DRAFT 1 16560-50 m* • »• »• • July 9, 1992 2 3 4 ENVIRONMENTAL PROTECTION AGENCY 5 6 40 CFR PART 52 7 8 [FRL- ] 9 10 State Implementation Plans for Serious PM-10 11 Nonattainment Areas; Addendum to the 12 General Preamble for the Implementation 13 of Title I of the Clean Air Act Amendments of 1990 14 15 16 . AGENCY: Environmental Protection Agency (EPA). 17 ACTION: Addendum to General Preamble for future proposed 18 rulemakings. 19 SUMMARY: To be added to final document. 20 FOR FURTHER INFORMATION CONTACT: Kenneth R. Woodard, Air 21 Quality Management Division, Mail Drop 15, Office of Air 22 Quality Planning and Standards, U.S. EPA, Research Triangle 23 Park, North Carolina 27711, (919) 541-5697. 24 SUPPLEMENTARY INFORMATION: NOTE: In accordance with 1 CFR 25 5.9(c), this document is published in the proposed Rules 26 category. References are available from the Public Docket 27 No. A-92-23. The docket is located at the U.S. EPA Air 28 Docket, Room M-1500, Waterside Mall, LE-131, 401 M Street, 29 S.W., Washington, D.C. 20460. The docket may be inspected 30 from 8:30 a.m. to 12 noon and from 1:30 p.m. to 3:30 p.m. on 31 weekdays, except for legal holidays. A reasonable fee may 32 be charged for copying. ------- 1 2 3 I. 4 II. 5 6 7 8 III. 9 10 11 IV. 12 V. 13 14 15 16 17 18 19 VI. 20 21 22 23 24 25 26 ~ -2- TABLE OF CONTENTS INTRODUCTION DESIGNATIONS AND CLASSIFICATIONS A. Designations E. Classifications C. Reclassifications INTERNATIONAL BORDER AREAS A. Statutory Requirement B. Policy SERIOUS AREA SIP REQUIREMENTS WAIVERS FOR CERTAIN PM-10 NONATTAINMENT AREAS A. 1990 Clean Air Act Amendments B. Historical Perspectives C. Requirements to Attain the Standards D. Waiver provisions E. Issues F. Waiver Policy Description BEST AVAILABLE CONTROL MEASURES A. Background B. Requirement for Best Available Control Measures C. EPA's Historical Classification of Control Technology D. BACM for Serious PM-IO Nonattainment Areas ------- 1 2 3 4 5 VII. 6 VIII. 7 8 9 10 11 -3- E. Procedures for Determining Best Available Control Measures F. Selection of BACM for Area Sources G. Selection of BACT for Point Sources CONTINGENCY MEASURES QUANTITATIVE MILESTONES AND REASONABLE FURTHER PROGRESS A. General Discussion B. Reasonable Further Progress C. Quantitative Milestones ------- -4- 1 I. Introduction 3 Issues are discussed in this document regarding policy and guidance that will be applicable to areas that have been 2 4 designated nonattainment for particulate matter having an 5 aerodynamic diameter less than or equal to a nominal 10 microns (PM-10) and reclassified as serious areas.1 6 7 Initially, all areas designated as nonattainment for PM-10 8 are classified as moderate areas [see section 188(a)]. 9 Subsequently, in accordance with section 188(b)(1) of the 10 Clean Air Act (Act) as amended November 15, 1990, n[t]he 11 Administrator may reclassify as a Serious PM-10 12 nonattainment area. . . any area that the Administrator 13 determines cannot practicably attain the national ambient 14 air quality standard for PM-10 by the attainment date (as 15 prescribed in subsection (c)) for Moderate Areas.n The EPA 16 proposed on November 21, 1991 (56 FR 58656) to reclassify as 17 serious 14 moderate areas that were initially designated as 18 non attainment for PM-10 upon enactment of the 1990 19 Amendments. 21 This guidance document will be published as an,addendum to the General Preamble for the Implementation of Title I of 20 22 the Clean Air Act Amendments of 1990 (General Preamble) 23 24 25 26 27 28 29 1The 1990 Amendments to the Clean Air Act made significant changes to the air quality planning requirements for areas that do not meet (or that significantly contribute to ambient air quality in a nearby area that does not meet) the PM-10 national ambient air quality standards (see Pub. L. No. 101-549, 104 Stat. 2399). References herein are to' the Clean Air Act, as amended, 42 U.S.C. ~~7401 et seq. ------- 1 -5- published April 16, 1992 (57 FR 13498).2 This serious PM- 2 10 nonattainment area guidance document describes EPA's 3 preliminary views on how EPA should interpret various 4 provisions of Title I with regard to requirements for 5 PM-10 serious area state implementation plans (SIP's). 6 Although the guidance includes various statements that 7 States must take certain actions, these statements are made 8 pursuant to EPA's preliminary interpretations, and thus do 9 not bind the States and the public as a matter of law. Of 10 course, the use of prescriptive language is appropriate in 11 those instances where the policy is simply reiterating 12 statutory mandates which provide that States must take 13 certain actions. 14 possible approaches to implementing the general SIP 15 requirements of section 172(c) and the specific requirements 16 in subpart 4 of Part 0 of Title I in serious PM-10 17 nonattainment areas, the issues involved and means of 18 resolving those issues are discussed in the following 19 sections. The topics discussed include treatmerit of 20 international border areas; waivers for areas impacted by 21 nonanthropogenic sources; SIP requirements such as 22 provisions to assure that best available control measures 23 24 25 26 27 28 2A supplemental notice was published at 57 FR 18070, April 28, 1992, which provides certain appendices to the April 16, 1992 General Preamble. Subsequent references in this notice to the General Preamble are inclusive of both documents. !?~O~E~W Of [~A lIBRARV. RTF. He . ------- -6- 1 are implemented, requirements for quantitative milestones, 2 reasonable further progress (RFP) and contingency measures. 3 II. Designations and Classifications 4 A. Designations 5 section 107(d) of the Act provides generally for the 6 designation of areas of each state as attainment,' 7 nonattainment or unclassifiable for each pollutant for which 8 there is a national ambient air quality standard (NAAQS). 9 certain areas meeting the qualifications of section 10 107(d)(4)(B) of the Act were designated nonattainment for 11 PM-10 by operation of law upon enactment of the 1990 12 Amendments (initial PM-10 nonattainment areas). A Federal 13 Register notice announcing all of the areas designated 14 nonattainment for PM-10 at enactment and classified as 15 moderate was published on March 15, 1991 (56 FR 11101). A 16 follow-up notice correcting some of these area designations 17 was published August 8, 1991 (56 FR 37654). The boundaries 18 of the nonattainment areas were formally codified in 40 CFR 19 Part 81, effective January 6, 1992 (56 FR 56694, November 6, 20 1991). All those areas of the country not designat~d 21 nonattainment for PM-10 at enactment were designated 22 unclassifiable [see section 107(d)(4)(B)(iii) of the Act]. 23 B. Classifications 24 Once an area is designated nonattainment, section 188 25 of the Act outlines the process for classification of the 26 area and establishes the area's attainment date. In ------- -7- 1 accordance with section 188(a), all PM-10 nonattainment 2 areas are initially classified as moderate by operation of 3 law upon their designation as nonattainment. 4 C. Reclassifications 5 1. General Conditions 6 A moderate area can subsequently be reclassified as a 7 serious nonattainment area under two general conditions. 8 First, EPA has general discretion under section 188(b)(1) to 9 reclassify a moderate area as a serious area at any time the 10 Administrator determines the area cannot practicably attain 12 the NAAQS by the statutory attainment date for moderate' areas.3 11 13 Second, under section 188(b)(2) a moderate area is 14 reclassified as serious by operation of law after the 15 statutory attainment date has passed if the Administrator 16 finds that the area has not attained the NAAQS. The EPA 18 must publish a Federal Register notice identifying the areas that have failed to attain and were reclassified, within 6 17 19 months following the attainment date [see section 20 188(b)(2)(B)]. 21 2. Reclassification of Initial PM-10 Nonattainment Areas 22 section 188(b)(1)(A) mandates an accelerated schedule 23 by which EPA is to reclassify appropriate initial PM-10 24 nonattainment areas. The EPA proposed on November 21, 1991 25 26 3See the detailed discussion of this provision in section III.C.1(b) of the General Preamble (57 FR at 13537-38). ------- -8- 1 (56 FR 58656) to reclassify 14 of the 70 initial moderate 2 areas as serious. The 14 areas EPA proposed to reclassify 3 were identified largely based on the magnitude and frequency 5 of ambient PM-10 measurements above the 24-hour NAAQS of 150 micrograms per cubic meter (~g/m3) during calendar years .4 6 1988 - 199C. The EPA pr.esumed for the purpose of that 7 proposal that areas with 24-hour design concentrations 58 8 percent or more above the NAAQS (greater than or equal to 237 ~g/m3) and with 6 or more expected exceedances of the 9 10 24-hour NAAQS could not practicably attain the standards by 11 December 31, 1994, the statutory attainment date. The final 12 decision to reclassify the areas proposed will be based on 13 the criteria utilized in the proposal, comments received in 14 response to the proposal and on information in the moderate 15 area SIP's that were due on November 15, 1991 for each of 16 the areas. 17 In the future, EPA anticipates that, generally, any 18 proposal to reclassify an initial PM-10 nonattainment area 19 before the attainment date will be based on the State's 20 demonstration that the NAAQS cannot practicably be attained 22 in the area by December 31, 1994 [the statutory attainment date specified in section 188(c)(1) for initial PM-10 21 23 nonattainment areas]. 24 3. Reclassification of Future PM-10 Nonattainment Areas 25 In addition to EPA's general authority under section 26 188(b)(1) to reclassify as serious any area the ------- -9- 1 Administrator determines cannot practicably attain the PM-10 3 NAAQS by the applicable date, for areas subsequently designated nonattainment for PM-10, subparagraph (B) of 2 4 section 188(b)(1) mandates a timeframe within which EPA is 5 to reclassify appropriate areas designated nonattainment 6 subsequent to enactment of the 1990 Amendments. Appropriate 7 areas are to be reclassified as serious within 18 months 8 after the required date for the state's submission of a 9 moderate area SIP [see section 188(b)(1)(B)].4 Taken 10 together with the statutory requirement that PM-10 SIP's are 11 due at anytime EPA determines that an area cannot 12 practicably attain the NAAQS by the applicable attainment 13 date within 18 months after an area is designated 14 nonattainment [see section 189(a)(2)(B)], the statute thus 15 requires that EPA reclassify appropriate moderate areas as 16 serious within 3 years of the nonattainment designation. 17 Because the moderate area SIP's are due before this 18 reclassification deadline, EPA anticipates that any 19 determination that such areas should be reclassified will be 20 based upon the State's demonstration that the NAAQS,cannot 21 practicably be attained by the statutory deadline. In 22 addition, delays in adopting, submitting, and implementing 23 SIP requirements may be a basis for concluding that an area 24 cannot practicably attain by the applicable date. For 25 26 27 4This directive does not restrict EPA's general authority but simply specifies that it must be exercised, as appropriate, in accordance with certain dates. ------- -10- 1 example, if a state fails to submit a PM-10 SIP, EPA could 3 conclude that the area could not practicably attain the standards by the applicable attainment date based on the 2 4 severity of the nonattainment problem, the feasibility of 5 implementing control measures within the time allowed and 6 other pertinent factors. Any decision by EPA to reclassify 7 an area as serious will be based on facts specific to the 8 nonattainment area at issue and will only be made after 9 providing notice in the Federal Register and an opportunity 10 for public comment on the basis for EPA's proposed decision. 11 The EPA does not believe that generally reclassifying 12 moderate areas as serious rewards areas which delay 13 development and implementation of PM-10 control measures. 14 Rather, EPA believes its policy creates an incentive for the 15 timely submittal and effective implementation of moderate 16 area SIP requirements and facilitates the PM-10 attainment 17 objective. For example, if an area that fails to submit a 18 timely moderate area SIP is reclassified, this does not 19 obviate the requirement that the area submit and implement 20 the moderate area SIP requirements. Accordingly, the area 21 could be subject to sanctions for its delay in submitting 22 the moderate area SIP [see sections 110(m) and 179]. Also, 23 reclassification before the applicable attainment date will 24 ensure that more stringent control measures are implemented 25 sooner and will expedite the application of more stringent 26 ------- -11- 1 new source review requirements to the area [see sections 2 189(b)(1) and 189(b)(3)]. 3 III. International Border Areas 4 A. statutory Requirement 5 section 818 of the 1990 Clean Air Act Amendments added 6 a new section, 179B, to Subpart 1, Part D of Title I. 7 section 179B applies to areas that could attain the relevant 8 NAAQS by the statutory attainment date but for emissions 9 emanating from outside the united states. For PM-10 10 nonattainment areas, section 179B(a) provides that EPA must 11 approve the moderate area SIP if (1) the SIP meets all the 12 applicable requirements under the Act other than a 13 requirement that such plan or revision demonstrate 14 attainment and maintenance of the PM-10 NAAQS by the applicable attainment date, and (2) the State demonstrates 15 16 to EPA's satisfaction that the SIP would be adequate to 17 attain and maintain the PM-10 NAAQS by the attainment date 18 but for emissions emanating from outside the united States. 19 In addition, section 179B(d) provides that if a State 21 demonstrates that an area would have timely attaine~ the PM- 10 NAAQS but for emissions emanating from outside the united 20 22 States, the area must not be subject to the reclassification 23 provisions of section 188(b)(2). section 188(b)(2) provides 25 that any moderate PM-10 nonattainment area that is not in attainment after the applicable attainment date shall be 24 26 reclassified to serious by operation of law. Therefore, the ------- -12- 1 statute provides that areas that could attain but for 2 emissions emanating from outside the u.s. must not be 3 reclassified as serious after failing to attain by the applicable date5. 4 5 B. Policy 6 The state must show that an area is eligible to have 7 its SIP approved and not be reclassified as serious under 8 section 179B by evaluating the impact of emissions emanating 9 from outside the United states and demonstrating that the 10 SIP would bring about attainment but for those emissions. 11 The impact of emissions emanating from outside the united 12 13 14 15 16 17 18 19 20 21 22 23' 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 5AS noted, section 179B(d) states that areas demonstrating attainment of the standards but for emissions emanating from outside the united states shall not be subject to section 188(b)(2) (reclassification for failure to attain). By analogy to this provision and applying canons of statutory construction, EPA will not reclassify before the applicable attainment date areas which can demonstrate attainment of the standards but for emissions emanating from outside the united states [see section 188(b)(1)]. First, section 179B evinces a general congressional intent not to penalize areas where emissions emanating from outside the country are the but-for cause of the PM-10 nonattainment problems. Further, if EPA were to reclassify such areas before the applicable attainment date, EPA, in effect, would be reading section 179B(d) out of the statute. Specifically, if EPA proceeded to reclassify before the applicable attainment date those areas qualifying for treatment under section 179B, an area would never be sUbject to the provision in section 179B(d) which prohibits EPA from reclassifying such areas after the applicable attainment date. Canons of statutory construction counsel against interpreting the law such that language is rendered mere surplusage. Finally, note that section 179B(d) contains a clearly erroneous reference to carbon monoxide instead of PM-10, and that this section contains other clear errors [see, e.g., section 179B(c) reference to section 186(b)(9), which does not exist]. ------- -13- 1 states may be evaluated using a combination of the following 2 techniques. 3 1. Inventorying the sources and comparing the '4 magnitude of PM-10 emissions originating within the 5 nonattainment area and those emanating from outside the 6 united states; 7 2. Establishing an ambient PM-10 monitoring network 8 (including directional samplers), both in the nonattainment 9 area and across the border, based on guidance provided in 40 10 CFR, Part 58; 11 3. Analyzing ambient sample filters for pollutants 12 emanating from across the border; and/or 13 4. Performing air dispersion and/or receptor modeling 14 (receptor modeling combines the results of filter analysis 15 with meteorological information) to quantify the relative 16 impacts of the united states and foreign sources of PM-10 17 emissions. 18 The EPA will consider all of the information presented by 19 the state for individual areas on a case-by-case basis in 20 determining whether an area may qualify for treatment under 21 section 179B. 22 In addition to demonstrating that the SIP for the area 23 would be adequate to timely attain and maintain the NAAQS 24 but for emissions emanating outside the U.S., the SIP must 25 continue to meet all applicable moderate area SIP 26 requirements in order to qualify for the special SIP ------- -14- 1 approval under section 179B. Among other things, the SIP 2 must provide for the implementation of reasonably available 3 control measures (HACM), including reasonably available 4 control technology (HACT), to the extent necessary to 5 demonstrate that the NAAQS could be attained in the 6 nonattainment area by the applicable attainment date if 7 emissions emanating from outside the united States were not 8 included in the analysis. EPA believes that this 9 interpretation of the degree of HACM the State is required 10 to implement in moderate PM-10 areas affected by emissions 11 emanating from outside the united States is consistent with 12 the purpose of section 179B. By directing EPA, under 13 section 179B, to approve the plan or plan revision of a 14 moderate PM-10 area which shows it would attain the NAAQS 15 but for foreign emissions and by excluding such an area from 16 reclassification to serious, Congress clearly wanted to 17 avoid penalizing such areas by not making them responsible 18 for control of emissions emanating from a foreign country 19 over which they have no jurisdiction. Moreover, by 20 excluding the area from reclassification, Congress ~lso 21 elected to avoid subjecting such areas to the more stringent 22 control measures applicable in serious PM-10 areas. In 23 addition, as set forth in section 179B(a)(2), the second 24 condition which must be met before EPA may approve a 25 moderate area plan showing attainment but for foreign 26 emissions, by its plain terms, requires the State to ------- -15- 1 establish only that the plan submitted would be "adequate" 2 to timely attain and maintain the NAAQS, but for emissions 3 from outside the united states. Nothing in section 1798 4 relieves the state from meeting al its applicable moderate 5 PM-10 SIP requirements, including the requirement to 6 implement nACM. Nonetheless, if, in doing so, such an area 7 were also required, because of contributions to PM-10 8 violations caused by foreign emissions, to shoulder more of 9 a regulatory and economic burden than States not similarly 10 affected by implementing measures which go well beyond those 11 which the SIP demonstrates would otherwise be adequate to 12 attain and maintain the PM-10 NAAQS, i.e., "super" RACM, 13 such a requirement would unfairly penalize that area and 14 effectively undermine the purpose of section 1798. Indeed, 15 to the extent an affected state can satisfactorily 16 demonstrate that implementation of such measures clearly 17 would not advance the attainment date, EPA could conclude 18 they are unreasonable and hence do not constitute RACM. 19 Notwithstanding the above, in light of the overall health 20 and clean air objectives of the Act, EPA does encourage 21 affected states to reduce emissions beyond the minimum 22 necessary to satisfy the but for test in order to reduce the PM-10 concentrations to which their populations are exposed. 23 24 25 26 ------- -16- 1 2 3 In addition to section 179B, the waiver policy, 4 discussed below, could apply to an international border area 5 if it is determined that non anthropogenic sources of PM-10 within the united states significantly contribute to 6 7 violations in the area [see section 188(f)]. 8 IV. serious Area SIP Requirements 9 New revisions must be made to the PM-10 SIP in 10 accordance with section 189(b) of the Act for areas that are 11 reclassified as serious nonattainment areas. First, 12 provisions must be adopted to assure that BACM (including BACT) will be implemented in the area [see section 13 14 189(b)(1)(B)]. Second, a demonstration (including air 15 quality modeling) must be submitted showing that the plan will attain the NAAQS either by the applicable attainment 16 17 date or, if an extension is granted under section 188(e), by 18 the most expeditious alternative date practicable [see 19 section 189(b)(1)(A)]. 20 The SIP revisions to require the use of BACM m~st be 21 submitted to EPA within 18 months after an area is 22 reclassified as serious [see section 189(b)(2)]. The BACM 23 are to be implemented no later than 4 years after an area 'is 24 reclassified [see section 189(b)(1)(B)]. The EPA's policies 25 regarding the requirement to implement BACM in serious areas 26 are discussed in section VI of this document. ------- -17- 1 The serious area attainment demonstration required 2 under section 189(b)(1)(A) must be submitted to EPA within 4 3 years after an area is reclassified based on a determination 4 by EPA that the area cannot practicably attain by the 5 statutory deadline for moderate areas. It is due within 18 7 months after an area is reclassified for actually having failed to attain by the moderate area attainment date [see 6 8 section 189(b)(2)]. 9 The new attainment date for initial PM-10 nonattainment 10 areas that are reclassified as serious is to be as 11 expeditiously as practicable but not later than December 31, 12 2001. For areas that are designated nonattainment for PM-10 13 in the future and subsequently become serious, the 14 attainment date is to be as expeditiously as practicable but 15 no later than the end of the tenth calendar year beginning 16 after the area's designation as nonattainment [see section 17 188(c)(2)]. 18 In addition to the specific PM-10 SIP requirements 19 contained in Subpart 4 of Part D, Title I, States containing 20 serious areas must meet all of the applicable general SIP 21 requirements set forth in section 110(a)(2) and the 22 nonattainment area SIP requirements set forth in subpart 1 23 of Part D, Title I to the extent that these provisions are 24 not otherwise subsumed by, or integrally related to, the 25 more specific PM-10 requirements.6 The general SIP 26 6See 57 FR 13538 (April 16, 1992). ------- -18- 1 requirements applicable to all nonattainment areas are 2 discussed in the General Preamble at 57 FR 13556-57. 3 serious PM-10 nonattainment areas must meet, among .4 other things, the following requirements which are discussed 5 in this document: 6 a. current actual and allowable emissions inventories, 7 that meet EPA guidelines (see section V below); 8 b. additional control measures beyond BACM, if 9 necessary, in order to attain the NAAQS by the most 10 expeditious date practicable (see sections 188(e) and 11 189(b)(1)(A)(ii»; 12 c. contingency measures (see section VII below); 13 d. quantitative milestones that are to be achieved 15 every 3 years until the area is redesignated attainment and which demonstrate RFP toward attainment of the NAAQS as 14 16 required in section 189(c) of the Act (see section VIII 17 below); 18 e. revised definitions for the terms "major source" 19 and "major stationary source" as required in section 20 189(b)(3) of the Act; 21 f. BACM for major stationary sources of PM-10 22 precursors except in those areas where EPA has determined 23 that such sources do not contribute significantly to PM-10 24 levels which exceed the NAAQS (see 57 FR 13541-42). The demonstration required under section 189(b)(1)(A) 25 26 should follow the existing modeling guidelines addressing ------- -19- 1 PM-I0 (e.g., "PM-I0 SIP Development Guideline" (June 1987); "Guideline on Air Quality Models" (Revised); memorandum from 2 3 Joseph Tikvart and Robert Bauman dated July 5, 1990); and 4 any applicable regulatory requirements. A supplementary 5 attainment demonstration policy applicable to initial 6 moderate PM-I0 nonattainment areas facing special 7 circumstances was issued in a memorandum from EPA's Office 9 of Air Quality Planning and Standards to the Directors of EPA Regional Office Air Divisions on March 4, 1991.7 8 10 That supplementary policy is not applicable to serious area 11 SIP demonstrations. 12 If the State demonstrates that attainment by the 13 statutory deadline for serious areas (as set forth in 14 section 188(c) of the Act) is impracticable, the State must 15 demonstrate that the SIP provides for attainment by the most 16 expeditious alternative date practicable. The State may 17 apply to EPA for an extension of the serious area attainment 18 date under section 188(e) of the Act. A State requesting an 19 extension under section 188(e) for an area must, among other 20 things, demonstrate that the plan for the area includes the 21 most stringent measures that are included in the 22 implementation plan of any State or are achieved in practice 23 in any State, and can feasibly be implemented in the area. 24 25 26 27 7"PM-I0 SIP Attainment Demonstration Policy for Initial Moderate Nonattainment Areas," memorandum from John Calcagni and William Laxton to Director, Air Division, EPA Regions I-X, March 4, 1991. ------- -20- 1 The EPA will issue guidance in the future on applying for an 2 extension of the serious area attainment date. 3 v. Waivers for Certain PM-10 Nonattainment Areas 4 A. 1990 Clean Air Act Amendments 5 The Act, as amended in November 1990, was designed to 6 assure that attainment and maintenance of the PM-10 7 standards, which were promulgated in 1987 (52 FR 24634, 8 July 1, 1987), be as expeditious as practicable. Thus, the 9 Act requires states to submit several revisions of the SIP 10 for PM-10 nonattainment areas, if necessary, to ensure 11 attainment of the PM-10 NAAQS as expeditiously as 12 practicable. The SIP revisions must first provide for the 13 implementation of RACM on PM-10 sources. If RACM is not 14 adequate to attain the NAAQS, subsequent" revisions must 15 provide for implementation of additional, more stringent 16 control measures until the NAAQS are attained. 17 However, the Act also authorizes the Administrator of 18 EPA to waive certain requirements for certain PM-IO 19 nonattainment areas under the provisions of section 188(f). 21 Congress apparently recognized that there may be areas where the NAAQS may never be attained because of PM-10 emissions 20 22 from "nonanthropogenic sources,,,8 and that the imposition 23 24 25 26 27 28 8The legislative history of the 1990 indicates that Congress intended that the "nonanthropogenic" sources of PM-10 refer where the human role in the cause of such highly attenuated (see H.R. Rep. No. 490, Sess. 265 (1990)). Amendments term to activities emissions is 101st Cong., 2d ------- -21- 1 of certain requirements in such areas may not significantly 2 advance the PM-10 attainment objective. 3 Under section 188(f), the Administrator may waive a specific attainment date for areas where EPA determines that 4 5 nonanthropogenic sources of PM-10 contribute significantly 6 to the violation of the PM-10 NAAQS. The Administrator may 7 also, on a case-by-case basis, waive any requirements 9 applicable to serious areas under Subpart 4 of Part D of Title I where EPA determines that anthropogenic sources do 8 10 not contribute significantly to the violation of the NAAQS 11 in the area. 12 B. Historical Perspectives 13 1. Rural Fugitive Dust Policy 14 The EPA in the past has focused some of its air 16 pollution control efforts on industrial point source emissions and other traditional sources of air pollution.9 15 17 For instance, EPA's 1977 guidance on SIP development gave 18 priority to control of urban fugitive dust on the grounds 19 that (1) urban soil was believed to be contaminated and, 20 21 22 23 24 25 26 27 28 29 30 31 9The EPA distinguished between "traditional" and "nontraditional" sources. The term "nontraditional source" first appeared in official print in 1976 in EPA's "National Assessment of the Urban Particulate Problem," EPA-450/3-76- 024, July 1976, and was coined as a catch-all to refer to' those sources not traditionally considered in air pollution control strategies, including construction and demolition, tailpipe emissions, tire wear, and various sources of fugitive dust. Since then, the use of the term has expanded to include such sources as prescribed agricultural and silvicultural burning, open burning, and residential wood combustion. ------- -22- 1 therefore, potentially more harmful than the native soils in 2 rural areas; (2) the potential for significant population 3 exposures aDd attendant health effects was much greater in 4 urban areas; and (3) scarce resources at the Federal, state, 5 and local agency levels could be most effectively brought to 6 bear on the more pronounced problems found in urban 7 areas.10 Accordingly, EPA's policy was to require greater 8 control of emissions in urban areas, including control of 9 fugitive dust from all major sources. In contrast, control 10 requirements for rural areas were far less ambitious, 11 focussing on the control of major industrial sources, with 12 little attention given to natural or nonindustrial 13 emissions. This policy of giving a lower priority to 15 controlling natural or nonindustrial emissions in rural areas became known as the "Rural Fugitive Dust pOlicy."ll 14 16 The EPA's policy focus shifted away from the type and 17 location of the emission sources (i.e., traditional or 18 nontraditional sources, urban or rural locations) to the 19 size of the particles emitted when the indicator for the 20 NAAQS was changed in 1987 from total suspended particulate 21 22 23 24 10"Guidance on SIP Development and New Source Review in Areas Impacted by Fugitive Dust," Edward F. Tuerk, Acting Assistant Administrator for Air and Waste Management, to Regional Administrators. 11see, e.g., "Model Letter Regarding state Designation of Attainment Status," David H. Hawkins, Assistant Administrator for Air and Waste Management to Regional Administrators, October 7, 1977; see also, "Fugitive Dust Policy: SIP's and New Source Review" (August 1984). 25 26 27 28 29 ------- -23- 1 matter to PM-10. While revisions to the rural fugitive dust 2 policy were being considered, the policy was continued 3 during the initial phases of implementing the PM-10 NAAQS on .4 an interim basis.12 However, EPA believes that the 1990 5 Amendments to the Clean Air Act provide a statutory 6 alternative that wholly supplants the rural fugitive dust 7 policy. See sections 107(d)(4)(B) and 188(f) of the amended 8 Act; 56 FR 37659 (August 8, 1991). 9 C. Requirements to Attain the Standards 10 As noted previously, the Act requires States to submit 11 several SIP revisions, if necessary, providing for 12 implementation of increasingly stringent control measures and demonstrating when those control measures will bring 13 14 about attainment of the PM-10 NAAQS. The first SIP revision 15 was due November 15, 1991 for the initial PM-10 16 nonattainment areas. For areas redesignated nonattainment 17 for PM-10 in the future under section 107(d)(3), the first 18 SIP revision will be due within 18 months after the area is 19 redesignated [see section 189(a)(2)]. This SIP revision 20 must, among other things, provide for implementatio~ of RACM 21 on sources in the area [see sections 189(a)(1)(C) and 22 172(c)(1)]. All technologically and economically feasible 23 control measures would be considered RACM for areas that 24 cannot attain the NAAQS by the December 31, 1994 attainment 25 26 12See 52 FR 24716 (July 1, 1987). ------- -24- 1 date for initial moderate PM-10 nonattainment areas (see 57 FR 13544).13 2 3 If EPA determines that a moderate area cannot 4 practicably attain the NAAQS by the applicable attainment 5 date and reclassifies the area as a serious nonattainment 6 area under section 188(b), a second SIP revision for the 7 area is required under section 189(b). For example, within 8 18 months after the area is reclassified as serious the 9 affected State must submit provisions to assure that 10 available control measures (BACM) are implemented in the 11 area no later than 4 years after the date the area is 12 reclassified [see section 189(b)(1)(B)]. In addition, under 13 section 189(b)(1)(A), the State must submit a demonstration 14 of attainment for the area (or if the State is seeking an 15 extension of the attainment date under section 188(e), a 16 demonstration that attainment by that date would be 17 impracticable, and that the plan provides for attainment by 18 the most expeditious alternative date practicable). Such 19 demonstration is due within 4 years after an area is 20 reclassified based on a determination by EPA that the area 21 cannot practicably attain by the deadline for moderate areas 22 or it is due within 18 months if the area is reclassified by 23 24 25 26 27 28 13Note that if it can be shown that measures are unreasonable because emissions from the sources affected are insignificant or de minimis, such measures may be excluded from consideration as they would not represent RACM for that area. See 57 FR 13540. ------- -25- 1 operation of law for having failed to attain the NAAQS [see 2 section 189(b)(2)]. 3 Another SIP revision must be submitted if the State 4 demonstrates to EPA, among other things, that the serious 5 area cannot practicably attain by the statutory serious area 6 attainment date described above. This revision must 7 accompany an application for the attainment date to be 8 extended under section 188(e) of the Act. The SIP revision 9 must include a demonstration of attainment by the most 10 expeditious alternative date practicable, not to exceed 5 11 years beyond the serious area attainment deadline. Further, 12 the State must demonstrate, among other things, that the 13 plan for the area includes the most stringent measures that 14 are included in the plan of any State or. are achieved in 15 practice in any State, and can feasibly be implemented in 16 the area. 17 If a serious area fails to attain by the applicable 18 attainment date (which may be an extended attainment date), 19 another SIP revision is required within 12 months that 20 provides for attainment and until then for annual reductions 21 in PM-10 or PM-10 precursor emissions within the area of not 22 less than 5 percent of the amount of such emissions as 23 reported in the most recent emission inventory for the area 24 [see section 189(d)]. 25 D. waiver provisions 26 Due to the character of certain nonattainment ------- -26- 1 situations, not all of the state planning efforts described 2 above may be justified for some PM-10 nonattainment areas. 3 Therefore, under section 188(f) of the Act, Congress 4 provided a means for EPA to waive a specific date for 5 attainment and certain control and planning requirements 6 when certain conditions are met in the nonattainment area. 7 section 188(f) allows two types of waivers. First, the 8 Administrator may waive a specific date for attainment of 9 the standards where EPA determines that nonanthropogenic 10 sources of PM-10 contribute significantly to the violation 11 of the standards in the area. Also, the Administrator may, 12 on a case-by-case basis, waive any requirement under Subpart 13 4 applicable to any serious nonattainment area where EPA 14 determines that anthropogenic sources of PM-10 do not 15 contribute significantly to the violation of the standards 16 in the area. 17 E. Issues 18 Several questions must be answered before the waiver 19 provisions above can be used. Each of these questions are 20 discussed in the subsections that follow. 21 1. What types of sources should be considered 22 anthropogenic and nonanthropogenic? 23 The legislative history of the 1990 Amendments 24 indicates that Congress intended that the term 25 "nonanthropogenic" sources of PM-10 refer to activities 26 where the human role in the cause of such emissions is ------- -27- 1 highly attenuated (see H.R. Rep. No. 490 at 265). Naturally 2 occurring events such as wildfires, volcanic eruptions, 3 unusually high pollen counts and high winds which generate 4 dust from undisturbed land (e.g., the desert) are examples 5 of nonanthropogenic sources that EPA believes meet the 6 intent of Congress. 7 Anthropogenic sources of PM-10 emissions are those 8 resulting from human activities. Some of the traditional 9 and nontraditional anthropogenic sources generally 10 considered in PM-10 SIP's are commercial, institutional, and 11 residential fuel combustion; fossil fuel-fired electric' 12 power plants; industrial processes; vehicular traffic on 13 paved and unpaved roads; construction activities; 14 agricultural activities; and other sources of fugitive dust 16 which are directly traceable to human activities and which are reasonably foreseeable incidents of such activities.14 15 17 2. What criteria should be used in determining when 18 nonanthropogenic sources contribute significantly and when 19 anthropogenic sources do not contribute significantly to 20 violation of the NAAQS in the area? 21 To determine the availability of a waiver under section 22 188(f), it must first be established whether anthropogenic 23 source emissions do not and whether nonanthropogenic source 24 emissions do contribute significantly to violation of the 25 26 27 14"PM-10 SIP Development Guideline," EPA-450/2-86-001, u.S. Environmental Protection Agency, Research Triangle Park, North Carolina, 1987, pp. 5-5, Table 5.1. ------- -28- 1 PM-10 NAAQS in the area. The Act does not define the term 2 "contribute significantly" as it is used in section 188(f), 3 nor does the legislative history provide any useful .4 guidance. 15 Where a statute is silent or ambiguous with 5 respect to the meaning of a statutory term, a reasonable 6 agency interpretation of the term must be given deference by 7 a reviewing court [see Chevron U.S.A.. Inc. v. Natural 8 Resources Defense Council, Inc., 467 U.S. 837, 842-845 9 (1984)]. The EPA thus believes it has the authority to 10 select appropriate criteria by which to determine when 11 nonanthropogenic/anthropogenic sources in an area do/do not 12 "contribute significantly" to levels of pollution which 13 exceed the NAAQS, as well as to consider for this purpose 14 criteria utilized in other statutory contexts. 15 The criteria which EPA believes provides a reasonable 16 approach to determining whether nonanthropogenic sources do 17 and anthropogenic sources do not "contribute significantly" 18 to violations of the PM-10 NAAQS in the area, as well as a 19 20 21 22 23 24 25 26 27 28 29 30 31 32 15It should be noted, however, that the term "contribute significantly" (or variations of that term) has been interpreted differently throughout the Act, e. g., in the ozone/CO programs [see section 107(d)(4)(A)(iv) and (v)], the new source review (NSR) program, and in specific provisions of the statute, such as sections 110(a)(2)(D)(i)(I) and 126(a)(1)(B). An agency is permitted, but not required, to gi ve a similar meaning to similar terms which appear in different parts of a statute. Thus, although EPA is not bound to adopt the interpretation given the term "contribute significantly" in other parts of the statute, it is likewise not precluded from according this use of similar language some interpretive weight. ------- -29- 1 discussion of the basis for selecting these criteria, are 2 set forth below. 3 In light of the different legal tests set forth in 4 section 188(f), the EPA believes that no single numerical 5 indicator of significance would serve the statutory purpose 6 of encouraging protection of public health and welfare while 7 avoiding unreasonable control actions. Further, the 8 character and extent of anthropogenic and nonanthropogenic 9 contributions--individually and in relation to each other-- 10 differ widely from one area to the next: meteorological and 11 terrain characteristics have markedly different influences 12 on various areas' tendencies to experience violations given 13 a particular quantity of nonanthropogenic emissions; and 14 different categories of nonanthropogenic emissions are more 15 or less amenable to actions that can reasonably be taken to 16 minimize their contributions to violations. 17 Generally, where a nonattainment area's anthropogenic 18 sources contribute very little to violations, it is likely 19 that controlling those emissions to the extent feasible for 20 the area will be insufficient to attain the NAAQS. ,In such 21 cases, it would be unreasonable to require the area to 22 implement more stringent and more expensive controls on 24 anthropogenic sources since they would contribute little to attainment or to reducing the pUblic's exposure to unhealthy 23 25 air quality. In similar fashion, where nonanthropogenic 26 emission contributions are great, even after the area has ------- -30- 1 taken reasonable steps to reduce them, at some point it may not be feasible for the area to reduce nonanthropogenic (or 2 3 anthropogenic) emissions sufficiently enough to effect any 4 real change in ambient concentrations. Consequently, it 5 would be unreasonable to require the area to continue to 6 pursue control measures that are beyond the area's 7 practicable abilities. 8 In selecting an appropriate "significance" contribution 9 from anthropogenic sources, EPA has elected to rely on the 10 test of significance that is applied under new source 11 permitting programs. Under the NSR permit program, the EPA 12 requires state permitting programs to consider new major 13 sources or major modifications as causing or contributing to 15 a violation of the PM-10 NAAQS when the source would add, at a minimum, over 5 ~g/m3 to the 24-hour average or over 1 14 16 ~g/m3 to the annual average PM-10 concentrations in an area 17 that does not or would not meet the PM-10 NAAQS [see 40 CFR 18 51.165(b)]. Given that the purpose of new source permitting 19 programs is also to protect air quality in both attainment 20 and nonattainment areas, EPA believes that the test of 21 significant contribution to violations under that program 22 should also be applicable when determining significant 23 contributions of anthropogenic sources under section 188(f) 24 of the Act. However, in determining "significance" for 25 purposes of section 188(f), the plain terms of that provision and its underlying purpose dictate that EPA 26 ------- -31- 1 consider the impact of the anthropogenic sources as a whole. 3 Consequently, where emissions from all anthropogenic sources as a whole contribute less than or equal to 5 ~g/m3 to 24- 2 4 hour average design concentrations and less than or equal to 1 ~g/m3 to annual mean design concentrations in a 5 6 nonattainment area, after all RACM have been implemented,16 EPA will conclusively regard such 7 8 contributions as insignificant for purposes of waiving requirements applicable to serious PM-I0 nonattainment areas 9 10 pursuant to section 188(f). 11 If an area meeting this test has not yet been 12 reclassified as serious and the area would qualify for a 13 waiver of all of the serious area requirements (see 14 discussion below), EPA will not require reclassification, 15 since the action would have no practical effect. If the 16 contribution of anthropogenic emission sources to the 24- hour design concentration exceeds 5 ~g/m3, or if the 17 18 contribution to the annual design concentration exceeds 1 ~g/m3, even after the application of all RACM, then the area 19 20 should be reclassified as serious, and serious area. 21 requirements, including BACM, should be implemented. 22 As explained more fully in response to the third 23 24 25 26 27 28 16Implementation of RACM (including RACT) is required in all moderate PM-I0 nonattainment areas and that requirement is not waived under the provisions of section 188(f). Therefore, the issue is whether anthropogenic sources still contribute significantly to violations of the NAAQS in an area, after implementing RACM. ------- -32- 1 question below, note that special considerations apply to the determination whether nonanthropogenic sources 2 3 contribute significantly to violation of the PM-I0 NAAQS in 4 a moderate area and whether such area therefore qualifies 5 for an attainment date waiver. This is because the effect 6 of waiving the attainment date for a moderate area is to 7 relieve it of the serious area requirements. Thus, a 8 moderate area may be subject to an attainment date waiver 9 only if it also qualifies for a waiver of the serious area 10 requirements. As provided in section 188(f), in order to 11 qualify for such a waiver of the serious area. requirements the moderate area must demonstrate that the anthropogenic 12 13 sources in the area do not contribute significantly. since 14 this second test is more stringent, a moderate area that 15 meets this test by demonstrating that anthropogenic sources 16 do not contribute significantly will necessarily demonstrate 17 that nonanthropogenic sources do contribute significantly. 18 These special considerations would not be relevant where EPA 19 is determining whether to waive the attainment date for a 20 serious area since waiving the date in such circumstances 21 would not as a matter of course have the effect of relieving 22 the area of the serious area requirements. 23 Because the basic purpose of Title I is to protect 25 public health and welfare through attainment and maintenance of the NAAQS, EPA believes that before it may conclusively 24 26 presume a serious area's nonanthropogenic emissions ------- -33- 1 contribution to be significant, that contribution should by 2 itself prevent the area from attaining the NAAQS after 3 reasonable steps have been taken to reduce or minimize their .4 impacts. Consequently, EPA will consider nonanthropogenic 5 sources to contribute significantly only if, after the 6 application of RACM to nonanthropogenic sources, their 7 contribution to the 24-hour average design concentration exceeds 150 ~g/m3, or their contribution to the annual mean 8 9 design concentration exceeds 50 ~g/m3. 10 Information derived from chemical and optical analysis 11 of ambient filter catches, area emission inventories, and 12 dispersion modeling to determine maximum source impacts can 13 be used to evaluate the impact of anthropogenic and 14 nonanthropogenic sources. Analysis of filters collected 15 with a network of monitors over a long period (lor more 16 years) should reveal the portions of normal area PM-10 17 concentrations attributable to background, nonanthropogenic, 18 and anthropogenic sources, respectively. 19 3 . Should moderate areas where nonanthropogenic 20 sources contribute significantly to violation of the PM-10 21 NAAQS be reclassified as serious before EPA considers 22 waiving the attainment date? 23 Section 188(f) contains two different legal standards. 24 The first sentence applies to a waiver of the serious area 25 requirements and requires that EPA determine that 26 anthropogenic sources do not contribute significantly before ------- -34- 1 EPA grants such a waiver. The second sentence applies to 2 waiver of an area's attainment date and requires that EPA 3 determine that nonanthropogenic sources contribute 4 significantly before waiving the attainment date. As 5 illustrated in the following example, the first test is more 6 stringent than the second. Assume, for example, that 7 non anthropogenic sources contribute 60% of the problem in an 8 area and that anthropogenic sources contribute 40%. In such 9 case, non anthropogenic sources are significant and the area 10 would appear to qualify for an attainment date waiver. 11 However, anthropogenic sources also would contribute 12 significantly and therefore the area would not qualify for 13 waiver of the serious area requirements. In fact, the area 14 would need a much smaller contribution from anthropogenic 15 sources (and correspondingly, a much larger contribution 16 from nonanthropogenic sources) to qualify for the serious 17 area requirements waiver. 18 The significantly disparate legal standards set out in 19 188(f) may lead to an absurd result. In particular, if a 20 moderate area met the less stringent attainment date waiver 21 test and the attainment date for the area was actually 22 waived, the area would never be reclassified.17 The 23 24 25 26 27 28 29 17If EPA waives a specific attainment date for a moderate area consistent with its authority under section 188(f), the attainment date for the area will be vacated. Therefore, the moderate area would not be subject to reclassification under section 188(b) because there simply. would be no attainment date that the area cannot practicably meet or that the area fails to meet. However, since section ------- -35- 1 result would be that a moderate area would be effectively 2 relieved from the serious area requirements without having 3 met the more stringent test that Congress expressly required 4 be met as a prerequisite to a waiver of such requirements. 5 The more stringent test for determining whether to waive 6 serious area requirements would be rendered meaningless. 7 Moderate areas would qualify for the attainment date waiver, 8 be effectively relieved of all serious area requirements and 9 never have to meet the required test for such waiver. 10 To avoid this absurd result and only grant a waiver of 11 the serious area requirements consistent with the legal 12 standard set out in the Act, EPA has construed section 13 188(f) in the following manner. A moderate area may only 14 qualify for an attainment date waiver if. it also qualifies 15 for a waiver of the serious area requirements. Therefore, 16 EPA must determine that anthropogenic sources in the area do 17 not contribute significantly to violation of the PM-10 NAAQS 18 and the serious area requirements should be waived before 19 EPA can grant an attainment date waiver for a moderate area. 20 If such a determination is made, then the attainment date 21 may be waived and the area would not be reclassified. Note, 22 however, that an area already reclassified as serious could 23 24 25 26 27 28 188(f) only authorizes waiving the attainment date, the moderate area would still be subject to all the remaining moderate area SIP requirements. Therefore, the moderate area SIP submitted to meet the applicable requirements of subparts 1 and 4 should continue to provide for implementation of RACM. ------- -36- 1 qualify for an attainment date waiver solely by showing that 2 it meets the attainment date waiver test. And, consistent 3 with the discussion in question 2 above, EPA would consider 4 waiving the attainment date for a serious area if 5 nonanthropogenic emissions alone prevent the area from 6 attaining the PM-10 NAAQS. 7 4. For what period may a specific attainment date be 8 waived? 9 When nonanthropogenic sources have been determined to 10 contribute significantly to violations in an area, in 11 accordance with the above criteria, those sources may 12 permanently prevent the area from attaining the standards. 13 Therefore, the attainment date for such areas could be 14 waived indefinitely.18 However, the phrase "waive a 15 specific date" does not require that the attainment date be 16 waived indefinitely, nor does it lessen the state's 17 obligation to strive to expeditiously attain the NAAQS at 18 some time in the future through available means. While EPA 19 does not expect states to exhaust their resources to meet 20 standards that may be unattainable, it does expect them to 21 22 23 24 25 26 27 28 29 18In cases where it is feasible to implement measures that will reduce future emissions from nonanthropogenic sources (i.e., planting indigenous vegetation or establishing wind breaks), EPA has the authority under section 188(e) to extend the attainment date for a serious area if it is possible that the NAAQS could be attained in the future. Such measures should be considered by States before seeking waivers of the attainment date. ------- -37- 1 continue efforts to minimize exposures to unhealthy air 2 quality. 3 5. Should the area's emissions and control strategy be 4 reviewed periodically to determine whether any factors have 5 changed that would make it practicable to attain the NAAQS? 6 Even though a specific attainment date and serious area 7 requirements may be waived indefinitely for an area where 8 nonanthropogenic sources contribute significantly to 9 violations and anthropogenic sources do not, the State 10 should periodically review the status of anthropogenic and 11 nonanthropogenic source contributions in the area. Such a 12 review would entail determining whether nonanthropogenic 13 sources still contribute significantly and anthropogenic 14 sources do not contribute significantly to violation of the 15 PM-10 NAAQS in the area. Since emissions from anthropogenic 16 sources increase with population growth and new sources 17 being added to the area, the contribution of anthropogenic 18 sources to violations can become significant over time. 19 Therefore, the need for reinstating a specific attainment 20 date and/or previously waived requirements should be 21 reconsidered periodically. 22 The EPA has the authority under section 172(c)(3) to 23 require periodic updates of the area's emissions inventory 24 to assure that the requirements of Part D are met. The EPA 25 plans to use this authority to periodically review the 26 waiver status of areas, as described above. A specific ------- -38- 1 attainment date and applicable requirements should be 2 reinstated if it is determined that nonanthropogenic sources 3 no longer contribute significantly or anthropogenic sources .4 begin contributing significantly to violations in the area. 5 6. What requirements applicable to serious 6 nonattainment areas under Subpart 4 of Part D should be 7 waived? 8 The requirements applicable to serious areas under 9 Subpart 4 are found primarily in section 189. Those 10 requirements include: 11 a. submission of a SIP, under section 189(b)(1)(A), 12 that includes a demonstration that the plan provides for 13 attainment by the applicable attainment date [December 31, 14 2001 for the areas initially designated nonattainment for 16 PM-10 by operation of law under section 107(d)(4) and no later than the end of the tenth year beginning after the 15 17 area's designation for areas subsequently designated nonattainment], or a demonstration that attainment by the 18 19 above date is not practicable and that the plan provides for 20 attainment by the most expeditious alternative date, 21 practicable; 22 b. provisions, under section 189(b)(1)(B), to assure 23 that BACM will be implemented no later than 4 years after 24 the area is reclassified as serious; 25 c. a requirement, under section 189(b)(3), that the 26 terms "major source" and "major stationary source," used in ------- -39- 1 implementing a new source permitting program under section 2 173 and control of PM-10 precursors under section 189(e), 3 include any stationary source or group of stationary sources 4 located within a contiguous area and under common control 5 that emits, or has the potential to emit, at least 6 70 tons per year of PM-IO; 7 d. quantitative milestones, [applicable to both 8 moderate and serious area SIP's under section 189(c)], which 9 are to be achieved every 3 years until the area is 10 redesignated attainment, and which demonstrate RFP toward 11 attainment by the applicable date. The provision includes a 12 requirement for periodic reports demonstrating whether the 13 milestones have been met; 14 e. annual reductions in inventoried PM-10 and PM-10 15 precursor emissions within the area of not less than 16 5 percent, under section 189(d), if the serious area fails 17 to attain the standards; and 18 f. as applicable, RACT-level, BACT-level, and new 19 source review control of PM-I0 precursors from major 20 stationary sources of precursors in the airshed, [applicable 21 to both moderate and serious area SIP's under section 22 189(e)]. 23 The Subpart 4 requirements will be waived only on a 24 case-by-case basis for serious areas where anthropogenic 25 sources do not contribute significantly and have been 26 controlled to the degree practicable. A decision by EPA to ------- -40- 1 waive any Subpart 4 requirements in any area will likely be 2 made only after providing public notice and an opportunity 3 for comment on the bases for EPA's decision. 4 F. waiver Policy Description 5 The EPA intends to implement its authority to grant 6 waivers under section 188(f) in a manner described by the 7 logic diagram presented in Figure 1. The figure presents 8 six decision questions. A SIP submitted for a moderate 9 nonattainment area seeking a waiver is expected to address 10 the first three questions: 11 1. Can the area attain the NAAQS by the applicable 12 statutory attainment date (December 31, 1994 for the initial 13 nonattainment areas) after implementing HACM (including 14 reasonably available control technology--HACT) for 15 contributing anthropogenic and nonanthropogenic sources? 16 2. Do nonanthropogenic sources of PM-l0 as a whole 17 contribute significantly to violations in the area? 18 3. Do anthropogenic sources of PM-l0 as a whole 19 contribute significantly to violations in the area? 20 If the moderate area SIP demonstrates that the,area can 21 attain with HACM (including HACT) by the attainment date, 22 the answer to the first question is yes and the waiver 23 provisions are not available. If the area cannot attain 24 with HACM (including HACT) and nonanthropogenic sources do 25 not contribute significantly to violations then, logically 26 anthropogenic sources must contribute significantly by ------- 1. Can area attain with RACM? Yes No waivers 2. Nonanthropogenic sources si nlficant? Yes 3. Anthropogenic sources significant after RACM? Yes No Waive specific attainment date and/or appropriate serious area requirements Can area attain with annual reductions emissions? ~o waivers Waive attainment date No waivers Grant an extension Yes ) Implement annual reductions FIGURE 1. WAIVER POLICY LOGIC DIAGRAM Reclassify area as serious 4. Can area attain by the deadline for serious areas? No 5. Can area attain with an extension of the attainment date? III- ------- -42- 1 default. Therefore, the area would not qualify for a waiver 2 of any kind under section 188(f). 3 If the area cannot attain with RACM (including RACT) 4 and nonanthropogenic sources do contribute significantly to 5 violations and, moreover, anthropogenic sources, after RACM 6 (including RACT) have been implemented, will not contribute 7 significantly, then the waiver provisions may be 8 exercised. 19 A specific attainment date for the moderate 9 area may be waived if the area would qualify for a waiver of 10 all of the serious area requirements. The practical effect 11 of waiving the attainment date for a moderate area is to 12 relieve it from reclassification as serious and, therefore, 13 to relieve it from all serious area requirements. However, 14 the state should reevaluate the impact of anthropogenic 15 sources on the area periodically to determine whether or not 16 they contribute significantly to violations. 17 If the state determines that anthropogenic sources will 18 still contribute significantly to violations after RACM 19 (including RACT) are implemented, then the area will be 20 reclassified as serious and will not qualify for waiver of 21 any serious area requirements. However, the area may still 22 be eligible for waiver of a specific serious area attainment 23 24 25 26 27 28 29 19section 188(f) authorizes EPA to waive requirements applicable to serious areas and not the requirements applicable to moderate areas. Therefore, EPA believes the best reading of the statute requires that the emission reductions attributable to RACM (including RACT) should be. considered before evaluating the significance of anthropogenic contributions. ------- -43- 1 date depending on the answers to questions 4, 5, and 6. 2 4. Can the serious area attain by the statutory 3 deadline after implementing the serious area control .4 strategy [i.e., BACM, (including BACT)], for significant 5 anthropogenic sources? 6 5. C&n the area attain with an extension of the 7 attainment date? 8 6. Can the area attain in the future if PM-I0 and 9 PM-I0 precursor emissions within the area, as reported in 10 the most recent inventory, are reduced annually by not less 11 than 5 percent? 12 If the answers to questions 4-6 are no and the area 13 cannot attain the NAAQS by controlling emissions from 14 anthropogenic sources and reducing emissions from 15 nonanthropogenic sources, then a specific attainment date 16 for the area may be waived. 17 However, if EPA determines that it is practicable for 18 an area, where both nonanthropogenic and anthropogenic 19 sources contribute significantly to violations, to attain 20 the NAAQS at any time in the future, a specific attainment 21 date would not be waived. Rather, the state would be 23 expected to reduce emissions until the NAAQS are attained. The EPA may grant an extension of the attainment date for 22 24 serious areas of no more than 5 years under the conditions ------- -44- 1 of section 188(e) of the Act.20 Also, if th~ area fails 2 to attain by the end of the extension period, the state must 3 plan to achieve annual reductions of not less than 5 percent 4 of PM-10 and PM-10 precursor emissions within the area, as 5 reported in the most recent inventory [see section 189(d)]. 6 . VI. BEST AVAILABLE CONTROL MEASURES 7 A. Background 8 There are two circumstances, as discussed earlier, 9 under which a moderate PM-10 nonattainment area may be 10 reclassified as serious. First, an area may be reclassified 11 whenever EPA determines that the PM-10 NAAQS cannot 12 practicably be attained by the statutory attainment 13 date.21 Such a determination may be made before the 14 attainment date if a review of the SIP for an area shows 15 that RACM, including RACT, will not bring the area into 16 attainment or if delays in adopting, submitting, and 17 implementing SIP requirements form a basis for EPA to 18 conclude that an area cannot practicably attain the NAAQS by 19 the statutory attainment date. The second circumstance is 20 when the area is reclassified by operation of law upon a 21 determination by EPA that the area has failed to attain the 22 NAAQS on schedule [see section 188(b)]. 23 24 20Guidance on demonstrating that a state qualifies for an attainment date extension will be issued in the future. 25 26 27 28 21The statutory attainment date for the initial group of areas designated nonattainment by operation of law upon enactment of the 1990 Amendments, under section 107(d)(4), is December 31, 1994. ------- -45- 1 Reclassification of an area as serious does not obviate 2 the legal requirement to submit a moderate area SIP. The 3 moderate area SIP must, among other things, provide for 4 implementing RACM/RACT on PM-10 sources as required by 5 section 189(a). The moderate area SIP's for the initial 6 group of PM-10 nonattainment areas were due November 15, 7 1991. The EPA notified the Governors of any States that 8 failed to submit moderate area SIP's of its intent .to impose 9 sanctions under section 110(m) and 179 of the Act and of the 10 requirement for EPA to adopt a Federal implementation plan 11 (FIP) under section 110(c) of the Act.22 Once imposed, 12 the sanctions will not be removed until the State has 13 satisfied all the applicable PM-10 SIP requirements [see 56 14 FR 58658]. 15 The EPA described RACM (including RACT) for moderate areas in the General Preamble (57 FR 13537-45 and 13560-61) 16 17 as those available control measures that are reasonable 18 considering their technological feasibility and the cost of 19 control in the area to which the SIP applies, and 20 considering the attainment needs of the area. The General 21 Preamble also states that EPA considers it reasonable for a 22 State to adopt all available control measures that are 23 24 25 26 27 28 22A finding of nonsubmittal was made by EPA in December 1991 if a SIP was not submitted for one of the initial moderate nonattainment areas. See 57 FR 19906 (May 8, 1992). Subsequently, at least one sanction under section 179(b) will be imposed in those areas within 18 months of the finding unless the deficiency is corrected. ------- -46- 1 technologically and economically feasible for areas that do 2 not demonstrate attainment by the statutory deadline. See 3 57 FR at 13544. However, EPA believes it may be reasonable, 4 in some limited circumstances, for States to consider the 5 compatibility of RACT with BACT that will ultimately be 6 implementec under serious area plans for those moderate 7 areas which do not demonstrate attainment. Id. The EPA 8 indicated in the General Preamble that for specific stack 9 and process sources, installation of RACT-level controls may 10 involve substantial capital costs for technology that is 11 significantly incompatible with BACT-level technology. In 12 the event that BACT is later required for those same 13 sources, the installation of the first set of controls would 14 be unreasonable. Accordingly, EPA indicated that SIP's for 15 the initial moderate areas reclassified as serious in the 16 mandatory reclassification rulemaking for initial areas need 17 not require major changes to the control systems for 18 specific stack and process sources where a State reasonably 19 demonstrated that such changes would be significantly 20 incompatible with the application of BACT-level control 21 systems. A State's demonstration should include, for 22 example, a showing of what the State believes are RACT and 23 BACT for the source and why those technologies are 24 significantly incompatible. 25 B. Requirement for Best Available Control Measures 26 As noted, additional control requirements are ------- -47- 1 established in section 189(b) for PM-10 nonattainment areas 2 that are reclassified as serious by EPA. Under section 3 189(b)(1)(B), states must provide for implementation of the best available control measures (BACM) for control of PM-10 4 5 emissions in such areas. The EPA believes the requirement 6 to implemer.t BACM in serious PM-10 nonattainment areas, 7 should, in one key respect, be interpreted similarly to the 8 comparable requirement, under section 189(a)(1)(C), to 9 implement RACM in moderate PM-10 nonattainment areas. 10 In addition to the specific plan requirements contained 11 in Subpart 4 of Part D of Title I for PM-10 nonattainment 12 areas, section 172 (in Subpart 1) sets forth general 13 statutory requirements which apply to all nonattainment 14 areas. These general requirements clearly establish that 15 the RACM requirement for plans required to be submitted 16 under Part D of Title I must include reasonably available 17 control technology (RACT). section 172(c)(1) states that 18 RACM for Part D nonattainment area plans shall include "such 19 reductions in emissions from existing sources in the area as 20 may be obtained through the adoption, at a minimum, ,of 21 reasonably available control technology. . .." Thus, 22 moderate PM-10 nonattainment area RACM plans, which are 23 submitted to meet the requirements of section 189(a)(1)(C), 24 must include provisions ensuring the adoption of RACT (see 25 57 FR 13540, Col. 1). 26 Under the PM-10 subpart, for areas reclassified as ------- -48- 1 serious, the moderate nonattainment control requirements 2 (i.e., RACM) are carried over and elevated to a higher level 3 of stringency (i.e., BACM). So, by analogy, just as RACM .4 includes RACT, in the same way, BACM includes BACT. Thus, 5 just as moderate PM-10 SIP revisions when implementing RACM 6 under section 189(a)(1)(C) must provide for the adoption of 7 RACT, similarly, PM-10 SIP revisions under section 8 189(b)(1)(B), implementing BACM in serious PM-10 9 nonattainment areas, must include provisions ensuring the 10 adoption of BACT. Even without the RACM analogy, the best 11 available technological control measures by their plain 12 terms are a subset of the universe of best available control 13 measures. This point was explicitly addressed in the House 14 Committee Report: "[S]erious areas must include in their 15 submission provisions to require that the best available 16 control measures for the control of PM-10 emissions are 17 implemented no later than four years after the area is 18 classified or reclassified as serious. Such provisions must 19 include the application of the best available control 20 technology to existing stationary sources." H.R. Rep. No. 21 490, 101st Cong., 2nd Sess. 266-67 (1990). The,section 22 189(b)(1)(B) SIP revisions must be submitted to EPA within 23 18 months after an area is reclassified and must assure that 25 the measures are implemented no later than 4 years after the area is reclassified as serious [see section 189(b)(1) and 24 26 189(b)(2)]. ------- -49- 1 C. EPA's Historical Classification of Control Technology 2 The Act does not define the term BACM as it applies to 3 serious PM-10 nonattainment areas. However, the Act does 4 refer to different levels of emission control technology 5 required for existing or new sources as "reasonable," 6 "best," (i.e., RACT and BACT) and lowest achievable emission 7 rate (LAER). It is helpful to consider EPA's interpretation 8 and implementation of these control levels in determining the control level appropriate for BACM for serious PM-10 9 1"0 nonattainment areas. 11 The term "reasonably available" was applied to control 12 measures and control technology required to be implemented 13 at existing sources in nonattainment areas by the 1977 Clean 14 Air Act Amendments. 42 U.S.C. 7502(c)(1). At that time, 15 EPA defined RACT as the lowest emission limitation that a 16 particular source is capable of meeting by the application 17 of technology that is reasonably available considering 18 technological and economic feasibility.23 EPA determined 19 control measures to be reasonable after considering their 20 energy and environmental impacts and their annualized 21 capital and operating costs. The cost of using a control 22 measure is considered reasonable if those same costs are 23 borne by other comparable facilities. since Congress did 24 25 26 27 28 23see, for example, 44 FR 53726 (September 17, 1979) and footnote 3 of that notice. Note that EPA's emissions trading policy statement has certified that RACT requirements may be satisfied by aChieving "RACT equivalent" emissions reductions from existing sources. ------- -50- 1 not modify EPA's interpretations of those earlier provisions 2 of the Act dealing with RACM and RACT in the 1990 3 Amendments, it can be presumed to have given its endorsement 4 to EPA's definition of the term. 5 Congress defined the term best available control 6 technology.(BACT) in section 169(3) of the 1977 Clean Air 7 Act Amendments for use in implementing the requirement to 8 prevent significant deterioration (PSD) of air quality under 9 Part C of that Act. BACT is defined as an emission 10 limitation based on the "maximum degree of reduction of each 11 pollutant. . . emitted from or which results from any major 12 emitting facility, which the permitting authority, on a 13 case-by-case basis, taking into account energy, 14 environmental, and economic impacts and other costs, 15 determines is achievable for such facility through 16 application of production processes and available methods, 17 systems, and techniques. . . for control of each such 18 pollutant." Thus, BACT is to be determined for the PSD 19 program on a case-by-case basis taking into account the 20 energy, environmental, and economic impacts and oth~r costs. 21 Finally, section 169(3) also requires that BACT be at least 22 as stringent as any corresponding new source performance 23 standard (NSPS) or national emission standard for hazardous 25 air pollutants (NESHAP). Under the PSD program, BACT applies through 24 26 preconstruct ion permits issued to major new and major ------- -51- 1 modified facilities in areas where the air quality is better 2 than the NAAQS. 42 U.S.C. 7475(a)(4). BACT is determined 3 by identifying the technologically feasible control .4 measures, from the universe of all available control 5 techniques, which yield the maximum degree of emission 6 reduction, -after considering the energy, environmental and 7 economic impacts of the technology, and other costs. This 8 may include consideration of the annualized capital and 9 operating costs for the facility. Of course, the costs of 10 control for a major new facility or major modification of an 11 existing facility are only a portion of the overall costs of 12 the new investment which is a distinction between 13 determining, "best available control" and determining 14 "reasonably available control." 15 The term LAER refers to the level of control required 16 for issuing a preconstruction permit to major new or major 17 modified facilities in areas where the air quality is worse 18 than the NAAQS (i.e., nonattainment areas). 42 U.S.C. 19 7503(a)(2) LAER is defined at 40 CFR 51.165(a)(1)(xiii) as 20 the more stringent emission rate based on either the most 21 stringent state emission limit or the most stringent 22 emission limit achieved in practice by another source in 23 that class or category of sources. Like BACT, the LAER 24 level of control must be at least as stringent as the NSPS 25 applicable to the source. Unlike RACT and BACT, it is not 26 necessary to consider energy or cost impacts adverse to the ------- -52- 1 source in determining LAER. In general, the costs of 2 achieving LAER in a nonattainment area must be considered as 3 a portion of the overall cost of investing in a major new or 4 major modified facility, as they are with BACT in attainment 5 areas. 6 D. BACM for Serious PM-10 Nonattainment Areas 7 1. Definition 8 Although section 189(b)(1)(B) requires best available 9 control measures (BACM) [including best available control 10 technology (BACT)] to be implemented in serious PM-10 11 nonattainment areas, the Act does not define either BACM or 12 BACT for PM-10 nonattainment purposes. The U.S. Supreme 13 Court has held that where a statute is silent or ambiguous with respect to the meaning of a statutory term, a 14 15 reasonable agency interpretation must be given deference by 16 a reviewing court.24 In considering how to reasonably 17 interpret the provisions requiring BACM (including BACT) for 18 serious PM-10 nonattainment areas, EPA has looked at several 19 factors: the ordinary grammatical usage associated with the 20 21 22 23 24 25 26 27 28 29 30 31 32 24Chevron. U.S.A. / Inc. v. Natural Resources' Defense Council. Inc., 467 U.S. 837, 843-44 (1984). The Court's decision created a two-step statutory interpretation test. Under the first step, if the language of the statute is plain, "that is the end of the matter," and the agency and the courts must give effect to that plain meaning. If, under the second step, the statute is "silent or ambiguous" with respect to legislative intent, a court must defer to a permissible agency interpretation, unless that interpretation is "arbitrary, capricious, or manifestly contrary to the statute." If, further, the statute contains an explicit or implicit delegation of legislative authority to an agency, a court must defer to a "reasonable" agency interpretation. ------- -53- 1 word "best," the way in which the terms have been 2 interpreted in other sections or titles of the Act, and the 3 overall structure and purpose of Title I of the statute. 4 A plain-English interpretation of the term "best" 5 implies a generally higher standard of performance than one 6 that may be considered "reasonable." In addition, the 7 structural scheme throughout Title I of the Act is to 8 require the implementation of increasingly stringent control 9 measures in areas with more serious pollution problems, 10 while providing such areas a longer time to attain the 11 applicable standards. This structural scheme reflects a 12 basic underlying premise of Title I, namely that tougher 13 control measures are needed in cases where it appears that 14 less stringent controls will be insufficient to bring a 15 particular area into attainment and that, faced with such 16 circumstances, it is reasonable, in light of the overall 17 purpose of the Act, to require states to implement control 18 measures of greater stringency, despite the greater burdens 19 such measures are likely to incur. However, in those areas 20 where more stringent controls are required, the Act,attempts to balance the greater burden imposed by affording the state 21 23 additional time to implement them. For example, under section 188(e), EPA is given 22 25 authority to extend the attainment date for a serious PM-I0 area beyond the specified statutory date, provided certain 24 26 conditions are met, among them that the state must ------- -54- 1 demonstrate to EPA's satisfaction that "the plan for that 2 area includes the most stringent measures that are included 3 in the implementation plan of any state or are achieved in 4 practice in any state, and can feasibly be implemented in 5 the area." Thus, although, under this section, the Act 6 provides PM-10 serious areas an opportunity to get 7 additional time to attain the NAAQS, the consequence of 9 getting additional time is that the state must demonstrate that its PM-10 implementation plan contains the toughest 8 10 extant control standard feasible, i.e., the "most stringent 11 measures" that can feasibly be implemented in the relevant 12 area from among those which are either included in any other 13 SIP or have been achieved in practice by any other State. 14 Similarly, the fact that the Act requires the application of 15 control measures that are "reasonable" in moderate PM-10 16 nonattainment areas (RACM) and control measures that are 17 "best" (BACM) whenever it is determined that a moderate area 18 can't "practicably" attain or fails to attain the NAAQS and 19 is therefore reclassified as serious and given a new, 20 extended attainment date, is consistent with the overall 21 statutory structure and, thus, strongly suggests that BACM 22 is intended to be a more stringent standard. 23 Accordingly, for the reasons stated above, EPA believes 24 it is reasonable to conclude that Congress intended a 25 greater level of stringency to apply in areas that are 26 required to implement "best available" controls than in ------- -55- 1 those required only to implement controls that are 2 "reasonably available." 3 Furthermore, as noted earlier, an array of different 4 control measures are applicable under various Title I 5 programs. A key factor, among others, in determining the 6 level of centrol appropriate for a given area from among the 7 different emission control measures and technologies 8 referred to throughout Title I is the severity of the air 9 pollution problem in that area. In addition to the general 10 categorization of areas as "attainment," "nonattainment," 11 and "unclassifiable," the Act characterizes the severity of 12 an area's air pollution problem by classifying the area, for 13 example, as "marginal," "moderate," "serious," and so on. 14 As discussed above, under Title I of the Act, the different 15 control measures are required to be implemented as follows: 16 as to new (or modified) sources, BACT applies in PM-10 17 unclassifiable areas under the PSD program, while LAER 18 applies in moderate and serious PM-10 nonattainment areas 19 under the nonattainment new source review (NSR) program; as 21 to existing sources, RACM (including RACT) applies in moderate PM-10 nonattainment areas, while BACH (including 20 22 BACT) applies in serious areas. In each case above, the 23 more serious the pollution problem, the more stringent the 24 control standard that's required. 25 It is apparent that in requiring BACM to be applied to 26 existing sources in serious PM-10 areas, Congress implied ------- -56- 1 that these sources should be subject to a more stringent 2 level of control than the RACM required to be applied to 3 existing sources in moderate PM-10 nonattainment areas, but 4 not as stringent as the LAER required to be applied to new 5 or modified sources in moderate and serious areas. In view 6 of this, EPA believes that, as a starting point in 7 interpreting BACM (including BACT) for PM-10 nonattainment 8 purposes, it is reasonable to consider BACT as applied in 9 the PSD program under section 169(3) as an analogue. Under 10 accepted principles of statutory interpretation, similar 11 terms in a statute generally suggest a similar meaning, and 12 an agency is permitted, but not required, to give a similar 13 meaning to similar terms which appear in different parts of 14 a statute. In the instant case, because PSD BACT and PM-10 15 BACM (including BACT) are similar terms, EPA does not 16 believe it is unreasonable to assume that this use of 17 similar language should be accorded some interpretive 18 weight. 19 However, despite the similarity in terminology between 20 control measures applicable in the two programs, certain key 21 differences must be recognized. For example, PSD BACT 22 applies only in areas already meeting the NAAQS, while PM-10 24 BACM applies in areas which are seriously violating the NAAQS, a difference which, arguably, suggests that the 23 25 latter should be a stricter control standard. On the other 26 hand, under normal conditions, the burden, in the PSD ------- -57- 1 context, of preventing the construction of (or even 2 modifying) a new source. would generally be less onerous than 3 retrofitting an existing PM-10 source. Taken as a whole, 4 the different regulatory and economic burdens in the latter 5 context tend to offset the different policy purposes in the 6 former. Nevertheless, EPA believes that the differences in 7 policy goals--i.e., preventing further pollution under the PSD program and reducing existing pollution under the PM-10 8 9 nonattainment program--counsel against adopting the 10 interpretation and implementation of PSD BACT in its 11 entirety for PM-10 nonattainment purposes. Rather, EPA 12 considers it reasonable to use the approach adopted in the 13 PSD BACT program as defined in section 169(3) of the Act as 14 an analogue for determining appropriate PM-10 nonattainment 15 control measures in serious areas, while at the same time 16 retaining the discretion to depart from that approach on a 17 case-by-case basis as particular circumstances warrant. 18 BACM, therefore, is the maximum degree of emissions 19 reduction for PM-10 and PM-10 precursors emitted from or 20 which result from a major emitting facility which is 21 determined on a case-by-case basis, taking into account 22 energy, environmental, and economic impacts and other costs, 23 to be achievable for such facility through application of 24 production processes and available methods, systems, and 25 techniques for control of each such pollutant. For PM-10, 26 BACM must be applied to existing source categories in ------- -58- 1 nonattainment areas that cannot attain within the moderate area timeframe.25 Energy and environmental impacts of the 2 3 control measures and the cost of control should be 4 considered in determining BACM. In general, for the reasons 5 stated above, the test of economic and technological 6 feasibility will be higher for source categories in serious 7 areas than for source categories in moderate areas because 8 of the greater need for emission reductions to attain the 9 NAAQS. As noted earlier, this interpretation is consistent 10 with the overall statutory scheme, which requires, as an 11 areas's air quality worsens, the adoption of increasingly 12 stringent control measures in conjunction with the area 13 receiving more time to attain the NAAQS. Thus, measures 14 that were not considered reasonable to implement by the 15 moderate area attainment date, may be BACM for serious areas 16 because of the additional time available for implementing 17 18 19 20 21 22 23 24 25 26 27 28 29 30 25The term "source categories" for which BACM will be required, refers to categories of area-wide sources or large individual stationary sources of PM-10 or PM-10 precursor emissions that may be regulated under a specific rule, generic emission limit, or standard of performance, or a specific control program in a SIP. For example, the SIP may regulate emissions from unpaved roads, construction activities, residential wood combustion, asphalt concrete batch plants, etc., as source categories. Note that in some instances an entire source category may consist of one large individual stationary source that is regulated separately. under the SIP such as a single iron and steel manufacturing facility and the various processes therein. ------- -59- 2 them26 and because of the higher degree of stringency implied by the statutory scheme and the term "best... 1 3 Therefore, BACM could include, though it is not limited to, 4 expanded use of some of the same types of control measures 5 as those included as RACM in the moderate area SIP. 6 2. Preventive Measures 7 The EPA considers measures that prevent PM-10 emissions 8 over the long-term (e.g., requiring gas logs in new 9 fireplaces) to be preferable to those measures that will 10 only temporarily reduce emissions (e.g. curtailment of 11 woodstove use during air pollution episodes or treatment of 12 fugitive dust sources with water). This is because such 13 measures are inherently more reliable and involve 14 significantly fewer resources for surveillance, enforcement, 15 and administration. Moreover, increasing emphasis on 16 prevention over mitigation is more likely to be both economically and environmentally beneficial over the long 17 18 term. 19 3. De Minimis Source Categories 20 BACM are required for all categories of sources in 21 serious areas unless the State conclusively demonstrates 22 that additional control of a particular source category 23 24 25 26 27 28 29 26The statutory attainment date for initial moderate PM-10 nonattainment areas reclassified as serious will be December 31, 2001. For areas designated nonattainment subsequent to enactment of the 1990 amendments that become serious, the attainment date will be before the end of the tenth year beginning after the area's designation as nonattainment [see section 188(c)]. ------- -60- 1 would not contribute significantly to accelerating 2 attainment of the NAAQS. While EPA regards the BACM 3 standard applicable in PM-10 serious areas as a more .4 stringent control standard which calls for a greater degree 5 of emissions control for the source categories to which it 7 applies, EPA also believes that it has the authority to limit the applicability of BACM to those source categories 6 8 which "contribute significantly" to the nonattainment 9 problem. The Act leaves unresolved the question of whether 10 BACM is intended to be an all-inclusive requirement 11 applicable to every PM-10 serious area source category. It 12 should be noted that in section 189(b)(1)(B), which contains 13 the requirement that serious area PM-10 SIP's provide for 14 the implementation of BACM, Congress has not used the word 15 "all" in conjunction with BACM. Congress has also not 16 stated, either expressly or impliedly, anywhere in the 17 relevant law or legislative history that BACM must be 18 applied to all serious area source categories. Even if EPA 19 was required to impose BACM on all source categories in 20 serious PM-10 areas, the Agency believes it has the, 21 authority to exempt from regulation those source categories 22 in the area which contribute only negligibly to ambient 23 concentrations which exceed the NAAQS. The inherent 24 authority of administrative agencies to exempt de minimis 25 situations from a statutory command has been upheld in 26 contexts where an agency is invoking a de minimis exemption ------- -61- 1 as "a tool to be used in implementing the legislative 2 design" on the ground that "the burdens of regulation yield 3 a gain of trivial or no value." Alabama Power Co. v. .4 Costle, 636 F.2d 323, 360-61 (D.C. Cir. 1979). The EPA 5 believes the court's test for invoking the de minimis 6 exemption authority would be satisfied in circumstances 7 where a state demonstrates conclusively that the imposition 8 of additional controls, such as BACM, on a particular source 9 category in the area would not contribute significantly to 10 the Act's purpose of aChieving attainment of the NAAQS "as 11 expeditiously as practicable."27 The EPA will have to 12 demonstrate from the record that, with respect to particular 13 serious area PM-10 source categories which contribute to 14 emissions in excess of the NAAQS, requiring application of 15 BACM would produce an insignificant regulatory benefit. rd. 16 The EPA will, in general, rely on the criteria applied 17 under new source permitting programs [40 CFR 51.165(b)] to 18 determine when a source category contributes significantly 19 to violations of the NAAQS in a serious nonattainment area. 20 The criteria will also be applied spatially and temporally 21 22 23 24 25 26 27 28 27The sixth circuit, in Air Pollution Control District of Jefferson County. Kentucky v. U.S.E.P.A., 739 F.2d 1071, 1093 (6th Cir. 1984), deciding the extent to which one state should be held accountable for contributing to levels of air pollution in excess of the NAAQS in another state, held that the term "significantly contributes" does not extend to de minimis contributions. ------- -62- 2 in the same way it is under new source permitting programs. 28 1 3 As discussed above, a moderate PM-10 nonattainment area 4 may be reclassified as serious based on evidence that the 5 area cannot practicably attain the NAAQS by the statutory 6 attainment date or evidence that it has failed to attain by 7 that date. The evidence, whether modeled or measured, will 8 generally indicate the standard (24-hour or annual), the 9 day, and the location of the expected violation. Therefore, 10 under this policy, a source category (see footnote 25) will 11 be presumed to contribute significantly to a violation of 12 the 24-hour NAAQS if its PM-10 impact at the location and for the year of the expected violation would exceed 5 ~g/m3. 13 15 Likewise, a source category will be presumed to contribute significantly to a violation of the annual NAAQS if its 14 17 PM-10 impact at the time and location of the expected violation would exceed 1 ~g/m3. 16 18 Procedures for identifying source categories that continue to significantly affect the air quality of a 19 20 serious area [even after RACM (including RACT) are 21 implemented] and procedures for identifying the appropriate 22 mix of control measures applicable to those source 23 categories are discussed below in section E. 24 25 26 27 28See "Interpretation of 'Significant Contribution,'" memorandum from Richard G. Rhoads to Alexandra Smith, December 16, 1980, OAQPS POlicy and Guidance Notebook, PN 165-80-12-16-007. ------- -63- 1 4. Independent of Attainment Needs 2 The overall structure and purpose of Title I of the 3 amended Act, the standard suggested by the word "best," and 4 differences in the statute between the requirements for BACM 5 as compared to those for RACM lead EPA to believe that 6 unlike RACM, BACM are to be established generally 7 independent of an analysis of the attainment needs of the 8 serious area. 9 As noted earlier in this section, the overall 10 structural scheme throughout Title I of the Act is to 11 require the implementation of increasingly stringent control 12 measures in areas with more serious pollution problems, 13 while providing such areas a longer time to attain the 14 applicable standards. These tougher measures are deemed 15 necessary in cases where it appears that less stringent 16 - controls will be insufficient to reduce emissions in an area 17 to the level of the NAAQS. The fact that the Act requires 18 the application of control measures that are "reasonable" in 19 moderate PM-10 areas and control measures that are "best" 20 whenever it is determined that a moderate area can not 21 "practicably" attain or actually fails to attain the NAAQS 22 and is therefore reclassified as serious strongly suggests 23 that BACM is intended to be a more stringent standard than 24 RACM. This being so, it is reasonable to interpret the 25 statute as requiring a different analysis for determining 26 BACM from the practice in the moderate area context of ------- -64- 1 analyzing RACM, according to what is reasonable in light of 2 the overall attainment needs of the area. Moreover, it is 3 hard to avoid the conclusion, when comparing the terms 4 "reasonable" and "best" as applied to control measures, that 5 the word "best" strongly implies that there should be a 6 greater emphasis on the merits of the technology alone and 7 less flexibility in considering other factors. 8 Additionally, for PM-10 areas reclassified as serious 9 before the moderate area attainment date, states have up to 10 4 years, under section 189(b)(1)(A), in which to submit 11 their serious area attainment demonstration. However, under 12 section 189(b)(2), states must submit their plans requiring 13 the use of BACM for those same areas within 18 months after 14 reclassification from moderate to serious. Thus, for such 15 areas, Congress provided a difference of as much as 2 1/2 16 years between the required date for submitting BACM plans 17 and the date by which to submit a new attainment 18 demonstration satisfying the requirements of section 19 189(b)(1)(A) for areas reclassified as serious before the 20 moderate area attainment date. This pronounced difference 21 in timing for the serious area submittals described above is 22 to be contrasted with the timing for submittal of similar 23 provisions for moderate areas. Under section 189(a)(2)(B), 24 both the RACM plans and the attainment demonstration for 25 moderate PM-10 areas which are designated nonattainment 26 subsequent to the initial designations must be submitted at ------- -65- 1 the same time. The fact that the Act requires BACM to be 3 adopted and implemented (at least initially for areas that are reclassified before the moderate area attainment date) 2 4 by an appreciable time before the attainment demonstration 5 is required suggests that Congress intended that BACM 6 determinations be based more on the feasibility of implementing the measures rather than on an analysis of the 7 8 attainment needs of the area. The EPA believes this 9 interpretation of the Act is reasonable, even if, as to 10 areas which are classified in the future as serious PM-10 11 nonattainment areas, for example, the difference in timing 12 between the date BACM plans must be submitted and the date 13 the serious area" attainment demonstration is due should 14 happen to be less pronounced, since there is no rational 15 basis for interpreting BACM differently depending merely on 16 when an area happens to be reclassified. Therefore, the 17 steps described below for making a BACM determination are 18 intended to be carried out independently from the analysis 19 to determine the emission reductions that would be necessary 20 to merely attain the NAAQS by the statutory deadline. If 21 the attainment demonstration for the area subsequently shows 23 that BACM will bring the area into attainment before the statutory deadline, then the plan provides for attainment of 22 24 the NAAQS as expeditiously as practicable. However, if the 25 BACM are not adequate to meet the standards by December 31, 2001, then the state may request an extension under section 26 ------- -66- 1 188(e) which requires, among other things, a demonstration 2 that the plan for the area includes the most stringent 3 measures included in a SIP for any State or achieved in 4 practice by any State, and can feasibly be implemented in 5 the area. 6 E. Procedures for Determining Best Available 7 Control Measures 8 1. Inventory Sources of PM-10 and PM-10 Precursors 9 The BACM (including BACT) applicable in a nonattainment 10 area must be determined on a case-by-case basis since the 11 nature and extent of a nonattainment problem may vary within 12 the area and from one area to another. Nonattainment 13 problems range from reasonably well-defined areas of 14 violation caused by a specific source or group of sources to violations over relatively broad geographical areas due 15 16 predominantly to large numbers of small sources widely- 17 distributed over the area. BACM are required for all source 18 categories for which the state cannot conclusively 19 demonstrate that their impact is de minimis. As stated 20 above, the EPA will generally presume the contribution to 21 nonattainment of any source category to be de minimis if the 22 source category causes a PM-10 impact in the area of less 23 than 5 ~g/m3 for a 24-hour average and less than 1 ~g/m3 24 annual mean concentration. 25 The starting point for making a BACM determination 26 would be to reevaluate the emission inventory submitted with ------- -67- 1 the moderate area SIP. Section 172(C)(3) of the Act calls 2 for all nonattainment areas to submit comprehensive, 3 accurate, and current emissions inventories. If there have 4 been any significant changes in PM-10 sources in the area 5 since the inventory was first compiled (i.e., sources 6 permanentl~ shutdown or new sources started) or if the 7 inventory is not adequate to support the more rigorous 8 analysis required for serious area SIP demonstrations, it 9 should be revised. All anthropogenic sources of PM-10 10 emissions and PM-10 precursors (if applicable)29 and 11 nonanthropogenic sources in a nonattainment area should be 12 included in the emission inventory. 13 Because of its importance in identifying anthropogenic 14 and nonanthropogenic sources and the applicability of BACM 15 requirements, the breakdown of sources to consider when 16 compiling an emissions inventory are as follows: 17 Major point sources (i.e., sources with the 18 potential to emit at least 70 tons per year of PM- 19 10 (or PM-10 precursors) as required in sections 20 189(b)(3) and 189(e) of the Act); 21 Minor point source categories; and 22 Area source categories such as fugitive dust from 23 anthropogenic sources (e.g., construction 24 activities, paved and unpaved roads, agricultural 25 26 27 29Ambient filter analysis and inventory information were to be presented in the moderate area SIP to indicate the significance of secondary particles (see 57 FR 13541-42). ------- -68- 1 activities, etc.), residential wood combustion, 2 prescribed burning, and commercial/institutional 3 fuel combustion; and 4 Nonanthropogenic sources. 5 2. Evaluate Source Category Impact 6 The second step in determining BACM for an area is to 7 identify those source categories having greater than a de 8 minimis impact on PM-10 concentrations. The potential 9 maximum impact of various source categories may have been 10 determined with receptor or dispersion modeling performed 11 for the attainment demonstration submitted with the moderate 12 area SIP. In addition, the impact of some source categories 13 may be apparent from analysis of ambient sampling filters 14 from days when the standards are exceeded. If modeling was 15 not performed during development of the moderate area SIP, 16 receptor modeling, screening modeling or, preferably, 17 refined dispersion modeling will be necessary at this time 18 to identify key source categories. 19 3. Evaluate Alternative Control Techniques 20 In developing a fully adequate BACM SIP, the State is 21 expected to evaluate the technological and economic feasibility of the control measures discussed in the BACM 22 23 guidance documents and other relevant materials for all 24 source categories impacting the nonattainment area except 25 those with a de minimis impact considering emission 26 reductions achieved with RACM. ------- -69- 1 As distinct from the surfaces on which they travel, it does not currently appear that mobile sources contribute 2 3 significantly to the PM-10 air quality problem in a 4 sufficient number of areas to warrant issuing national 5 guidance on best available transportation control measures 6 for PM-10 under section 190 of the Act. However, in those 7 areas where mobile sources do contribute significantly to PM-10 violations, the state must consider implementing 8 9 transportation control measures, including those listed in 10 section 108(f) of the Act, and explain why measures that are 11 not adopted are not needed in or appropriate to the area. The technological feasibility of reducing emissions 12 13 from area sources depends on the ability to alter the 14 characteristics that affect emissions from the sources. 15 Those characteristics have to do with the size or extent of 16 the sources, their physical characteristics and the 17 operating procedures. Reducing emissions of fugitive dust 18 from construction activities, for example, could require the 19 most effective combination of reducing the size of the 20 sources (i.e., acres cleared at one time or vehicle,miles 21 traveled on unpaved surfaces), changing the physical 22 characteristics (i.e., silt loading on travel surfaces or 23 moisture content of materials handled), and/or changing the 25 operating practices (i.e., lower vehicle speeds, less surface area exposed to the wind, treating or paving travel 24 26 surfaces). ------- -70- 1 The technological feasibility of applying an emission 2 reduction method to a particular point source should 3 consider the source's process and operating procedures, raw .4 materials, physical plant layout, energy requirements, and 5 any collateral environmental impacts (e.g. water pollution 6 and waste disposal). The process, operating procedures, and 7 raw materials used by a source can affect the feasibility of 8 implementing process changes that reduce emissions and the 9 selection of add-on emission control equipment. The 10 operation of and longevity of control equipment can be 11 significantly influenced by the raw materials used and the 12 process to which it is applied. The feasibility of 13 modifying processes or applying control equipment is also 14 influenced by the physical layout of the particular plant. 15 The space available in which to implement such changes may 16 limit the choices and will also affect the costs of control. 17 4. Evaluate Costs of Control 18 Economic feasibility considers the cost of reducing 19 emissions from a particular source category and costs 20 incurred by similar sources that have implemented e~ission 21 reductions. As it has done under RACT determinations and in 22 BACT/LAER analyses in other statutory contexts, EPA believes 23 for PM-10 BACM purposes as well that it is reasonable for 24 similar sources to bear similar costs of emission reduction. 25 As such, when identifying BACM, consideration of economic 26 feasibility need not emphasize claims regarding the ability ------- -71- 1 of a particular source to "afford" to reduce emissions to 2 the level of similar sources. otherwise, less efficient 3 sources might be rewarded for their inefficiency by being .4 allowed to bear lower emission reduction costs. Instead, 5 economic feasibility for PM-10 BACM purposes should focus 6 upon evidence that the control technology in question has 7 previously been implemented at other sources in a similar 8 source category. 9 Another approximate way to consider economic 10 feasibility is by analyzing the cost per unit of incremental 11 reduction of ~M and/or its precursors by one particular 12 control option as compared to the next most stringent 13 option. That incremental cost may be evaluated in 14 determining whether it is appropriate under the 15 circumstances and considering other factors. 16 Where the economic feasibility of a measure (e.g., road 18 paving) depends on public funding, EPA will consider past funding of similar activities as well as availability of 17 20 funding sources to determine whether a good faith effort is being made to expeditiously implement the available,control 19 21 measures. In other words, if 20 miles of unpaved roads are 22 typically paved each year, then the BACM fugitive dust 24 program should include paving no less than 20 miles per year of existing roads and offer evidence of ambitious efforts to 23 25 increase funding and increase the priority for use of 26 existing funds. ------- -72- 1 The capital costs, annualized costs, and cost 2 effectiveness of an emission reduction technology should be 3 considered in determining its economic feasibility. The 4 "OAQPS Control Cost Manual, Fourth Edition," EPA-450j3-90- 5 006, January 1990, describes procedures for determining 6 these costs. The above costs should be determined for all 7 technologically feasible emission reduction options. 8 F. Selection of BACM for Area Sources 9 Once the significant PM-10 area source categories have 10 been identified, the State should select area source control 11 measures from the BACM listed in the technical information 12 documents for fugitive dust, RWC, prescribed burning or any 13 other technical information documents issued by EPA. This 14 guidance is based on EPA's analysis of available control 15 alternatives for the identified source categories. While 16 the guidance is intended to be comprehensive, it is by no 17 means exhaustive. Consequently, the State is encouraged to 18 consider other sources of information and is not precluded 19 from selecting other measures and demonstrating to the 20 public and EPA that they constitute BACM. 21 As stated earlier, EPA considers measures that prevent 22 PM-10 emissions over the long term to be preferable to 23 short-term curtai!ment measures. Therefore, when selecting 24 BACM for area sources, a State should first consider 25 pollution preventive measures and measures that provide for 26 long-term sustained progress toward attainment in preference ------- -73- 1 to quick, temporary control. For example, a state should 2 consider adopting programs to encourage or require 3 replacement of old woodstoves with cleaner burning 4 woodstoves or alternative fuels over time. Such programs 5 would complement and reduce dependance on wood-burning 6 curtailment programs adopted as HACM for the moderate area 7 SIP. However, EPA recognizes that such long-term measures 8 may entail significant lead time and that temporary measures 9 like wood-burning curtailments may need to be continued in 10 serious areas, at a minimum, to provide interim health 11 protection. 12 Once the list of available measures for an area source 13 has been identified, the State must evaluate the 14 technological and economic feasibility of implementing the 15 controls. The State may refer to the technical information 16 documents for procedures to determine feasibility. 17 When evaluating economic feasibility, States should not 18 restrict their analysis to simple acceptance/rejection 19 decisions based on whether full application of a measure to 20 all sources in a particular category is feasible. Rather, a 21 State should consider implementing a control measure on a 22 percentage of the sources in a category if it is determined 23 that 100 percent implementation of the measure is 24 infeasible. This would mean, for example, that an area 25 should consider the feasibility of paving 75 percent of the 26 unpaved roadways even though paving all of the roads may be ------- -74- 1 infeasible. Alternatively, the state should consider 2 whether measures not feasible to be implemented in their 3 entirety prior to the statutory deadline could be completed 4 over an extended period. 5 The following example is presented to illustrate how a 6 moderate area program of RACM for fugitive dust control may 7 be complemented with additional BACM after the area is 8 reclassified as serious. Assume that the following control 9 measures were adopted as RACM: 10 o Reduce the speed limit on unpaved county roads to 25 11 miles per hour; 12 o Treat all unpaved county roads, monthly, 'with 13 chemical dust suppressants within 500 feet of their 14 intersections with paved roads; 15 o Treat 10 miles of the most heavily traveled unpaved 16 county roads with chemical dust suppressants once per month; 17 o Pave 4 miles of unpaved city streets; 18 o Treat unpaved parking lots in the city with chemical 19 dust suppressants once per month; and 20 o Clean anti-skid materials from 50 miles of city 21 streets within 48 hours after snow melt begins. 22 The same area, after being reclassified as serious, may 23 adopt the following BACM to complement the RACM program: 24 o Pave 10 miles of the most heavily traveled unpaved 25 county roads; 26 ------- -75- 1 o Treat 10 miles of unpaved county roads with chemical 2 dust suppressants once per month; 3 o Pave 25 unpaved county roads within 500 feet of 4 their intersections with paved roads; 5 o Chemically treat or pave both shoulders of 30 miles 6 of state highways within the county; 7 o Pave all parking lots within the city; 8 o Revise the specifications for winter anti-skid 9 materials to require cleaner, less friable materials, and 10 reduce the quantity used per lane-mile; 11 o Require crop rotations on highly erodible land&; 12 o Retire 1000 acres of farmland and plant indigenous 13 vegetation as a cover instead of leaving land fallow; 14 o Plant crops and windbreaks across the prevailing 15 wind direction on highly erodible lands. 16 In summary, the state must document its selection of 17 BACM by showing what control measures applicable to each 18 source category (not shown to be de minimis) were 19 considered. The control measures selected should preferably 20 be measures that will prevent PM-10 emissions rather than 21 te~porarily reduce them. The documentation should compare 22 the control efficiency of technologically feasible measures, 23 their energy and environmental impacts and the costs of 24 implementation. 25 G. Selection of BACT for Point Sources 26 The reviewing authority determines BACT on a case-by- . ------- -76- 1 case basis. It selects an emissions limitation that 2 reflects the maximum degree of reduction of each pollutant 3 subject to regulation, taking into account energy, 4 environmental, and economic impacts and other costs, that it 5 determines is achievable for such facility. In no event may 6 a technology be selected that would not meet any applicable 7 standard of performance under 40 CFR 60 [new source 8 performance standards (NSPS)] or 61 [national emission 9 standards for hazardous air pollutants (NESHAP)]. 10 In so doing, two core criteria are critical. First, 11 the range of available control technologies must be 12 considered including the most stringent. Second, the 13 ultimate selection must be justified relative to. the other 14 control options, and according the relevant factors. 15 In addition, if the reviewing authority determines that 16 there is no economically-reasonable or technologically- 17 feasible way to accurately measure the emissions, and hence 18 to impose an enforceable emissions standard, it may require 19 the source to use design, alternative equipment, work 20 practice, or operational standards to reduce emissions of 21 the pollutant to the maximum extent [40 CFR 52.21(b)(12); 40 22 CFR 51.166(b)(12)]. 23 Alternative approaches to reducing emissions of 24 particulate matter including PM-10 are discussed in "Control 25 Techniques for Particulate Emissions From Stationary 26 Sources" - Volume I (EPA-450/3-81/005a) and Volume II (EPA- ------- -77- 1 450/3-81-005b), September 1982. The design, operation, and 2 maintenance of general particulate matter control systems 3 such as mechanical collectors, electrostatic precipitators, 4 fabric filters, and wet scrubbers are discussed in Volume I. 5 The collection efficiency of each system is discussed as a 6 function of~ particle size. Information is also presented 7 regarding energy and environmental considerations and 8 procedures for estimating costs of particulate matter 9 control equipment. The emission characteristics and control 10 technologies applicable to specific source categories are 11 discussed in Volume II. Secondary environmental impacts are 12 also discussed. 13 The BACT/LAER Clearinghouse, the EPA Control Technology 14 Center, and past BACT analyses for new and modified major sources under the PSD program may be used to assist in 15 16 identifying available control options and maximum achievable 17 emission reductions. The EPA will continue to evaluate the 18 need for additional guidance and will produce additional 19 materials as appropriate. 20 VII. CONTINGENCY MEASURES 21 section 172(c)(9) requires that SIP's provide for 22 specific measures to be undertaken if the Administrator 23 finds that the nonattainment area has failed to make RFP 24 toward attainment or to attain the NAAQS by the applicable 25 statutory deadline. Following the Administrator's finding, 26 ------- -78- 1 the measures are to take effect immediately without the 2 further action by the state or EPA. 3 The EPA interprets this requirement to be that no 4 further rulemaking actions by the state or EPA would be 5 needed to implement the contingency measures [see generally 6 57 FR 13512 and 13543-544]. The EPA recognizes that certain 7 actions, such as the notification of sources, modification 8 of permits, etc., would probably be needed before a measure 9 could be implemented. However, states must show that their 10 contingency measures can be implemented with minimal further 11 action on their part and with no additional rulemaking 12 actions such as public hearings or legislative review. 13 After EPA determines that a moderate PM-I0 nonattainment 14 area has failed to attain the PM-I0 NAAQS, EPA generally 15 expects all actions needed to affect full implementation of the measures to occur within 60 days after EPA notifies the 16 17 state of the area's failure. The state should ensure that 18 he measures are fully implemented as expeditiously as 19 practicable after they take effect. 20 The purpose of contingency measures is to ensure that 21 additional measures beyond or in addition to the required 22 control measures immediately take effect when the area fails 23 to make RFP or to attain the PM-I0 NAAQS in order to provide 24 interim public health and welfare protection. The 25 protection is considered "interim" because the statute often 26 provides for a more formal SIP revision in order to correct, ------- -79- 1 for example, the failure of an area to attain the PM-10 2 NAAQS. E.g.. section 189(b) (serious area plan required 3 upon finding of failure of moderate area to attain the PM-10 4 NAAQS under 188(b)(2)) and 189(d) (plan revisions required 5 upon failure of serious area to attain the PM-10 NAAQS). 6 Thus, EPA has noted previously that contingency measures 7 should consist of other available control measures not 8 contained in the applicable control strategy [57 FR at 9 13543]. In designing its contingency measures, the state 10 should also take into consideration the potential nature and 11 extent of any attainment shortfall for the area. The 12 magnitude of the effectiveness of the measures should be 13 calculated to achieve the appropriate percentage of the 14 actual emission reductions required by the SIP control 15 strategy to bring about attainment. EPA has recommended 16 that contingency measures provide the emission reductions 17 required in 1 year's increment of RFP. 18 Once moderate areas are subsequently reclassified as 19 serious, the affected States must ensure that adequate 20 contingency measures, as described above, are in place for 21 such areas. This is explicitly required under the statute. 22 Section 189(b)(1) requires areas reclassified as serious to 23 submit "an implementation plan." Under section 172(c), in 25 turn, "plan provisions" required. under Part D must provide for the implementation of contingency measures. 24 26 Accordingly, for those moderate areas reclassified as ------- -80- 1 serious, if all or part of the contingency measures become 2 part of the required serious area control measures (i.e., 3 BACM), then additional contingency measures must be .4 submitted. For example, this may be the case where a 5 moderate area was reclassified as serious for its failure to 6 attain and has implemented all of the contingency measures 7 contained in the moderate PM-10 plan for the area. Further, 8 the affected states must ensure that serious areas have 9 adequate contingency measures considering, among other 10 things, new information about the potential attainment 11 shortfall for the newly reclassified serious area. The 12 states must submit contingency measures for serious areas or 13 otherwise demonstrate that adequate measures are in place 14 within 18 months of reclassification, as an adjunct of the 15 required serious area BACM submittal [see section 189(b)]. 16 VIII. Quantitative Milestones and Reasonable 17 Further Progress 18 A. General Discussion 19 PM-10 nonattainment area SIP's must include 20 quantitative milestones which are to be achieved every 3 21 years until the area is redesignated attainment and which demonstrate RFP toward attainment by the applicable date 22 23 [see section 189(c) of the amended Act]. section 171(1) of 24 the Act defines RFP as "such annual incremental reductions 25 in emissions of the relevant air pollutant as are required 26 by this part [Part D] or may reasonably be required by the ------- -81- 1 Administrator for the purpose of ensuring attainment of the 2 applicable national ambient air quality standard by the 3 applicable date." .4 A discussion of these requirements follows. 5 B. Reasonable Further Progress 6 Historically, for some pollutants RFP has been met by 7 showing annual incremental emission reductions sufficient 8 generally to maintain at least linear progress toward 9 attainment by the specified deadline. Requiring linear 10 progress reductions in emissions to maintain RFP may be 11 appropriate in four situations: 12 1. when pollutants are emitted by numerous and diverse 13 sources, 14 2. where the relationship between any individual 15 source and the overall air quality is not explicitly 16 quantified, 17 3. where a chemical transformation is not involved, 18 and 4. where the emission reductions necessary to attain 19 the standard are inventory-wide. 20 For example, in those areas where the nonattainment 21 problem is attributed to area type sources (e.g., fugitive 22 dust, residential wood combustion, etc.), RFP should be met 23 by showing annual incremental emission reductions sufficient 24 generally to maintain linear progress towards attainment. 25 Total PM-10 emissions should not remain constant or increase 26 from one year to the next in such an area. ------- -82- 1 Requiring linear progress reductions in emissions to 2 maintain RFP is less appropriate: 3 1. where there are a limited number of sources, 4 2. where the relationships between individual sources 5 and air quality are relatively well-defined, 6 3. where the emission control systems utilized (e.g., 7 at major point sources) will result in swift and dramatic 8 emission reductions, and 9 4. where there are chemical transformations that form 10 PM-I0. 11 For example, in those areas where the PM-I0 12 nonattainment problem is attributed to a few stationary 13 sources, RFP should be met by "adherence to an ambitious compliance schedule,,30 which is likely to periodically 14 15 yield significant emission reductions. Adherence to "an 16 ambitious compliance schedule" does not necessarily mean 17 that it would be unreasonable to achieve annual incremental 18 emission reductions or generally linear progress, however. 19 The SIP's for PM-10 nonattainment areas must include 20 detailed schedules for compliance with emission regulations 21 in the areas and accurately indicate the corresponding 22 annual emission reductions to be realized from each 23 milestone in the schedule. In reviewing the SIP, EPA will 24 25 26 27 28 30U.S. Environmental Protection Agency, Office of Air Quality Planning and Standards, "Guidance Document for Correction of Part D SIP's for Nonattainment Areas," Research Triangle Park, North carolina, January 27, 1984, Page 25. ------- -83- 1 determine whether the annual incremental emission reductions 2 to be achieved are reasonable in light of the statutory 3 objective to ensure timely attainment of the PM-I0 NAAQS. Additionally, EPA believes that it is appropriate to require 4 5 early implementation of the most cost effective control 6 measures (e.g., controlling fugitive dust emissions at the 7 stationary source) while phasing in the more expensive 8 control measures, such as those involving the installation 9 of hew hardware. 10 Section 189(c) provides that the quantitative 11 milestones submitted by a State for an area also must 12 demonstrate RFP for the area. Thus, EPA will determine an 13 area's compliance with RFP in conjunction with determining 14 its compliance with the quantitative milestone requirement. 15 Because RFP is an annual emission reduction requirement and 16 the quantitative milestones are to be achieved every three 17 years, when a State demonstrates an area's compliance with 18 the quantitative milestone requirement it should also 19 demonstrate that RFP has been achieved during each of the 20 relevant three years. Thus, in the discussion of 21 quantitative milestones below, we refer to both the 22 "RFP/milestone" submittal dates, achievement dates and 23 demonstration (or reporting) requirements. 24 25 c. Quantitative Milestones 26 1. Nature of Quantitative Milestones ------- -84- 1 As mentioned above, PM-10 nonattainment SIP's are to 2 contain quantitative milestones [see section 189(c)]. These 3 quantitative milestones should consist of elements which 4 allow progress to be quantified or measured. Specifically, 5 States should submit milestones providing for the amount of 6 emission reductions adequate to achieve the NAAQS by the 7 applicable attainment date. The following are examples of 8 measures which support and demonstrate how the milestones 9 may be met: 10 a. percent implementation of various control 11 strategies (e.g., pave 50 percent of culpable streets, . 12 replace 75 percent of residential wood heaters with natural 13 gas heating units); 14 b. percent compliance with implemented control 15 measures; and 16 c. adherence to a compliance schedule. 17 18 2. RFP/Milestone Due Dates 19 As mentioned above, PM-10 nonattainment SIP's are to 20 contain quantitative milestones which are to be achieved 21 every 3 years until the area is redesignated attainment. 22 There is a gap in the law in that the text of section 189(c) 23 does not articulate the starting point for counting the 24 3-year period. The EPA believes it is reasonable to begin 25 counting the 3-year milestone deadline from the due date 26 (and not the submittal date) for the applicable moderate ------- -85- 1 area implementation plan revision. See section III.C.1.(f) 3 of the General Preamble (57 FR 13539) for an explanation of why EPA believes it is appropriate to begin counting the 3- 2 4 year milestone deadline from the SIP due date. 5 The first "RFP/milestone" achievement date for those 6 areas initially designated as nonattainment for PM-10 by 7 operation of law when the Act was amended, will be the 8 moderate area attainment date of December 31, 1994, as 9 stated in section III.C.1.f. of the General Preamble (57 FR 10 13539). The RFP/milestone achievement date would normally 11 be November 15, 1994, 3 years after the SIP due date of' 12 November 15, 1991. The achievement date was delayed 46 13 days, however, because the de minimis timing differential 14 made it administratively impracticable to require separate 15 milestones and attainment demonstrations for these areas. 16 Thus, for these initial areas EPA's policy is to deem that 17 the emissions reductions progress made between the SIP 18 submittal due date and the attainment date as sufficient to 19 satisfy the milestone requirement [57 FR 13539]. Thus the initial RFP/milestone will be met by showing 20 21 that emission reductions scheduled to be made between the 22 SIP due date and the attainment date for these moderate 23 areas were actually achieved. Most of the emission 24 reductions will result from implementation of RACM 25 (including RACT) adopted as part of the moderate area SIP. 26 The Act requires that RACM be implemented by December 10, ------- -86- 1 1993 in the initial PM-I0 nonattainment areas [see section 2 189(a)]. 3 Subsequent RFP/milestones for these initial PM-I0 4 nonattainment areas that are reclassified as serious will be 5 due every three years after the original due date for the 6 moderate area SIP.31 Therefore, the second RFP/milestone 7 for the initial nonattainment areas that are reclassified as 8 serious must be achieved by November 15, 1997. The third 9 RFP/milestone achievement date will be November 15, 2000, 10 etc. These RFP/milestones will be met by quantifying the 11 annual incremental emission reductions resulting from 12 implementation of BACM/BACT (required within 4 years after 13 the area is reclassified as serious) and additional measures 14 included in the final serious area SIP that are adequate to 15 achieve the NAAQS by the applicable attainment date. The 16 annual incremental emission reductions must be sufficient to 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 31The plain terms of section 189(c) require that milestones be achieved "every 3 years until the area is designated nonattainment" and, therefore, do not contemplate any breaks in the milestones due to an area's reclassification. Further, reclassifying an area to serious does not obviate the State from controls and emission reductions required in the moderate area implementation plan. See section 189(b) (1). A continuous series of control measures must be implemented in PM-I0 nonattainment areas beginning with RACM (including RACT) and followed by contingency measures which are to be implemented if the moderate area fails to attain. Next, BACM (including BACT) must be implemented within 4 years after the area is reclassified as serious. subsequently, it may be necessary to implement additional control measures beyond BACM/BACT to attain the NAAQS. Therefore, the structure of the Act requires a series of measures which can provide for RFP/milestones. ------- -87- 1 assure attainment by not later than December 31, 2001. In 2 some cases it may also be appropriate to require that the 3 annual incremental emission reductions maintain at least 4 linear progress toward attainment, as discussed earlier. 5 3 . RFP/Milestone Report 6 The state must demonstrate to EPA, within 90 days after 7 the milestone achievement date, that the SIP measures are 8 being implemented and the RFP/quantitative milestones have 9 been met [see section 189(c)(2)]. The RFP/milestone report 10 must be submitted from the Governor or Governor's designee 11 to the Regional Administrator of the respective EPA Regional 12 Office which serves the State where the affected area is 13 located. 14 The RFP/milestone report must contain technical support 15 sufficient to document completion statistics for appropriate 16 milestones. For example, the demonstration should 17 graphically display RFP over the course of the relevant 3 18 years and indicate how the emission reductions achieved to 19 date compare to those required or scheduled to meet RFP and 20 the required milestones. The calculations (and any. 21 assumptions made) necessary to determine the emission 22 reductions to date should also be submitted. The 23 demonstration should also contain an evaluation of whether 24 the PM-10 NAAQS will be attained by the projected attainment 25 date in the SIP, i.e., answer the question "Are the emission 26 reductions to date sufficient to ensure timely attainment?". ------- -88- 1 within 90 days of its receipt, EPA must determine 2 whether or not the state's demonstration is adequate and 3 meets all the requirements discussed above. The EPA will 4 notify the state of its determination by sending a letter to 5 the appropriate Governor or Governor's designee. 6 4. F~ilure to Submit RFP/Milestone Report or Meet 7 RFP/Milestones 8 If a State fails to submit the RFP/milestone report 9 within the required timeframes or if EPA determines that 10 the State has not met any applicable RFP/milestone, EPA 11 shall require the State, within 9 months after such failure 12 or determination to submit a plan revision that assures that 13 the state will achieve the next milestone (or attain the PM- 14 10 NAAQS, if there is no next milestone) by the applicable 15 date [see section 189(c)(3)]. For example, with respect to 16 RFP, if the required annual emission reductions are not 17 achieved for the relevant years according to the RFP 18 schedule and the implementing milestone requirement, EPA 19 will require the State to submit a SIP revision so that 20 these deviations can be corrected and attainment assured by 21 the applicable date. This may also necessitate 22 implementation of appropriate contingency measures pursuant 23 to section 172(c)(9). 24 Note also that failure to meet RFP, if not 25 expeditiously corrected, could also result in the application of sanctions as described in sections 110(m) and 26 ------- -89- 1 179(b) of the amended Act [pursuant to a finding under 2 section 179(a)(4)]. 3 4 5 6 7 8 9 10 11 Date ------- |