Regional Haze Regulations and Guidelines for Best Available Retrofit Technology (BART) Determinations

Federal RegisterMay 5, 2004

Ask Donna

What actually matters in this document.

Text

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 51

[FRL-7653-6]

RIN 2060-AJ31

Regional Haze Regulations and Guidelines for Best Available Retrofit Technology (BART) Determinations

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Proposed rule.

SUMMARY:

On July 1, 1999, EPA promulgated regulations to address regional haze, (64 FR 3714). These regulations were challenged, and on May 24, 2002, the U.S. Court of Appeals for the District of Columbia Circuit issued a ruling vacating the regional haze rule in part and sustaining it in part.

American Corn Growers Ass'n

EPA,

291 F.3d 1 (D.C. Cir. 2002). Today's proposed rule addresses the court's ruling in that case.

In addition, prior to the court's decision, EPA had proposed guidelines for implementation of the best available retrofit technology (BART) requirements under the regional haze rule, (66 FR 38108; July 20, 2001). The proposed guidelines were intended to clarify the requirements of the regional haze rule's BART provisions. We proposed to add the guidelines and also proposed to add regulatory text requiring that these guidelines be used for addressing BART determinations under the regional haze rule. In addition, we proposed one revision to guidelines issued in 1980 for facilities contributing to “reasonably attributable” visibility impairment.

In the American Corn Growers case, the court vacated and remanded the BART provisions of the regional haze rule. To respond to the court's ruling, we are proposing new BART provisions and reproposing the BART guidelines. The American Corn Growers court also remanded to the Agency its decision to extend the deadline for the submittal of regional haze plans. Subsequently, Congress amended the deadlines for regional haze plans (Consolidated Appropriations Act for Fiscal Year 2004, Public Law 108-199, January 23, 2004). We are proposing to amend the rule to conform to the new statutory deadlines.

DATES:

Comments on this proposal must be received by July 6, 2004.

ADDRESSES:

Submit your comments, identified by Docket ID No. OAR-2002-0076 by one of the following methods:

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

Follow the on-line instructions for submitting comments. Agency Web site:

http://www.epa.gov/edocket.

EDOCKET, EPA's electronic public docket and comment system, is EPA's preferred method for receiving comments. Follow the on-line instructions for submitting comments.

E-mail: http://www.epa.gov/edocket.

Fax:

202-566-1741.

Mail:

OAR Docket, Environmental Protection Agency, Mailcode: B102, 1200 Pennsylvania Ave., NW., Washington, DC 20460. Please include a total of 2 copies.

Hand Delivery:

EPA/DC, EPA West, Room B102, 1301 Constitution Ave., NW., Washington, DC. Such deliveries are only accepted during the Docket's normal hours of operation, and special arrangements should be made for deliveries of boxed information.

Instructions:

Direct your comments to Docket ID No. OAR-2002-0076. EPA's policy is that all comments received will be included in the public docket without change and may be made available online at

http://www.epa.gov/edocket,

including any personal information provided, unless the comment includes information claimed to be Confidential Business Information (CBI) or other information whose disclosure is restricted by statute. Do not submit information that you consider to be CBI or otherwise protected through EDOCKET, regulations.gov, or e-mail. The EPA EDOCKET and the federal regulations.gov Web sites are “anonymous access” systems, which means EPA will not know your identity or contact information unless you provide it in the body of your comment. If you send an e-mail comment directly to EPA without going through EDOCKET or regulations.gov, your e-mail address will be automatically captured and included as part of the comment that is placed in the public docket and made available on the Internet. If you submit an electronic comment, EPA recommends that you include your name and other contact information in the body of your comment and with any disk or CD-ROM you submit. If EPA cannot read your comment due to technical difficulties and cannot contact you for clarification, EPA may not be able to consider your comment. Electronic files should avoid the use of special characters, any form of encryption, and be free of any defects or viruses. For additional information about EPA's public docket visit EDOCKET on-line or see the

Federal Register

of May 31, 2002 (67 FR 38102).

For additional instructions on submitting comments, go to unit II of the

SUPPLEMENTARY INFORMATION

section of this document.

Docket:

All documents in the docket are listed in the EDOCKET index at

http://www.epa.gov/edocket.

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

i.e.

, CBI or other information whose disclosure is restricted by statute. Certain other material, such as copyrighted material, is not placed on the Internet and will be publicly available only in hard copy form. Publicly available docket materials are available either electronically in EDOCKET or in hard copy at the OAR Docket, EPA/DC, EPA West, Room B102, 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 OAR Docket is (202) 566-1742.

FOR FURTHER INFORMATION CONTACT:

Kathy Kaufman at 919-541-0102 or by e-mail at

Kaufman.Kathy@epa.gov

or Todd Hawes at 919-541-5591 or by e-mail

Hawes.Todd@epa.gov.

SUPPLEMENTARY INFORMATION:

I. Regulated Entities

The promulgation of the proposed rule would affect the following: State and local permitting authorities and Indian Tribes containing major stationary sources of pollution affecting visibility in federally protected scenic areas.

This list is not intended to be exhaustive, but rather provides a guide for readers regarding entities likely to be regulated by this action. This list gives examples of the types of entities EPA is now aware could potentially be regulated by this action. Other types of entities not listed could also be affected. To determine whether your facility, company, business, organization, etc., is regulated by this action, you should examine the applicability criteria in Part II of this preamble. If you have any questions regarding the applicability of this action to a particular entity, consult the person listed in the preceding

FOR FURTHER INFORMATION CONTACT

section.

II. What Should I Consider as I Prepare My Comments for EPA?

1. Submitting CBI. Do not submit this information to EPA through EDOCKET, regulations.gov or e-mail. Clearly mark the part or all of the information that you claim to be CBI. For CBI information in a disk or CD-ROM that you mail to EPA, mark the outside of the disk or CD-ROM as CBI and then identify electronically within the disk or CD-ROM the specific information that

is claimed as CBI). In addition to one complete version of the comment that includes information claimed as CBI, a copy of the comment that does not contain the information claimed as CBI must be submitted for inclusion in the public docket. Information so marked will not be disclosed except in accordance with procedures set forth in 40 CFR part 2.

2. Tips for Preparing Your Comments. When submitting comments, remember to:

A. Identify the rulemaking by docket number and other identifying information (subject heading,

Federal Register

date and page number).

B. Follow directions—The agency may ask you to respond to specific questions or organize comments by referencing a Code of Federal Regulations (CFR) part or section number.

C. Explain why you agree or disagree; suggest alternatives and substitute language for your requested changes.

D. Describe any assumptions and provide any technical information and/or data that you used.

E. If you estimate potential costs or burdens, explain how you arrived at your estimate in sufficient detail to allow for it to be reproduced.

F. Provide specific examples to illustrate your concerns, and suggest alternatives.

G. Explain your views as clearly as possible, avoiding the use of profanity or personal threats.

H. Make sure to submit your comments by the comment period deadline identified.

Outline. The contents of today's preamble are listed in the following outline.

I. Overview of Today's Proposed Actions

II. Background

A. Regional Haze Rule

B. Partial Remand of the Regional Haze Rule in American Corn Growers

C. Proposed Changes to the Visibility Regulations

D. Reproposal of the BART Guidelines

III. Detailed Discussion of Reproposed BART Guidelines

A. Introduction

B. How to Identify BART-eligible Sources

C. How to Determine Which BART-eligible Sources are Subject to BART

D. The BART Determination Process

E. Trading Program Guidance

IV. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and 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 That Significantly Affect Energy Supply, Distribution, or Use

I. National Technology Transfer Advancement Act

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

I. Overview of Today's Proposed Actions

Today's rulemaking provides for the following proposed changes to the regional haze regulations:

(1) Revised regulatory text in response to the American Corn Growers court's remand, to require that the BART determination includes an analysis of the degree of visibility improvement resulting from the use of control technology at each source subject to BART,

(2) revised regulatory text in 40 CFR 51.308(b) and deletion of 40 CFR 51.308(c) Options for regional planning in response to Congressional legislation amending the deadlines for submittal of regional haze implementation plans. This provision had provided for an alternative process for States to submit regional haze implementation plans in attainment areas,

(3) BART guidelines, contained in a new appendix Y to 40 CFR part 51,

(4) new and revised regulatory text, to be added to 40 CFR 51.308(e) to require the use of appendix Y in establishing BART emission limits, and

(5) revised regulatory language at 51.302 to clarify the relationship between New Source Performance Standards (NSPS) and BART for reasonably attributable visibility impairment.

How This Preamble Is Structured. Section II provides background on the regional haze rule, the D.C. Circuit Court decision which remanded parts of the rule, and the proposed changes to the rule and reproposal of the BART guidelines in response to the remand. Section III discusses in more detail the reproposed BART guidelines, including changes from the July 2001 proposal based the court decision and certain comments that we received on the initial proposal. Section IV provides a discussion of how this rulemaking complies with the requirements of Statutory and Executive Order Reviews.

II. Background

A. Regional Haze Rule

In 1999, we published a final rule to address a type of visibility impairment known as regional haze (64 FR 35714; July 1, 1999). The regional haze rule requires States to submit implementation plans (SIPs) to address regional haze visibility impairment in 156 Federally-protected parks and wilderness areas. These 156 scenic areas are called “mandatory Class I Federal areas” in the Clean Air Act (CAA),

but are referred to simply as “Class I areas” in today's rulemaking. The 1999 rule was issued to fulfill a long-standing EPA commitment to address regional haze under the authority and requirements of sections 169A and 169B of the CAA.

See,

e.g.,

CAA Section 169A(a)(1).

As required by the CAA, we included in the final regional haze rule a requirement for BART for certain large stationary sources that were put in place between 1962 and 1977. We discussed these requirements in detail in the preamble to the final rule (64 FR 35737-35743). The regulatory requirements for BART were codified at 40 CFR 51.308(e), and in definitions that appear in 40 CFR 51.301.

The CAA, in sections 169A(b)(2)(A) and in 169A(g)(7), uses the term “major stationary source” to describe those sources that are the focus of the BART requirement. To avoid confusion with other CAA requirements which also use the term “major stationary source” to refer to a somewhat different population of sources, the regional haze rule uses the term “BART-eligible source” to describe these sources. The BART-eligible sources are those sources which have the potential to emit 250 tons or more of a visibility-impairing air pollutant, were put in place between August 7, 1962 and August 7, 1977, and whose operations fall within one or more of 26 specifically listed source categories. Under the CAA, BART is required for any BART-eligible source which “emits any air pollutant which may reasonably be anticipated to cause or contribute to any impairment of visibility in any such area.” Accordingly, for stationary sources meeting these criteria, States must address the BART requirement when they develop their regional haze SIPs.

Section 169A(g)(7) of the CAA requires that States must consider the following factors in making BART determinations:

(1) The costs of compliance,

(2) The energy and nonair quality environmental impacts of compliance,

(3) Any existing pollution control technology in use at the source,

(4) The remaining useful life of the source, and

(5) The degree of improvement in visibility which may reasonably be

anticipated to result from the use of such technology.

These statutory factors for BART were codified at 40 CFR 51.308(e)(1)(ii).

In the preamble to the regional haze rule, we committed to issuing further guidelines to clarify the requirements of the BART provision. The purpose of this proposed rulemaking is to fulfill this commitment by providing guidelines for States to use in identifying their BART-eligible sources, in identifying which of those sources must undergo a detailed BART analysis (

i.e.

, which are “sources subject to BART”), and in conducting the technical analysis of possible controls in light of the statutory factors listed above (“the BART determination”).

B. Partial Remand of the Regional Haze Rule in American Corn Growers

In response to challenges to the regional haze rule by various petitioners, the D.C. Circuit in American Corn Growers

et al.

v. EPA, 291 F.3d 1 (2002) issued a ruling striking down the regional haze rule in part, and upholding it in part. This section discusses the court's opinion in that case, as background for the discussion of specific changes to the regional haze rule and the BART guidelines presented in the next two sections, respectively.

We explained in the preamble to the 1999 regional haze rule that the BART requirements in section 169A(b)(2)(A) of the CAA demonstrate Congress' intent to focus attention directly on the problem of pollution from a specific set of existing sources (64 FR 35737). The CAA requires that any of these existing sources “which, as determined by the State, emits any air pollutant which may reasonably be anticipated to cause or contribute to any impairment of visibility [in a Class I area],” shall install the best available retrofit technology for controlling emissions.

In determining BART, the CAA requires the State to consider several factors that are set forth in section 169(g)(2) of the CAA, including the degree of improvement in visibility which may reasonably result from the use of such technology.

CAA Sections 169A(b)(2) and (g)(7).

The regional haze rule addresses visibility impairment resulting from emissions from a multitude of sources located across a wide geographic area. Because the problem of regional haze is caused in large part by the long-range transport of emissions from multiple sources, and for certain technical and other reasons explained in that rulemaking, we had adopted an approach that required States to look at the contribution of all BART sources to the problem of regional haze in determining both applicability and the appropriate level of control. Specifically, we had concluded that if a source potentially subject to BART is located within an upwind area from which pollutants may be transported downwind to a Class I area, that source “may reasonably be anticipated to cause or contribute” to visibility impairment in the Class I area. Similarly, we had also concluded that in weighing the factors set forth in the statute for determining BART, the States should consider the collective impact of BART sources on visibility. In particular, in considering the degree of visibility improvement that could reasonably be anticipated to result from the use of such technology, we stated that the State should consider the degree of improvement in visibility that would result from the cumulative impact of applying controls to all sources subject to BART. We had concluded that the States should use this analysis to determine the appropriate BART emission limitations for specific sources.

See 66 FR 35737-35743 for a discussion of the rationale for the BART requirements in the 1999 regional haze rule.

In American Corn Growers v. EPA, industry petitioners challenged EPA's interpretation of both these aspects of the BART determination process and raised other challenges to the rule. While rejecting industry's other challenges, the court in American Corn Growers concluded that the BART provisions in the 1999 regional haze rule were inconsistent with the provisions in the CAA “giving the states broad authority over BART determinations.” 291 F.3d at 8. Specifically, with respect to the test for determining whether a source is subject to BART, the court held that the method that EPA had prescribed for determining which eligible sources are subject to BART illegally constrained the authority Congress had conferred on the States. Id. However, the court expressly declined to hold that the general collective contribution approach to determining BART applicability was necessarily inconsistent with the CAA, were it not for the infringement on State authority. Id. at 9. Rather, the court stated that the collective contribution approach may have been acceptable if EPA had allowed for a State exemption process based on an individualized contribution determination. Id. at 12.

The court in American Corn Growers also found that EPA's interpretation of the CAA requiring the States to consider the degree of improvement in visibility that would result from the cumulative impact of applying controls in determining BART was inconsistent with the language of the Act. 291 F.3d at 8. Based on its review of the statute, the court concluded that the five statutory factors in section 169A(g)(2) “were meant to be considered together by the states.” Id. at 6.

Finally, the court remanded the schedule in the regional haze rule for the submission of implementation plans for areas that commit to regional planning, indicating that the use of such a “committal SIP” does not appear to satisfy statutory requirements. The court declined to vacate the provision, however, in light of the need to change SIP requirements in order to satisfy the ruling on the BART issue. Id. at 15.

C. Proposed Changes in the Visibility Regulations

Today's proposed rule responds to the American Corn Growers court's decision on the BART provisions by proposing changes to the regional haze rule at 40 CFR 51.308, and by reproposing the BART guidelines. This section outlines the changes to the regional haze rule due to the court's remand and to subsequent Congressional action regarding deadlines for the submission of regional haze implementation plans. It also explains the minor change we are proposing to the section of the regulation governing the use of the 1980 BART guidelines when conducting BART analyses for certain power plants for reasonably attributable (

i.e.

, localized) visibility impairment.

1. Determination of Which Sources Are Subject to BART

Today's proposed action addresses the American Corn Growers court's vacature of the requirement in the regional haze rule requiring States to assess visibility impacts on a cumulative basis in determining which sources are subject to BART. Because this requirement was found only in the preamble to the 1999 regional haze rule (see 291 F.3rd at 6, citing 64 FR 35741), no changes to the regulations are required. Instead, this issue is addressed in the BART guidelines, which provide States with a number of options for determining which BART-eligible sources “may reasonably be anticipated to cause or contribute to any impairment of visibility in any mandatory Class I Federal area.” These options have been designed to address the holding of American Corn Growers by eliminating the previous constraint on State discretion, as explained in

further detail in sections II.D. and III below.

2. Consideration of Anticipated Visibility Improvements in BART Determinations

Pursuant to the remand in American Corn Growers, we are proposing to amend the regional haze rule to require the States to consider the degree of visibility improvement resulting from a source's installation and operation of retrofit technology, along with the other statutory factors set out in CAA section 169A(g)(2), when making a BART determination. This would be accomplished by listing the visibility improvement factor with the other statutory BART determination factors in section 308(e)(1)(A), so that States will be required to consider all five factors, including visibility impacts, on an individual source basis when making each individual source BART determination.

In addition, Section 308(e)(1)(B), which formerly required States to assess visibility on a cumulative basis (

i.e.

, for all BART-eligible sources), would be replaced with a requirement to use the BART guidelines at appendix Y. The guidelines, as will be explained in the next section and in greater detail in section III, provide for source-specific analysis of anticipated improvement in visibility. These changes, therefore, address the court's holding with respect to the isolation of the visibility improvement factor at this stage of the BART analysis.

3. Implementation Plan Deadlines

As noted above, the 1999 regional haze rule contained a committal SIP mechanism (section 308(c)) which the American Corn Growers court remanded without vacating. This mechanism was intended to allow states to harmonize regional haze SIP submittals for all areas within the state. At the time the rule was promulgated, the deadline for regional haze SIPs varied depending on the PM

2.5

attainment or nonattainment status of the area.

Transportation Equity Act for the 21st Century, Pub. L. 105-178, 112 Stat. 107, 463 (1998) (TEA-21).

In the Omnibus Appropriations Act of 2004,

Congress harmonized both designations and regional haze SIP deadlines. Under the Omnibus Appropriations Act, we are required to promulgate PM

2.5

designations for all areas of each state no later than December 31, 2004. Designations will become effective 30 days afterward, or no later than January 31, 2005. The Omnibus Appropriations Act further provides that regional haze SIPs, for each entire state, are then due not later than 3 years after promulgation of the PM

2.5

designation.

Thus, regional haze SIPs are due no later than January, 31, 2008. We are proposing to amend 40 CFR 51.308(b) and 51.308(c) to comport with the new statutory deadlines, and to eliminate the “comittal” SIP provision.

Consolidated Appropriations Act for Fiscal Year 2004, Pub. L. 108-199, January 23, 2004.

CAA Section 107(d)(7)(A), as amended by the Consolidated Appropriations Act for Fiscal Year 2004, now reads: “In General.—Notwithstanding any other provision of law, not later than 3 years after the date on which the Administrator promulgates the designations referred to in Paragraph (6)(B) for a State, the State shall submit, for the entire State, the State implementation plan revisions to meet the requirements promulgated by the Administrator under section 169B(e)(1) (referred to in this paragraph as ‘regional haze requirements’).”

We are also proposing to amend certain sections of 40 CFR 51.309 to comport with the new statutory deadlines. Under Section 309 as currently codified, the initial SIPs for states utilizing Section 309 were due in 2003, and a second set of SIPs for those states are due no later than December 31, 2008. This date was designed to coincide with the latest date Section 308 SIPs could be due under the statutory scheme prior to amendment by the Omnibus Act. The Omnibus Amendments contain a “no preclusion” provision, clarifying that nothing therein precludes the submission of section 309 SIPs by December 31, 2003.

The “no preclusion” provision does not expressly provide that the later (currently 2008) section 309 deadlines are not precluded. There is therefore some ambiguity as to whether the 3-year-after-designation deadline applies to subsequent section 309 SIPs. We believe that policy interests of certainty, clarity, and coordination of efforts are best served by establishing consistent deadlines for SIPs under sections 308 and 309 where appropriate, and by avoiding any ambiguity regarding future section 309 SIP deadlines. Therefore, we are proposing to amend sections 309(d)(4)(v), 309(g)(2), and 309(g)(3), by replacing “December 31, 2008” with “January 31, 2008”, to coincide with section 308 SIPs.

CAA section 107(d)(7)(B) “No Preclusion of Other Provisions.—Nothing in this paragraph precludes the implementation of of the agreements and recommendations stemming from the Grand Canyon Visibility Transport Commission Report dated June 1996, including the submission of State implementation plan revisions by the States of Arizona, California, Colorado, Idaho, Nevada, New Mexico, Oregon, Utah, or Wyoming by December 31, 2003, for implementation of regional haze requirements applicable to those States.”

These are the section of 309 establishing deadlines for SIP revisions which contain major new policy initiatives which should, for efficiency, be coordinated with the development of section 308 SIPs; specifically long term strategies and BART requirements for stationary source NO

and PM, if determined to be necessary (section 309(d)(4)(v)), and reasonable progress provisions for additional (non-Colorado Plateau) class I areas (section 309(g)(2)-(g)(3)).

We are aware that 2008 deadlines also appear in section 309(d)(10) (progress reports) and section 309(b)(6) (mobile source tracking and revisions if necessary). We are not proposing to amend these sections because they are part of a scheme establishing check points for § 309 strategies in 2008, 2013, and 2018, rather than development of new strategies, and thus do not require integration with § 308 SIPs.

4. Proposed Revisions to the 1980 BART Guidelines

Background. One of the primary purposes of this reproposal is to provide BART guidelines for the regional haze program. As described in the 2001 proposed BART guidelines (66 FR 38108, 38109), however, we are also proposing to make limited revisions to longstanding guidelines for BART under the 1980 visibility regulations for localized visibility impairment that is “reasonably attributable” to one or a few sources.

The visibility regulations require States to use a 1980 guidelines document when conducting BART analyses for certain power plants for reasonably attributable visibility impairment. While the analytical process set forth in these guidelines is still generally acceptable for conducting BART analyses for “reasonably attributable” visibility impairment, there are statements in the 1980 BART Guidelines that could be read to indicate that the NSPS may be considered to represent best control for existing sources. While this may have been the case in 1980 (

e.g.

, the NSPS for sulfur dioxide (SO

) from boilers had been recently issued in June 1979), best control levels for recent plant retrofits have exceeded NSPS levels. Therefore, we are proposing to amend this provision of the 1980 visibility regulations to clarify that BART should not be interpreted under the 1980 regulations to preclude control options which are more stringent than NSPS standards.

U.S. Environmental Protection Agency,

Guidelines for Determining Best Available Retrofit Technology for Coal-fired Power Plants and Other Existing Stationary Facilities,

EPA-450/3-80-009b, Office of Air Quality Planning and Standards, Research Triangle Park, N.C., November 1980 (1980 BART Guidelines).

D. Reproposal of the BART Guidelines

Prior to the American Corn Growers decision, we had proposed guidelines for the regional haze BART process. Specifically, on July 20, 2001, the proposed BART guidelines were published in the

Federal Register

(66 FR 13108-13135). We requested written

comments on the proposal and conducted two public hearings. The deadline for written comments was extended from September 18, 2001 to October 5, 2001 in a separate

Federal Register

notice (66 FR 50135).

Public hearings were held on August 21, 2001 in Alexandria, Virginia and on August 27, 2001 in Chicago, Illinois. Transcripts for these public hearings are available in the public docket for the regulation (Docket A-2000-28, Docket numbers IV-F-01 and IV-F-02). Oral testimony in both public hearings was predominantly from private citizens supportive of the proposed BART guidelines.

We received written comments on the package from many citizens and stakeholder groups.

Today, we are reproposing the BART guidelines to take into account the changes that we are proposing to make to the regional haze rule. Although in reproposing the BART guidelines we have taken into account some of the comments that we received in response to the 2001 action, much of what is set forth in the BART guidelines proposed today is identical to the earlier proposal. Both for those proposed requirements in the BART guidelines which are unchanged from the 2001 proposal, as well as for those that we have changed since 2001, you do not need to resubmit comments unless you have additional information that you would like us to consider, because we will carefully consider all comments previously submitted during the comment period on the 2001 proposal in making our final decision on the BART guidelines.

The proposed BART process is set forth in the BART guidelines we are reproposing today in response to the remand. The rest of this section provides an overview of this proposed BART process. The overview summarizes both (1) the process for determining which BART-eligible sources may be reasonably anticipated to cause or contribute to visibility impairment, and thus should be subject to BART, and (2) the process for evaluating visibility impacts for an individual source's BART determination. (We will discuss these issues in further detail in section III below.)

The BART Process

The process of establishing BART emission limitations can be logically broken down into three steps: First, States identify those sources which meet the definition of “BART-eligible source” set forth in 40 CFR 51.301.

Second, States determine whether such sources “emit[] any air pollutant which may reasonably be anticipated to cause or contribute to any impairment of visibility [in a Class I area.]” A source which fits this description is “subject to BART.” Third, for each source subject to BART, States then identify the appropriate type and the level of control for reducing emissions.

“BART-eligible source” is defined as a stationary source of air pollutants that falls within one of 26 listed categories which was put into operation between August 7, 1962 and August 7, 1977, with the potential to emit 250 tons per year of any air pollutant. CAA §§ 169(b)(2)(A) and (g)(7); 40 CFR § 51.301.

Identifying BART-Eligible Sources

The CAA defines BART-eligible sources as those sources which fall within one of 26 specific source categories, were built during the 15-year window of time from 1962 to 1977, and have potential emissions greater than 250 tons per year. The remand did not address the step of identifying BART-eligible sources, which is conceptually the simplest of the three steps.

Sources Reasonably Anticipated To Cause or Contribute To Visibility Impairment (Sources Subject to BART)

As we noted in the preamble to the 1999 regional haze rule, defining the individual contributions of specific sources of the problem of regional haze can be time-consuming and expensive. Moreover, Congress established a very low threshold in the CAA for determining whether a source is subject to BART. We are accordingly proposing several approaches for States for making the determination of whether a source “emits any pollutants which may reasonably be anticipated to cause or contribute to any visibility impairment.” The first two of these approaches would allow States to avoid undertaking unnecessary and costly studies of an individual source's contribution to haze by allowing States to adopt more streamlined processes for determining whether, or which, BART-eligible sources are subject to BART.

In 1999, we adopted an applicability test that looked to the collective contribution of emissions from an area. In particular, we stated that if “a State should find that a BART-eligible source is “reasonably anticipated to cause or contribute” to regional haze if it can be shown that the source emits pollutants within a geographic area from which pollutants can be emitted and transported downwind to a Class I area.”

Under today's proposal, a State has the discretion to consider that all BART-eligible sources within the State are “reasonably anticipated to cause or contribute” to some degree of visibility impairment in a Class I area.

64 FR 335740, July 1, 1999. The regional haze rule discusses at length why we believe that States should draw this conclusion. 64 FR 35739-40.

This option is consistent with the American Corn Growers court's decision. As previously noted, the court's concern with our original approach governing BART applicability determinations was that it would have “tie[d] the states” hands and force[d] them to require BART controls at sources without any empirical evidence of the particular source's contribution to visibility impairment.” 291 F.3d at 8. By the same rationale, we believe it would be an impermissible constraint of State authority to force States to conduct individualized analysis in order to determine that a BART-eligible source “emits any air pollutant which may reasonably be anticipated to cause or contribute to any impairment of visibility in any [Class I] area.”

In this respect, we believe that it is important to note that the court in American Corn Growers expressly declined to hold that consideration of visibility impact on a cumulative basis would be invalid in all circumstances. 291 F.3d at 9. Given the court's emphasis on the importance of the role of the States in making BART determinations, we believe that a State's decision to use a cumulative analysis at the eligibility stage would be consistent with the CAA and the findings of the D.C. Circuit.

CAA § 169A(b)(2)(A).

We believe there is ample technical evidence supporting a finding by a State that all BART-eligible sources within the State are subject to BART, without further analysis at that stage in the process.

Any potential for inequity towards sources would be addressed at the BART determination stage, where we are proposing to require the individualized consideration of a source's contribution in establishing BART emission limits.

See 64 FR 35714, 35721. See also July 29, 1997 memorandum to the regional haze docket A-95-38, “Supporting Information for Proposed Applicability of Regional Haze Regulations,” by Richard Damberg, EPA, Office of Air Quality Planning and Standards.

The reasoning underlying this approach is discussed in more detail in section III below.

We are also proposing to provide States with the option of performing an analysis to show that the full group of BART-eligible sources in a State cumulatively do not cause or contribute

to any visibility impairment in Class I areas. We anticipate that in most, if not all States, the BART-eligible sources are likely to cause or contribute to some visibility impairment in Class I areas. However, it is possible that using a cumulative approach, a State could show that its BART sources do not collectively pose a measurable problem.

Finally, we are also proposing that States may consider the individualized contribution of a BART-eligible source to determine whether a specific source is subject to BART. Specifically, States may choose to undertake an analysis of each BART-eligible source in the State in considering whether each such source meets the test set forth in the CAA of “emit[ting] any air pollutant which may reasonably be anticipated to cause or contribute to any impairment of visibility in any [Class I] area.” Alternatively, States may choose to presume that all BART-eligible sources within the State meet this applicability test, but provide sources with the ability to demonstrate on a case by case basis that this is not the case. This approach is consistent with the D.C. Circuit's statement that a collective contribution approach may be appropriate so long as the States are allowed to exempt sources on the basis of an individualized contribution determination. 291 F.3d at 8.

For assessing the impact of BART-eligible sources located greater than 50 kilometers (km) from a Class I area, we are proposing that the States use an air quality model able to estimate a single source's contribution to visibility impairment. We are also requesting comment on methods appropriate for Class I areas closer than 50 km; and on other potential methods of assessing a source's individualized contribution to regional haze visibility impairment. (This is explained in greater detail in section III below).

The BART Determination

The State must determine the appropriate level of BART control for each source subject to BART. Section 169A(g)(7) of the CAA requires States to consider the following factors in making BART determinations: (1) The costs of compliance, (2) the energy and nonair quality environmental impacts of compliance, (3) any existing pollution control technology in use at the source, (4) the remaining useful life of the source, and (5) the degree of improvement in visibility which may reasonably be anticipated to result from the use of such technology. The remand did not address the first four steps of the BART determination (the “engineering analysis”). The remand did address the final step, mandating that EPA must provide a way for States to take into account the degree of improvement in visibility that would result from imposition of BART on each individual source.

The BART engineering analysis, comprising the first four factors, is addressed in detail in section IV below, and is substantially similar to the engineering analysis in the original BART guidelines proposed in July, 2001. Section IV also contains a detailed discussion of available and cost-effective controls for reducing SO

and nitrogen oxicdes (NO

) emissions from large coal-fired electric generating units (EGUs).

For assessing the fifth factor, the degree of improvement in visibility from various BART control levels, we are proposing that States require individual sources to run CALPUFF, or other EPA-approved model, using site-specific data. To estimate a source's impact on visibility, the source would run the model using current allowable emissions, and then again at the post-control emissions level (or levels) being assessed. Results would then be tabulated for the average of the 20% worst modeled days at each receptor. The difference in the resulting level of impairment predicted is the degree of improvement in visibility expected.

Alternatively, we request comment on the option of using the hourly modeled impacts from CALPUFF and assessing the improvement in visibility based on the number of hours above a visibility threshold for the pre- and post-control emission rates.

III. Detailed Discussion of Reproposed BART Guidelines

A. Introduction

In this section of the preamble, we discuss the details of the reproposed BART guidelines where we are proposing to make changes to, or to clarify, the BART guidelines proposed in July, 2001. As noted in section II, we will be reviewing the comments received during the comment period on the 2001 proposal and responding to those comments when we issue a final guideline. For each provision of the guidelines that we are changing or clarifying, we provide discussion of, as appropriate:

—Background information,

—What we proposed in the July 2001 action,

—A summary or partial summary of the comments received on the provision, and

—The changes or clarifications that we are proposing and the reasons for these changes or clarifications.

B. How To Identify BART-Eligible Sources

The CAA, in section 169A(g)(7), provides a specific list of the types of “major stationary sources” that are covered by the BART requirement. Our visibility regulations include this same list in 40 CFR 51.301 in the definition of the term “existing stationary facility” and by reference, “BART-eligible source.” Because the terms “major stationary source” and “existing stationary facility” are general in nature and used for other air quality programs, we decided to eliminate any potential confusion by using the term “BART-eligible source” in the regional haze portions of the visibility regulations that were published in 1999. As defined in 40 CFR 51.301, a “BART-eligible source” means the same thing as an “existing stationary facility” as defined in EPA's 1980 visibility regulations, and means the same thing as a “major stationary source” as defined in CAA section 169A(g)(7).

Section II of the reproposed BART guidelines contains a step-by-step process for identifying stationary sources that are “BART-eligible” under the definitions in the regional haze rule. Today's action reproposing the BART guidelines includes the same four basic steps as in the proposed rule. The four basic steps are:

Step 1: Identify the emission units in the BART categories

Step 2: Identify the start-up dates of those emission units

Step 3: Compare the potential emissions from units identified in Steps 1 and 2 to the 250 ton/yr cutoff

Step 4: Identify the emission units and pollutants that constitute the BART-eligible source.

We received a number of comments on this proposed approach to identifying BART-eligible sources. In this section of the preamble, we discuss some of the previously submitted comments and any changes we are proposing in light of these comments.

Step 1:

Identify the emission units in the BART cateories.

Background. The CAA uses the following 26 source category titles to describe the types of stationary sources that are BART-eligible:

(1) Fossil-fuel fired steam electric plants of more than 250 million British thermal units (BTU) per hour heat input,

(2) Coal cleaning plants (thermal dryers),

(3) Kraft pulp mills,

(4) Portland cement plants,

(5) Primary zinc smelters,

(6) Iron and steel mill plants,

(7) Primary aluminum ore reduction plants,

(8) Primary copper smelters,

(9) Municipal incinerators capable of charging more than 250 tons of refuse per day,

(10) Hydrofluoric, sulfuric, and nitric acid plants,

(11) Petroleum refineries,

(12) Lime plants,

(13) Phosphate rock processing plants,

(14) Coke oven batteries,

(15) Sulfur recovery plants,

(16) Carbon black plants (furnace process),

(17) Primary lead smelters,

(18) Fuel conversion plants,

(19) Sintering plants,

(20) Secondary metal production facilities,

(21) Chemical process plants,

(22) Fossil-fuel boilers of more than 250 million BTUs per hour heat input,

(23) Petroleum storage and transfer facilities with a capacity exceeding 300,000 barrels,

(24) Taconite ore processing facilities,

(25) Glass fiber processing plants, and

(26) Charcoal production facilities.

Most of the source category titles are general descriptors that are inclusive of all the operations at a given plant. Some plant sites may have more than one of the categories present. Examples of this would include plants with both “petroleum refineries” and “sulfur recovery plants,” or with both “iron and steel mill plants” and “sintering plants.” On the other hand, some plant sites may include some emissions units meeting one of these 26 descriptions, but other emissions units that do not.

2001 Proposed Rule. In the 2001 proposed BART guidelines, we noted that the category titles were generally clear and we proposed to clarify a few issues, including interpretations where we believed there were ambiguities in the source category titles. We requested comment on whether any other clarifications were needed. The 2001 proposed guidelines clarified that in identifying emissions units for inclusion as a BART-eligible source, States should identify all emissions units at a plant site meeting one or more of the source category descriptions. The 2001 proposed rule provided specific interpretations for five of the 26 source category titles:

(1) “Steam electric plants of more than 250 million BTU/hr heat input.” The 2001 proposal noted that because the category title refers to “plants,” boiler capacities must be aggregated to determine whether the 250 million BTU/hr threshold is reached.

(2) “Fossil-fuel boilers of more than 250 million BTU/hr heat input.” We proposed two options for interpreting this source category title. The first option, the approach used in the regulations for prevention of significant deterioration (PSD) program, would be to aggregate boiler capacities to determine whether the 250 million BTU/hr threshold is reached. Under the second option, only those boilers that are individually greater than 250 million BTU/hr would fall within the BART source category.

(3) “Petroleum storage and transfer facilities with a capacity exceeding 300,000 barrels.” In the 2001 proposal, we noted our interpretation that the 300,000 barrel cutoff refers to total, facility-wide tank capacity for tanks that were put in place within the 1962-1977 time period, and includes gasoline and other petroleum-derived liquids.

(4) “Phosphate rock processing plants.” In the 2001 proposal, we noted that this category descriptor should be interpreted broadly to include all types of phosphate rock processing facilities, including elemental phosphorous plants as well as fertilizer production plants.

(5) “Charcoal production facilities.” In the 2001 proposal, we noted information provided by the National Association of Manufacturers (NAM) on the legislative history for this source category. In its letter, NAM suggested that the legislative history supported a conclusion that BART should cover only a subset of the charcoal production industry. While we indicated that we did not agree with this assessment, we requested comment on whether and how the information cited by NAM is relevant to the interpretation of this or other categories.

Finally, in the 2001 proposal, we requested comment generally on whether any additional source category titles needed clarification.

Comments on the 2001 Proposal. We received a number of comments related to the interpretation of the source category titles. Some of these comments related to the category-specific clarifications we provided in the proposed guidelines. In addition, there were a few comments in response to our request for additional category titles needing clarification. In this section, we only discuss the previously submitted comments that have led to the changes we are proposing in today's action.

We received many comments related to our interpretation of the term “fossil-fuel boilers of more than 250 million BTUs per hour heat input.” A number of comments from environmental groups and States were supportive of an interpretation which would require States to compare the aggregate capacities of boilers against the 250 million BTU/hr cutoff. These comments agreed with our assessment that this would promote consistency with the PSD program. Environmental group comments also noted that the plural term “boilers” was used in the CAA, rather than the singular term “any boiler.”

Many commenters from industry groups and some State agencies supported the alternative interpretation of the category, which would require States to consider as BART-eligible only those boilers which are individually greater than 250 million BTU/hr. These commenters generally asserted that this was the plain reading of the source category title, and also that such an approach would be consistent with EPA programs such as NSPS and the NO

SIP Call.

These commenters noted that, unlike the PSD program, circumvention of the requirements is not possible because BART only applies to boilers already in existence. Other commenters noted that aggregation of boilers may result in inclusion of very small boilers for which BART controls would not be cost effective.

The NO

SIP call requires a number of Eastern States to reduce the Summertime emissions of NO

from sources within these States. 63 FR 57356 (Oct. 27, 1998).

In addition to the general comments on the interpretation of the size cutoff for boilers, we received comments on two other aspects of the term “fossil fuel boilers.” Some boilers burn solid fuels that are not fossil fuels, such as wood products. A number of industry commenters suggested that we should interpret the term “fossil fuel” as it was interpreted for the NO

SIP Call, which treats as “fossil fuel” only those boilers that burn more than 50 percent fossil fuels, on an annual heat input basis. One commenter noted as an example that a boiler that has fossil fuel capacity greater than 250 million BTU/hr, but that only burns such fuels during startup and shutdown, should not be considered as a “fossil fuel fired boiler” for purposes of BART. Comments from the paper industry requested that EPA clarify in the guidelines that a multi-fuel boiler, with a capacity of greater than or equal to 250 million Btu/hr, would not be considered BART-eligible if the boiler is subject to an enforceable limitation that would prohibit combustion at greater than 250 million BTU/hr.

Several commenters requested that we provide a specific interpretation for the term “secondary metal production facilities.” The commenters requested that we formally define the term to include only those facilities within the Standard Industrial Classification (SIC) code 3341, “Secondary Smelting and Refining of Nonferrous Metals.” Also, the commenters recommended that a “Secondary Metal Production Facility” be defined to mean one or more emission units that derive more than fifty percent of the metal(s) it produces from purchased scrap and dross.

Reproposal. After considering these comments, we are proposing some changes to the source category definitions.

We agree that the interpretation of “fossil-fuel boilers of more than 250 million BTU/hr heat input” is best read to include only those boilers at a power plant individually greater than 250 million BTU/hr. We agree with comments that this interpretation is a better reading of the category title than the alternative under which States would compare the cumulative boiler capacity over all boilers at a power plant to the 250 million BTU/hr cutoff. We do not agree with comments that any particular meaning can be taken from the use of the plural word “boilers” in the category title. On the other hand, if a boiler smaller than 250 million BTU/hr is an integral part of an industrial process in a BART source category other than electric utilities—for example, part of the process description at a chemical process plant—then we believe that the boiler should be considered for controls as part of the BART source. The logic here is that a State should consider all emission points at an integral industrial process to be part of the BART-eligible source, so that later, when making the actual BART determination, the State would be certain that it has not prematurely ruled out any sensible control options for that process as a whole. That way the State will have retained as much discretion as possible to require control on all or part of an industrial process, on a case-by-case basis, considering all of the BART factors.

We do not believe that this interpretation is likely to have a substantial impact on the amount of BART emissions reductions achieved, because smaller boilers are generally less cost effective to control. Also, we believe that covering only individual utility boilers greater than 250 million BTU/hr may help address States' concerns over the implementation burden of the program.

We also agree with the two clarifications suggested by commenters relating to the term “fossil fuel.” We propose to add a statement to the reproposed guidelines clarifying that “fossil fuel boilers” refers to boilers burning greater than 50 percent fossil fuels. We believe that this is a reasonable approach to interpreting the definition in the CAA. Also, we agree that enforceable operational limits for a multi-fuel boiler would be relevant to determining whether its “fossil fuel” capacity exceeds 250 million BTU/hr and that it would be reasonable for States to take such limitations into account. We are proposing to add this clarification to the BART guidelines.

We also wish to clarify that, consistent with other EPA rules, the definition of “steam electric plants of more than 250 million BTU/hr heat input” refers only to plants that generate electricity for sale. We are proposing to add this clarfication to the BART guidelines.

The reproposed guidelines do not take a position on the recommendations in the comments regarding “petroleum storage and transfer facilities with a capacity exceeding 300,000 barrels.” We believe that this question is largely moot given that these storage and transfer facilities are already subject to maximum achievable control technology (MACT) standards and in many cases stringent SIP regulations related to ozone nonattainment. Regardless of the interpretation, we believe that it is unlikely that BART emissions limitations will require further controls.

We have reviewed comments suggesting that “secondary metal production facilities” may be interpreted to include only those facilities within SIC code 3341. We note that the term “secondary metal production” is broader than SIC code 3341. “Secondary metal production” would include secondary ferrous metals facilities such as secondary iron and steel facilities. On the other hand, SIC code 3341 includes only nonferrous metals facilities such as secondary copper, aluminum and lead facilities. We believe, however, that secondary iron and steel facilities are also included within the broad category “iron and steel mill plants.” Accordingly, we are proposing that in identifying unique “secondary metal production” facilities that are not in any other BART category, States may identify those unique facilities based upon SIC code 3341.

Step 2:

Identify the start-up dates of those emission units. The EPA interpretation of the terms “in existence” and “in operation.”

Background. Step 2 in the proposed process for identifying BART-eligible sources would be to identify all emissions units within the listed categories which met the two tests in the definitions in the regional haze rule: (1) The unit was “in existence on August 7, 1977 and (2) the unit began operation after August 7, 1962. Our visibility regulations define “in existence” and “in operation” in 40 CFR 51.301. We are proposing to retain the same definitions of “in existence” and “in operation” as we had included in the 2001 proposal. The term “in existence” includes sources not yet in operation where the owner or operator has not begun operating but which has:

—Obtained all necessary preconstruction approvals,

—Began on-site construction, or

—Entered into binding agreements or contractual obligations to begin construction of the facility within a reasonable time period.

In contrast, the term “in operation” includes only sources which are actually operating. In the reproposed BART guidelines, as in the previous proposal, we provide examples that illustrate the definitions in the regional haze rule.

We also wish to eliminate any confusion over power plants having boilers built both before 1962 and boilers built within the 1962-1977 time period. The BART guidelines would not require States to find that all boilers at a facility are BART-eligible if one or more boilers at the facility were put in place between the 1962 and 1977 dates. Under Step 2 of the proposed process for identifying BART-eligible sources, States would identify

only

those boilers that were put in place within the 1962-1977 time period. Only those boilers are carried over to Step 3, and only those boilers would be subject to a BART engineering analysis. We have included clarifying language in the reproposed guidelines on this issue.

Step 3:

Compare the potential emissions from the units identified in steps 1 and 2 to the 250 ton/yr cutoff.

Background. Under the definition of “major stationary source” in CAA section 169A(g)(7) and the corresponding definition of “BART-eligible source” in the regional haze rule, BART applies only to a stationary source if it meets the category description and time window criteria described above, and only if it has the potential to emit 250 tons or more of “any pollutant.”

There are two issues needing clarification with respect to the 250 tons per year threshold—one regarding what pollutants should be addressed, and two, the definition of stationary source.

What Pollutants Should I Address?

2001 Proposed Rule. The 2001 proposal clarified that the 250 tons per year cutoff applies only to visibility-impairing pollutants and included a list of pollutants to address: SO

, NO

, particulate matter, volatile organic compounds (VOC), and ammonia.

Comments. We received a number of comments related to the proposed inclusion of ammonia. One comment cited three reasons for not including ammonia on the list of visibility-impairing pollutants. First, the commenters believed that we had provided no scientific basis for suggesting that ammonia contributes to visibility impairment. Second, the commenters believed that we should not include ammonia on the list of pollutants without fully discussing the implications for other programs. For example, if ammonia became a “regulated pollutant” under the CAA based upon its inclusion in the guidance, the commenters believed that there would be implications for PSD and other program requirements. Third, the commenters believed that inclusion of ammonia would have the unintended consequence of discouraging selective catalytic reduction (SCR) as a control measure for NO

, because of the unavoidable but small amount of “ammonia slip” that occurs in using SCR technology.

Reproposal. Based on the comments received on ammonia, and based on our current state of knowledge regarding the role of ammonia in PM

2.5

formation and the effects on regional haze that would be expected from reductions in ammonia emissions, we believe that ammonia should not be included on the list at this time.

The following is a our rationale for proposing not to include ammonia. Ammonia is a gas and does not impair visibility directly. It can, however, react with acidic particles or gases in the air to form ammonium compounds. The most common acidic substances with which ammonia reacts are sulfuric acid and nitric acid, which in turn are formed from the reaction of SO

and NO

with other substances in the atmosphere. Because ammonia generally forms visibility-impairing fine particles in the presence of acidic particles or gases, reductions in SO

and NO

emissions will tend to reduce concentrations of ammonia-based particles in the air.

In other words, to reduce ammonium fine particles, States may either require the reduction of ammonia or of SO

and NO

emissions. In determining the proper approach to reducing ammonium, it is worth noting that as SO

and NO

emissions are decreased, the marginal effectiveness of hypothetical ammonia controls will also tend to decrease.

The available ammonia emissions inventory is uncertain, although EPA and other organizations are pursuing improvements. Consequently, compared to the case for SO

and NO

, the ability to identify opportunities for emissions control and to quantify the effects of such actions in advance is limited.

For a more in-depth discussion of the contribution of ammonia emissions from stationary sources to long-range transport of PM

2.5

see

discussion in the proposed Interstaste Air Quality Rule (IAQR): 69 FR 4566, January 30, 2004.

Because of the uncertainties in assessing the impact of ammonia emissions reductions on visibility, and because PM

2.5

will decrease due to SO

and NO

controls, we are proposing not to include ammonia on the pollutant list at this time. We request comment on this determination.

Also included in the original pollutant list are VOCs. We propose that VOCs remain on the list.

Our understanding of the relationship between VOC emissions and the formation of PM

2.5

is rapidly evolving. We recognize that VOC emissions are most likely to contribute to particle formation, and thus to visibility impairment, in the presence of NO

. In rural areas, anthropogenic VOC emissions generally do not appear likely to be a significant contributor to PM

2.5

formation,

while VOC emissions in urban areas are likely to be a contributor to PM

2.5

formation. This is because VOC emissions are most often present with NO

emissions in urban areas. In rural areas, by contrast, VOC emissions are not as often present with NO

emissions.

See

discussion in the NO

SIP call at 63 Fed. Reg. 57,356 (Oct. 27, 1998).

We also recognize that some specific uncertainties about VOCs remain. For example, only certain organic gases are precursors to PM

2.5

, but available inventories cover VOC as an aggregate. It is therefore difficult to estimate emissions of the precursor compounds from these inventories. In addition, available models for estimating air quality from individual source emissions have more uncertainty in predicting ambient PM

2.5

changes from reductions in emissions of organic gases.

Finally, we recognize that many industrial sources and most mobile sources of organic gases have been subjected to VOC control requirements that have the effect of reducing emissions of the particular compounds that are PM

2.5

precursors. Given that fact, as well as the uncertainties about VOCs outlined above, we request comment on the level of discretion States should exercise in making BART determinations. Specifically, we request comment on whether States should focus greater control requirements on VOC emissions from BART sources in urban areas. We also request comment on the circumstances under which, in rural areas, for sources subject to BART, States may determine that BART would be no control for VOC.

What Is a “Stationary Source?”

The definition of “building, structure or facility” in the regional haze rule is based, in part, upon grouping of pollutant-emitting activities by 2-digit category according to the SIC Manual. As in the NSR program, however, facilities that convey, store or otherwise assist in the production of the principal product, are considered to fall within the same industrial grouping as the primary facility. Despite this general rule, however, we would like to clarify that in practice, this so-called “support facility” test for BART is narrower than for other programs. We are proposing to add language to the guidelines noting that emission units at a plant, even if they are a “support facility” for purposes of other programs, would not be considered for BART-eligibility unless they were within one of the 26 listed source categories, and unless they were put in place within the 1962 to 1977 time period. For example, a mine, even if a “support facility” for a power plant, would not be considered for BART eligibility.

Step 4:

Identify the emission units and pollutants that constitute the BART-eligible source.

Background. The final step in the identification of BART-eligible sources would be to use the results from the previous three steps to identify the universe of equipment that is BART-eligible. If the total allowable emissions from the stationary source exceed a potential to emit of 250 tons per year for any individual visibility-impairing pollutant, then that collection of emissions units is a BART-eligible source. A BART analysis would be required for each visibility-impairing pollutant emitted from this collection of emissions units.

2001 Proposed Rule. The 2001 proposed guidelines included two examples to clarify this point. In the first example, a source has two emissions units having cumulative emissions exceeding 250 tons for SO

, but not for NO

and particulate matter (PM). For this example, we noted that BART would be required for all three pollutants. In the second example, the source has potential emissions that are less than 250 tons for each individual pollutant, but more than 250 tons from the sum over all pollutants. For this second example, we noted that the source would not be BART-eligible.

Reproposal. We received comments on the 2001 proposal suggesting that some BART-eligible sources emit visibility-impairing pollutants at levels that would make a de minimis contribution to regional haze. For example, a source may be BART-eligible because it emits 500 tons per year of one visibility-impairing pollutant, but it may also emit only one ton per year of another pollutant, the emission of which would have little effect on regional emissions loadings and visibility impairment. A 1 ton/yr amount from a given BART-eligible source would likely represent a de minimis fraction of a total regional inventory.

As noted previously, we believe that once a source is BART-eligible according to the definition in CAA section 169A(g)(7), CAA section 169A(b)(2)(A) requires BART for “any” visibility-impairing pollutant regardless of the amount. Notwithstanding this apparent directive, we are proposing to provide the States with the flexibility to identify de minimis levels of pollutants at BART-eligible sources. We believe that it would be appropriate for States to have this flexibility once they have collected more information on the BART population. We also agree with comments that sources emitting pollutants at values considered de minimis under the PSD program could be de minimis for BART as well. Accordingly, the reproposal includes a provision that any de minimis values that States adopt should not be higher than the PSD levels: 40 tons per year for SO

, NO

and VOC, and 15 tons/yr for PM

. We request comment on this provision, and on the idea of including de minimis values. Finally, if a commenter contends that ammonia should be included as a precursor to PM

2.5

, then the commenter should also comment on an appropriate de minimis value for ammonia.

C. How To Determine Which BART-Eligible Sources Are Subject to BART

Background. Section 169A of the Act establishes a low triggering threshold for determining whether a BART eligible source is required to procure and install appropriate retrofit technology. States must determine whether BART eligible sources emit “any air pollutant which may reasonably be anticipated to cause or contribute to any impairment of visibility in [a Class I] area.” In the Regional Haze Rule, we interpreted these statutory provisions as requiring a State to find that a BART-eligible source is “reasonably anticipated to cause or contribute” to regional haze if it can be shown that the source emits pollutants within a geographic area from which pollutants can be emitted and transported downwind to a Class I area.

64 FR at 35740.

Reproposal. As explained earlier, as part of the BART process, a State identifies and lists all “BART-eligible” sources. The State must then determine which of those BART-eligible sources may “emit any air pollutant which may reasonably be anticipated to cause or contribute to any impairment of visibility in any [Class I] area.” A source which fits this description is “subject to BART.” This section explains our proposed process for determining which BART-eligible sources should be subject to BART. We request comment on all aspects of this process.

Determining Which Sources Are Reasonably Anticipated To Cause or Contribute To Visibility Impairment (Sources Subject to BART)

Three options are proposed. First, the State may choose to consider that all BART-eligible sources in the State are subject to BART (

i.e.,

that none are exempt). As explained previously, we believe this conclusion is reasonable in light of currently available information [reference 1999 study]. We also believe that given American Corn Growers' emphasis on State's prerogatives in making BART determinations, we may lack the authority to deny this option to States.

Second, the State may choose to demonstrate, using a cumulative approach, that none of its BART-eligible sources contribute to visibility impairment. We propose that States should have the option of performing an analysis to show that the full group of BART-eligible sources in a State cumulatively do not cause or contribute to any visibility impairment in Class I areas. We request comment on the types of analyses that could be used. For instance, one approach may be for States to use a regional scale grid model

to demonstrate that its BART-eligible sources do not cause or contribute to regional haze. We anticipate that in most, if not all States, the BART-eligible sources are likely to cause or contribute to visibility impairment in Class I areas. However, it is possible that, using regional scale modeling, a State could show that its BART sources do not collectively cause or contribute to visibility impairment. In such a case, a State could complete its BART analysis relatively quickly, without the need for investing in studies of source-specific contributions to regional haze. At this time, we are neither requiring nor encouraging all States to undertake a cumulative approach.

For regional haze applications, regional scale modeling typically involves use of a photochemical grid model that is capable of simulating aerosol chemistry, transport, and deposition of airborne pollutants, including particulate matter and ozone. Regional scale air quality models are generally applied for geographic scales ranging from a multi-state to the continental scale. Such modeling may not be appropriate for all States, as regional models are most applicable to situations involving multiple BART-eligible sources. Because of the design and intended applications of grid models, they may not be appropriate for all BART assessments, so States should consult with the appropriate EPA Regional Office prior to carrying out any such modeling.

Finally, the State may choose to determine which sources are subject to BART through the use of an individual exemption process, described below.

Individualized Source Exemption Process

We are proposing to provide States with the option of determining which sources are subject to BART through the use of an individualized exemption process. For this option, we propose that States use an air quality model for an individual source to demonstrate no contribution to visibility impairment in a Class I area. We also request comment on alternative approaches that may be used in lieu of this approach, or as a first step in the process by which States may determine which BART-eligible sources, if any, to exempt.

For modeling an individual BART-eligible source located more than 50 km from a Class I area, we propose that an air quality model, such as CALPUFF, be used. The CALPUFF system consists of a diagnostic meteorological model, a gaussian puff dispersion model with algorithms for chemical transformation and complex terrain, and a post processor for calculating concentration fields and visibility impacts. CALPUFF was incorporated into the “Guideline on Air Quality Models” (the Guideline) (40

CFR Part 51, Appendix W) in April 2003.

Traditionally, EPA has used transport and diffusion modeling to predict the effect of directly emitted PM

2.5

emissions on PM

2.5

ambient concentrations. To simulate the effect of precursor pollutant emissions on PM

2.5

concentrations requires air quality modeling that not only addresses transport and diffusion, but also chemical transformations. While we believe that it is technically feasible to model secondary PM formation, and there is at least one model, described above, which incorporates algorithms for estimating secondary transformation, we have not yet fully tested such modeling to determine whether its application is justified as a sole determinant of air quality impacts involving secondary transformation. However, where the statutory criteria for determining regulatory applicability involve relatively low thresholds, or where regulatory decisions involve considerations of multiple factors including, but not limited to, model results, we believe transport and diffusion models such as CALPUFF can be appropriate regulatory tools for evaluating air quality impacts involving secondary transformation. Consequently, we believe its use by States to assess whether a source is reasonably anticipated to cause or contribute to impairment of visibility in Class I areas is reasonable.

We are proposing that a CALPUFF assessment of an individual source be used as the preferred approach for determining whether a BART-eligible source may be exempt from BART. The CALPUFF assessment is specific to each source, taking into account the individual source's emission characteristics, location, and particular meteorological, topographical, and climatological conditions, any of which may have an impact on the transport of PM

2.5

and its precursors. Thus, this approach may be more determinative than a non-modeling approach in determining which sources are not contributing to visibility impairment in a Class I area.

Results from the CALPUFF assessment would be used to determine the source's impact on visibility in a Class I area. If a source has an estimated impact on visibility that is lower than the established threshold (described in the section below), then the State may choose to exempt the source from further BART analysis. If the source's impact is equal to or greater than the threshold, the State would determine that the source is subject to BART.

The State or source would apply CALPUFF for source-receptor distances greater than 50 km, since CALPUFF is generally intended for use on scales from 50 km from a source to hundreds of kilometers. However as the modeling domain increases in size, the requirements for experience in the application of CALPUFF becomes more demanding (

e.g.,

in processing and quality assurance of the meteorology, in understanding the implications of the various model processing options). Therefore we propose that any application of CALPUFF for distances greater than 200 km requires development of a written modeling protocol describing the methods and procedures to be followed, and that the protocol be approved by the appropriate reviewing authority. For source-receptor distances less than 50 km, we are recommending that States use their discretion for determining visibility impacts giving consideration to both CALPUFF and other EPA-approved methods. For example, States would have the option of exempting these sources if air quality modeling results, using an appropriate local-scale model such as PLUVUEII,

show that their emissions are below a level that would be reasonably anticipated to cause or contribute to visibility impairment in any Class I area.

PLUVUEII is a model used for estimating visual range reduction and atmospheric discoloration caused by plumes resulting from the emissions of particles, nitrogen oxides, and sulfur oxides from a single source. The model predicts the transport, dispersion, chemicals reactions, optical effects and surface deposition of point or area source emissions. It is available at

http://www.epa.gov/scram001/tt22.htm#pluvue.

Metric for Visibility Degradation

In providing an individual source exemption option, a metric is needed to assess a source's contribution to visibility degradation. The metric we are using in the regional haze rule is the deciview, which is derived directly from light extinction, an index commonly used to measure visibility degradation.

As outlined in the 1999 Regional Haze rule (64 FR 35725-35727, July 1, 1999), a one deciview change in haziness is a small but noticeable change in haziness under most circumstances when viewing scenes in a Class I area. The deciview can be used to express changes in visibility impairment that correspond to a human perception in a linear, one for one, manner. The deciview concept was introduced in 1994 in an article appearing in a peer-reviewed journal (Pitchford and Malm, Atmospheric Environment, 28 (5), 1994). We believe that visible changes of less than one deciview are likely to be perceptible in some cases, especially where the scene being viewed is highly sensitive to small amounts of pollution. We acknowledge that for other types of scenes, with other site-specific conditions, a change of more than one deciview might be required in order for the change to be perceptible.

Threshold Levels

A 1991 report from the National Acid Precipitation Assessment Program (NAPAP) states that “changes in light extinction of 5% will evoke a just noticeable change in most landscapes.”

Converting a 5 percent change in light extinction to a change in deciviews yields a change of approximately 0.5 deciviews. This is a natural breakpoint at which to set the exemption level, since visibility degradation may begin to be recognized by human observer at this extinction level.

Thus, we are proposing a 0.5 deciview change as the threshold for determining that an individual source is causing visibility impairment at a Class I area. This level would be calculated by measuring the air quality screening modeling results for an individual source against natural visibility conditions. Natural visibility conditions are those conditions that are estimated to exist in a given Class I area in the absence of human-caused impairment.

We believe that measuring against natural visibility conditions is appropriate because the ultimate goal of the regional haze program is a return to natural conditions. Additionally, regional haze strategies are developed to make reasonable progress towards this goal, and visibility degradation and improvement are appropriately measured against natural conditions.

National Acid Precipitation Assessment Program (NAPAP). Acid Deposition: State of Science and Technology Report 24, Visibility: Existing and Historical Conditions—Causes and Effects, Washington, DC, 1991. See Appendix D, p. 24-D2.

Ibid.

U.S. EPA. September 2003. Guidance for Estimating Natural Visibility Conditions Under the Regional Haze Rule.

http://www.epa.gov//ttncaaa1/t1/memoranda/rh_envcurhr_gd.pdf

This document has estimates of default conditions as well as measures to develop refined estimates of natural conditions.

We also request comment on using a threshold that is more or less than 0.5 deciviews. Given uncertainties over the deciview change that is perceptible, and the modeling of a source's contribution to haze in a Class I area, a different threshold may be appropriate. Furthermore, we recognize that there may be situations where impacts from

more than one BART-eligible source, when taken together, would adversely affect visibility at a particular Class I area even though the impact of each individual source would be below the visibility threshold. In this case, there would be a noticeable impact on visibility from BART-eligible sources because of the contribution of multiple sources, yet impacts from an individual source alone would not be noticeable. Given the statutory language that a source “which may reasonably be anticipated to cause or contribute to visibility impairment” is subject to BART,

a lower threshold may be appropriate as it would effectuate Congress's intent that the BART applicability test not establish a high hurdle. We accordingly request comment on what threshold would be appropriate to address these issues.

CAA § 169A(b)(2) (emphasis added).

Alternative Approaches to the Assessment Using CALPUFF

The CALPUFF assessment described previously can be a time-consuming and data-intensive approach; we are concerned about the resource burdens this might pose for States and sources. Therefore, we are also considering alternative approaches that would be credible and require fewer resources. These approaches could serve as a first step in the process for determining whether a source contributes to visibility impairment in a Class I area. We are considering several alternative approaches for making this exemption determination. These approaches, in no particular order, include: (1) A simpler screening assessment using CALPUFF (2) look-up tables (

i.e.

, tables that require emissions and distance information for making an exemption determination), (3) source ranking, and (4) using Emissions divided by Distance, known as the Q/D method.

Each approach has strengths and limitations. We request comment on all of these approaches. A more complete and detailed explanation of the four alternative approaches, including examples, is available in a memo to the docket.

Memorandum to the docket: Summary of Alternative Approaches for Individual Source BART exemptions, Todd Hawes, March 12, 2004. Docket No. OAR-2002-0076.

A Screening Assessment Using CALPUFF

We are proposing that CALPUFF be run in a screening assessment to evaluate individual sources. This approach would be less data- and time-intensive than running CALPUFF in the assessment described previously due to greatly simplified preparation and processing of input data. This simpler screening assessment utilizes source and receptor location, as well as meteorological, topographical and climatological conditions from a regionally-specific profile. However, like the assessment described previously, this screening assessment also utilizes the individual source's particular emission characteristics. The table below illustrates the differences between the screening assessment of the kind described previously as the preferred approach and the simpler, more generalized screening assessment.

Type

CALPUFF Assessment

CALPUFF Screening Assessment.

Model used

CALPUFF

CALPUFF.

Input meteorology

Process 5 years of location-specific, meteorology data

Representative met location (data already processed).

Terrain included

Site-specific terrain included

No (assumed flat).

Source-Receptor distances

Source to Class I area receptor

Source to Class I area receptor.

Location of Visibility impact

Maximum impact at receptor using appropriate distance and direction from source

Maximum impact in any direction at source-receptor distance.

Results from this screening assessment would be used to determine the source's impact on visibility in a Class I area. If a source has an estimated impact on visibility that is lower than the established threshold, the State may choose to exempt the source from further BART analysis. If the source's impact is equal to or greater than the threshold, the State would determine that the source is subject to BART. The source would then have the option of performing the screening assessment described previously as the preferred approach to demonstrate that its visibility impacts do not exceed the threshold level and that it qualifies for exemption.

We request comment on the use of this approach as an assessment of individual source impacts on visibility.

Look-Up Tables Developed From Screening-Level Air Quality Modeling

For even greater ease of use, look-up tables could be developed for application in the individual source exemption process. Under this approach, a State or source would use a look-up table developed by EPA to determine the source's predicted impact on a Class I area and, consequently, its exemption status. The State or source would use the source's emissions information and distance from a Class I area to determine if it is exempt from BART.

The look-up tables could be developed by first using CALPUFF in screening assessments to estimate levels of visibility impairment (in deciviews) associated with different combinations of distance to a Class I area and tons per year of emissions. A table would show the distance from the representative BART-eligible source to a Class I area and the associated allowable emissions of visibility-impairing pollutants (

e.g.,

, NO

, and direct PM

2.5

) at that distance that will yield a modeled impact of 0.5 deciviews. A State or source could “look up” a source's distance and emission combination and compare its allowable emissions of visibility-impairing pollutants to the table to make the BART exemption determination for the source.

If a BART-eligible source has emissions of visibility-impairing pollutants that are less than the emissions shown on the table for sources that are the same distance as the source from a Class I area, the State could exempt the source from BART. Alternatively, if a BART-eligible source's emissions of visibility-impairing pollutants are greater than the emissions shown on the table, the State could determine that the source is subject to BART. The source would have the option of running the CALPUFF model, or other EPA-approved model, to demonstrate that its visibility impacts do not exceed a change in light extinction of 0.5 deciviews and that it qualifies for exemption.

An example of a look-up table for EGUs is shown in the technical memo

to the docket.

A more in-depth discussion of the look-up table development is given in the Summary of Technical Analysis for the Proposed Rule.

The advantages of the look-up tables are that they are easy to use and no modeling would be required. However, they may be too general to represent all source categories. For instance, the source category in the example is for EGUs. Another source category will likely have entirely different source and emissions characteristics which may require development of a separate look-up table. Several sets of look-up tables requiring several sets of assumptions would be cumbersome and complex.

Ibid.

Summary of Technical Analyses for the Proposed Rule, Mark Evangelista, U.S. Environmental Protection Agency, April 12, 2004, Docket No. OAR-2002-0076.

Source Ranking

A source ranking approach is another possible option for determining whether an individual source may be exempted from BART. This approach would require a separate analysis for each Class I area.

First, a State would determine the universe of BART-eligible sources within a prescribed distance from the Class I area. Then, using a pre-determined common metric, such as total emissions of visibility impairing pollutants at each source, a State would sort the sources in descending order according to the metric and determine the cumulative frequency (a running total or percentage) of the ranked sources according to the chosen metric. The sources that fall below a pre-determined frequency level could be presumed to be insignificant contributors, and the State could exempt them from BART. A source that falls above the pre-determined frequency level would be subject to BART. The source would have the option of running the CALPUFF screening model, or other EPA-approved model, to demonstrate that its visibility impacts do not exceed the threshold level and that it qualifies for exemption. A more complete and detailed explanation of this approach, including an example, is available in a memo to the docket.

Memorandum to the docket: Summary of Alternative Approaches for Individual Source BART Exemptions, Todd Hawes, March 12, 2004. Docket No. OAR-2002-0076.

We request comment on the source ranking approach and on an appropriate frequency level for determining individual source exemption.

Emissions Divided by Distance (Q/D) Method

Another option for exemption for which we request comment is a non-modeling based approach identified as Q/D (with “Q” being allowable emissions, in tons per year, and “D” representing the distance, in km, to the nearest Class I area, multiplied by a prescribed constant). The method, originally developed by the North Carolina Department of Environment and Natural Resources, is a tool to eliminate distant, insignificant emission sources from ambient assessments submitted under the Prevention of Significant Deterioration (PSD) program.

The Q/D method determines a source to be insignificant if the allowable emissions in tons per year (Q) divided by a constant times the distance in kilometers (D) is greater than a value of 1. For example, North Carolina uses a constant of 20, which was determined empirically. Therefore, a source could be considered insignificant if its emissions divided by 20 times its distance, in km, from the nearest Class I area is greater than 1. For this application for determining exemption from BART, the combined emissions of SO

, NO

, and PM

2.5

of a BART-eligible unit could be divided by the distance to the nearest Class I area. If that quotient is less than 1, the source would not be subject to BART. If a source is not found to be exempt under this approach, the CALPUFF screening analysis could still be used for an exemption determination.

A Screening Method for PSD, Memorandum from Bruce P. Miller, U.S. Environmental Protection Agency, to Eldewins Haynes, North Carolina Department of Natural Resources and Community Development, September 12, 1985, Docket No. OAR-2002-0076.

We request comment on the Q/D method, including comment on what value for the constant would be appropriate and why.

D. The BART Determination Process

Background. Section 169A(g)(7) of the CAA requires States to consider the following factors in making BART determinations: (1) The costs of compliance, (2) the energy and nonair quality environmental impacts of compliance, (3) any existing pollution control technology in use at the source, (4) the remaining useful life of the source, and (5) the degree of improvement in visibility which may reasonably be anticipated to result from the use of such technology. The D.C. Circuit's decision did not address the first four steps of the BART determination (the “engineering analysis”), which are discussed in detail in the guideline. The court's opinion did address the final step, mandating that the degree of improvement in visibility that would result from imposition of BART on each individual source be taken into account in determining BART.

2001 Proposed Rule. Section IV of the 2001 proposed BART guidelines was entitled “Engineering Analysis of BART Options.” The purpose of this section was to address the requirement in 40 CFR 51.308(e)(1)(ii)(B) in the regional haze rule that States identify the “best system of continuous emissions control technology” taking into account “the technology available, the costs of compliance, the energy and nonair quality environmental impacts of compliance, any pollution control equipment in use at the source, and the remaining useful life of the source.” Thus, in the 2001 proposed guidelines, section IV addressed four of the five statutory factors to be considered in the BART determination. Section V, “Consideration of Visibility Impacts,” contained a consolidated discussion, addressing visibility considerations in deciding both which BART-eligible sources should be subject to BART, as well as the fifth statutory factor—assessing the degree of visibility improvement which may reasonably be anticipated to result from control technology.

Reproposal. In the proposed guidelines, we are adding a fifth step to the Engineering Analysis. The five proposed steps in the engineering analysis are as follows:

1—Identify all available retrofit control technologies,

2—Eliminate technically infeasible options,

3—Rank remaining control technologies by control effectiveness,

4—Evaluate impacts and document the results, and

5—Evaluate the visibility impacts of applying controls.

In this portion of the preamble, we discuss a number of other issues.

1. How does BART relate to maximum achievable control technology (MACT) standards developed under CAA section 112?

In the 2001 proposed rule, we did not provide any discussion of the relationship of BART controls to MACT requirements. A number of commenters suggested that there are cases where additional controls beyond MACT are not warranted. We believe that for VOC and PM sources subject to MACT standards, States may streamline the BART analysis by including a discussion of the MACT controls and whether any major new technologies

have been developed subsequent to the MACT standards.

We believe that there are many sources, particularly sources of VOC and PM emissions, that are well-controlled because they are regulated by the MACT standards. Examples of MACT sources which effectively control VOC and PM emissions include (among others) secondary lead facilities, organic chemical plants subject to the hazardous organic national emissions standard for hazardous air pollutants (HON), pharmaceutical production facilities, and equipment leaks and wastewater operations at petroleum refineries. (We believe this is also true for emissions standards developed for municipal waste incinerators under the CAA amendments of 1990.) In many cases, it will be unlikely that States will identify emission controls more stringent than the MACT standards without identifying control options that would cost many thousands of dollars per ton. Unless there are new technologies subsequent to the MACT standards which would lead to cost-effective increases in the level of control, we believe that States may conclude that a source meeting MACT standards in these cases will satisfy the BART requirement.

The reproposed guidelines have been revised to include the discussion of MACT standards. The reproposed guidelines would require that a State identify any source where they are relying on MACT standards to achieve a BART level of control. Moreover, the reproposed guidelines would require a State to provide the public with a discussion of its decision to rely on a MACT standard as BART for a given source and pollutant.

2. How do I identify all available retrofit emission control techniques?

2001 Proposed Rule. In the 2001 proposed guidelines, we discussed a number of concepts regarding the identification of “all available” retrofit technologies. This discussion noted that “all” means a reasonable set of technologies. For example, the guidelines noted that it is not necessary to list all permutations of available control levels that exist for a given technology—the list is complete if it includes the maximum level of control each technology is capable of achieving.

The proposed guidelines made clear that the list of “available” technologies should reflect a comprehensive review, including technologies applied outside of the United States, and including technologies that may have only been applied previously to new sources. The proposed guidelines noted that control measures could include add-on control devices, switching to inherently lower-emitting processes, or a combination of the two. The proposed guidelines stated that BART did not require a source to undertake a complete replacement of the source with a lower-emitting design. The guidelines included a list of references which are available for identifying possible control measures, noting that the list was not necessarily all-inclusive. Finally, this passage of the proposed guidelines noted that sources with existing control devices in place must consider any available options for improving the performance of those control devices.

Comments. We received a few comments on this part of the 2001 proposal. Some comments recommended that controls typically used at new sources, such as those representing best available control technology (BACT) or lowest acheiveable emission rate (LAER), would be more stringent than BART should require. One commenter representing a utility company noted that the requirement to consider all controls, including those outside of the United States, could be burdensome to States. This commenter recommended that the analysis be limited to a “reasonable range” of technologies.

Reproposal. We are proposing to amend the language in the BART guidelines on the topic of identification of “all” retrofit technologies. We do not believe that it is necessary that States conduct detailed evaluations of control measures that are very unlikely to be selected as BART. Accordingly, we believe that, in order to reduce the administrative burden, States may consider developing screening levels based on the “cost effectiveness” of emissions control (

i.e.

the cost of emission control technology per each ton of emissions reduced). We view such dollar/ton screening levels as criteria for rejecting control options for consideration on the basis of costs and not as the sole basis for a BART decision. The overall BART decision must be made in consideration of all of the statutory factors.

We also recognize that there may be cases where States may wish to consider control measures above whatever screening levels they may establish. For example, the effect of nitrate particles varies and there are a few areas where nitrates are likely to be more important than for the rest of the nation. Also, a few sources may emit levels of NO

higher than the presumptive control level of 0.2 lbs/MMBtu, even after consideration of all available control technologies (such as low NO

burners and other combustion controls) below any established screening levels (see discussion in section III. 6. below).

Within the above constraints, we believe that the BART analysis should begin with a comprehensive review of those technologies that could be used to reduce emissions from a given BART-eligible source. We note that this analysis may be limited to a reasonable range of options and need not consider all permutations of control levels for a given technology.

In this proposal, we are seeking comment on two alternative approaches for conducting a BART engineering analysis. We prefer the first approach. Under this first alternative, the BART analysis would be very similar to the BACT review as described in the New Source Review Workshop Manual (Draft, October 1990). Consistent with the Workshop Manual, the BART engineering analysis would be a process which provides that all available control technologies be ranked in descending order of control effectiveness. Under this option, you must first examine the most stringent alternative. That alternative is selected as the “best” unless you demonstrate and document that the alternative cannot be justified based upon technical considerations, costs, energy impacts, and non-air quality environmental impacts. If you eliminate the most stringent technology in this fashion, you then consider the next most stringent alternative, and so on.

We also request comment on an alternative decision-making approach that would not necessarily begin with an evaluation of the most stringent control option. Under this approach, you would have more choices in the way you structure your BART analysis. For example, you could choose to begin the BART determination process by evaluating the least stringent technically feasible control option or an intermediate control option drawn from the range of technically feasible control alternatives. Under this approach, you would then consider the additional emission reductions, costs, and other effects (if any) of successively more stringent control options. Under such an approach, you would still be required to (1) display and rank all of the options in order of control effectiveness, including the most stringent control option, and to identify the average and incremental costs of each option; (2) consider the energy and non-air quality environmental impacts of each option; and (3) provide a justification for adopting the control technology that you select as the “best” level of control, including an explanation as to why you rejected other more stringent control

technologies. While both approaches require essentially the same parameters and analyses, we prefer the first approach described above, because we believe it may be more straightforward to implement than the alternative and would tend to give more thorough consideration to stringent control alternatives.

3. Consideration of Nonair Quality Environmental Impacts

2001 Proposed Rule. The 2001 proposal called for States to address environmental impacts other than air quality, and energy impacts, due to controlling emissions of the pollutant in question. Such environmental impacts include solid or hazardous waste generation and discharges of polluted water from a control device.

The proposed guidelines contained a number of examples of the types of nonair quality impacts that should be considered. The guidelines noted that States should take into account that there are beneficial nonair quality environmental impacts that could result from control measures. For example, control measures under consideration for BART may reduce acid deposition.

The guidelines clarified that the procedure for conducting an analysis of nonair quality environmental impacts should be based on a consideration of site-specific circumstances. Under the proposed guidelines, in Step 3 it would not be necessary to perform this analysis of environmental impacts for the entire list of technologies, if a State proposes to adopt the most stringent alternative. Instead, the analysis need only address those control alternatives with any significant or unusual environmental impacts that have the potential to affect the selection or elimination of a control alternative.

Comments. One utility commenter requested that EPA better clarify the BART determination factors other than costs of compliance. A State commenter wanted EPA to explain the bounds of a nonair quality review on environmental effects, citing possible requirements to assess statewide water quality standards as an example of how broad and open-ended the analysis could be. Several environmental groups asked us to be more specific with respect to consideration of the beneficial nonair quality related effects of implementing emissions controls as part of the BART determination. The comments pointed out that acid and total nitrogen loading affects water quality in rivers, lakes, coastal waters and also affects soil chemistry. These comments point out that these impacts can be magnified at higher elevations due to direct cloud deposition. Acidic deposition and increased nitrogen loading appear to be linked to damage to forested ecosystems, such as declines in sensitive tree species, death of aquatic organisms and poor water quality. Some comments pointed out that even a qualitative assessment of these beneficial impacts can inform the BART determination and should be part of the process. Comments from several Midwestern States requested that the guidelines provide that incompatibility with control for another pollutant, such as mercury, should be a criterion for rejecting (or modifying) a BART control option.

Reproposal. The Guidelines discussion of energy impacts remains the same as the discussion in the 2001 proposal. For nonair quality impacts, we agree that more clarification is needed. We do not see this factor as requiring an open-ended analysis of every affected nonair resource. We also do agree with commenters that the nonair quality assessment should include the beneficial effects of control options being considered in the BART determination. Both quantitative and qualitative information can be used in this assessment. We do not view this factor as requiring States to conduct an analysis of every possibly affected nonair quality effect, but rather as requiring States to consider clearly documented nonair quality effects. Moreover, we expect the Federal Land Managers to provide available information for assessing the ability of emission controls to reduce impacts on forests, soils, native species and other resources through the consultation requirement for regional haze SIP development contained in 40 CFR 51.308(i)(2)of the regional haze rule. This information should identify the specific nonair quality effects to consider and specific criteria for evaluating their significance, so that States are not faced with open-ended analyses.

States should also consider other information on beneficial effects which include specific data on nonair quality concerns made available to them, such as through public comments, in making the BART determination. We also agree with the Midwestern States comments that when controls for a visibility-impairing pollutant are shown to be incompatible with control of another air pollutant, this may create air quality or nonair quality related environmental concerns that should be taken into account in comparing control alternatives. At the same time, we note that it is important to evaluate fully and document the magnitude and nature of the concern identified. The mere presence of an actual or theoretical concern should not be cited as the reason for eliminating an option. Also, once a source-specific BART determination is made for two regulated pollutants, if the result is two different BART technologies that do not work well together, a State could then substitute a different technology or combination of technologies that achieve at least the same emissions reductions for each pollutant.

4. Evaluating the Significance of the Costs of Control

2001 Proposed Rule. The 2001 proposed rule requested comment on evaluating the significance of the costs of compliance—specifically, on whether the guidelines should contain specific criteria, and on whether such criteria would improve implementation of the BART requirement.

Comments. A few industry commenters, and two State commenters, suggested that specific criteria for evaluating cost, or for comparing cost with visibility benefits, should be included, but did not suggest what those specific criteria should be. Several environmental groups and environmental consulting firms suggested that specific cost criteria would not improve BART determinations, because BART sources and source categories vary considerably.

Reproposal. We are proposing a sequential process for conducting the impacts analysis that includes a complete evaluation of the costs of control. For evaluating the significance of the costs of control, we continue to request comment on whether such criteria would improve implementation of the BART requirement. If commenters believe such criteria are warranted, we request comment on what criteria would be appropriate. For example, we request comment on whether it would be helpful to include criteria such as those in the work of the Western Regional Air Partnership (WRAP),

wherein a system is described which views as “low cost” those controls with an average cost effectiveness below $500/ton, as “moderate” those controls with an average cost effectiveness between $500 to $3000 per ton, and as “high” those controls with an average cost effectiveness greater than $3000 per ton.

Technical Support Documentation. Voluntary Emissions Reduction Program for Major Industrial Sources of Sulfur Dioxide in Nine Western States and a Backstop Market Trading Program. An Annex to the Report of the Grand Canyon Visibility Transport Commission.

Section 6A.

5. Sulfur Dioxide Controls for Utility Boilers

2001 Proposed Rule. In the 2001 proposed guidelines, we cited a report by EPA's Office of Research and Development to support a presumption that, for utility boilers where there is no existing control technology in place, a 90-95 percent reduction in SO2 is generally cost effective to achieve using scrubbers. This document is entitled

Controlling

Emissions: A Review of Technologies, EPA-600/R-00-093. We also provided, in a memorandum to the docket for the proposal, calculations showing scrubber costs of about $200-$1000 per ton of SO

removed for the 90-95 percent control levels. The proposal made clear that we would allow States to consider case-by-case variations (for example, type of fuel used, severe space limitations, and presence of existing control equipment) that could affect the costs of applying retrofit controls. We requested comments on whether the 90-95 percent presumption is appropriate or whether another presumption should be established instead.

Comments. We received many comments on the 90-95% control presumption for utility boilers.

Many utility industry comments were critical of the presumptive level. These comments did not address whether the 90-95 percent level was achievable, nor did they address EPA's cost calculations. Instead, the comments were generally critical of the provision as a Federal mandate that would reduce State flexibility in making BART determinations.

Comments from States in the Northeast and from environmental groups were generally supportive of the presumptive levels of control. Some of these comments expressed concerns that the technology may advance to greater levels of achievable control before BART decisions are made. Accordingly, those comments recommended that we add language to the final guidelines to ensure that the 90-95 percent level would not be considered to represent the maximum level of control that States could consider.

Comments from several Midwestern States recommended that the presumptive level be expressed as a performance level, for example as a pounds/million BTU level, rather than as a percent control level. These comments expressed concerns that facilities which have already reduced emissions for purposes of the acid rain program could inappropriately be treated in the same way as those that had not yet reduced their emissions.

Reproposal. In today's action reproposing the BART guidelines, we are proposing a level of SO

control that is generally achievable for electric generating units (EGU)s of a certain size. Specifically, we are proposing that in establishing BART emission limits, States, as a general matter, must require owners and operators of greater than 750 MW power plants to meet specific control levels of either 95 percent control, or controls in the range of .1 to .15 lbs/MMBtu, on each EGU greater than 250 MW. We are proposing to establish such a default requirement based on the consideration of certain factors discussed below. Although we believe that this level of control is likely appropriate for all greater than 750 MW power plants subject to BART, a State may establish a different level of control if the State can demonstrate that an alternative determination is justified based on a consideration of the evidence before it. In addition, for power plants 750 MW and less in size, we are establishing a rebuttable presumption that States should require any EGU between 250 MW and 750 MW in size to meet these same control levels.

This presumption would apply unless the State has persuasive evidence that an alternative determination is justified. Our intent is that it should be extrememly difficult to justify a BART determination less than the default control level for a plant greater than 750 MW, and just slightly less difficult for a plant 750 MW or smaller.

As stated earlier, by specifically singling out, in section 169A of the CAA, a specific set of existing sources to be addressed by the States (or the Administrator) in their plans, Congress clearly signaled through the BART requirements a particular concern that the States and EPA focus on pollution from these sources. The CAA gives the States the authority “to decide which sources impair visibility and what BART controls should apply to those sources.” American Corn Growers v. EPA, 291 F.3d at 8. However, section 169A further states that “[i]n the case of a fossil-fuel fired generating plant having a total generating capacity in excess of 750 MW, the [BART] emission limitations * * * shall be determined pursuant to guidelines' issued by EPA. This language, and the legislative history, indicate that although Congress generally left the determination of BART emission limits to the States (subject to the requirements of EPA's implementing regulations), it intended EPA to take a more active role in the process of establishing BART emission limits for large power plants. Furthermore, the legislative history from 1977 makes clear that Congress understood 25 years ago that a specific type of SO

controls (flue gas desulfurization (FGD) or “scrubbers”) was readily available for these plants. We believe it is consistent with Congress' mandate that EPA establish guidelines for determining BART emission limitations for this category of sources and, given the availability and low cost of controls for these sources, for EPA to require that these power plants meet specific control levels, unless the State has persuasive evidence that an alternative determination is justified.

In addition to the statutory language and the legislative history, we believe that requiring specific BART emission limitations for greater than 750 MW power plants in most cases is supported by sound policy considerations and a careful review of the information we have regarding these sources' emissions, costs of control, and impacts on visibility. First, sulfates resulting from SO

emissions are an important contributor to visibility impairment nationwide, and preliminary data that we have suggests that the estimated 28 BART-eligible EGUs located at 750 MW power plants emit over one million tons of SO

per year, or, on an individual EGU basis, an average of over 39,000 tons of SO

per year.

In other words, these sources are some of the largest emitters of SO

in the United States.

See

http://www.epa.gov/airmarkets/epaipm/results2003.html.

This is the Table of Parsed Run Data for EPA Modeling Applications Using IPM. Most of the 750 MW power plants addressed by this provision contain one or more 250 MW boilers constructed between 1962 and 1977. Thus, on average, most (each) plant emits far more than 39,000 tons per year of SO

from units covered by the BART requirement.

Second, as discussed below, highly effective control technologies (

i.e.,

FGD) are available to control SO

emissions from utility boilers; the average costs per ton of emissions removed from such EGUs (usually between $200 and $1300 per ton) are well within the levels considered for application under many CAA regulatory programs. Based on the cost models in the

Controlling SO

Emissions

report,

for example, it appears that, where there is no existing control technology in place, 95 percent control can generally be achieved at EGUs using coal with relatively high

sulfur content at cost-effectiveness values cited above.

Similarly, for EGUs using relatively low sulfur coal, reducing SO

emission levels to 0.1 to 0.15 lbs/MMBtu is also cost-effective as compared to other measures to reduce pollution, falling within the same range of cost effectiveness as that discussed above.

Documentation of the presumption that 90-95 percent control is achievable is contained in a recent report entitled

Controlling SO

Emissions:

A Review of Technologies,

EPA-600/R-00-093, available on the internet at

http://www.epa.gov/ORD/WebPubs/so2.

This report summarizes percentage controls for FGD systems worldwide, provides detailed methods for evaluating costs, and explains the reasons why costs have been decreasing with time.

We have used the cost models in the

Controlling SO

Emissions

report to calculate cost-effectiveness ($/ton) estimates for FGD technologies for a number of example cases. (See note to docket A-2000-28 from Tim Smith, EPA/OAPS, December 29, 2000). We also believe it is reasonable to expect States to consider the maximum level that these scrubbers are capable of achieving. Thus, for example, we believe that a scrubber installation which allowed part of the flue gas stream to bypass the scrubber and remain uncontrolled, or be controlled to a lesser degree, should not be considered to represent BART.

Ibid.

Third, we believe that individual BART-eligible EGUs subject to this provision contribute substantially to visibility impairment in Class I areas. For example, based on modeling runs using CALPUFF for a typical 250 MW EGU, modeling results have shown visibility effects greater than 7 deciviews at Class I areas at distances of 200 km.

At 90 percent control for a 250 MW source, the maximum modeled impact would improve to 1.3 deciviews. A 95 percent control level would yield further substantial improvement in visibility to just under 1 deciview. Note however that even at a 95 percent control level, just one source can have maximum impacts above the threshold of the visible range (0.5 deciviews) and may still impair visibility at the nearest Class I area.

Summary of Technical Analyses for the Proposed Rule, Mark Evangelista, U.S. Environmental Protection Agency, April 12, 2004, Docket No. OAR-2002-0076.

Therefore considering the range of the costs of compliance for these sources and the degree of improvement in visibility that may be anticipated from the use of the highly effective control technologies that are available for these sources, we have determined that it is appropriate to establish in these guidelines specific control levels for States to use in determining BART for these sources. We are proposing that as a general matter, States must find that for EGUs greater than 250 MW at 750 MW power plants subject to BART, the appropriate BART emission limitation reflects either at least 95 percent control, or a comparable performance level of 0.1 to 0.15 lbs of SO

per million BTU range, unless the State has persuasive evidence (as discussed below) that an alternative determination is justified.

We are proposing a performance level as an alternative to a percentage reduction to account for the difference between coal with higher, as opposed to lower, sulfur content. As noted, we received comments on the proposed 2001 BART guidelines that the control technology presumption should be expressed as a performance level (lb/million BTU) rather than as a percentage control. In response to these comments, we are taking into account the fact that the actual level of performance after application of scrubber technologies will be influenced not only by the percentage control, but also by the sulfur content of the fuel used.

As discussed above, we believe that this proposal of 95 percent control, or a comparable performance level of 0.1 to 0.15 lbs of SO

per million BTU, represents controls that are achievable at reasonable cost-effectiveness levels. These control levels are functionally equivalent to the 90-95% control levels contained in the 2001 proposal. However the choice between 95 percent and an emission rate in the range of 0.1 to 0.15 lbs/MMBtu better reflects a recognition of the differences in overall emissions that are achievable by using different coal types. For example, coal boilers in the West generally use lower sulfur content Western coals. The low end of the range in the 2001 proposal recognized that dry scrubbers employed in the West would have difficulty achieving a 95% level of control. However, the 2001 proposal did not explicitly recognize that 90% control in the West may actually represent a lower overall sulfur emission rate, given the lower sulfur content in the coal used. Conversely, wet scrubbers employed in the East could easily get 95% control or more. But because Eastern coal boilers generally use higher sulfur content Eastern coals, the overall sulfur emission rate might still remain higher in the East than in the West.

While emission rates vary by both sulfur content and scrubber type, the following table illustrates demonstrated control efficiencies for the West and East.

Emission Rates and Scrubber Control Percentages for Bituminous Coal

Sulfur

Coal

(percent)

Scrubber

(percent)

/MMBtu

(lbs)

WEST

0.7

0.10

1.0

0.15

EAST

2.5

0.18

2.5

0.15

Assume: 13,000 lb Coal/Btu and 1 MW = 10.5 x 10

Btu/hr, from AP-42

Examples of SO

control calculations for various sulfur contents in bituminous coal, Note from Todd Hawes to Docket OAR-2002-0076, April 8, 2004.

We request comment on whether these control levels are appropriate, or whether different levels should be established instead. We also request comment on which specific target number in the 0.1 to 0.15 lb/million BTU range should be considered to represent BART, especially for those EGUs that cannot achieve 95 percent control. For whatever target levels commenters wish to offer, they should provide documentation supporting the basis for their proposals.

Although we are proposing to establish a requirement that these control levels are BART for 250 MW EGUs at greater than 750 MW power plants that are subject to BART, States would still have the ability to take into account any unique circumstances that support an alternative determination. The CAA identifies five factors that the States generally must consider in making a BART determination. CAA section 169A(g)(2). If, in any specific case, the State finds that these factors demonstrate that the presumed control levels do not represent BART, we propose that the State may make a reasoned determination as to the appropriate level of control. If a State chooses to deviate from the required level, it must provide documentation supporting and explaining its determination.

Nevertheless, we believe that it would be extremely difficult to argue, in any instance, that the above control levels should not be determined to be BART for these units at these large power plants. For the reasons outlined above, we believe that only in extremely rare and unique circumstances could a State determine that such controls are not cost effective, or that the visibility impact of such a plant does not warrant

such controls. We also believe that only under extreme circumstances would consideration of any of the remaining three factors (energy and nonair quality environmental impacts, existing pollution control technology in place, and remaining useful life of the source) suggest that these control levels are too stringent to be determined to be BART. For example, a source might show proof that it will be shutting down within the next 5 years. Or a source might be located in a remote desert area, where use of water for FGD would deplete an aquifer. As discussed above, however, in the vast majority of cases, we believe that these control levels should be considered to represent BART.

In addition, the control levels at issue are based on our understanding of the current capabilities of scrubbers, as well as the costs faced by the utility industry for installing these controls. We recognize that it is possible that capabilities of scrubber technologies may improve and it is likely that scrubber costs will continue to decline as scrubber technologies improve.

Accordingly, we have added a brief discussion to the reproposed guidelines to ensure that States take into account updated information on scrubber performance as scrubber technology improves.

Zipper and Gilroy, Sulfur Dioxide Emissions and Market Effects under the Clean Air Act Acid Rain Program (Air and Waste Management Association, 1998, vol. 48, pp. 829-37) shows that capital costs for FGD fell by 50 percent between 1989 and 1996. See

http://www.awma.org/journal/ShowAbstract.asp?Year=1998&PaperID=748.

See also, Market-Based Advanced Coal Power Systems—Final Report (Office of Fossil Energy, US Department of Energy, 1999), section 1, at

http://fossil.energy.gov/programs/powersystems/publications/marketbasedsystems/.

We also believe that States should find that the control levels described above are cost effective for all utility boilers greater than 250 MW in size, regardless of the size of the power plant at which they are located. There appears to be no significant difference in utility boilers at power plants that are greater than 750 MW, and those 750 MW or less, other than the number of boilers located at the facility. For the most part, plants greater than 750 MW generally consist of multiple units, many of which are smaller than 750 MW each.

Absent unusual circumstances which would lead to substantially higher costs than for typical facilities, a utility boiler greater than 250 MW in size should be able to achieve either a 95 percent reduction in SO

emissions or a comparable performance level of 0.1 to 0.15 lbs/MMBtu at a very reasonable cost. We request comment on whether this level of control is reasonable for such sources. Such unusual circumstances could be similar to the examples cited above with regard to greater than 750 MW plants (that a source might show proof that it will be shutting down within the next 5 years, or a source might be located in a remote desert area, where use of water for FGD would deplete an aquifer.) Although the hurdle for not achieving the default control level for greater than 750 MW plants is intended to be higher than the hurdle for less than 750 MW plants, we are unable to think of an example that would apply to 250 MW units and above at one size plant but not the other. We request comment on any such examples that might exist.

See

http://www.epa.gov/airmarkets/epaimp/#documentation.

This is the NEEDS (National Electric Energy System) Database for IPM V.2.1, NEEDS (National Electric Energy System) Database for IPM 2003. The NEEDS database contains the generation unit records used to construct the “Model” plants that represent existing and planned/committed units in EPA modeling applications of IPM. NEEDS includes basic geographic, operating, air emissions, and other data on all the generation units that are represented by “model” plants in EPA's v. 2.1 update of IPM. See Chapter 4 of the Documentation Report (link) for a discussion of the data sources underlying NEEDS.

6. Nitrogen Oxide Controls for Utility Boilers

Background. In addition to being a major source of SO

emissions, EGUs and other combustion units are a major source of NO

emissions. NO

emissions also contribute to regional haze, both through formation of light scattering nitrate particles in a manner similar to sulfate formation from SO

emissions, but also through promoting the formation of sulfate particles. Based on an examination of the contribution to haze in Class I areas from the IMPROVE network, SO

emissions comprise the most significant contribution. However, in some areas and at some times, the NO

contribution can be greater than the SO

contribution. Also, NO

emissions can be an important direct and indirect contributor to PM2.5 formation. In addition, in areas with high EGU SO

and NO

contributions, a reduction only of SO

emissions would result in nitrate ‘substitution’ for sulfates, reducing the regional haze benefits.

See

http://vista.cira.colostate.edu/improve/Publications/Reports/2000/PDF/Cahpter3final100.pdf.

These are summary statistics of exctinction by species from the IMPROVE network.

2001 Proposed Rule. In discussing the process for identifying all available retrofit emission control techniques in the 2001 proposed guidelines, we identified general information sources that address NO

control strategies (66 FR 38123). The proposed guidelines, however, did not contain a detailed discussion of available NO

control strategies for utilities.

Comments. We received several comments from environmental and multi-state organizations requesting that we specifically address technologies for control of NO

at BART sources. These commenters provided information showing that NO

emissions result in the formation of visibility-impairing nitrate particles. In addition, these commenters requested that we establish a presumptive 90 percent removal of emissions of NO

from currently uncontrolled utility boilers. The commenters provided information regarding the level of visibility impairment in Class I areas, as well as in urban areas, created by secondary particles related to emissions of NO

. The commenters noted that, while nitrate contributes less to visibility impairment, relative to sulfate, on the worst impaired days in summer, it has a more significant role in visibility impairment in winter when some of the worst days occur. In addition, the commenters point out that major reductions in SO

emissions, and the ammonium sulfate particles they create in the atmosphere, could lead to increases in nitrate particles. The reason for this is that reductions in ammonium sulfate particles could “free up” ammonia, making it available to form ammonium nitrate particles. The commenters argued that BART should control SO

and NO

simultaneously.

In addition to direct visibility concerns in and around Class I areas, commenters stated that NO

emissions reductions would contribute to improved public health. One commenter noted that reductions of NO

emissions from BART sources would result in enhanced benefits to ecosystems in high elevation Class I areas. Another commenter noted increasing trends in particulate nitrate concentrations at several Class I areas and suggested that EPA conduct a review of technologies, similar to the ORD report on SO

emissions controls, to be used as basis for a presumptive level of control.

Reproposal. We agree that emissions of NO

from sources subject to BART, and the resulting nitrate particles formed by NO

in the atmosphere, should be appropriately addressed in a BART analysis. We also agree with commenters that greater control of SO

at large coal-fired utility plants may result in greater availability of NO

in the atmosphere. Recent data from EPA's IMPROVE monitoring networks confirms that the contribution of

nitrates to visibility impairment is significant, and may be increasing, at a number of sites in the West.

See

http://wrapair.org/forums/ioc/meetings/030728/index.html

(especially presentation by John Vimont, National Park Service).

The approach to assessing the available methods for removal of NO

differs from the approach used to assess controls for removal of SO

. The engineering approach for removal of SO

from existing combustion sources is generally removal technology applied to the flue gas stream. For reducing emissions of NO

at existing combustion sources, there are two somewhat distinct engineering approaches available.

One is to use combustion modifications (including careful control of combustion air and/or low-NO

burners) and the other is removal technology applied to the flue gas stream (selective catalytic reduction (SCR) or selective non-catalytic reduction (SNCR)). These overall techniques can be applied alone or in combination.

An overview of NO

control technologies is available at the following Web site:

http://www.fetc.doe.gov/coalpower/environment/nox/index.html.

Unlike the methods for controlling SO

, which overall fall within a fairly narrow range of cost effectiveness and control efficiencies, the removal efficiencies and costs associated with the two overall categories of control techniques for NO

vary considerably, depending upon the design and operating parameters of the particular boiler being analyzed.

In general combustion controls and low-NO

burners are cost effective for utility boilers burning sub-bituminous coal, and may be less cost effective for units burning lignite.

See

http://www.epa.gov/ttn/catc/products.html#cccinfo

(EPA Air Pollution Control Cost Manual), section 4 (NO

controls), chapter 2.

See

http://www.epa.gov/airmarkets/epa-ipm/#documentation.

This is the NEEDS Database for IPM V.2.1, the NEEDS Database for IPM 2003. The NEEDS database contains the generation unit records used to construct the “model” plants that represent existing and planned/committed units in EPA modeling applications of IPM. The NEEDS database includes basic geographic, operating, air emissions, and other data on all the generation units that are represented by “model” plants in EPA's v. 2.1 update of IPM. See Chapter 4 of the Documentation Report for a discussion of the data sources underlying NEEDS. Data on units, their controls and characteristics are also part of the NEEDS database.

In this rulemaking, we are proposing that States, in establishing BART emission limits for NO

, must, as a general matter, require sources to determine BART as discussed below. For sources currently using controls such as SCR to reduce NO

emissions during part of the year, we are proposing that a State should presume in a BART determination that using these same controls year-round would be cost effective.

As the most significant costs associated with SCR are capital costs, the additional costs of operating this control technology throughout the year would be relatively modest.

In 1998, we issued a rule requiring a number of Eastern States to reduce the summertime emissions of NO

from sources within these States. 63 FR 57356, October 27, 1998). As a result of this rule, 19 States and the District of Columbia have required power plants to reduce NO

emissions seasonally.

See Status Report on NO

Control Technologies and Cost-Effectiveness for Utility Boilers, Northeast States for Coordinated Air Use Management and Mid-Atlantic Regional Air Management Association, June 1998, at:

http://www.nescaum.org/pdf/execsum_nox.pdf.

For all other power plants subject to BART, we believe that States should require the lowest emission rate that can be achieved without the installation of post-combustion controls. Thus, we are proposing that the States must, as a general matter, require these sources to achieve a control level of 0.2 lbs/MMBtu.

We are proposing to establish such a presumption because for most of the utilities subject to this rule, a 0.2 lb/MMBtu emission rate can be generally achieved through the use of combustion controls or low-NO

burners. We request comment on this emission rate. We also request comment on whether another emission rate higher or lower than 0.2 lb/MMBtu reflects an emission rate that can generally be achieved through the use of combustion controls or low-NO

burners. These controls are applicable to most EGUs, are relatively inexpensive,

and are already widely applied. We recognize that a small number of the largest power plants may need to install an SCR unit to meet this control level. In such relatively rare cases, a State, at its discretion, may find SCR to be appropriate if the source causes visibility impacts sufficiently large to warrant the additional capital cost.

The EPA Clean Air Market Division's “Cost Tool” gives information on control effectiveness (dollar/ton removed) and overall NO

control efficiencies for various control technologies.

http://www.epa.gov/airmarkets/epa-ipm/#documentation

This is the Documentation Report (2003 Analyses), and Documentation Report (V. 2.1 Update). Data on units, their controls and characteristics are also part of the NEEDS database, referenced above.

Notwithstanding the general assessment presented above, we ask for comment in particular on the question of what rate of NO

emissions can be achieved with low NO

burners or advanced combustion controls on certain specific types of boilers. For instance, we recognize that some wall-fired dry bottom boilers may not be able to meet an emissions rate of 0.2 lb/MMBtu without post-combustion controls. Similarly, we also recognize that, without post-combustion controls, wet bottom, cyclone, and cell burners probably cannot achieve a rate of 0.2 lb/MMBtu due to unique design and operational characteristics, such as relatively small furnace size or relatively large heat release rate. We also seek comment on the impact of coal rank on NO

emissions rates that can be achieved without post-combustion controls.

If you choose to comment on any of these issues, please provide data or technical information supporting your comments and recommendations.

We believe that States should determine in almost every case that these control levels represent a reasonable determination of BART for large EGUs. As discussed above, achieving these emissions reductions is generally cost effective. In addition, as commenters on the 2001 guideline noted, nitrates contribute significantly to regional haze. Thus, a State considering the costs of meeting these control levels and the degree of improvement in visibility should, in most instances, find that at a minimum, these controls represent BART. We acknowledge that there could be unique or extreme circumstances, for those few of the largest EGUs that cannot achieve 0.2 lbs/MMBtu without SCR or SNCR, under which a State might find SCR or SNCR to be unreasonable. We request comment on what specific circumstances might exist, if any, to justify a lesser degree of control. Commenters should provide documentation for any such examples.

7. Consideration of Visibility Impacts.

2001 Proposed Rule. Under the 2001 proposed guidelines, States would have been required to use a regional modeling analysis to assess the cumulative impact on visibility of the controls selected in the engineering analysis. States would use this cumulative impact assessment to make a determination of whether the controls, in their entirety, provide a sufficient visibility improvement to justify installation.

Comments. We received many comments regarding the cumulative nature of our process for considering the degree of visibility improvement. These commenters believed that the degree of visibility analysis should consider source-specific visibility impacts. These commenters also asserted that our process was not consistent with the requirements for BART in the CAA.

Reproposal. The fifth statutory factor addresses the degree of improvement in visibility which may reasonably be anticipated to result from the use of control technology. The American Corn Growers decision, discussed in detail in section II above, vacated the approach in the regional haze rule of requiring States to assess the degree of visibility improvement from the imposition of controls on all sources subject to BART in a State. We understand the court decision to require that we allow for an analysis of impacts that focuses on each individual source undergoing a BART determination.

Therefore, this reproposal focuses on the use of single source emissions modeling for assessing the degree of improvement in visibility from various BART control levels. For the purpose of the BART determination, a State or individual source would run the CALPUFF model, or other EPA-approved model, using source-specific and site-specific data. We recognize that such models may be useful in analyses where modeling results alone are not determinative of regulatory consequences. We believe that CALPUFF is based on sufficiently sound technical grounds to inform regulatory decisions that are based on a cumulative weight of evidence such as the statutorily-defined factors for consideration in assessing BART for regional haze.

For sources subject to BART that are located greater than or equal to 50 km from all receptors in a Class I area, the State or source would run the model at the current allowable emissions level, and then again at the post-control emissions level (or levels) being assessed. Results would be tabulated for the average of the 20% worst modeled days at each receptor. The difference in the resulting level of impairment predicted is the degree of improvement in visibility expected. For example, if the average impact from the 20% worst days for a source's pre-control emission rate for a particular receptor is a change of 1.0 deciviews, and its post-control impact is 0.4 deciviews, the net visibility improvement is 0.6 deciviews (60 percent). All receptors in the Class I area should be analyzed.

For sources subject to BART that are located less than 50 km from a Class I area, the State would use its discretion in determining visibility impacts for current allowable versus post-control emissions giving consideration to both CALPUFF and other EPA-approved methods such as PLUVUEII.

We request comment on this and other possible approaches to calculating the degree of visibility improvement expected for sources located less than 50 km from a Class I area.

PLUVUEII is a model used for estimating visual range reduction and atmospheric discoloration caused by plumes resulting from the emissions of particles, nitrogen oxices, and sulfur oxides from a single source. The model predicts the transport, dispersion, chemical reactions, optical effects and surface deposition of point or area source emissions. It is available at

http://www.epa.gov/scram001/tt22.htm#pluvue.

We also note that the proposed methodology is for Regional Haze Rule BART determination only; other metrics may be used for BART determinations made in response to certification of impairment by a Federal Land Manager.

Alternatively, we are requesting comment on the option of using the hourly modeled impacts from CALPUFF and assessing the improvement in visibility based on the number of hours above the 0.5 deciview threshold for the pre- and post-control emission rates. We also request comment on combinations of the proposed and alternative options above. For example, the deciview change for each hour of the 20% worst modeled days could be assessed. Finally, we request comment on the use of the simpler screening version of CALPUFF to do the analysis.

E. Trading Program Guidance

Background. The regional haze rule allows States the option of implementing an emissions trading program or other alternative measure instead of requiring BART (40 CFR 51.308(e)(2)). This option provides the opportunity for achieving better environmental results at a lower cost than under a source-by-source BART requirement. A trading program must include participation by BART sources, but may also include sources that are not subject to BART.

2001 Proposed Rule. In the 2001 proposed guidance, we provided an overview of the steps involved in developing a trading program consistent with 40 CFR 51.308(e)(2). We focused this discussion on emission cap and trade programs which we believe will be the most common type of economic incentive program (EIP) developed as an alternative to BART. The BART guidelines discussed three basic steps for cap and trade programs: (1) Developing emission budgets; (2) allocating emission allowances to individual sources; and (3) developing a system for tracking individual source emissions and allowances.

The proposal noted that an emissions budget generally represents a total emissions amount for a single pollutant such as SO

. As noted in the preamble to the regional haze rule (64 FR 35743, July 1, 1999), we believe that unresolved technical difficulties generally preclude interpollutant trading for addressing visibility impairment.

Once an emissions budget or “cap” is set, the next step in an emission trading program alternative to BART is to issue allowances to individual sources, consistent with the cap. Once the allowances are established, it is also necessary to have in place a tracking system to ensure that the allowances are met.

In the 2001 proposed guidelines, we did not include detailed recommendations on how to allocate emissions or how to develop a tracking system. We noted that it would not be appropriate for us to require a particular process and criteria for individual source allocations. The 2001 proposal noted that we did, however, agree to provide information on allocation processes to State and local agencies.

Comments. Regarding the sources to include in a trading program, some commenters suggested that a trading program could be expanded beyond the set of BART-eligible sources.

With regard to the geographic area covered by a trading program for BART, the WRAP enquired whether the backstop emissions trading program under section 309 of the regional haze rule could be expanded to other western States when they submit their section 308 SIPs.

Comments from the environmental officials for Indian Tribes suggested that the guidelines should ensure that some number of allowances are set aside for Tribes. Otherwise, the commenters believed that a trading program may perpetuate historical barriers to economic development in Indian country.

Reproposal. The reproposed guidelines largely reflect the same overall approach and level of detail as the 2001 proposal. We continue to believe that the trading program alternative provided by the regional haze rule can serve to reduce the administrative burden of the program while providing greater long-term environmental benefits. We discuss specific issues below.

Consistent with the regional haze rule, we propose that the guidelines continue to require participation by BART sources and allow for the option of additional participation. We note that by enlarging the universe of sources affected, it will be more likely that more sources with relatively low-cost emission reduction potential will be included. Therefore broader participation in the program is likely to

provide greater opportunities for emissions trading and cost savings. In addition, regional trading programs can potentially lower transaction costs and produce efficiencies by creating uniform requirements for firms which operate sources in multiple states. Therefore, we believe that States should consider whether it is appropriate to design and implement a trading program in conjunction with other States. Consistent with this overall approach, in the proposed Interstate Air Quality rule (IAQR) (69 FR 4566, January 30, 2004), we requested comment on whether compliance with the IAQR by affected EGUs in affected States would satisfy, for those sources, the BART requirements of the CAA, provided that a State imposes the full amount of SO

and NO

We continue to believe that there are no legal or regulatory obstacles to expanding the WRAP trading program to other States in the WRAP area, provided that technical analyses support such a plan.

Consistent with the regional haze rule, such a program must demonstrate greater reasonable progress for the Class I areas affected by sources in those States. We continue to request comment on how greater reasonable progress could be demonstrated, including in particular on whether overall visibility improvements across Class I areas, on balance, would be sufficient to determine that such a trading program is “better than BART.”

Letter from Lydia Wegman to Rick Sprott, Director, Utah Division of Air Quality, July 31, 2002.

Finally, in 1980, we published regulations addressing visibility impairment from one or more sources close to a Class I area. This type of visibility impairment is referred to as “reasonably attributable” impairment under the 1980 regulations. These regulations included a requirement for BART to address reasonably attributable impairment in 40 CFR 51.302. Given that these requirements remain in place even after publication of the regional haze rule, one issue needing clarification in the BART guidelines is the interface between these BART requirements established in 1980 and the requirements for BART under the regional haze program, and between the 1980 BART requirements and the provisions of a trading program alternative to BART.

We believe that the proposed guidelines appropriately clarify that the 1980 provisions for reasonably attributable impairment, including the BART requirement, remain in effect until the BART requirement is satisfied. We believe that it is relatively unlikely that many—if any—sources will be found to be subject to the 1980 BART requirement, given that Federal Land Managers (FLMs) have certified impairment on only a few occasions since 1980. Nonetheless, if evidence were to suggest that an individual source was causing localized visibility impairment, we believe that it would be improper to remove FLMs' and States' ability to craft a solution using the tools provided by our visibility regulations. We note that the regional haze rule includes provisions allowing “geographic enhancements” to trading programs that can address local visibility concerns up front. Accordingly, we continue to believe that States and FLMs have the ability to provide assurances to sources that any trading program established for regional haze will satisfy all of the BART provisions in EPA's visibility regulations.

IV. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review

Under Executive Order 12866 (58 FR 51735, October 4, 1993), EPA must determine whether the regulatory action is “significant” and, therefore, subject to Office of Management and Budget (OMB) review and the requirements of the Executive Order. The Order defines “significant regulatory action” as one that is likely to result in a rule that may:

(1) Have an annual effect on the economy of $100 million or more or adversely affect in a material way the economy, a sector of the economy, productivity, competition, jobs, the environment, public health or safety, or State, local, or Tribal governments or communities;

(2) Create a serious inconsistency or otherwise interfere with an action taken or planned by another agency;

(3) Materially alter the budgetary impacts of entitlements, grants, user fees, or loan programs or the rights and obligations of recipients thereof; or

(4) Raise novel legal or policy issues arising out of legal mandates, the President's priorities, or the principles set forth in the Executive Order.

Pursuant to the terms of Executive Order 12866, it has been determined that this rule is a “significant regulatory action,” thus EPA has submitted this rule to OMB for review. The drafts of the rules submitted to OMB, the documents accompanying such drafts, written comments thereon, written responses by EPA, and identification of the changes made in response to OMB suggestions or recommendations are available for public inspection at EPA's Air and Radiation Docket and Information Center (Docket Number OAR-2002-0076). The EPA has prepared the document entitled “Regulatory Impact Analysis of the Proposed Guidelines for Best Available Retrofit Technology Determinations Under the Regional Haze Regulations' (RIA) to address the requirements of this executive order.

The RIA presents estimates of the health and welfare benefits and the estimated costs of the BART reproposal in 2015 and the estimated benefits and costs of the recently signed IAQR proposal (69 FR 4566, January 30, 2004). Reviewing these results, it is important to recognize that the BART and IAQR proposals are likely to be overlapping actions that address many of the same power plants. However, IAQR as proposed will affect a 29 State and the District of Columbia region in the eastern U.S., and the BART rule is applicable nationwide. In the proposed IAQR, we requested comment on whether compliance with the IAQR by affected EGUs in affected States would satisfy, for those sources, the BART requirements of the CAA, provided that a State imposes the full amount of SO

and NO

emissions reductions on EGUs that the IAQR deemed highly cost effective. We are in the process of evaluating those comments. Based on our current evaluation, we believe the IAQR, as proposed, is clearly better than BART for those affected EGUs in the affected States which we propose to cover under the IAQR. We thus expect that the final IAQR would satisfy the BART requirements for affected EGUs that are covered pursuant to the final IAQR. EPA projects that both of these rules are likely to achieve significant health and welfare benefits. The BART analysis presented here is limited to the electric utility sector because of limitations in the data currently available on non-EGU sources. It is also important to note that States will make the ultimate decisions as to how the BART requirements are implemented.

Thus, the analysis results reported reflect the EPA's best estimate of the benefits and costs of this State determined process.

Significant health and welfare benefits are likely to occur as a result of this rule. Based upon EPA estimates, thousands of premature deaths and other serious health effects would be prevented each year. The EPA estimates monetized annual benefits of approximately $44 billion (assuming a 7 percent discount rate) or $47 billion (assuming a 3 percent discount rate) in 2015 (1999$). Table IV-1 presents the primary estimates of reduced incidence of PM health effects for 2015 for the source-specific BART proposal and the IAQR proposed rule. Specifically, the table lists the PM-related benefits associated with the reduction of ambient PM.

In interpreting the results, it is important to keep in mind the limited set of effects we are able to monetize. Thus, the benefits reported for this rule are understated due to the omissions listed in Table II-4.

Nonetheless, the benefits quantified and monetized are substantial both in incidence and dollar value. In 2015, we estimate that reduction in exposure to PM

2.5

from the BART rule will result in approximately 7,400 fewer premature deaths annually associated with PM

2.5

, as well as 3,900 fewer cases of chronic bronchitis, 9,800 fewer nonfatal heart attacks (acute myocardial infarctions), 6,000 fewer hospitalizations (for respiratory and cardiovascular disease combined), and significant reductions in days of restricted activity due to respiratory illness (with an estimate of 4.4 million fewer cases). We also estimate substantial health improvements for children from reductions in upper and lower respiratory illnesses, acute bronchitis, and asthma attacks.

Table IV-2 presents the estimated monetary value of reductions in the incidence of health and welfare effects. PM-related health benefits are estimated to be approximately $43 billion (assuming a 7 percent discount rate) or $46 billion (assuming a 3 percent discount rate) in 2015. Estimated annual visibility benefits in the U.S. brought about by the BART rule due to visibility improvements in federal Class I areas in the Southeast, Southwest, and California are estimated to be approximately $940 million in 2015. All monetized estimated values are stated in 1999$. Table IV-2 shows the total annual monetized benefits for the year 2015. This table also indicates with a “B” those additional health and environmental effects that we were unable to quantify or monetize. These effects are additive to the estimate of total benefits, and the EPA believes there is considerable value to the public of the benefits that could not be monetized.

Table IV-1.—Estimated Reductions in Incidence of Health Effects of the BART Rule

[In 2015]

Endpoint

Constituent

BART

IAQR proposal

Premature Mortality—adult

2.5

7,400

13,000

Mortality-infant

2.5

Chronic bronchitis

2.5

3,900

6,900

Acute myocardial infarction—total

2.5

9,800

18,000

Hospital admissions—respiratory

2.5

3,200

*8,100

Hospital admissions—cardiovascular

2.5

2,800

5,000

Emergency room visits, respiratory

2.5

5,300

9,400*

Acute bronchitis

2.5

9,000

16,000

Lower respiratory symptoms

2.5

110,000

190,000

Upper respiratory symptoms

2.5

350,000

620,000

Asthma exacerbation

2.5

150,000

240,000

Acute respiratory symptoms (MRADs)

2.5

4,400,000

8,500,000

Work loss days

2.5

740,000

1,300,000

School loss days

390,000

This text is long and has been trimmed here. Open the source document for the complete record.

This is a copy of a public record, reproduced as it was published. It is not legal advice, and it may not be the version a court would rely on. Check the official source before you cite it.