new emission controls to reduce risk; therefore, no risk modeling was conducted to estimate risk reductions following installation of emission controls for this proposal.

6. Conducting Facilitywide Risk Assessments

To put the source category risks in context, we also 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. Nearly all 171 major sources in the subpart S category include boilers, and 111 of the 171 major sources include chemical recovery combustion sources (

e.g.,

recovery furnace, smelt dissolving tank, lime kiln). Pulp and paper mills also include paper coating, landfills, petroleum storage and transfer and other operations. Therefore, where data were available, we performed a facilitywide risk assessment for these major sources as part of today's action.

We estimated the risks due to the inhalation of HAP that are emitted “facilitywide” for the populations residing within 50 km of each facility, consistent with the methods used for the source category analysis described above. For these facilitywide risk analyses, the modeled source category risks were compared to the facilitywide risks to determine the portion of facilitywide risks that could be attributed to the source categories addressed in this proposal. We specifically examined the facilities associated with the highest estimates of risk and determined the percentage of that risk attributable to the source category of interest. The risk documentation available through the docket for this action provides all the facilitywide risks and the percentage of source category contribution for all source categories assessed.

The methodology and the results of the facilitywide analyses for each source category are included in the residual risk documentation as referenced in section IV.A of this preamble, which is available in the docket for this action.

7. Considering Uncertainties in Risk Assessment

Uncertainty and the potential for bias are inherent in all risk assessments, including that performed for the source category addressed in this proposal. Although uncertainty exists, we believe the approach that we took, which used conservative tools and assumptions to bridge data gaps, ensures that our decisions are health-protective. A brief discussion of the uncertainties in the emissions dataset, dispersion modeling, inhalation exposure estimates and dose-response relationships follows below.

A more thorough discussion of these uncertainties is included in the risk assessment documentation (

Draft Residual Risk Assessment for the Pulp and Paper Category

) available in the docket for this action.

a. Uncertainties in the Emissions Dataset

Although the development of the RTR dataset involved QA/QC processes, the accuracy of emissions values will vary depending on: (1) The source of the data, (2) the degree to which data are incomplete or missing, (3) the degree to which assumptions made to complete the datasets are accurate, (4) whether and to what extent errors were made in estimating emissions values, (5) whether the emissions were based on or extrapolated from stack tests or estimates of fugitive emissions, and (6) miscellaneous other factors.

The annual HAP emissions estimates used in the risk assessment are derived from data provided by mills in response to the Part II survey. Many of these emissions estimates are based on emission factors, developed from the most comprehensive dataset available for this industry, provided by NCASI. The uncertainties associated with emission factors include the uncertainties in the measurement of the data, limitations in the size and quality of the dataset, the presence of non-detects and outliers in the dataset, the emission factor calculations used,

etc.

As noted in section III.A.1 of this preamble, acrolein emissions were not modeled due to uncertainties in the emissions estimates.

For more information, see the memorandum in the docket titled,

Inputs to the Pulp and Paper Industry October 2011 Residual Risk Modeling.

b. Uncertainties in Dispersion Modeling

Although the analysis employed the EPA's recommended regulatory dispersion model, AERMOD, we recognize that there is uncertainty in ambient concentration estimates associated with any model, including AERMOD. In circumstances where we had to choose between various model options, where possible, we selected model options (

e.g.,

rural/urban, plume depletion, chemistry) that provided an overestimate of ambient concentrations of the HAP rather than an underestimate. However, because of practicality and data limitation reasons, some factors (

e.g.,

building downwash) have the potential in some situations to overestimate or underestimate ambient impacts. Despite these uncertainties, we believe that at offsite locations and census block centroids, the approach considered in the dispersion modeling analysis should generally yield overestimates of ambient HAP concentrations.

c. Uncertainties in Inhalation Exposure

The effects of human mobility on exposures were not included in the assessment. Specifically, short-term mobility and long-term mobility between census blocks in the modeling domain were not considered.

The assumption of not considering short- or long-term population mobility does not bias the estimate of the theoretical MIR, nor does it affect the estimate of cancer incidence since 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 risk levels.

Short-term mobility is movement from one microenvironment 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 for any one individual but is an unbiased estimate of average risk and incidence.

The assessments evaluate the projected cancer inhalation risks associated with pollutant exposures over a 70-year period, which is the assumed lifetime of an individual. In reality, both the length of time that modeled emissions sources at facilities actually operate (

i.e.,

more or less than 70 years), and the domestic growth or decline of the modeled industry (

i.e.,

the increase or decrease in the number or size of United States facilities), will influence the future risks posed by a given source or source category. Depending on the characteristics of the industry, these factors will, in most cases, result in an overestimate both in individual risk levels and in the total estimated number of cancer cases. However, in rare cases, where a facility maintains or increases its emissions levels beyond 70 years, residents live beyond 70 years at the same location and the residents spend most of their days at that location, then the risks could potentially be underestimated. Annual cancer incidence estimates from exposures to emissions from these sources would not be affected by uncertainty in the length of time emissions sources operate.

The exposure estimates used in these analyses assume chronic exposures to ambient levels of pollutants. Because most people spend the majority of their time indoors, actual exposures may not be as high, depending on the characteristics of the pollutants modeled. For many of the HAP, indoor levels are roughly equivalent to ambient levels, but for very reactive pollutants or larger particles, these levels are typically lower. This factor has the potential to result in an overstatement of 25 to 30 percent of exposures for some HAP.

U.S. EPA.

National-Scale Air Toxics Assessment for 1996.

EPA 453/R-01-003; January 2001; page 85.

In addition to the uncertainties highlighted above, there are several factors specific to the acute exposure assessment that should be highlighted. The accuracy of an acute inhalation exposure assessment depends on the simultaneous occurrence of independent factors that may vary greatly, such as hourly emissions rates, meteorology and human activity patterns. In this assessment, we assume that individuals remain for 1 hour at the point of maximum ambient concentration as determined by the co-occurrence of peak emissions and worst-case meteorological conditions. These assumptions would tend to be worst-case actual exposures since it is unlikely that a person would be located at the point of maximum exposure during the time of worst-case impact.

d. Uncertainties in Dose-Response Relationships

There are uncertainties inherent in the development of the dose-response values used in our risk assessments for cancer effects from chronic exposures and noncancer effects from both chronic and acute exposures. Some uncertainties may be considered quantitatively, and others generally are expressed in qualitative terms. We note as a preface to this discussion a point on dose-response uncertainty that is brought out in the EPA's

2005 Cancer Guidelines;

namely, that “the primary goal of EPA actions is protection of human health; accordingly, as an agency policy, risk assessment procedures, including default options that are used in the absence of scientific data to the contrary, should be health protective” (

EPA 2005 Cancer Guidelines,

pages 1-7). This is the approach followed here as summarized in the next several paragraphs. A complete detailed discussion of uncertainties and variability in dose-response relationships is given in the residual risk documentation which is available in the docket for this action.

Cancer URE values used in our risk assessments are those that have been developed to generally provide an upper bound estimate of risk. That is, they represent a “plausible upper limit to the true value of a quantity” (although this is usually not a true statistical confidence limit).

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 limitations for other uses (

e.g.,

priority-setting or expected benefits analysis).

IRIS glossary (

http://www.epa.gov/NCEA/iris/help_gloss.htm

An exception to this is the URE for benzene, which is considered to cover a range of values, each end of which is considered to be equally plausible and which is based on maximum likelihood estimates.

Chronic noncancer reference (RfC and 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 UF approach (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,

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. 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. Uncertainty factors 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).

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.

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 peer-reviewed reference values for cancer and noncancer effects for all pollutants emitted by the sources included in this assessment, some HAP continue to have no reference values for cancer or chronic noncancer or acute effects. Since exposures to these pollutants cannot be included in a quantitative risk estimate, an understatement of risk for these pollutants at environmental exposure levels is possible. For a group of compounds that are either unspeciated or do not have reference values for every individual compound (

e.g.,

glycol ethers), we conservatively use the most protective reference value to estimate risk from individual compounds in the group of compounds.

Additionally, chronic reference values for several of the compounds included in this assessment are currently under the EPA IRIS review (

e.g.,

formaldehyde), and revised assessments may determine that these pollutants are more or less potent than the current value. We may re-evaluate residual risks for the final rulemaking if these reviews are completed prior to our taking final action for this source category and if a dose-response metric changes enough to indicate that the risk assessment supporting this notice may significantly understate human health risk.

e. Uncertainties in the Multipathway and Environmental Effects Screening

We generally assume that when exposure levels are not anticipated to adversely affect human health, they also are not anticipated to adversely affect the environment. For each source category, we generally rely on the site-specific levels of PB-HAP emissions to determine whether a full assessment of the multipathway and environmental effects is necessary. Our screening methods use worst-case scenarios to determine whether multipathway impacts might be important. The results of such a process are biased high for the purpose of screening out potential impacts. Thus, when individual pollutants or facilities screen out, we are confident that the potential for multipathway impacts is negligible. On the other hand, when individual pollutants or facilities do not screen out, it does not mean that multipollutant impacts are significant, only that we cannot rule out that possibility. The site-specific PB-HAP emission levels were almost all far below levels which would trigger a refined assessment of multipathway impacts. The only PB-HAP to exceed the screening threshold was POM with emissions exceeding the screening threshold by a factor of 2. Thus, we are confident that these types of impacts are insignificant for the facilities in this source category.

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

As discussed in the previous section of this preamble, we apply a two-step process for determining whether to develop standards 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 level on maximum individual lifetime [cancer] risk (MIR)

of approximately one in 10 thousand [

i.e.,

100 in 1 million].” 54 FR 38045. In the second step of the process, the EPA determines what level of the standard is needed to provide an ample margin of safety “in consideration of all health information, including the number of persons at risk levels higher than approximately one in one million, as well as other relevant factors, including costs and economic impacts, technological feasibility, and other factors relevant to each particular decision.”

Id.

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 maximum level of a pollutant for a lifetime.

In past residual risk actions, the EPA presented and considered a number of human health risk metrics associated with emissions from the category under review, including: the MIR; the numbers of persons in various risk ranges; cancer incidence; the maximum noncancer HI; and the maximum acute noncancer hazard. See,

e.g.,

75 FR 65068, 65072-74 (October 21, 2010) and 76 FR 22566, 22575 (April 21, 2011). In estimating risks, the EPA considered sources under review that are located near each other and that affect the same population. The EPA developed risk estimates based on the actual emissions from the source category under review as well as based on the maximum emissions allowed pursuant to the source category MACT standards. The EPA also discussed and considered risk estimation uncertainties. The EPA is providing this same type of information in support of this action.

The agency is considering all available health information to inform our determinations of risk acceptability and ample margin of safety under CAA section 112(f). Specifically, as explained in the Benzene NESHAP, “the first step judgment on acceptability cannot be reduced to any single factor” and thus “[t]he Administrator believes that the acceptability of risk under [previous] section 112 is best judged on the basis of a broad set of health risk measures and information” (54 FR 38046). Similarly, with regard to making the ample margin of safety determination, as stated in the Benzene NESHAP, “[in the ample margin decision, the agency again considers all of the health risk and other health information considered in the first step. Beyond that information,

additional factors relating to the appropriate level of control will also be considered, including cost and economic impacts of controls, technological feasibility, uncertainties, and any other relevant factors.”

Id.

The agency acknowledges that the Benzene NESHAP provides flexibility regarding what factors the EPA might consider in making determinations and how they might be weighed for each source category. In responding to comment on our policy under the Benzene NESHAP, the EPA explained that: “The policy chosen by the Administrator permits consideration of multiple measures of health risk. Not only can the MIR figure be considered, but also incidence, the presence of noncancer health effects, and the uncertainties of the risk estimates. In this way, the effect on the most exposed individuals can be reviewed as well as the impact on the general public. These factors can then be weighed in each individual case. This approach complies with the Vinyl Chloride mandate that the Administrator ascertain an acceptable level of risk to the public by employing [her] expertise to assess available data. It also complies with the Congressional intent behind the CAA, which did not exclude the use of any particular measure of public health risk from the EPA's consideration with respect to CAA section 112 regulations, and, thereby, implicitly permits consideration of any and all measures of health risk which the Administrator, in [her] judgment, believes are appropriate to determining what will `protect the public health.'” (54 FR at 38057).

Thus, the level of the MIR is only one factor to be weighed in determining acceptability of risks. The Benzene NESHAP explained that “an MIR of approximately 1 in 10 thousand should ordinarily be the upper end of the range of acceptability. As risks increase above this benchmark, they become presumptively less acceptable under CAA section 112, and would be weighed with the other health risk measures and information in making an overall judgment on acceptability. Or, the agency may find, in a particular case, that a risk that includes MIR less than the presumptively acceptable level is unacceptable in the light of other health risk factors” (

Id.

at 38045). Similarly, with regard to the ample margin of safety analysis, the EPA stated in the Benzene NESHAP that: “* * * EPA believes the relative weight of the many factors that can be considered in selecting an ample margin of safety can only be determined for each specific source category. This occurs mainly because technological and economic factors (along with the health-related factors) vary from source category to source category” (

Id.

at 38061).

C. How did we perform the technology review?

Our technology review focused on the identification and evaluation of developments in practices, processes and control technologies that have occurred since the 1998 NESHAP was promulgated. In cases where the technology review identified such developments, we conducted an analysis of the technical feasibility of applying these developments, along with the estimated impacts (costs, emissions reductions, risk reductions,

etc.

) of applying these developments. We then made decisions on whether it is necessary and appropriate to propose amendments to the regulation to require any of the identified developments.

Based on specific knowledge of the source category, we began by identifying known developments in practices, processes and control technologies. For the purpose of this exercise, we considered any of the following to be a “development”:

• Any add-on control technology or other equipment that was not identified and considered during development of the 1998 NESHAP;

• Any improvements in add-on control technology or other equipment (that were identified and considered during development of the 1998 NESHAP) that could result in significant additional emissions reductions;

• Any work practice or operational procedure that was not identified or considered during development of the 1998 NESHAP; and

• Any process change or pollution prevention alternative that could be broadly applied to the industry and that was not identified or considered during development of the 1998 NESHAP.

In addition to reviewing the practices, processes or control technologies that were not considered at the time we developed the 1998 NESHAP, we reviewed a variety of data sources in our evaluation of whether there were additional practices, processes or controls to consider for the pulp and paper industry. To aid in our evaluation of whether there were additional practices, processes or controls to consider, one of these sources of data was subsequent air toxics rules. Since the promulgation of the MACT standards for the source category addressed in this proposal, the EPA has developed air toxics regulations for a number of additional source categories. In these subsequent air toxic regulatory actions, we consistently evaluated any new practices, processes and control technologies. We reviewed the regulatory requirements and/or technical analyses associated with these subsequent regulatory actions to identify any practices, processes and control technologies considered in these efforts that could possibly be applied to emission sources in the source category under this current RTR review.

We also consulted the EPA's RBLC to identify potential technology advances.

Control technologies, classified as RACT, BACT or LAER apply to stationary sources depending on whether the sources are existing or new, and on the size, age and location of the facility. Best available control technology and LAER (and sometimes RACT) are determined on a case-by-case basis, usually by state or local permitting agencies. The EPA established the RBLC to provide a central database of air pollution technology information (including technologies required in source-specific permits) to promote the sharing of information among permitting agencies and to aid in identifying future possible control technology options that might apply broadly to numerous sources within a category or apply only on a source-by-source basis. The RBLC contains over 5,000 air pollution control permit determinations that can help identify appropriate technologies to mitigate many air pollutant emission streams. We searched this database to determine whether it contained any practices, processes or control technologies for the types of processes covered by the pulp and paper source category. We also further analyzed a number of BACT determinations listed in the RBLC to obtain further information.

See the memorandum in the docket titled,

Summary of RBLC and Other Findings to Support Section 112(d)(6) Technology Review for Pulp and Paper NESHAP.

Additionally, we conducted a general search of the Internet and other sources for information on control technologies applicable to pulp and paper production. Finally, we conducted a search of the database containing the responses received from the Part I survey to obtain information on process and emission controls currently in use in pulp and paper production.

Each of the evaluations listed above considered and reviewed the technologies suitable to demonstrate compliance with the requirements listed in §§ 63.440 through 63.449 (subpart S).

See the memoranda titled,

Section 112(d)(6) Technology Review for Pulping and Papermaking

Processes

and

Summary of Pulp Bleaching Technology Review,

in the docket for this rulemaking.

D. What other issues are we addressing in this proposal?

In addition to the analyses described above, we also reviewed other aspects of the MACT standards for possible revision as appropriate and necessary. Based on this review, we have identified aspects of the MACT standards that we believe need revision.

This includes proposing revisions to the SSM provisions of the MACT rule in order to ensure that they are consistent with the court decision in

Sierra Club

EPA,

551 F. 3d 1019 (DC Cir. 2008). In addition, we are proposing various changes based on our review of the rule for testing and monitoring sufficiency, including a requirement for 5-year repeat air emissions testing for selected equipment and additional test methods for measuring methanol. We are also proposing minor changes with regards to editorial errors. The analyses and proposed decisions for these actions are presented in section IV of this preamble.

IV. Analytical Results and Proposed Decisions

This section of the preamble provides the results of our RTR for the pulp and paper source category and our proposed decisions concerning changes to the 1998 NESHAP.

A. What are the results of the risk assessments?

For the pulp and paper source category, we conducted an inhalation risk assessment based upon actual and allowable emissions for all HAP emitted, as well as a multipathway analysis. This assessment also included a whole-facility analysis to estimate inhalation risks from all source categories for the pulp and paper industry.

1. Inhalation Risk Assessment Results

Table 3 provides an overall summary of the results of the inhalation risk assessment from the 171 modeled mills subject to this source category. We also conducted an assessment of facilitywide risk. Details of the risk assessments and analyses can be found in the residual risk documentation referenced in section IV.A of this preamble, which is available in the docket for this action.

Table 3—Pulp and Paper Production Inhalation Risk Assessment Results

Maximum individual cancer risk

(in 1 million)

Based on actual emissions level

Based on allowable emissions level

Estimated population at increased risk of cancer ≥ 1 in 1 Million

Estimated annual cancer incidence

(cases per year)

Maximum chronic noncancer TOSHI

Based on actual emissions level

Based on allowable emissions level

Worst-case maximum refined screening acute noncancer HQ

76,000

0.01

0.4

0.6

REL

= 20

ERPG-1

= 0.4

(acetaldehyde)

REL

= 6.

ERPG-1

= 0.004 (chloroform).

REL

= 5.

AEGL-1

= 0.2 (formaldehyde)

REL

= 2.

ERPG-1

= 0.2 (methanol)

As noted in section III.A.1 of this preamble, acrolein emissions were not modeled due to uncertainties in the emissions estimates.

Estimated maximum individual excess lifetime cancer risk due to HAP emissions from the source category.

Maximum TOSHI. The target organ with the highest TOSHI for the pulp and paper source category is the respiratory system.

See section III.B of this preamble for explanation of acute dose-response values.

As shown in Table 3, the results of the inhalation risk assessment performed using actual emissions data indicate the maximum lifetime individual cancer risk could be up to 10 in 1 million, primarily due to hexachloroethane emissions; the maximum chronic noncancer TOSHI value could be up to 0.4, primarily due to acetaldehyde emissions; and the maximum offsite worst-case acute HQ value could be up to 20, based on the REL value for acetaldehyde. The HQ of 20 represents an upper-bound risk estimate and is located in an uninhabited location with limited public access or an offsite area that is owned by the facility. An acute noncancer HQ of 3 reflects the risk where people are living with access to a public road. This would then result in the next highest HQ of 6 for this source category based on the acute REL dose-response value for chloroform. One hundred sixty-two of the 171 facilities in this source category had an estimated worst-case HQ less than or equal to 1; the remaining 9 facilities had an estimated worst-case HQ less than or equal to 6.

The acute refined HQ values for this source category can be found in Appendix 6, Table 1 of the Risk Assessment report. A summary of the refined acute 1-hour HQ values that were greater than 1 for this source category are as follows: 20,6,5,5,4,3,2,2,2,2,2.

To better characterize the potential health risks associated with estimated worst-case acute exposures to HAP, and in response to a key recommendation from the SAB's peer review of EPA's RTR risk assessment methodologies,

we examine a wider range of available acute health metrics than we do for our chronic risk assessments. This is in response to the acknowledgement that there are generally more data gaps and inconsistencies in acute reference values than there are in chronic reference values. By definition, the acute CalEPA REL represents a health-protective level of exposure, with no risk anticipated below those levels, even for repeated exposures; however, the health risk from higher-level exposures is unknown. Therefore, when a CalEPA REL is exceeded and an AEGL-1 or ERPG-1 level is available (

i.e.,

levels at which mild effects are anticipated in the general public for a single exposure), we have used them as a second comparative measure. Historically, comparisons of the estimated maximum offsite 1-hour exposure levels have not been typically made to occupational levels for the purpose of characterizing public health risks in RTR assessments. This is because occupational ceiling values are not generally considered protective for the general public since they are

designed to protect the worker population (presumed healthy adults) for short-duration (less than 15-minute) increases in exposure.

As a result, for most chemicals, the 15-minute occupational ceiling values are set at levels higher than a 1-hour AEGL-1, making comparisons to them irrelevant unless the AEGL-1 or ERPG-1 levels are exceeded. Such is not the case when comparing the available acute inhalation health effect reference values for formaldehyde.

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.

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 on-line at

http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=211003.

The worst-case maximum estimated 1-hour exposure to formaldehyde outside the facility fence line for the pulp and paper source category is 0.25 mg/m

. This estimated worst-case exposure exceeds the 1-hour REL by a factor of 5 (HQ

REL

=5) and is below the 1-hour AEGL-1 (HQ

AEGL-1

=0.2). This exposure estimate is below the AEGL-1, and exceeds the workplace ceiling level guideline for the formaldehyde value developed by NIOSH

“for any 15 minute period in a work day” (NIOSH REL-ceiling value of 0.12 mg/m

; HQ

NIOSH

=2). The estimate is at the value developed by the ACGIH

as “not to be exceeded at any time” (ACGIH TLV-ceiling value of 0.37 mg/m

; HQ

ACGIH

=1). Additionally, the estimated maximum acute exposure exceeds the Air Quality Guideline value that was developed by the World Health Organization

for 30-minute exposures (0.1 mg/m

; HQ

WHO

=2.5).

National Institutes for Occupational Safety and Health (NIOSH). Occupational Safety and Health Guideline for Formaldehyde;

http://www.cdc.gov/niosh/docs/81-123/pdfs/0293.pdf

ACGIH (2001) Formaldehyde. In Documentation of the TLVs® and BEIs® with Other Worldwide Occupational Exposure Values. ACGIH, 1300 Kemper Meadow Drive, Cincinnati, OH 45240 (ISBN: 978-1-882417-74-2) and available on-line at

http://www.acgih.org

WHO (2000). Chapter 5.8 Formaldehyde, in Air Quality Guidelines for Europe, second edition. World Health Organization Regional Publications, European Series, No. 91. Copenhagen, Denmark. Available on-line at

http://www.euro.who.int/_data/assets/pdf_file/0005/74732/E71922.pdf

All other HAP and facilities modeled had worst-case acute HQ values less than 1, indicating that they carry no potential to pose acute concerns. The maximum HQ based on an ERPG-1 dose-response value is 0.4 for acetaldehyde. In characterizing the potential for acute noncancer impacts of concern, it is important to remember the upward bias of these exposure estimates (

e.g.,

worst-case meteorology coinciding with a person located at the point of maximum concentration during the hour) and to consider the results along with the uncertainties related to the emissions estimates and the screening methodology. However, it is acknowledged that the acute emission multipliers ranged from 1.4 to 3 and approached the annual hourly average emission rate for the facilities within the source category.

The total estimated cancer incidence from these facilities based on actual emissions levels is 0.01 excess cancer cases per year, or 1 case in every 100 years. The cancer incidence is primarily driven by emissions of acetaldehyde and formaldehyde from papermaking and kraft wastewater operations.

We note that the MIR for this source category would not change if the CIIT URE for formaldehyde had been used in the assessment; however, the total cancer incidence would decrease by about 36 percent. There is an ongoing IRIS reassessment for formaldehyde and future RTR risk assessments will use the cancer potency for formaldehyde that results from that reassessment. As a result, the current results many not match those of future assessments.

There are 68 facilities with maximum individual cancer risks of 1 in 1 million or greater and two facilities with maximum individual cancer risks of 10 in a million that represented the highest cancer risks for the source category. The MIR of 10 in a million for the source category was driven by emissions of hexachloroethane.

As explained above, our analysis of potential differences between actual emissions levels and emissions allowable under the pulp and paper MACT standards indicate that MACT-allowable emission levels are roughly equal to the actual emission levels.

The risk results from the inhalation risk assessment indicate the maximum lifetime individual cancer risks are the same at 20 in a million, and the maximum chronic noncancer TOSHI value could be up to 0.6 at the MACT-allowable emissions level.

For more information, see the memorandum in the docket titled Inputs to the Pulp and Paper Industry October 2011 Residual Risk Modeling.

2. Multipathway Risk Screening Results

The results of a multipathway screening analysis showed that emissions of POM, cadmium and mercury were almost all below their respective screening emission rates, thereby indicating a negligible risk of adverse health effects associated with multipathway exposures. The only PB-HAP to exceed the screening threshold was POM, with emissions exceeding the screening threshold by a factor of 2.

3. Facilitywide Risk Assessment Results

A facilitywide risk analysis was also conducted based on actual emissions levels. Table 4 displays the results of the facilitywide risk assessment.

For detailed facilityspecific results, see Appendix 6 of the

Draft Residual Risk Assessment for Pulp and Paper

in the docket for this rulemaking.

Table 4—Pulp and Paper Facilitywide Risk Assessment Results

Number of facilities analyzed

171

Cancer Risk:

Estimated maximum facilitywide individual cancer risk (in 1 million)

Number of facilities with estimated facilitywide individual cancer risk of 10 in 1 million or more

Number of pulp and papermaking operations contributing 50 percent or more to facilitywide individual cancer risk of 10 in 1 million or more

Number of facilities with facilitywide individual cancer risk of 1 in 1 million or more

Number of pulp and papermaking operations contributing 50 percent or more to facilitywide individual cancer risk of 1 in 1 million or more

Chronic Noncancer Risk:

Maximum facilitywide chronic noncancer TOSHI

Number of facilities with facilitywide maximum noncancer TOSHI of 1 or more

Number of pulp and papermaking operations contributing 50 percent or more to facilitywide maximum noncancer TOSHI of 1 or more

The maximum individual cancer whole-facility risk from all HAP emissions at any mill is estimated to be 30 in 1 million based on actual emissions. Of the 171 mills included in this analysis, seven have facilitywide maximum individual cancer risks of 10 in 1 million or greater. At these mills, pulp and papermaking operations account for 30 percent of the total facilitywide risk. There are 99 facilities with facilitywide maximum individual cancer risks of 1 in 1 million or greater. Of these 99 mills, 57 have pulp and papermaking operations that contribute greater than 50 percent to the facilitywide risks. The facilitywide cancer risks at these 57 mills, and at the 7 mills with risks of 10 in a million or more, are primarily driven by emissions of arsenic compounds, chromium compounds and nickel compounds from boiler and lime kiln operations. However, we note that there are uncertainties in the amount and form of chromium emitted from these mills. For many of the mills, the emissions inventory used for the risk assessment included estimates for the two main forms of chromium (

i.e.,

hexavalent and trivalent chromium). However, for other mills, we only had estimates of total chromium emitted. For those mills, we applied a hexavalent chromium speciation factor assigned by SCC for this source category.

Although, hexavalent chromium is toxic and is a known human carcinogen, trivalent chromium is less toxic and is currently “not classified as to its human carcinogenicity.”

Therefore, the relative emissions of these two forms can have a significant effect on the cancer risk estimates.

See the memorandum in the docket titled,

Inputs to the Pulp and Paper Industry October 2011 Residual Risk Modeling.

EPA's IRIS Weight-of-Evidence Characterization for trivalent chromium

http://www.epa.gov/iris/subst/0028.htm#refinhal.

The facilitywide maximum individual chronic noncancer TOSHI is estimated to be 2 based on actual emissions. Of the 171 mills included in this analysis, only four mills have a HI value greater than 1, with all mills having an HI value less than or equal to 2. The chronic noncancer risks at these mills are primarily driven by acrolein emissions from industrial boilers and antimony emissions from smelt dissolving tank kraft process units, which are not regulated under the Pulp and paper source category.

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

1. Risk Acceptability

As noted in section III.B of this preamble, we weigh all health risk factors and measures in our risk acceptability determination, including the MIR; the number of persons in various cancer and noncancer risk ranges; cancer incidence; the maximum noncancer HI; the maximum acute noncancer HQ; the extent of noncancer risks; the potential for adverse environmental effects; distribution of cancer and noncancer risks in the exposed population; and risk estimation uncertainty (54 FR 38044, September 14, 1989).

For the pulp and paper source category, the risk analysis we performed indicates that the cancer risks to the individual most exposed could be up to 10 in 1 million due to actual or MACT-allowable emissions. These risks are considerably less than 100 in 1 million, which is the presumptive upper limit of risk acceptability. The risk analysis also shows generally low cancer incidence (1 case every 100 years); no potential for adverse environmental effects or human health multipathway effects; no potential for chronic noncancer impacts; and, while a potential exists for some acute inhalation impacts, they are likely to be minimal.

Additional analysis of facilitywide risks showed that there are five mills with maximum facilitywide risks in between a cancer risk of 10 in 1 million and 30 in a million and four mills with a maximum chronic noncancer TOSHI between 1 and 2; it also showed that the pulp and paper source category did not drive these risks. The number of people exposed to cancer risks of 1 in 1 million or greater due to emissions from the source category is relatively low (76,000). Considering these factors and the uncertainties discussed in section III.B of this preamble, we propose that the risks from the Pulp and paper source category are acceptable.

2. Ample Margin of Safety

Under the ample margin of safety analysis, we evaluate the cost and feasibility of available control technologies and other measures (including the controls, measures and costs reviewed under the technology review) that could be applied in this source category to further reduce the risks due to emissions of HAP identified in our risk assessment.

As noted in our discussion of the technology review below in section IV.C, no technologies (beyond those already in place) were identified for reducing HAP emissions from pulp and paper production processes.

We are proposing to amend the kraft condensate standards to reflect increased performance of existing controls observed in the technology review, resulting in an estimated HAP reduction of approximately 4,000 tpy. Incrementally increasing the stringency of the kraft condensate standards is expected to reduce risks from kraft wastewater operations. As a result, we conclude that the current standard, before the amendments proposed here are put in place, protects public health with an ample margin of safety.

See the docket memoranda titled,

Section 112(d)(6) Technology Review for Pulping and Papermaking Processes

and

Summary of Pulp Bleaching Technology Review.

Though we did not identify any new technologies to reduce risk from this source category beyond incremental improvements in the performance of existing technology used to meet the kraft condensate standards, we are specifically requesting comment on whether there are additional cost-effective control measures that may be able to reduce risks from the pulp and paper subpart S source category. In particular, we are requesting states to identify any controls they have already required for these facilities, any controls they are currently considering or any other controls of which they may be aware.

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

We evaluated developments in practices, processes and control technologies applicable to emission sources subject to the pulp and paper MACT. This included a search of the RBLC, the Internet and our database containing the 2011 Part I survey responses. For chemical pulping and bleaching, we have determined that there have been no advances in emission control measures since the subpart S standard was originally promulgated in 1998.

For kraft pulping process condensates, we have determined that the technology has sufficiently advanced since the 1998 MACT rule to warrant the development of an updated standard. The 1998 MACT rule required kraft pulp mills to either: (1) Recycle the condensates back to equipment that meet the control standards for pulping system vents

(LVHC, HVLC), (2) treat the condensates to reduce or destroy the HAP by at least 92 percent by weight, (3) treat the condensates to remove a specified amount of HAPs (at least 10.2 lb/ODTP at mills performing bleaching or 6.6 lb/ODTP at mills without bleaching), or (4) treat the condensates to meet a specified HAP concentration at the control device outlet (330 ppmw at mills performing bleaching or 210 ppmw at mills without bleaching). The three control strategies expected to be used by most mills are recycling the condensates, biological treatment and steam stripping.

Additional details on our technology review are provided in docket memoranda titled,

Section 112(d)(6) Technology Review for Pulping and Papermaking Processes,

and

Summary of Pulp Bleaching Technology Review.

Our technology review of kraft condensates did not yield any information about new technologies that could become the basis for regulatory options. We then reviewed the 2011 pulp and paper ICR database. In our review of the database, we found that most kraft pulp mills chose the 92 percent control option for compliance demonstration for kraft condensates rather than recycling. Only five mills use recycling, two mills use both recycling and steam stripping, and four mills use the aforementioned ppmw option to control kraft condensates. Consequently, the focus of our technology review was on the control efficiencies of wastewater treatment systems and steam stripping.

We reviewed the 2011 pulp and paper ICR database to determine if, under the current control technologies, there were mills demonstrating greater than the 92 percent minimum level of control (or any equivalent demonstrations). We found that all kraft pulp mills are performing at a higher level than the 92 percent minimum level of control.

For regulatory options, we developed an incremental scale of improvement over the minimum 92 percent control, set up by percent increments from 93 percent to 98 percent. An estimated four mills would be impacted under the 93 percent option, 15 mills under the 94 percent option, 28 mills under the 95 percent option, 41 mills under the 96 percent option, 54 mills under the 97 percent option and 66 under the 98 percent option.

We did not take the analysis beyond 98 percent because that level was determined to be at the limit of control efficiency for one the major control techniques, steam stripping, and it was equivalent to the control level required for non-condensable gases ducted to controls from LVHC and HVLC sources in 40 CFR 63.443(d)(1). After setting up the percent increments, we established an equivalency between the different percent control options and the lb/ODTP and ppmw options:

Percent control,

lb/ODTP option

Mills

performing bleaching

Mills without bleaching

ppmw option

Mills

performing bleaching

Mills without bleaching

Annual cost, $million

HAP

emissions

reduction, tpy

11.5

7.4

289

184

$0.99

2.0

12.8

8.3

248

158

4.1

14.0

9.1

206

131

9.0

6.1

15.3

9.9

165

105

8.2

16.6

10.7

124

17.9

11.6

Finally, we estimated the costs and HAP emissions reductions associated with each percent control option. Total annual costs for the options ranged from $1 million to $34 million, and HAP emissions reductions ranged from 2,000 to 12,000 tpy. Taking these costs and emissions reductions into consideration, we are proposing the 94 percent option for controlling kraft condensates emissions, which is estimated to cost $4 million per year, with an emissions reduction of 4,000 tpy and a cost effectiveness of $1,000 per ton of HAP.

Additional details on our kraft condensate technology review and cost analysis are provided in the memoranda,

Summary of Kraft Condensate Control Technology Review,

and

Costs and Environmental and Energy Impacts for Subpart S Risk and Technology Review,

in the docket for this proposed action.

D. What other actions are we proposing?

1. Startup, Shutdown and Malfunction

The U.S. Court of Appeals for the District of Columbia Circuit vacated portions of two provisions in the EPA's CAA section 112 regulations governing the emissions of HAP during periods of SSM.

Sierra Club

EPA,

551 F.3d 1019 (DC Cir. 2008),

cert. denied,

130 S. Ct. 1735 (U.S. 2010). Specifically, the Court vacated the SSM exemption contained in 40 CFR 63.6(f)(1) and 40 CFR 63.6(h)(1), that are part of a regulation, commonly referred to as the “General Provisions Rule,” that the EPA promulgated under CAA section 112(d). When incorporated into CAA section 112(d) regulations for specific source categories, these two provisions exempt sources from the requirement to comply with the otherwise applicable CAA section 112(d) emission standard during periods of SSM. In its decision, the

Sierra Club

court held that CAA section 112 and section 302(k) are properly read together to require continuous CAA section 112-compliant standards. 552 F.3d at 1027-28.

There are several provisions in the current regulations that include an exemption for SSM events, akin to the exemption in 40 CFR 63.6(f)(1) and 40 CFR 63.6(h)(1). The DC Circuit vacated the SSM exemption in 40 CFR 63.6(f)(1) and 40 CFR 63.6(h)(1), and we are proposing to remove similar language in this rule. In addition, we are proposing to remove the parenthetical language excluding periods of startup, shutdown or malfunction from excess emissions calculations contained within 40 CFR 63.443(e) and 40 CFR 63.459(b)(11)(ii) of this rule, because this language is inconsistent with

Sierra Club

EPA.

The EPA is further proposing to eliminate the parenthetical language in 40 CFR 63.446(g) that includes startup, shutdown and malfunction periods in excess emissions calculations because retaining such language may incorrectly suggest that other excess emissions provisions such as 40 CFR 63.443(e) that lack such language allow exclusion of such periods in excess emissions calculations. In sum, retaining the parenthetical concerning startup, shutdown and malfunction periods in 40 CFR 63.443(g) is unnecessary and may create confusion.

We are also proposing several revisions to Table 1 (the General Provisions Applicability table). For example, we are proposing to eliminate the incorporation of the General Provisions' requirement that the source develop a SSM plan. We are further proposing to eliminate or revise certain recordkeeping and reporting that related to the SSM exemption. The EPA has attempted to ensure that we have not included in the proposed regulatory language any provisions that are inappropriate, unnecessary or

redundant in the absence of the SSM exemption. We are specifically seeking comment on whether there are any such provisions that we have inadvertently incorporated or overlooked.

Finally, we are requesting comment on whether to remove, or modify, the excess emissions provisions for LVHC, HVLC and steam strippers in 40 CFR 63.443(e), 40 CFR 63.446(g), and 40 CFR 63.459(b)(11)(ii). The basis for these provisions is discussed in the preamble to the final rule at 63 FR 18529-18530, April 15, 1998. The basis for these excess emission allowances (discussed in the preamble to the final rule at 63 FR 18529-18530) was to approximate the level of backup control that exists at the best-performing mills and the associated periods of time when no control device is available. For LVHC systems, one percent of the operating hours on a semi-annual basis was determined to represent the best performers; for HVLC systems four percent was established to account for downtime due to flow balancing problems and unpredictable pressure changes inherent in the HVLC system; and for steam stripper systems ten percent was established to account for activities such as stripper tray damage or plugging, efficiency losses in the stripper due to contamination of condensate with fiber or black liquor, steam supply downtime, and combustion control downtime. We request comment on whether these provisions should be removed or modified in the final rule, as the provisions create time periods during which a source does not have to comply with a CAA section 112-compliant standard, which we believe is arguably at odds with Sierra Club.

We specifically solicit comment on a variety of issues and request that commenters provide data and information supporting their views. We first request comment and information on the circumstances under which such provisions have been relied upon in the past to remain in compliance with subpart S, and whether such circumstances meet the definitions of startup, shutdown or malfunction (as defined in 40 CFR 63.2), and if they do not, why not. We also seek information on the frequency with which these provisions are used. The annual emissions rates used in risk modeling for today's proposal incorporated emissions that occur during excess emissions periods and the EPA has already collected information on the use of backup controls through Part I of the ICR. We are thus interested in additional information that distinguishes between routine releases for which a source may be using the excess allowance provisions and malfunction events. We request information on: (1) The typical reasons for the releases, including a description of the nature and cause of the release, (2) the frequency of the releases, (3) the duration of such releases, (4) the estimated amount of emissions that occurs during such periods, (5) any work practices employed during excess emissions periods to reduce emissions, and (6) any procedures currently used to monitor such releases. Further, the EPA is interested in knowing whether the excess emissions periods are necessary for technological reasons (

e.g.,

equipment or operational), and the amount of time needed to switch between routine controls and any available backup controls (and whether venting is necessary during these times for technological reasons).

As an alternative to removing the excess allowance provisions, we request comment on whether such provisions should be revised by, for example, (1) narrowing the provisions (such as limiting the circumstances to which they apply), (2) setting an alternative numerical emission limit during these periods, or (3) setting a work practice standard during such periods consistent with the requirements of CAA section 112(h). Accordingly, we are requesting comments that would provide us information to evaluate these options, including sufficient supporting emissions data or other information. We also request comment on whether the current standard should be applied over a longer averaging period, and whether a longer averaging period would obviate the need for excess emissions periods. To the extent that any person suggests that a work practice is appropriate, they will need to provide support for the conclusion that work practices are permissible under section 112(h) because a numerical standard is “not feasible” within the meaning of section 112(h)(2). This should include cost information regarding monitoring, testing and controlling of emissions from the sources during these periods. Finally, to the extent that any person suggests that the excess emissions periods should be retained in some form, they should explain how the revisions that they are suggesting are consistent with the CAA.

In proposing the standards in this rule, the EPA has taken into account startup and shutdown periods and is not proposing a different standard for those periods. Nothing in the record suggests that the operations (and attendant emissions) are significantly different during startup or shutdown than during normal operation.

Periods of startup, normal operations and shutdown are all predictable and routine aspects of a source's operations. However, by contrast, malfunction is defined as a “sudden, infrequent, and not reasonably preventable failure of air pollution control and monitoring equipment, process equipment or a process to operate in a normal or usual manner * * *” (40 CFR 63.2). The EPA has determined that CAA section 112 does not require that emissions that occur during periods of malfunction be factored into development of CAA section 112 standards. Under section 112, emissions standards for new sources must be no less stringent than the level “achieved” by the best controlled similar source and for existing sources generally must be no less stringent than the average emission limitation “achieved” by the best performing 12 percent of sources in the category. There is nothing in section 112 that directs the agency to consider malfunctions in determining the level “achieved” by the best performing or best controlled sources when setting emission standards. Moreover, while the EPA accounts for variability in setting emissions standards consistent with the section 112 case law, nothing in that case law requires the agency to consider malfunctions as part of that analysis. Section 112 uses the concept of “best controlled” and “best performing” unit in defining the level of stringency that section 112 performance standards must meet. Applying the concept of “best controlled” or “best performing” to a unit that is malfunctioning presents significant difficulties, as malfunctions are sudden and unexpected events.

Further, accounting for malfunctions would be difficult, if not impossible, given the myriad different types of malfunctions that can occur across all sources in the category and given the difficulties associated with predicting or accounting for the frequency, degree and duration of various malfunctions that might occur. As such, the performance of units that are malfunctioning is not “reasonably” foreseeable. See,

e.g., Sierra Club

EPA,

167 F. 3d 658, 662 (DC Cir. 1999) (The EPA typically has wide latitude in determining the extent of data-gathering necessary to solve a problem. We generally defer to an agency's decision to proceed on the basis of imperfect scientific information, rather than to “invest the resources to conduct the perfect study.”). See also,

Weyerhaeuser

Costle,

590 F.2d 1011, 1058 (DC Cir. 1978) (“In the nature of things, no general limit, individual permit, or even

any upset provision can anticipate all upset situations. After a certain point, the transgression of regulatory limits caused by `uncontrollable acts of third parties,' such as strikes, sabotage, operator intoxication or insanity, and a variety of other eventualities, must be a matter for the administrative exercise of case-by-case enforcement discretion, not for specification in advance by regulation.”). In addition, the goal of a best controlled or best performing source is to operate in such a way as to avoid malfunctions of the source, and accounting for malfunctions could lead to standards that are significantly less stringent than levels that are achieved by a well-performing non-malfunctioning source. The EPA's approach to malfunctions is consistent with section 112 and is a reasonable interpretation of the statute.

In the event that a source fails to comply with the applicable CAA section 112(d) standards as a result of a malfunction event, the EPA would determine an appropriate response based on, among other things, the good faith efforts of the source to minimize emissions during malfunction periods, including preventative and corrective actions, as well as root cause analyses to ascertain and rectify excess emissions. The EPA would also consider whether the source's failure to comply with the CAA section 112(d) standard was, in fact, “sudden, infrequent, not reasonably preventable” and was not instead “caused in part by poor maintenance or careless operation.” 40 CFR 63.2 (definition of malfunction).

Finally, the EPA recognizes that even equipment that is properly designed and maintained can sometimes fail and that such failure can sometimes cause an exceedance of the relevant emission standard. (See,

e.g., State Implementation Plans: Policy Regarding Excessive Emissions During Malfunctions, Startup, and Shutdown

(Sept. 20, 1999);

Policy on Excess Emissions During Startup, Shutdown, Maintenance, and Malfunctions

(Feb. 15, 1983)). The EPA is therefore proposing to add to the rule an affirmative defense to civil penalties for exceedances of emission limits that are caused by malfunctions. See § 63.456 for this proposed addition (and see § 63.441 for a definition of “affirmative defense” that means, in the context of an enforcement proceeding, a response or defense put forward by a defendant, regarding which the defendant has the burden of proof and the merits of which are independently and objectively evaluated in a judicial or administrative proceeding.). We also are proposing other regulatory provisions to specify the elements that are necessary to establish this affirmative defense; the source must prove by a preponderance of the evidence that it has met all of the elements set forth in § 63.456. (See 40 CFR 22.24). The criteria ensure that the affirmative defense is available only where the event that causes an exceedance of the emission limit meets the narrow definition of malfunction in 40 CFR 63.2 (sudden, infrequent, not reasonable preventable and not caused by poor maintenance and or careless operation). For example, to successfully assert the affirmative defense, the source must prove by a preponderance of the evidence that excess emissions “[w]ere caused by a sudden, infrequent, and unavoidable failure of air pollution control and monitoring equipment, process equipment, or a process to operate in a normal or usual manner * * *.” The criteria also are designed to ensure that steps are taken to correct the malfunction, to minimize emissions in accordance with § 63.456 and to prevent future malfunctions. For example, the source must prove by a preponderance of the evidence that “[r]epairs were made as expeditiously as possible when the applicable emission limitations were being exceeded * * *” and that “[a]ll possible steps were taken to minimize the impact of the excess emissions on ambient air quality, the environment and human health * * *.” In any judicial or administrative proceeding, the Administrator may challenge the assertion of the affirmative defense and, if the respondent has not met its burden of proving all of the requirements in the affirmative defense, appropriate penalties may be assessed in accordance with section 113 of the CAA (see also 40 CFR 22.27).

Specifically, we are proposing the following changes to the rule related to SSM:

(1) Revise 40 CFR 63.443(e), 63.446(g), and 63.459(b)(11)(ii) to eliminate reference to periods of SSM;

(2) Revise 40 CFR 63.453(q) to incorporate the general duty from 40 CFR 63.6(e)(1)(i) to minimize emissions;

(3) Add 40 CFR 63.454(g), and 40 CFR 63.455(g) to require reporting and recordkeeping requirements associated with periods of malfunction;

(4) Add 40 CFR 63.456 (formerly reserved) to include an affirmative defense to civil penalties for exceedances of emissions limits caused by malfunctions, as well as criteria for establishing the affirmative defense;

(5) Add 40 CFR 63.457(o) to specify the conditions for performance tests; and

(6) Revise Table 1 to specify that 40 CFR 63.6 (e)(1)(i) and (ii), 63.6(e)(3), 63.6(f)(1); 40 CFR 63.7(e)(1), 40 CFR 63.8(c)(1)(i) and (iii), and the last sentence of 63.8(d)(3); 40 CFR 63.10(b)(2)(i),(ii), (iv), and (v); 40 CFR 63.10(c)(10), (11), and (15); and, 40 CFR 63.10(d)(5) of the General Provisions do not apply.

We have attempted to ensure that we have not included in the proposed regulatory language any provisions that are inappropriate, unnecessary or redundant in the absence of the SSM exemption. We are specifically seeking comment on whether there are any such provisions that we have inadvertently incorporated or overlooked.

2. Repeat Testing

As part of an ongoing effort to improve compliance with various federal air emission regulations, we reviewed the testing and monitoring requirement of subpart S and are proposing the following change.

We are proposing to require repeat air emissions performance testing once every 5 years for facilities complying with the standards for kraft, soda and semi-chemical pulping vent gases (§ 63.443(a)); sulfite processes (§ 63.444); and bleaching systems (§ 63.445). Repeat performance tests are already required by permitting authorities for some facilities.

Further, we believe that requiring periodic repeat performance tests will help to ensure that control systems are properly maintained over time, thereby reducing the potential for acute emissions episodes.

Located in 11 states.

For information on the cost associated with the proposed repeat testing requirement, see the memorandum in the docket titled,

Costs and Environmental and Energy Impacts for Subpart S Risk and Technology Review.

With today's proposal, repeat air emissions testing would be required for mills complying with the kraft condensates standards in § 63.446 using a steam stripper (or other equipment serving the same function) since such equipment is, by definition, part of the LVHC system.

Quarterly sampling for four HAPs (acetaldehyde, methanol, MEK and propionaldehyde) is currently required for biological treatment systems to demonstrate compliance with the kraft condensates standards in § 63.446(e)(2). We believe this sampling sufficiently demonstrates compliance with the revised emissions standard we are proposing for kraft condensates. However, we are interested in receiving comment on the sampling and reporting methods used for these quarterly tests. We note that MEK was removed from the HAP list in 2005.

However, the subpart S equations were derived considering inclusion of MEK. We

request comment on the appropriateness of re-deriving these equations to eliminate MEK for the final rule.

See 70 FR 75047, December 19, 2005.

We are not proposing repeat air emissions testing for facilities complying with the CCA standards due to the complexity of this compliance approach (

e.g.,

comparison to baseline emissions calculations) and the fact that it often involves both air and/or liquid sampling depending on the CCA technology being used. Nevertheless, we are requesting comment on whether repeat air emissions testing is appropriate (or overly burdensome) for the CCA.

3. Electronic Reporting

The EPA must have performance test data to conduct effective reviews of CAA sections 112 and 129 standards, as well as for many other purposes including compliance determinations, emissions factor development and annual emissions rate determinations. In conducting these required reviews, the EPA has found it ineffective and time consuming, not only for us, but also for regulatory agencies and source owners and operators, to locate, collect and submit performance test data because of varied locations for data storage and varied data storage methods. In recent years, though, stack testing firms have typically collected performance test data in electronic format, making it possible to move to an electronic data submittal system that would increase the ease and efficiency of data submittal and improve data accessibility.

Through this proposal, the EPA is presenting a step to increase the ease and efficiency of data submittal and improve data accessibility. Specifically, the EPA is proposing that owners and operators of pulp and paper facilities submit electronic copies of required performance test reports to the EPA's WebFIRE database. The WebFIRE database was constructed to store performance test data for use in developing emissions factors. A description of the WebFIRE database is available at

http://cfpub.epa.gov/oarweb/index.cfm?action=fire.main

As proposed above, data entry would be through an electronic emissions test report structure called the ERT. The ERT would be able to transmit the electronic report through the EPA's CDX network for storage in the WebFIRE database making submittal of data very straightforward and easy. A description of the ERT can be found at

http://www.epa.gov/ttn/chief/ert/ert_tool.html

The proposal to submit performance test data electronically to the EPA would apply only to those performance tests conducted using test methods that will be supported by the ERT. The ERT contains a specific electronic data entry form for most of the commonly used EPA reference methods. A listing of the pollutants and test methods supported by the ERT is available at

http://www.epa.gov/ttn/chief/ert/ert_tool.html

. We believe that industry would benefit from this proposed approach to electronic data submittal. Having these data, the EPA would be able to develop improved emissions factors, make fewer information requests and promulgate better regulations.

One major advantage of the proposed submittal of performance test data through the ERT is a standardized method to compile and store much of the documentation required to be reported by this rule. Another advantage is that the ERT clearly states what testing information would be required. Another important proposed benefit of submitting these data to the EPA at the time the source test is conducted is that it should substantially reduce the effort involved in data collection activities in the future. When the EPA has performance test data in hand, there will likely be fewer or less substantial data collection requests in conjunction with prospective required residual risk assessments or technology reviews. This would result in a reduced burden on both affected facilities (in terms of reduced manpower to respond to data collection requests) and the EPA (in terms of preparing and distributing data collection requests and assessing the results).

State, local and tribal agencies could also benefit from more streamlined and accurate review of electronic data submitted to them. The ERT would allow for an electronic review process rather than a manual data assessment, making review and evaluation of the source provided data and calculations easier and more efficient. Finally, another benefit of the proposed data submittal to WebFIRE electronically is that these data would greatly improve the overall quality of existing and new emissions factors by supplementing the pool of emissions test data for establishing emissions factors and by ensuring that the factors are more representative of current industry operational procedures. A common complaint heard from industry and regulators is that emissions factors are outdated or not representative of a particular source category. With timely receipt and incorporation of data from most performance tests, the EPA would be able to ensure that emissions factors, when updated, represent the most current range of operational practices. In summary, in addition to supporting regulation development, control strategy development and other air pollution control activities, having an electronic database populated with performance test data would save industry, state, local, tribal agencies and the EPA significant time, money and effort while also improving the quality of emissions inventories and, as a result, air quality regulations.

Records must be maintained in a form suitable and readily available for expeditious review, according to § 63.10(b)(1). Electronic recordkeeping and reporting is available for many records, and is the form considered most suitable for expeditious review if available. Electronic recordkeeping and reporting is encouraged in this proposal, and some records and reports are required to be kept in electronic format. Records required to be maintained electronically include the output of continuous monitors and the output of the bag leak detection systems. Additionally, standard operating procedures for the bag leak detection system and fugitive emissions control are required to be submitted to the Administrator for approval in electronic format.

4. Other

The following lists additional minor changes to the subpart S NESHAP and minor changes to the part 63 General Provisions that we are proposing. This list includes proposed rule changes that address editorial and other corrections.

(1) Revise 40 CFR 63.457(b)(1) to specify part 60, appendix A-1 for Method 1 or 1A;

(2) Revise 40 CFR 63.457(b)(3) to specify part 60, appendix A-1 for Method 2, 2A, 2C, or 2D;

(3) Revise 40 CFR 63.457(b)(5)(i) to include four additional test methods—Method 320 of part 63, appendix A; Method 18 of part 60, appendix A-6; ASTM D6420-99; and ASTM D6348-03—for measuring methanol emissions from pulp and paper processes;

(4) Revise 40 CFR 63.457(b)(5)(ii) to specify part 60, appendix A-8 for Method 26A;

(5) Revise 40 CFR 63.457(d) to specify part 60, appendix A-7 for Method 21; and

(6) Revise 40 CFR 63.457(k)(1) to specify part 60, appendix A-2 for Method 3A or 3B, and include ASME PTC 19.10—Part 10 as an alternative to Method 3B;

(7) Revise 40 CFR 63.457(c)(3)(ii) to replace NCASI Method DI/MEOH-94.02 with the more recent version of this method, NCASI Method DI/MEOH-94.03;

(8) Add 40 CFR 63.14(f)(5) to incorporate by reference NCASI Method DI/MEOH-94.03; and

(9) Revise 40 CFR 63.14(i)(1) to incorporate by reference ANSI/ASME PTC 19.10-1981.

(10) Revise 40 CFR 63.14(b)(28) and (54) to incorporate by reference ASTM D6420-99 and ASTM D6348-03, respectively.

E. Compliance Dates

We are proposing that existing facilities must comply with all of the requirements in this action (other than affirmative defense provisions and electronic reporting, which are effective upon promulgation of the final rule) no later than 3 years after the effective date of this rule. All new or reconstructed facilities must comply with all requirements in this rule upon startup.

V. Summary of Cost, Environmental and Economic Impacts

A. What are the affected sources?

The affected source for kraft, soda, sulfite or semi-chemical pulping processes is the total of all HAP emission points in the pulping and bleaching systems. The affected source for mechanical, secondary or non-wood pulping processes is the total of all HAP emission points in the bleaching system.

B. What are the air quality impacts?

Under the proposed amendments, an estimated 15 mills would have to upgrade their steam strippers or biological treatment systems to comply with the more stringent kraft condensates standard. The current proposal is estimated to reduce HAP emissions by approximately 4,000 tpy.

The proposed amendments would require an estimated 114 mills to conduct repeat testing for pulping and bleaching operations and all 171 major sources in the category to operate without the SSM exemption. We were unable to quantify the specific emissions reductions associated with repeat emissions testing or eliminating the SSM exemption and excess emissions allowance. However, repeat testing would provide incentive for facilities to maintain their control systems and make periodic adjustments to ensure peak performance, thereby reducing emissions and the potential for periodic episodes of acute risk. Eliminating the SSM exemption would provide an incentive for facilities to minimize emissions during periods of SSM.

C. What are the cost impacts?

Under the proposed amendments, pulp and paper mills are expected to incur costs to upgrade their steam strippers or biological treatment systems to comply with the more stringent kraft condensates standard. These mills would also incur costs to conduct repeat testing and record malfunctions in support of the new affirmative defense in the rule. The total nationwide annual costs associated with these new requirements is $6.2 million.

D. What are the economic impacts?

The EPA performed an EIA of the proposed rule. The EIA, which documents the data sources and methods used and provides detailed results, can be found in the docket for this proposed action. This section provides an overview of key results.

The EPA performed a series of single-market partial-equilibrium analyses of national pulp and paper product markets to estimate the economic consequences of the proposal. The models predict how the regulatory program might affect prices and quantities for 10 paper and paperboard products that, aggregated, constitute the entire production of the papermaking industry. The EPA also conducted an economic welfare analysis that estimated the consumer and producer surplus changes associated with the regulatory program. The welfare analysis identifies how the regulatory costs are distributed across two broad classes of stakeholders: consumers and producers.

The market analysis found that the proposal is likely to induce minimal changes in the average national price of paper and paperboard products. Paper and paperboard product prices are predicted to increase less than 0.01 percent on average, while production levels decrease less than 0.01 percent on average, as a result of the proposal. The partial equilibrium models predict that consumers will see reductions in economic welfare of about $3.3 million as the result of higher prices and reduced consumption. Although producers' welfare losses are mitigated to some degree by slightly higher prices, market conditions limit their ability to pass on all of the compliance costs. As a result, producers are also predicted to experience a loss in economic welfare of about $2.9 million.

The EPA performed a screening analysis for impacts on small businesses by comparing estimated annualized engineering compliance costs at the company-level to company sales. The screening analysis found that the ratio of compliance cost to company revenue falls below 1 percent for the three small companies that are likely to be affected by the proposal. Based on this analysis, the EPA presumes there is no SISNOSE arising from the proposed NESHAP amendments.

Additionally, the EPA estimated the annual labor required to comply with the requirements of the proposal. To do this, the EPA first estimated the labor required for emission control equipment operation and maintenance, then converted this number to FTEs by dividing by 2,080 (40 hours per week multiplied by 52 weeks). The annual labor requirement to comply with the proposal is estimated at about five full-time-equivalent employees. The EPA notes that this type of FTE estimate cannot be used to make assumptions about the specific number of people involved or whether new jobs are created for new employees.

While a series of partial equilibrium models was used to analyze the economic impacts of this proposal, the EPA notes that it is currently developing the ISIS model for the United States pulp and paper industry. When completed, the ISIS model for the pulp and paper industry will be a dynamic engineering-economic model that facilitates analysis of emissions reduction strategies for multiple pollutants, while taking into account plant-level economic and technical factors, such as the type of mill, associated capacity, location, cost of production, applicable controls and costs. By considering various emissions reduction strategies, the model, when completed, will provide information on optimal industry operation and determine the most cost-effective controls to meet the demand for pulp and paper products and the emissions reduction requirements for a given time period of interest.

E. What are the benefits?

The proposed rule is expected to result in a reduction of approximately 4,000 tpy of HAP. We have not quantified the monetary benefits associated with these reductions.

VI. Request for Comments

We are soliciting comments on all aspects of this proposed action. In addition to general comments on this proposed action, we are also interested in any additional data that may help to reduce the uncertainties inherent in the risk assessments and other analyses. We are specifically interested in receiving corrections to the site-specific emissions profiles used for risk modeling. Such data should include supporting documentation in sufficient detail to allow characterization of the quality and representativeness of the data or information. Section VII of this preamble provides more information on submitting data.

VII. Submitting Data Corrections

The site-spec

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