# Appendix — Central Arizona Water Conservation District v. Environmental Protection Agency > Briefs, arguments, decisions, and more. URL: https://www.frixlaw.com/law-library/documents/brief%3Amicro_IA40386019_1069%3A2 ## Record - **Collection:** Supreme Court brief - **Document type:** Appendix - **Published:** January 1, 1993 - **Citation:** 510 U.S. 828 ## Text Supreme Court, U.S ns a) No. 23 3983 JUN 23 1993 | OFFICE OF pric i . j IN THE SUPREME COURT OF THE UNITED STATES October Term, 1993 CENTRAL ARIZONA WATER CONSERVATION DISTRICT, CENTRAL ARIZONA IRRIGATION AND DRAINAGE DISTRICT, MARICOPA-STANFIELD IRRIGATION & DRAINAGE DISTRICT, and NEW MAGMA IRRIGATION & DRAINAGE DISTRICT, Arizona Municipal corporations, Petitioners, v. UNITED STATES ENVIRONMENTAL PROTECTION AGENCY, Respondent. PETITION FOR A WRIT OF CERTIORARI TO THE UNITED STATES COURT OF APPEALS FOR THE NINTH CIRCUIT APPENDIX TO CENTRAL ARIZONA WATER CONSERVATION DISTRICT’S PETITION FOR WRIT OF CERTIORARI Marvin S. Cohen, Esq.* Leslie A. McCarthy, Esq. SACKS, TIERNEY & KASEN 2929 N. Central, 14th Floor Phoenix, Arizona 85012-2742 Telephone: (602) 279-4900 Counsel of Record * Douglas K. Miller, Esq. CENTRAL ARIZONA WATER ‘CONSERVATION DISTRICT 23636 North 7th Street Phoenix, Arizona 85024 Telephone: (602) 870-2333 Attorneys for Petitioner Central Arizona Water Conservation District Robert S. Lynch, Esq. 2001 North Third Street, Suite 204 Phoenix, Arizona 85004-1472 Telephone: (602) 254-5908 Attorney for Petitioners Central Arizona Irrigation and Drainage District and Maricopa-Stanfield Irrigation & Drainage District William D. Baker, Esq. ELLIS, BAKER, CLARK & PORTER, P.C. 4444 North 32nd Street, Suite 200 Phoenix, Arizona 85018 Telephone: (602) 956-8878 Attorneys tor Petitioner New Magma Irrigation & Drainage District INDEX TO APPENDIX TO CENTRAL ARIZONA WATER CONSERVATION DISTRICT’S PETITION FOR A WRIT OF CERTIORARI TO THE UNITED STATES COURT OF APPEALS FOR THE NINTH CIRCUIT Page Opinion Regulations 56 Fed. Reg. 50172 (October 3, 1991) .....-.-.+---- 53 Fed. Reg. 35956 (September 15, 1988 .........-- 52 Fed. Reg. 7802 (March 12, 1987) .......----+--- 45 Fed. Reg. 80084 (December 2, 1980) ......-.---- 45 Fed. Reg. 34762 (May 22, 1980) ......------- 40 C.F.R. § 51.300 ef seq. .. 2... ee eee eee eee tk © ag pS. ee a ere ee eee 40 CPR. BSZAG OG. 2 nn ccc ccc ewncass Statutes Te bk wo es ee ee eee eee kee 62 2 ol S| ae aera ia are eee ce Te Fe ik ON a ERE RS Miscellaneous EPA Docket A-79-40, II-A-5 "Protecting Visibility: An EPA Report to oe ee EPA Docket A-79-40, V-A-6 "User's Manual for the Plume Visibility Model (PLUVUE), November, 1980 ......------ FOR PUBLICATION UNITED STATES COURT OF APPEALS FOR THE NINTH CIRCUIT Te CENTRAL ARIZONA WATER CONSERVATION District, CENTRAL ARIZONA IRRIGATION AND DRAINAGE DistTRICT, MARICOPA-STANFIELD IRRIGATION & DRAINAGE DistrICT, New MAGMA IRRIGATION & DRAINAGE DISTRICT, AND HARQUAHALA VALLEY IRRIGATION DISTRICT, No. 91-70731 Petitioners, " OPINION Untrep STATES ENVIRONMENTAL PROTECTION AGENCY, Respondent, SALT RIVER PROJECT AND POWER District, GRAND CANYON TRUST, AND THE WILDERNESS SOCIETY, Respondents-Intervenors. f Appeal from the United States Environmental Protection Agency Argued and Submitted January 13, 1993—San Francisco, California Filed March 25, 1993 Before: Ruggero J. Aldisert,* Alfred T. Goodwin, and Betty B. Fletcher, Circuit Judges. *Honorable Ruggero J. Aldisert, Senior United States Circuit Judge for the Third Circuit, sitting by designation. 2712 CAWCD v. EPA Opinion by Judge Goodwin SUMMARY Environmental Law/Air The court of appeals denied a petition for review of a Final Rule issued by the Environmental Protection Agency. The court held that, pursuant to Clean Air Act requirements to reduce visibility impairments around national parks, imposi- tion by the EPA of emissions reduction requirements on a power facility in proximity to the Grand Canyon were not arbitrary and capricious or in excess of regulatory authority, when the regulations were based on reasonable interpretations of equivocal evidence. Petitioner Central Arizona Water Conservation District obtains electricity to pump its water from the Navajo Generat- ing Station, which is within twelve miles of the Grand Can- yon. Respondent United States Environmental Protection Agency, pursuant to the goal of the Clean Air Act to remedy visibility impairment in specified areas, including the national parks, required a 90 percent reduction in certain emissions from Navajo. Navajo is owned in part by the Bureau of Recla- mation, with which the District has a contractual relationship requiring it to repay most of the Bureau’s share of the costs of the required emission controls. The Act requires EPA to promulgate regulations to assure reasonable progress toward the goal. Following an extended process, which included a tracing study conducted by the National Park Service, which enabled emissions from Navajo to be identified in the ambient air; an evaluation of that study by the National Academy of Sciences, which both acknowl- edged the difficulty of determining the exact contribution to Grand Canyon haze reasonably attributable to Navajo, and CAWCD v. EPA 2713 noted that the EPA was not statutorily required to show such a precise relationship; and a monitoring study sponsored by Navajo’s operator, which concluded that emission controls at Navajo would produce at most a 2 percent improvement in average visibility, EPA proposed a 70 percent average reduc- tion in the Navajo emissions. After a public comment period and consultations with Navajo, environmental groups, includ- ing the Environmental Defense Fund and the Grand Canyon Trust, and the State of Arizona, EPA issued a final determina- tion concluding that Navajo was a dominant contributor to visibility impairment, and that emissions reduction by 90 per- cent would more adequately represent reasonable progress toward the visibility goal than the approach originally sug- gested by EPA. The District contended that EPA's Final Rule exceeded the scope of its regulatory authority, and that its action was arbi- trary and capricious. In turn, EPA contended that the District lacked standing to challenge its ruling. [1] The District had standing to litigate this issue. The Final Rule would likely cause it some amount of economic harm, given its contractual relationship with the Bureau of Reclama- tion. [2] The Final Rule was the direct cause of that harm, not- withstanding the involvement of a third party and a contractual relationship, and that harm was likely to be redressed by a favorable decision. [3] The District's interest was within the zone protected by the Act, since having to pay the costs of compliance could not be said to be marginally related to or inconsistent with the purposes of the Act. [4] EPA had statutory authority to regulate the contribution to visibility impairment reasonably attributable to Navajo, notwithstanding that it might only be a fraction of the total problem. [5] EPA had broad discretion in determining if impairment was reasonably attributable to a specific source. [6] The record reflected adequate technical and scientific sup- port for EPA‘s conclusion that impairment was reasonably 2714 CAWCD v. EPA attributable to Navajo. Its choice represented reasonable accommodation of conflicting policies committed to its care by the Act, and was therefore entitled to deference from a reviewing Court. [7] EPA relied on Congressional direction to assure reason- able progress toward the national goal as its statutory author- ity for promulgating its regulations. [8] Reliance on the reasonable progress provisions was a permissible construction of the statute, since reasonable progress was the overarching requirement to be addressed. [9] The Final Rule was the prod- uct of reasoned decisionmaking. EPA adequately considered relevant factors in its process. As long as its interpretation was reasonable, a reviewing Court may not substitute its own judgment for the agency’s. Deference to EPA’s judgment was appropriate because the agency was making predictions within its special expertise at the frontiers of science. [10] The limits of the Park Service's study were acknowledged, and EPA’s decision was adequately supported by substantial sci- entific evidence. Its decision was based on reasonable extrap- olations from some reliable evidence. COUNSEL Marvin S. Cohen, Sacks, Tiemey & Kasen, Phoenix, Arizona, for the petitioners. Scott A. Schachter, United States Department of Justice, Washington, D.C., for the respondent. Patrick M. Raher, Hogan & Hartson, Washington, D.C., for the respondents-intervenors. Beryl I. Dulsky, Assistant Attorney General, Phoenix, An- zona, for the amicus. mM CAWCD v. EPA 2715 OPINION GOODWIN, Circuit Judge: Petitioners Central Arizona Water Conservation District (“CAWCD”) and four irrigation districts’ (collectively “Petitioners” or the “Districts’) challenge an Environmental Protection Agency (“EPA”) Final Rule which requires a 90% reduction in sulfur dioxide (SO,) emissions at the Navajo Generating Station (“NGS”) in order to improve winter aver- age visibility in the Grand Canyon National Park (“Grand Canyon”). Petitioners argue (1) that, because the Final Rule seeks to regulate “regional haze” when EPA has yet to promulgate Phase II implementing regulations addressing regional haze, EPA exceeded the scope of its regulatory authority by issuing the Final Rule, and (2) that the Final Rule constitutes arbitrary and capricious agency action. In addition to responding to Petitioners’ substantive criticisms, EPA asserts that Petition- ers lack standing to bring this challenge. The Final Rule was issued by EPA under 42 U.S.C. §§ 7410(c)(1), 7491, and is directly appealable to this court under 42 U.S.C. § 7607(b)(1). Petitioners do have standing to bring this challenge. We hold, however, that EPA acted within its statutory and regulatory authority when it promul- gated the Final Rule, and that EPA has not acted arbitrarily and capriciously. I. BACKGROUND This case involves regulations promulgated by EPA in an attempt to remedy, at least partially, visibility impairment at ‘Central Arizona Irrigation and Drainage District, Maricopa-Stanfield Irrigation & Drainage District, New Magma Irrigation & Drainage Dis- trict, and Harquahala Valley Irrigation District. 2716 CAWCD v. EPA the Grand Canyon. In a final rule entitled “Approval and Pro- mulgation of Implementation Plans: Revision of the Visibility FIP for Arizona,” 56 Fed. Reg. 50,172 (1991) (codified at 40 C.F.R. § 52) (“Final Rule”), EPA required a 90% reduction in SO, emissions at NGS, a power plant situated approximately twelve miles from the Grand Canyon, near Page, Arizona. The Final Rule limits SO, emissions from NGS to 0.10 pound per million British thermal units (lb/MMBtu), with an esti- mated 7% winter average visibility improvement in the Grand Canyon. The estimated cost of the improvement, following an initial capital cost estimated at $430 million, is $89.6 million per year. The Salt River Project (“SRP”), a respondent-intervenor in this case,” is the operating agent of NGS. NGS is jointly owned by SRP, the U.S. Department of Interior, Bureau of Reclamation (“BOR”), Los Angeles Department of Water and Power, Arizona Public Service Co., Nevada Power Co. and Tucson Gas & Electric Co.* Petitioners are water districts that obtain electricity to pump their water primarily from NGS. They acknowledge that they are not owners of NGS, but nonetheless claim an economic interest in the Final Rule. CAWCD claims that it will be required, due to its contractual relationship with the BOR, to repay the major portion of the BOR’s 24.3% share of the costs of installing and maintaining the emission controls required by the Final Rule. 7It is noteworthy that SRP and the other joint-owners are the parties directly aggrieved by the Final Rule, yet they do not participate in Peti- tioners’ challenge. In fact, SRP argues in support of the Final Rule as a respondent-intervenor. *The joint-owners’ percentages of participation is as follows: BOR, 24.3%; SRP, 21.7%; Los Angeles Department of Water and Power, 21.2%; Arizona Public Service Co., 14%; Nevada Power Co., 11.3%; Tuc- son Gas & Electric Co., 7.5%. CAWC(D ~ ERA QT N7 A. Regulatory Framework 1. The Clean Air Act, Visibility Impairment, and the Grand Canyon In 1977, Congress substantially amended the Clean Air Act (the “Act™). Included in the 1977 amendments was section 169A, 42 U.S.C. § 7491, which declared “as a national goal the prevention of any future, and the remedying of any exist- ing, impairment of visibility in mandatory class I Federal areas which impairment results from manmade air pollution.” 42 U.S.C. § 7491(a)(1). Congress required EPA to promulgate regulations to assure “reasonable progress toward meeting th[is] national goal.” 42 U.S.C. § 7491(a)(4). EPA was further directed to require each state with a class I Federal area to revise its state implementation plan (“SIP”) “to contain such emission limits, schedules of compliance and other measures as may be necessary to make reasonable progress toward meeting the national goal.” 42 U.S.C. § 7491(b)(2). Measures for achieving “reasonable progress” generally include best available retrofit technology (“BART™)* and a long-term strat- egy. 42 U.S.C. §§ 7491(b)(2)(A), (B). If an individual state fails to fulfill its obligations under the Act, EPA is directed to take such measures as are required to achieve “reasonable “The regulations provide the following definition of BART: Best Available Retrofit Technology (BART) means an emission limitation based on the degree of reduction achievable through the application of the best system of continuous emission reduc- tion for each pollutant which is emitted by an existing stationary facility. The emission limitation must be established, on a case- by-case basis, taking into consideration the technology available, the costs of compliance, the energy and nonair quality environ- mental impacts of compliance, any pollution control equipment in use or in existence at the source, the remaining useful life of the source, and the degree of improvement in visibility which may reasonably be anticipated to result from the use of such tech- nology. 40 C.F.R. § 51.301 (c). 2718 CAWCD v. EPA progress” pursuant to a federal implementation plan (“FIP”) under section 110(c) of the Act. 42 U.S.C. § 7410(c)(1). The Act defines class I Federal areas as international parks, national wilderness areas or memorial parks which exceed 5,000 acres in size, and national parks which exceed 6,000 acres in size. 42 U.S.C. § 7472(a). The Grand Canyon has been classified as a class I Federal area. See 44 Fed. Reg. 69,122 (1979). Congress recorded its concern with the visibil- ity impairment at the Grand Canyon caused by NGS. See H.R. Rep. No. 294, 95th Cong., Ist Sess. 203-04 (1977). 2. EPA's 1980 Regulations In 1980, EPA promulgated visibility regulations under sec- tion 169A of the Act. 45 Fed. Reg. 80,084 (1980) (codified at 40 C.F.R. §§ 51.300-.307). The regulations adopted a “phased approach to visibility protection.” /d. at 80,085. Phase I was directed at controlling visibility impairment “that can be traced to a single existing stationary facility or small group of existing stationary facilities.” Jd. EPA refers to this type of impairment as “reasonably attributable” impairment. 45 Fed. Reg. 34,762, 34,779 (1980) (codified at 40 C.F.R. § 51). EPA deferred addressing other types of impairment such as “regional haze” for future phases due to the height- ened complexity and the scientific and technical limitations inherent in attempts to identify, measure, and control such broadscale visibility impairment. See 45 Fed. Reg. at 80,086; see also id. at 80,085 (defining regional haze as “widespread, regionally homogeneous haze from a multitude of sources which impairs visibility in every direction over a large area”). Generally, EPA’s “Phase I” regulations require affected states to coordinate the development of SIPs with the appro- priate Federal land managers, to develop programs to assess and remedy visibility impairment from new and existing sources, and to develop a long-term strategy to assure reason- able progress toward section 169A’s national visibility goal. CAWCD v. EPA 2719 See 40 C.F.R. §§ 51.300-.307. The regulations specifically require states to identify those existing sources “which may reasonably be anticipated to cause or contribute” to any visi- bility impairment which is “reasonably attributable to that existing stationary facility.” 40 C.F.R. § 51.302(c)(4)(i). Once the source is identified, the affected state is required to take such measures as are required to attain “reasonable progress”; such measures generally include determination of emissions limitations for that source under BART and the development of a long-term strategy. 40 C.F.R. §§ 51.302(c)(1), (2). The regulations define the term “visibility impairment” as “any humanly perceptible change iin visibility (visual range, contrast, coloration) from that which would have existed under natural conditions.” 40 C.F.R. § 51.301(x). The term “reasonably attributable” is defined as “attributable by visual observation or any other technique the State deems appropriate.” 40 C.F.R. § 51.301(s). The states, or EPA under § 7910(c), thus have broad discretion in determining how and whether impairment may be attributed to an individual source. See 45 Fed. Reg. at 80,094, 80,085. B. Prior Proceedings and the Rulemaking History In its implementation of Phase I, EPA required all states containing class I Federal areas to submit revised visibility SIPs within a nine-month period. Arizona was one of thirty- five states failing to submit a revised SIP to EPA. In 1982, the Environmental Defense Fund and other environmental groups brought a citizen suit against EPA to compel performance of the agency's nondiscretionary duty under 42 U.S.C. § 7410(c) (1)(A) to promulgate visibility FIPs when states fail to submit SIPs pursuant to the 1980 regulations. See EDF v. Reilly, No. C82-6850-RPA (N.D. Cal. Apr. 20, 1984). The parties reached a settlement agreement which the court approved in an April 20, 1984 consent decree. This consent decree required EPA to review existing SIPs for deficiencies and eT 2720 CAWCD v. EPA allow states to cure those deficiencies. If states remained defi- cient, the consent decree required EPA to issue visibility FIPs. The Department of Interior subsequently certified the exis- tence of visibility impairment in all class I Federal areas, and specifically declared NGS as a probable source of impairment at the Grand Canyon. Following this certification, the National Park Service (“Park Service”) conducted the Winter Haze Intensive Tracer Experiment (““WHITEX”’), a winter vis- ibility attribution study. In part, WHITEX involved the release from NGS of a unique “tracer” gas, CD; because CD is not found in the ambient air, its use “fingerprinted” NG emissions when detected downwind. In November 1987, EPA disapproved the SIPs of twenty- nine states, including Arizona, for failing to comply with the visibility regulations. See 52 Fed. Reg. 45,132, 45,133 (1987) (codified at 40 C.F.R. §§ 52, 81). Over the next few years, EPA further investigated visibility impairment at Grand Can- yon and other class I Federal areas. While acting on many of the areas, EPA delayed action on the Grand Canyon to allow the Park Service time to analyze the data obtained from the WHITEX study. The Park Service issued an April 1989 draft report which attributed to NGS 70% of the sulfates in the Grand Canyon during the WHITEX experiment period. See William Malm et al., National Park Service Report on the Winter Haze Intensive Tracer Experiment, Draft Final Report (Apr. 7, 1989). Relying on the Park Service’s April 1989 draft report, EPA preliminarily attributed to NGS several episodes of winter- time visibility impairment at the Grand Canyon. See 54 Fed. Reg. 36,948, 36,951 (1989) (codified at 40 C.F.R. § 52). EPA solicited public comment on the merits of its preliminary attri- bution finding, and began the informal rulemaking process to determine the appropriate action to be taken. Jd. In December 1989, the Park Service issued its final report on WHITEX. See William Malm et al., National Park Service Report on the ™ | CAWCD v. EPA 2721 Winter Haze Intensive Tracer Experiment, Final Report (Dec. 4, 1989). SRP and others, including Petitioners, submitted comments severely criticizing the analyses, methodologies, and conclu- sions of the Park Service's reports. In response to the con- cerns raised about the Park Service's analysis of the WHITEX data, the National Research Council of the National Academy of Sciences (“NAS”) was asked to evaluate the Park Service's WHITEX report and the other scientific evidence relevant to EPA’s preliminary attribution. In its October 1990 report, the NAS confirmed that “at some times during the study period, NGS contributed significantly to haze™ in the Grand Canyon. National Research Council, Haze in the Grand Canyon: An Evaluation of the Winter Haze Intensive Tracer Experiment 3, 37 (1990) [hereinafter Haze in the Grand Canyon}. NAS cau- tioned, however, that “aspects of the WHITEX data analysis preclude a quantitative determination of the exact fraction of the Grand Canyon haze problem that is attributable to NGS. These aspects are primarily related to problems with imple- mentation and interpretation of multiple linear regression models.” Jd. at 37. Still, NAS acknowledged that Congress did not “require EPA to show a precise relationship between a source’s emissions and all or a specific fraction of the visi- bility impairment within a Class I area.” Jd. at 5, 37. SRP sponsored its own monitoring study in the winter of 1990 — the Navajo Generating Station Visibility Study (“NGSVS") — to investigate the sources of visibility impair- ment in the Grand Canyon and to determine what improve- ment in visibility would result from a reduction of SO, emissions at NGS. The NGSVS data indicated that controlling SO, emissions from NGS would at most result in a 2% improvement in the winter seasonal average standard visual range. While detailing some episodes of visibility impairment attributable to NGS, the NGSVS report generally found that “the NGS was only part of a regional problem and that it was not the dominant contributor of sulfates.” Sonoma Technol- 2722 CAWCD v. EPA ogy Inc., Navajo Generating Station Visibility Study 2-11 (L. Willard Richards et al. eds., 1991). In February 1991, EPA proposed to revise the FIP for Ari- zona to include emission limits under BART to address win- tertime visibility impairment at the Grand Canyon reasonably attributable to NGS. See 56 Fed. Reg. 5,173 (1991) (codified at 40 C.F.R. §52). EPA solicited public comment on four possible regulatory options, and proposed one of those options — to require as BART for NGS a 70% continuous SO_ emission limitation, determined on a thirty-day rolling aver- age, to be phased-in between 1995 and 1999. Jd. at 5,183-84. After a public comment period of over nine weeks, senior EPA policy officials met with the NGS owners, representa- tives of the State of Arizona, and certain environmental groups, including the Grand Canyon Trust and the EDF, to explore further additional control options which might pro- duce a pareto optimal solution, more environmentally protec- tive and economically efficient.* These meetings resulted in a “memorandum of understanding” which recommended that EPA adopt a regulatory approach designed to achieve a greater degree of visibility improvement in the Grand Canyon at lower cost than the proposal published by EPA in February 1991. EPA published the proposal outlined in the memoran- dum of understanding and reopened the public comment period. See 56 Fed. Reg. 38,399, 38,401 (1991) (codified at 40 C.F.R. § 52). EPA received twenty-one comments during this supplemental period, eighteen of which supported the new proposal. See 56 Fed. Reg. at 50,177. In the Final Rule, dated October 3, 1991, EPA issued its final determination that certain visibility impairment episodes at the Grand Canyon were “traceable to NGS and that NGS is a dominant contributor to certain visibility impairment episodes,” and promulgated revisions to the Arizona visibility ‘Summaries of these meetings were placed in the administrative record. See 56 Fed. Reg. at 50,177. CAWCD v. EPA 2723 FIP to address the impairment. /d. The revisions adopted a regulatory approach consistent with the memorandum of understanding’s proposal, reducing SO, emissions 90% to a level of 0.10 Ib/MMBtu. Jd. EPA determined that this approach would more adequately achieve “reasonable progress” toward the national visibility goal under section 169A(b)(2) of the Act, 42 U.S.C. § 7491(b)(2), than would the alternative provided by BART analysis. See 56 Fed. Reg. at 50,177. As required by section 307(d) of the Act, EPA’s action was “accompanied by a response to each of the signifi- cant comments, criticisms, and new data submitted in written or oral presentations during the comment period.” 42 U.S.C. § 7607(d)(6)(B). EPA issued its responses in the regulation itself and in a supplementary ninety-one page document enti- tled “Response to Public Comments: Proposed Revisions to Arizona Visibility FIP for Navajo Generating Station” [here- inafter Response to Public Comments}. Il. STANDING First, as a threshold jurisdictional matter, EPA challenges whether the Districts have standing to bring this action. We find that the Districts do have standing. A. Constitutional Standing The Supreme Court recently outlined the three elements of the “irreducible constitutional minimum of standing” in Lujan v. Defenders of Wildlife, 112 S. Ct. 2130 (1992): First, the plaintiff must have suffered an “injury in fact"—an invasion of a legally-protected interest which is (a) concrete and particularized, and (b) “actual or imminent, not ‘conjectural’ or ‘hypothetical. “ Second, there must be a causal con- nection between the injury and the conduct com- plained of—the injury has to be “fairly trace[able] to the challenged action of the defendant, ee 2724 CAWCD v. EPA and not... th{e] result [of] the independent action of some third party not before the court.” Third, it must be “likely,” as opposed to merely “speculative,” that the injury will be “redressed by a favorable decision.” Id. at 2136 (footnote, citations omitted; ellipses in original). Justice Scalia elaborated that “when the plaintiff is not him- self the object of the government action or inaction he chal- lenges, standing is not precluded, but it is ordinarily ‘substanually more difficult’ to establish.” Jd. at 2137 (quot- ing Allen v. Wright, 468 U.S. 737, 758 (1984)). 1. Injury in Fact The Districts’ claimed injury is an economic one: CAWCD Claims it is contractually required to repay much of BOR’s 24.3% share of the costs of installing and maintaining emis- sion controls at NGS as required by the Final Rule. Pecuniary injury is Clearly “a sufficient basis for standing.” See Fair v. EPA, 795 F.2d 851, 853-54 (9th Cir. 1986) (citing cases). But while pecuniary or economic injury is generally a legally pro- tected interest, the “injury in fact” test “ ‘requires that the party seeking review be himself among the injured.’ ” Lujan, 112 S. Ct. at 2137 (quoting Sierra Club v. Morton, 405 U.S. 727, 734-35 (1972)). That party’s injury must be (a) concrete and particularized, and (b) actual or imminent, and not con- jectural or hypothetical. /d. at 2136. EPA argues that the owners of NGS are the ones directly aggrieved by the Final Rule, and that the indirect economic harm that the Districts may suffer as a result of their financial obligation to one of NGS’s owners is too attenuated an inter- est to provide them with standing to bring this challenge. EPA claims the Districts’ injury is purely speculative because: (1) CAWCD concedes it will attempt to pass on increased costs caused by the Final Rule to its water users and taxpayers (including the four petitioning irrigation districts); and (2) CAWCD v. EPA 2725 CAWCD has failed to demonstrate that BOR will in fact have to pay a portion of any existing compliance costs.° or that CAWCD will be required under contract to reimburse BOR for a portion of those costs assuming they exist. Thus, EPA argues, the Districts’ economic injury is too indirect, specula- tive, and hypothetical to provide them with standing. [1] We conclude that CAWCD’s economic injury is suffi- ciently concrete and imminent to accord it standing to litigate this action. The Districts’ claimed injury is by no means “a general or amorphous harm,” National Wildlife Fed'n v. Bur- ford, 871 F.2d 849, 852 (9th Cir. 1989), nor is it a mere gener- alized grievance. See Lujan, 112 S. Ct. at 2143. While the extent of CAWCD's economic harm is not readily determin- able, the record reveals that the Final Rule will likely cause Petitioners some amount of pecuniary harm given their obli- gation to repay BOR’s share of the costs imposed by the Final Rule. Neither the sale of marketable allowances nor the possi- bility of passing on increased costs to consumers undermine the Districts’ showing of the required “actual or threatened injury.” Valley Forge Christian College v. Americans United for Separation of Church & State, Inc., 454 U.S. 464, 472 (1982); Competitive Enter. Inst. v. NHTSA, 901 F.2d 107, 112 (D.C. Cir. 1990). 2. Causation and Redressability [2] In addition to the injury in fact requirement. the Dis- tricts must prove causation and redressability, i.e., that their alleged economic injury is fairly traceable to EPA’s chal- lenged action, and that the relief requested is likely to redress that injury. Lujan, 112 S. Ct. at 2136. EPA argues that since *Under section 403(b) of the Act, a regulated party may transfer SO allowances under an allowance trading program. See 42 USC. § 7651b(b). EPA notes that sale of allowances may offset the required capital investment for control equipment. Thus, EPA argues, capital costs may never be passed on to the District. 2726 CAWCD v. EPA the Districts’ alleged economic injury flows from obligations under the BOR/CAWCD agreement, the injury is not caused by or fairly traceable to the challenged agency action. This argument misses the point. While CAWCD’s contractual obli- gations may provide the basis for its economic liability for the increased costs imposed by the Final Rule, that hardly means that the Final Rule itself is not the direct cause of that liabil- ity. Further, the involvement of an intermediate third-party here does not undermine the Districts’ causation argument since “the government’s action [is] substantially likely to cause the petitioners’ injury despite the presence of intermedi- ary parties.” Competitive Enter., 901 F.2d at 114 (consumer organization has standing to challenge NHTSA fuel economy standards on grounds that organization members would be hindered in their ability to purchase larger vehicles). Finally, the Districts’ economic injury is likely to be redressed by a favorable decision since elimination of the Final Rule would necessarily eliminate the increased financial burden the rule causes. B. Prudential Standing [3] In addition to the constitutional standing requirements, Petitioners must also prove that their asserted interest is “within the zone of interests protected by” the Clean Air Act. See, e.g., Fair v. EPA, 795 F.2d at 854. EPA contends that the Districts’ economic injury is not within the zone of interests of the Act’s visibility provisions, which are designed to “preserve, protect, and enhance the air quality in national parks.” 42 U.S.C. § 7470(2). EPA’s argu- ment ignores the fact that “the zone of interest test is ‘not meant to be particularly demanding.’” National Wildlife Fed'n v. Burford, 871 F.2d at 852 (quoting Clarke v. Securi- ties Indus. Ass'n, 479 U.S. 388, 399 (1987)). As the Supreme Court clarified in Clarke: In cases where the plaintiff is not itself the subject of the contested regulatory action, the test denies a night a 6 CAWCD v. EPA 2727 of review if the plaintiff’s interests are so marginally related to or inconsistent with the purposes implicit in the statute that it cannot reasonably be assumed that Congress intended to permit the suit. 479 U.S. at 399. Under this permissive standard, the Districts’ economic injury sufficiently falls within the “zone of interests” protected by the visibility provisions of the Act. Section 169A of the Act requires the Administrator to con- sider “the costs of compliance” in setting standards to achieve reasonable progress towards the national visibility goal. 42 U.S.C. § 7491(g)(1). As entities required to pay those costs of compliance, the Districts’ interests cannot reasonably be described as “marginally related to or inconsistent with” the purposes of the Act. We therefore conclude that Petitioners have standing to bring this challenge. Il. STANDARD OF REVIEW The appropriate judicial review of the regulations at issue here is provided for in section 307(d) of the Act, 42 U.S.C. § 7607(d). In relevant part, section 307(d)(9) provides that a reviewing Court may reverse any action of the Administrator found to be (A) arbitrary, capricious, an abuse of discretion, or otherwise not in accordance with law; (C) in excess of statutory jurisdiction, authority, or limitations, or short of statutory right; or (D) without observance of procedure required by law, if (i) such failure to observe such procedure is arbitrary or capricious, (ii) the requirement of para- 2728 CAWCD v. EPA graph (7)(B) has been met, and (iii) the condition of the last sentence of paragraph (8) is met. 42 U.S.C. §§ 7607(d)(9)(A), (C)-(D). Paragraph (7)(B) generally limits judicial review to proce- dural objections “raised with reasonable specificity during the period for public comment.” /d. at § 7607(d)(7)(B). But para- graph (7)(B) does provide for mandatory reconsideration of the rule by the agency if an objecting party can “demonstrate to the Administrator” that (1) it was “impracticable” to prop- erly raise a given procedural objection, and (2) the “objection is of central relevance to the outcome of the rule.” /d.’ The last sentence of paragraph (8) further provides: In reviewing alleged procedural errors, the court may invalidate the rule only if the errors were so serious and related to matters of such central relevance to the rule that there is a substantial likelihood that the tule would have been significantly changed if such errors had not been made. 42 U.S.C. § 7607(d)(8). Review of EPA’s actions under section 307(d) of the Act is guided by the appropriate deference given to an agency s ’The relevant portion of paragraph (7)(B) more fully provides: If the person raising an objection can demonstrate to the Admin- istrator that it was impracticable to raise such objection within such time or if the grounds for such objection arose after the period for public comment (but within the time specified for judi- cial review) and if such objection is of central relevance to the outcome oi the rule, the Administrator shall convene a proceed- ing for reconsideration of the rule .... If the Administrator refuses to convene such a proceeding, such person may seek review of such refusal in the United States court of appeals for the appropriate circuit .... 42 U.S.C. § 7607(d)( 7B). CAWCD v. EPA 2729 interpretation of the statute Congress has entrusted it to administer. Chevron U.S.A. Inc. v. NRDC, Inc., 467 U.S. 837, 843 (1984) (where the Clean Air Act is either “silent or ambiguous with respect to the specific issue, the question for the court is whether the agency’s answer is based on a permis- sible construction of the statute”). “Deference also guides our review of the Administrator’s interpretation of EPA regula- tions if the interpretation is not unreasonable.” Citizens for Clean Air v. EPA, 959 F.2d 839, 844 (9th Cir. 1992); see also Hawaiian Elec. Co. v. EPA, 723 F.2d 1440, 1447 (9th Cir. 1984) (~[W]hen EPA is interpreting its own regulations, it is entitled to even more deference.”). Moreover, the Supreme Court has advised that “a reviewing court must generally be at its most deferential” when the agency is “making predic- tions, within its area of special expertise, at the frontiers of science.” Baltimore Gas & Elec. Co. v. NRDC, Inc., 462 U.S. 87, 103 (1983). In such situations, this court is to “defer to the agency's interpretation of equivocal evidence, so long as it is reasonable.” NRDC, Inc. v. EPA, 902 F.2d 962, 968 (D.C. Cir. 1990), vacated, in part, dismissed, 921 F.2d 326 (D.C. Cir.), certs. dismissed, 111 S. Ct. 806, cert. denied, 111 S. Ct. 952 (1991). While this court should not defer to the agency where it “simply has not exercised its expertise,” Public Citizen Health Research Group v. Tyson, 796 F.2d 1479, 1505 (D.C. Cir. 1986),° courts are “extremely deferential to administrative— agencies in cases involving technical rulemaking decisions.” New York v. Reilly, 969 F.2d 1147, 1152 (D.C. Cir. 1992): see also id. at 1150-51 (“We are particularly deferential when *For instance, in Motor Vehicle Manufacturers Association of United States, Inc. v. State Farm Mutual Automobile Insurance Co., 463 U.S. 29 (1983), the Supreme Court found an agency nuling arbitrary and Capricicus where the agency had “entirely failed to consider an important aspect of the problem.” /d. at 43. Siate Farm shows that the “expertise model” does nol necessarily mandate judicial deference, since the Court there took a “hard look” to ensure that the agency was in fact using its expertise in arriving at policy decisions. 2730 CAWCD v. EPA reviewing agency actions involving policy decisions based on uncertain technical information.”); Tyson, 796 F.2d at 1505 (“[A]s long as Congress delegates power to an agency to reg- ulate on the borders of the unknown, courts cannot interfere with reasonable interpretations of equivocal evidence.”). IV. DISCUSSION A. EPA’s Statutory Authority to Promulgate the Finai Rule Petitioners argue that in promulgating the Final Rule, EPA acted “in excess of statutory jurisdiction, authority, or limita- tions, or short of statutory right” under 42 U.S.C. § 7607(d)(9) (c). Petitioners claim that the Final Rule regulates “regional haze’ when EPA’s own regulations expressly defer regulation of that type of visibility impairment until future phases. See 45 Fed. Reg. at 80,086. We conclude that the Final Rule was legitimately promulgated under Phase I regulations directed at “reasonably attributable” visibility impairment. Petitioners rely on Vermont v. Thomas, 850 F.2d 99 (2d Cir. 1988), where EPA reaffirmed that it was without author- ity to regulate “regional haze and that measures addressing that type of impairment are outside the scope of EPA's juris- diction. This reliance is misplaced. In Thomas, the state of Vermont submitted to EPA an SIP which “proposed a feder- ally enforceable ‘long-term strategy’ to combat the effects of regional haze” at the Lye Brook National Wilderness Area. Id. at 101. The court held that without EPA rulemaking addressing regional haze, the state’s regional haze measures were “outside the scope” of EPA’s statutory and regulatory authority. Jd. at 103-04. Here, EPA properly promulgated its Final Rule under its Phase I regulations directed at “reasonably attributable” impairment.’ Thomas is thus distin- *in the Final Rule itself, EPA made eminently clear that its action addressed Phase | visibility impairment rather than Phase II “regional haze.” See 56 Fed. Reg at 50,172. Pursuant to Congress's 1990 amend- CAWCD v. EPA 2731 guishable since it involved a direct and explicit attempt to reg- ulate “regional haze.” [4] EPA has acknowledged that “NGS is not the only source of visibility impairment” at the Grand Canyon, 56 Fed. Reg. at 50,177, and that regional haze also adversely affects visibility there. Response to Public Comments at 23. Nonethe- less, these mere facts hardly mean that EPA is without statu- tory authority to remedy the impairment attributable to NGS. Even if the Final Rule addresses only a small fraction of the visibility impairment at the Grand Canyon, EPA still has the Statutory authority to address that portion of the visibility impairment problem which is, in fact, “reasonably attributable” to NGS. Congress mandated an extremely low triggering threshold, requiring the installment of stringent emission controls when an individual source “emits any air pollutant which may reasonably be anticipated to cause or contribute to any impairment of visibility” in a class I Federal area. 42 U.S.C. § 7491(b)(2)(A). The National Academy of Sciences correctly noted that Congress has not required iron- . clad scientific certainty establishing the precise relationship — between a source’s emission and resulting visibility impair- ment: The phrase “may reasonably be anticipated” suggests that Congress did not intend to require EPA to show a precise relationship between a source’s emissions and all or a specific fraction of the visibility impair- ments to the Act, EPA subsequently established the Grand Canyon Visi- bility Transport Commission (“GCVTC”), 42 U.S.C. § 7492(f), whose duty it is to make recommendations on “promulgation of regulations under section 7491 of this title to address long reuge strategies for addressing regional haze which impairs visibility in affected class 1 [Federal] areas” like the Grand Canyon. 42 U.S.C. § 7492(d)(2C). Congress envisioned GCVTC as a long-term complement to EPA’s then-pending efforts to rem- edy impairment at the Grand Canyon which was attributable to NGS. See 136 Cong. Rec. $2890 (March 21, 1990). : 2732 CAWCD v. EPA ment within a Class I area. Rather, EPA is to assess the risk in light of policy considerations regarding the respective risks of overprotection and underpro- tection. Haze in the Grand Canyon at 5. [5S] Acting in place of the state of Arizona pursuant to an FIP under 42 U.S.C. § 7410(c), EPA “stands in the shoes of the defaulting State, and all of the rights and duties that would otherwise fall to the State accrue instead to EPA.” 54 Fed. Reg. at 36,952. EPA is therefore granted broad discretion in determining whether visibility impairment is “reasonably attributable” to a given source. See 40 C.F.R. §51.301(s) (defining “reasonably attributable” as “attributable by visual Observation or any other technique the State deems appropriate’) (emphasis added). This broad, all-inclusive def- inition of the term “reasonably attributable” directly refutes Petitioners’ argument that EPA is limited to addressing visi- bility impairment caused by a noticeable plume that is directly traceable to a given source through the use of visual observa- tion or simple monitoring techniques. [6] We conclude that the technical, scientific record more than adequately supports EPA’s reasonable conclusion that visibility impairment in the Grand Canyon is “reasonably attributable” to NGS. We defer to the agency's reasonable interpretation of its own regulations and statutory mandate. Its interpretation is most certainly consonant with Congress's apparent intent. For instance, in his introduction of the Con- ference Committee report to the House, Representative Henry Waxman stated: Protecting the Grand Canyon simply must become a normal business practice of the American industry ... [T]he Four Corners and Navajo powerplants can expect to retrofit with additional pollution controls to ee CAWCD v. EPA 2733 limit the vast deterioration in visibility which their plumes have caused. impairment of visibility is the single most appar- ent impact air pollution has on the environment. It is our intent that aggressive steps be taken to reduce this eyesore which has defaced our grand vistas in the West. 123 Cong. Rec. 27,076 (1977) (statement of Rep. Waxman). EPA’s interpretation of its authority to determine whether vis- ibility impairment is “reasonably attributable” to NGS is enti- tled to deference from this court since the agency’s * “choice represents a reasonable accommodatior of conflicting policies that were committed to the agency’s care by the statute,” ” which this court “ ‘should not disturb’” since it does not appear “ ‘from the statute or its legislative history that the accommodation is not one that Congress would have sanctioned.’ Chevron, 467 U.S. at 845 (quoting United States v. Shimer, 367 U.S. 374, 383 (1961)). B. The Final Rule as the Product of “Reasoned Decisionmaking” Petitioners proffer various arguments that the Final Rule is not the product of “reasoned decisionmaking.” They assert that EPA has acted arbitrarily and capriciously by overesti- mating the improvements in visibility expected from the Final Rule’s emission controls at NGS, by purportedly failing to address criticisms to the scientific data and analyses on which it relied, and by allegedly ignoring certain evidence while placing undue reliance on other evidence. At bottom, how- ever, Petitioners’ real complaint appears to be that the Final Rule will most likely lead to minimal visibility improvement at the Grand Canyon while imposing a substantial financial burden on them. Nonetheless, we find unsupported Petition- ers’ legal claim that EPA acted arbitrarily and capriciously in promulgating the Final Rule. The Final Rule makes 2734 CAWCD v. EPA “reasonable progress” toward the national goal of remedying visibility impairment at the Grand Canyon. and is the product of reasoned decisionmaking. 1. The Final Rule as “Reasonable Progress” toward the National Goal of Remedying Visibility Impairment at the Grand Canyon In reviewing whether the agency's action in promulgating the Final Rule was arbitrary and capricious, this court “is not to substitute its judgment for that of the agency.” State Farm, 463 U.S. at 43. Instead, we inquire whether the agency has “examine[d] the relevant data and articulate[d] a satisfactory explanation for its action, including a ‘rational connection between the facts found and the choice made. ~ /d. (quoting Burlington Truck Lines, Inc. v. United States, 371 U.S. 156, 168 (1962)). Our review is limited to “whether the agency considered the relevant factors and whether there has been a clear error of judgment.” NRDC, Inc. v. EPA, 966 F.2d 1292, 1297 (9th Cir. 1992) (citing Citizens to Preserve Overton Park, Inc. v. Volpe, 401 U.S. 402, 416 (1971)). In this case, the relevant factors are provided by Congress’s definition of “reasonable progress” in 42 U.S.C. § 7491(g)(1). Addition- ally, as the D.C. Circuit recently noted in discussing a similar provision of the Act, “[bJecause Congress did not assign the specific weight the Administrator should accord each of these factors, the Administrator is free to exercise his discretion in this area.” New York v. Reilly, 969 F.2d at 1150 (discussing 42 U.S.C. § 7411(a)(1)(C)).”° Petitioners incorrectly suggest that EPA was required to engage in “cost-benefit” analysis. Congress has not required “cost-benefit” analysis in the Act. Cf. American Textile Mfrs. Inst., Inc. v. Donovan, 452 U.S. 490, 510 (1981) (“When Congress has intended that an agency engage in cost-benefit analysis, it has clearly indicated such intent cr the face of the Statute.”). CAWCD v. EPA 2735 a. The “Reasonable Progress” Provisions [7] In the Act, Congress directed EPA to promulgate regu- lations to assure “reasonable progress toward meeting the national goal” of preventing future, and remedying existing visibility impairment in Class I federal areas like the Grand Canyon. See 42 U.S.C. §§ 7491(a)(4), (a)(1), (b)(2), (b)(2)(B). Congress chose not to define the term “reasonable progress,” but instead set forth several factors for the agency to consider: In determining reasonable progress there shall be taken into consideration the costs of compliance, the time necessary for compliance, and the energy and nonair quality environmental impacts of compliance, and the remaining useful life of any existing source subject to such requirements[.] 42 U.S.C. § 7491(g)(1). In promulgating the Final Rule, EPA relied on the “reasonable progress” provisions as its statutory authority. See 56 Fed. Reg. at 50,177 (noting that EPA adopts the “reasonable progress” provisions of section 169A(b)(2), 42 U.S.C. § 7491(b)(2) as the “legal rationale” for the Final Rule). [8] Generally, the Act and its regulations require the appli- cation of BART once it has been determined that visibility impairment is “reasonably attributable” to an existing source like NGS. See 42 U.S.C. § 7491(b)(2); 40 C_E.R. § 51.302(c) (4)(i). Under the unique circumstances of this case, however, EPA chose not to adopt the emission control limits indicated by BART analysis, but instead to adopt an emission limita- tions standard that would produce greater visibility improve- ment at a lower cost. Congress’s use of the term “including” in § 7491(b)(2) prior to its listing BART as a method of attaining “reasonable progress” supports EPA’s position that it has the discretion to adopt implementation plan provisions other than those provided by BART anal’ses in situations where the agency reasonably concludes tha’ more “reasonable ieee aaa ai aii 2736 CAWCD v. EPA progress” will thereby be attained. Since the Act itself is ambiguous on the specific issue, we apply the Supreme Court’s deferential standard from Chevron and hold that the agency’s reliance on the “reasonable progress” provisions is a “permissible construction of the statute,” 467 U.S. at 843, since “reasonable progress” is the overarching requirement that implementation plan revisions under 42 U.S.C. § 7491(b) (2) must address. b. EPA Reasonably Considered the Relevant Factors [9] The administrative record reveals that EPA adequately considered the relevant factors in promulgating the Final Rule." Petitioners’ essential argument does not claim that EPA failed to consider the relevant factors, but instead contends that EPA erred in its consideration of those factors. This court is not to substitute Petitioners’ judgment, or its own, for that of EPA, as long as the agency's interpretation is reasonable. In fact, this is just the type of case in which the Supreme Court has stated that judicial review should “be at its most deferential,” because the agency is “making predictions, within its area of special expertise, at the frontiers of science.” Baltimore Gas & Elec. Co., 462 U.S. at 103. We therefore find that the agen- cy’s interpretation of the evidence, and its weighing of the rel- evant factors, are reasonable, and that the Final Rule is the product of “reasoned decisionmaking.” 2. Petitioners Have Failed to Demonstrate that EPA Acted in an Arbitrary and Capricious Manner Petitioners argue that EPA relied on discredited elements of a seriously flawed study, failed to refute significant criticisms which undercut the basis for EPA’s improvement estimate, and refused to consider highly relevant evidence which con- ‘Actually, EPA not only considered the “reasonable progress” factors, but also considered expected visibility improvement under the Final Rule, as required by BART analysis. CAWCD v. EPA 2737 tradicted its estimate. They conclude that EPA has acted arbi- trarily and capriciously. We reject these arguments. [10] The allegedly discredited study on which EPA relied was the Park Service’s analysis of the WHITEX data. The record reveals, however, that EPA acknowledged the limita- tions of the Park Service report (even seeking and obtaining NAS comment on it), and did not rely solely upon that report’s conclusions. As discussed supra, EPA’s determina- tion that visibility impairment at the Grand Canyon is “reasonably attributable” to emissions at NGS was eminently reasonable and adequately supported by a substantial body of scientific and technical evidence in the record. Further, as the D.C. Circuit noted in NRDC v. EPA: “The Administrator may apply his expertise to draw conclusions from suspected, but not completely sub- stantiated, relationships between facts, from trends among facts, from theoretical projections from imperfect data, from probative preliminary data not yet certifiable as ‘fact,’ and the like.” 902 F.2d at 968 (quoting Ethyl Corp. v. EPA, 541 F.2d 1, 28 (D.C. Cir.) (en banc), cert. denied, 426 U.S. 941 (1976)). While this court must still ensure that “the agency has made a reasoned decision based on ‘reasonable extrapolations from some reliable evidence,’ ” id. (quoting NRDC, Inc. v. Thomas, 805 F.2d 410, 432 (D.C. Cir. 1986)), this standard adequately has been met here. Petitioners further challenge as arbitrary and capricious EPA’s estimate of the quantum of visibility improvement which the agency expects to result from imposition of the Final Rule’s emission limits at NGS. In arriving at its estimate that the Final Rule “should improve the winter seasonal aver- age visibility above the rim of the [Grand Canyon] approxi- mately 7 percent,” 56 Fed. Reg at 50,180, EPA discussed the estimates of three studies: (1) the Park Service’s WHITEX 2738 CAWCD v. EPA estimate of 14% improvement, (2) the NGSVS estimate of at most a 2% improvement, and (3) a modelling study, con- ducted by Douglas Latimer and submitted during the com- ment period, which estimated a range of 4 to 8% improvement. Petitioners contend that EPA arrived at its 7% estimate in an arbitrary and capricious manner because, they contend, EPA failed to consider and place in the administra- tive record a new report prepared by Latimer in which he allegedly reconsiders his previous estimate of visibility improvement, reducing it to 3 to 4%. Petitioners additionally claim that failure to put this new report in the administrative record constitutes an abuse of discretion. We find Petitioners” challenge both legally untenable and factually misleading. First, the challenge is legally untenable because it relies on this court’s consideration of evidence — the new Latimer report — which is not a part of the administrative record. In the Act, Congress explicitly and unambiguously provided that “the record for judicial review shall consist exclusively” of certain specifically enumerated categories of materials. 42 U.S.C. § 7607(d)(7)(A) (emphasis added). “Nothing in the statute or its legislative history indicates that a party or the agency may reopen the record by placing additional materials (other than those required by the statute and wrongfully omit- ted by EPA) in the docket after promulgation of the rule.” Lead Indus. Ass’n v. EPA, 647 F.2d 1130, 1183 (D.C. Cir.), cert. denied, 449 U.S. 1042 (1980). The new Latimer report was not included in the administrative record, nor was it required to be. EPA explains that the report was not directly related to NGS, but was instead submitted to EPA in the con- text of the GCVTC regional haze efforts under section 169B of the Act. Petitioners’ reliance on Kent County v. EPA, 963 F.2d 391 (D.C. Cir. 1992) is misplaced because, unlike the Clean Air Act here, the statutory provision at issue in Kent County contained no special procedural provi- sions displacing general rules of administrative law governing the admin- istrative record for judicial review. Compare 42 U.S.C. §§ 7607(d)(1), (d) (7M A) with 42 U.S.C. § 9613(a). a anaemia Se CAWCD v. EPA 2739 Additionally, Petitioners ignore the route for administrative and judicial review of “new information” and alleged “procedural errors” in the creation of the administrative docket that Congress created: 42 U.S.C. § 7607(d)(7)(B)’s mechanism for reconsideration by the agency. Petitioners have failed to move for reconsideration and are now trying to circumvent this congressionally mandated route by petitioning for direct judicial review. We therefore deny Petitioners” motion to supplement the administrative record and direct Petitioners to consult section 7607(d)(7)(B) in order to fash- ion their claim as a petition for reconsideration to EPA, as Congress had envisioned. Second, even if this court were to consider Petitioners’ argument on the merits, their challenge is misleading because Latimer himself indicates that Petitioners have misrepresented the statements and conclusions contained in his new report. We therefore reject Petitioners’ argument that EPA has some- how acted arbitrarily or capriciously, or abused its discretion, through the manner in which it arrived at its estimate of visi- bility improvement. V. CONCLUSION In the final analysis, Petitioners simply adhere to a different interpretation of the rather disparate and equivocal scientific data in the record. While Petitioners may not be satisfied with - EPA’s responses, it is not EPA's duty to satisfy all of the con- cems of potentially affected or aggrieved parties. EPA con- ducted an extensive and involved notice and comment period, and adequately met its statutory obligation of responding to Significant comments and criticisms under 42 U.S.C. § 7607(d)(6)(B). Notwithstanding Petitioners’ challenge, the Final Rule is the result of a site-specific informal rulemaking process that included virtually unprecedented cooperation between the governmental agency and the directly affected parties. See generally D. Michael Rappoport & John F. Cooney, Visibility at the Grand Canyon: Regulatory Negotia- 2740 CAWCD v. EPA tions Under the Clean Air Act, 24 Ariz. St. LJ. 627 (1992). Petitioners’ arguments afford no reason for this court disrup- tively to interject itself into the picture. Because Congress del- egated to EPA the power to “regulate on the borders of the unknown, this court will not interfere with the agency's “reasonable interpretations of equivocal evidence.” Public Citizen Health Research Group v. Tyson, 796 F.2d at 150S. Even if this case highlights how hard it is to engage in “reasoned decisionmaking” in cases involving scientific uncertainty, EPA‘s actions in promulgating the Final Rule were reasonable and within the bounds of its statutory author- ity, and not arbitrary and capricious. The Districts” petition for review and motion to supplement the administrative record are accordingly DENIED. PRINTED FOR ADMINISTRATIVE OFFICE—U.S. COURTS BY BARCLAYS / ELECTROGRAPHIC—SAN FRANCISCO—{415) 588-1155 The summary, which does not constitute a part of the opinion of the court, is copyrighted © 1993 by Barclays Law Publishers. 50172 Federal Register/Vol. 56, No. 192/ Thursday, October 3, 1991/Rules and Regulations ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 52 A.[AD-FRL-4018-5] Approval and Promulgation of Implementation Plans: Revision of the Visibility FIP for Arizona AGENCY: U.S. Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: This notice revises the Federal implementation plan (FIP) for the State of Arizona to include a sulfur dioxide (SO,) emission limit of 42 nanograms per Joule (ng/J) [0.10 pound per million British thermal units (lb/MMBtu)], heat input for the Navajo Generating Station (NGS) to remedy visibility impairment in the Grand Canyon National Park (GCNP). Compliance with this emission limit will be phased-in by unit in 1997, 1998, and 1999 and determined on a plant-wide annual rolling average basis. In addition, NGS will be required to reschedule its maintenance such that 6 unit-weeks of maintenance will be performed during the winter months. This action is taken pursuant to sections 169A and 110(c) of the Clean Air Act (Act), 42 U.S.C. sections 7491 and 7410(c), which require EPA, upon default by a State, to take appropriate measures to remedy certain certified visibility impairments in mandatory Class I areas. The timing of today’s action is in accordance with the revised settlement agreement between EPA and Environmental Defense Fund (EDF) in EDF vy. Reilly, No. C82-6850 RPA (N.D. Cal.). EFFECTIVE DATE: This action will be effective on November 4, 1991. ADDRESSES: Docket: Pursuant to section 307(d)(1)(B) of the Act, 42 U.S.C. 7607(d)(1)(B), this action is Subject to the procedural requirements of section 307(d). Therefore, EPA established Docket A-89-02A for this action. Materials related to the development of this notice have been placed in this docket. 2 Materials related to EPA’s preliminary attribution determination (54 FR 36948 (September 5, 1989)) have been placed in Docket A-89- 02. For background information, materials related to the development of the visibility protection program (40 CFR 51.300 et seq.) are available in Docket A-79-40. Also, materials related to the development of the visibility new source review (NSR) and visibility monitoring strategies are available in Docket A-84-32. Materials related to the visibility long-term strategy, implementation of control strategy, and integral vista program are available in Docket A-85-26. All dockets are available for public inspection and copying between 8:30 a.m. to 12 noon and 1:30 p.m. to 3:30 p.m., Monday through Friday, at EPA’s Central Docket Section, Office of the General Counsel, room 1500, 401 M Street, SW., Washington, DC 20460. A reasonable fee may be charged for copies. FOR FURTHER INFORMATION CONTACT: Mr. David H. Stonefield, U.S. Environmental Protection Agency, Office of Air Quality Planning and Standards (MD-15), Research Triangle Park, North Carolina 27711, (919) 541-5350 or FTS 629-5350. SUPPLEMENTARY INFORMATION I. Background A. Regulatory Requirements Section 169A of the Act, 42 U.S.C. 7491, sets as a national goal “the prevention of any future, and the remedying of any existing, impairment of visibility in mandatory Class I Federal areas which impairment results from manmade air pollution." Mandatory Class I Federal areas are certain national parks, wildernesses, and international parks as described in section 162(a) of the Act, 42 U.S.C. 7472(a). Section 169A requires that EPA promulgate regulations to assure reasonable progress toward meeting the national goal for mandatory Class I Federal areas where EPA has determined that visibility is an important value. On November 30, 1979, EPA identified 156 such areas, including the GCNP in Arizona, where visibility is an important air quality-related value (44 FR 69122). Section 169A specifically requires EPA to a 3 promulgate regulations requiring States to amend their State implementation plans (SIP’s) to provide reasonable progress toward meeting the national goal for the 156 areas. On December 2, 1980, EPA promulgated the required visibility regulations (45 FR 80084, codified at 40 CFR 51.300 ef seq.). The visibility regulations require the 36 States listed in section 51.300(b), including Arizona, to: 1. Coordinate SIP development with the appropriate Federal land managers (FLM’s). 2. Develop programs to assess and remedy Phase I visibility impairment from existing sources and to prevent visibility impairment from new sources. 3. Develop a long-term (10 to 15 years) strategy to address, among other things, Phase I visibility impairment to assure reasonable progress toward the national goal. 4. Develop a visibility monitoring strategy to collect information on visibility conditions. 5. Consider in all aspects of visibility protection any “integral vistas" (important views of landmarks or panoramas that extend outside of the boundaries of the Class I area) identified by the FLM’s as critical to the visitors’ enjoyment of the Class I areas. The affected States were required to submit revised SIP’s satisfying these provisions by September 2, 1981 (see 45 FR 80091, codified at 40 CFR 51.302(a)(1)).' ' The EPA's 1980 regulations implementing the statutory requirements of section 169A address visibility impairment that is reasonably attributable to a single source or small group of sources (“Phase |" impairment) (see generally 45 FR 80084 (December 2, 1980)). Recognizing certain scientific and technical limitations, EPA, in promulgating the 1980 regulations, deferred regulatory action on more “complex problems such as regional haze and urban plumes.” id. at 80086. Today, in accordance with the 1980 regulations, EPA is taking regulatory action to remedy visibility impairment that is caused by NGS. The EPA is in the process of establishing the Grand Canyon Visibility Transport Commission as required by section 169B of the Act. The duties of that commission include making recommendations on “promulgation of regulations under section 169A to address long-range strategies for addressing regional haze which impairs visibility in * * * the GCNP” (section 169B(d)(2)(C)). 4 The second and third requirements listed above are of particular relevance to today’s action. Pursuant to 40 CFR 51.302(c)(2), each affected State is required to include in its SIP such emission limitations, schedules of compliance, and other measures as may be necessary to make reasonable progress toward the national visibility ~ goal. Under 40 CFR 51.302(c)(1), an FLM may certify to a State that there exists impairment of visibility in any mandatory Class I Federal area. Such impairment must be addressed in accordance with 40 CFR 51.302(c) which sets forth measures for achieving reasonable progress, including best available retrofit technology (BART) and a long-term strategy (see 40 CFR 51.302(c)(1) and (2), section 169A(b)(2)(A) and (B)). Pursuant to 40 CFR 51.302(c)(4)(i), where impairment is certified at least 6 months prior to plan submission, an affected State must identify each existing stationary facility which may “reasonably be anticipated to cause or contribute" to any such impairment which is “reasonably attributable to that existing stationary facility," and analyze for BART any facility so identified. _ "Reasonably attributable" impairment is impairment “attributable by visual observation or any other technique the State deems appropriate" (40 CFR 51.301(s)). Where a State defaults on its obligation sunder the visibility regulations, EPA may act in place of the State pursuant to . FIP under section 110(c) of the Act, 42 U.S.C. 7410(c),? and ? Section 110(c) requires EPA to promulgate FIP’s whenever a State fails to submit an implementation plan (or portion thereof) which meets the requirements of section 110, whenever the Administrator determines that a plan (or portion) is not in accordance with the requirements of section 110, or whenever the State fails to revise its plan within 60 days after notification by the Administrator in accordance with section 110(a)(2)(H). During the House of Representatives’ consideration of the Conference Report on the 1977 Amendments to the Clean Air Act, Congressman Rogers reiterated that the conferees had agreed that EPA was to act where States failed to carry out their duties in implementing the requirements of section 169A. The pertinent part of Congressman Rogers’ statement is as follows: “The conferees * * * rejected a motion to delete EPA's supervisory role under section 110 to assure that the required progress towards that goal (the national visibility goal) will be achieved by the revised State plan. If a State visibility protection plan is not adequate to assure such progress, the Administrator must PEL ott Sha Vin att Na 5 promulgate such limitation and measures as are required to achieve reasonable progress. In such cases, all of the rights and duties that would otherwise fall to the State accrue instead to EPA. The visibility regulations promulgated at 40 CFR 51 .302(c)(4)(i) require that once a Phase I impairment has been certified, a State (or EPA if the State’s visibility protection program addressing BART has not been approved, and EPA is acting in its place) must analyze for BART any specific existing stationary facility it identifies as a "reasonably attributable" source of the impairment. Pursuant to section 169A(b) of the Act (42 U.S.C. 7491(b)) and 40 CFR 51.302(C)(4)(iii), the emission limitation representing BART for fossil fuel-fired power plants with a generating capacity in excess of 750 megawatts (MW) must be determined pursuant to guidelines promulgated by the Administrator. This statutorily- required procedure for conducting a BART analysis is found in "Guidelines for Determining Best Available Retrofit Technology Analysis for Coal-Fired Power Plants and Other Stationary Facilities" (EPA-450/3-80-009b BART Guidelines). A copy of this document may be found in Docket A-89-02A. In December 1982, environmental groups, including EDF, filed a citizens suit in the United States District Court for the Northern District of California alleging that EPA had failed to perform a nondiscretionary duty under section 110(c) of the ACT, 42 U.S.C. 7410(c), to promulgate visibility FIP’s for the 35 States? that, at that time, had failed to submit SIP’s to EPA as called for by the 1980 visibility regulations, EDF v.. Reilly, No. C82-6850 RPA disapprove that portion of the SIP and promulgate a visibility protection plan under section 110(c). Thus, visibility protection in mandatory federal class I areas remains a national commitment, which is nationally enforceable." See Senate Comm. on Environment and Public Works, 95th Cong. 2d.Sess. “A Legislative History of the Clean Air Act Amendment of 1977" No. 16, vol. 3 at 311, 320-21 (Comm. Print 1978). * The State of Alaska had submitted a SIP which was approved on July 5, 1983 at 48 FR 30623. ee 6 (N.D. Cal.). The State of Arizona was one of the 35 States that failed to submit a revised SIP to EPA. The EPA and the plaintiffs negotiated a settlement agreement for the remaining States which the court approved by order on April 20, 1984. For more information on details of the provisions of the original settlement, including a schedule of actions by EPA, see EPA’s announcement of the agreement at 49 FR 20647 (May 16, 1984). B. Settlement Agreement To remedy the States’ failure to submit the necessary SIP revisions during the time specified by the regulations, the settlement agreement replaced the original regulatory deadlines for visibility SIP provisions with a rulemaking schedule agreed to by the parties and approved by the court. This schedule required EPA to review the existing SIP’s to determine any deficiencies, allow the States to cure those deficiencies, and to promulgate FIP’s on a specified schedule for those States that still did not submit visibility SIP revisions to EPA. Specifically, the first part of the agreement required EPA to promulgate FIP’s which cover the monitoring and NSR provisions of 40 CFR 51.305 and 51.307. The EPA promulgated its monitoring strategy for 23 States and its NSR provisions for 21 States, including Arizona, at 59 FR 28544 (July 12, 1985), 51 FR 5504 (February 1, 1986), and 51 FR 22937 (June 24, 1986). In separate notices, EPA approved the SIP’s of the other States with respect to monitoring and NSR. The second part of the settlement agreement required EPA to determine the adequacy of the SIP’s to meet the remaining provisions of the visibility regulations and gave the States until December 1986 to submit additional measures that would avoid the need for a FIP. These provisions are the general plan provisions for achieving reasonable progress toward the national visibility goal including BART and other implementation control strategies (§ 51.302), integral vista protection (§ 51-302-307), and long-term Strategies (§ 51.306). The settlement agreement required EPA to SIS et abtiee Ne OF 7 promulgate FIP’s to remedy any deficiencies on a specified schedule. Pursuant to 40 CFR 51.302(c)(1), on November 14, 1985, the Department of the Interior (DOI) certified the existence of visibility impairment in all Class I areas within its jurisdiction in the lower 48 States. On January 23, 1986, EPA determined that the SIP’s of 32 States (including Arizona) were deficient with respect to the remaining visibility provisions (51 FR 3046) and offered the States an Opportunity to submit corrective SIP revisions. Thereafter, EPA and the plaintiffs negotiated revisions to the settlement agreement which extended the deadlines for State action or, if the States failed to respond, Federal action proposing FIP’s to remedy these deficiencies. The court approved these revisions by its order of September 9, 1986.‘ On March 24, 1986, the DOI sent a letter to EPA which supplemented its earlier certification of visibility impairment. The letter addressed the GCNP and identified the NGS, a coal-fired power plant located near Page, Arizona, as a probable source of impairment in this Class I area. A copy of this letter may be found in Docket A-89-02. Thirty-two affected States failed to submit visibility SIP revisions in response to the notice of deficiency. Consequently, in accordance with the revised settlement agreement, on March 12, 1987 (52 FR 7802), EPA proposed to disapprove the SIP’s of 32 States, including Arizona, for failing to meet the remaining provisions of the visibility regulations, including general plan requirements to achieve reasonable progress toward the national visibility goal (which in turn includes BART, long-term strategies, and other control strategies). Also in accordance with the agreement, on November 24, 1987 (52 FR 45132), EPA took final action disapproving the affected SIP’s, again including Arizona. In "h copy of the settlement agreement and revisions is available in Docket A- 85-26 at the address given at the beginning of this notice. 8 that action, EPA also promulgated, as FIP measures under section 110(c), general plan requirements for these States. The EPA also determined that BART was unnecessary in 26 States because it could not reasonably attribute the visibility impairment of mandatory Class I Federal areas in these States to specific sources or small groups of sources. In addition, under the revised agreement, EPA deferred until August 31, 1988 a decision regarding the need for BART or other control measures in the FIP’s for the States of Arizona, Maine, Minnesota, and Utah to address certified visibility impairments in seven Class I areas in these States which potentially could be reasonably attributed to a specific source pending acquisition and evaluation of additional technical information regarding the potential sources of impairment. Because all of the additional information needed by EPA was forthcoming but still not available by August 1988, the Agency sought and received a second extension, until August 31, 1989, of the deadline for issuing a rulemaking proposal regarding the need for BART or other control measures to remedy visibility impairments in three of the remaining Class I areas (Moosehorn Wilderness, GCNP, and Canyonlands National Park). With regard to the impairment in the GCNP, EPA delayed action in order to allow the National Park Service (NPS) time to analyze the data from a 1987 winter visibility attribution study, termed the Winter Haze Intensive Tracer Experiment (WHITEX), conducted in the Colorado Plateau where the GCNP is located. In the meantime, on May 19, 1989 (54 FR 21904), in accordance with the second revision to the settlement agreement, EPA promulgated final decisions concerning certified visibility impairments in four of the seven Class I areas. B n_ monitoring con in e PA f at visibility impairments were r l i l ifi rc Th r PA i it_w n revi ’s for f Mai inn Arizon incl ART or n rategi m impairments in Roosevel Ilo Int i k AS LE A ARE my a Ng 9 Voyageurs National Park (Minnesota). Saguaro Wilderness (Arizona), and Petrified Forest National Park (Arizona. In April 1989, EPA received a draft report on WHITEX from the NPS.° Because of the delay in receiving this report, EPA believed that it lacked sufficient time to complete its analyses and issue a proposed rule by the August 31, 1989 deadline. Accordingly, EPA and EDF filed a joint motion to revise the settlement agreement for a third time, which was approved by order of the court dated July 6, 1989. Under this revision, there was no change in the deadlines for proposed action regarding Canyonlands National Park or Moosehorn Wilderness. As to GCNP, the third revision to the settlement agreement divided EPA’s duty into two parts. The EPA would proceed, on a preliminary basis, to issue a finding on reasonably attributable impairment by the August 31, 1989 deadline. However, if EPA did provisionally identify a specific source of impairment, it would solicit comments on that finding and would have additional time to conduct a BART analysis. The EPA was to issue a rulemaking proposal on the need for BART by February 1, 1990 unless, in response to comments, EPA rejected its proposed identification and instead determined that BART was unnecessary. In accordance with the third revision to the settlement agreement, EPA published a notice of proposed rulemaking on September 5, 1989 (54 FR 36948). Regarding Moosehorn Wilderness, EPA identified a source of the certified impairment but proposed that BART was unnecessary because the impairment would be adequately remedied by the retirement of certain _ existing emission units and the addition of pollution controls on other units pursuant to a permit issued under the Act’s prevention of significant deterioration provisions. As to Canyonlands National Park, EPA could not reasonably attribute the certified impairment to a specific source at that time and so proposed that BART was unnecessary. * Malm, et al., “The National Park Service Report on WHITEX Draft Final Report” (April 7, 1989). en 10 On June 13, 1990 (55 FR 24060), EPA issued final decisions that BART was not necessary to address impairment in either the Moosehorn Wilderness or the Canyonlands National Park. Regarding the GCNP, in the September 5, 1989 notice, EPA preliminarily attributed several episodes of wintertime visibility impairment to emissions form the NGS. In that regard, EPA reviewed the draft NPS report on WHITEX and concurred with the findings of the NPS. The EPA solicited comments on the merits of its preliminary attribution finding. On November 28, 1989, the Salt River Project Agricultural Improvement and Power District (SRP), et al.,[sic] and Alabama Power Company, et al., [sic] intervenors in EDF v. Reilly, filed a motion requesting a 1-year delay in the rulemaking schedule so that, among other things, the intervenors could conduct their own studies of the visibility impairment in the GCNP. By order dated January 9, 1990, the court granted the intervenors’ motion to extend the deadlines. This order set February 1, 1991, as the new deadline for EPA to propose whether or not to require BART emission limits for the NGS to remedy winter visibility impairment. The order also extended the deadline for final action on any proposal regarding BART until October 1991 (6 months after the close of the comment period).° C. Navajo Generating Station The NGS is a 2250 MW coal-fired power plant located near Page, Arizona, approximately 20 kilometers from the northern boundary of the GCNP. The NGS is a baseload generating station consisting of three 750 MW units which became operational between 1974 and 1976. ‘the SRP is the operating agent for NGS © The EDF has appealed the extension of rulemaking deadlines in this case, EDF v. Reilly, No. 90-15264 (9th Cir.). That appeal is pending. In a Memorandum of Understanding (MOU) discussed below, parties to this litigation have agreed, in light of today’s action, to petition (a) the Ninth Circuit to vacate the judgment below and remand the matter to the court below with instructions to dismiss and (b) the District Court for the Northern District of California to dismiss EDF v. Reilly, No. C82-6850. 11 which is jointly owned by the SRP,’ the Los Angeles Department of Water and Power, the Arizona Public Service Company, the Nevada Power Company, and the Tucson Electric Power Company. Existing pollution control equipment at NGS includes electrostatic precipitators for particulate matter (PM) removal and specific burner design for nitrogen oxides (NO,) control. D. February 8, 1991 Proposal On February 8, 1991, EPA proposed to revise the FIP for Arizona to include emission limits to address the visibility impairment observed in GCNP. The following is a summary of the main issues discussed in the proposal notice. 1. Emission Limitation The EPA proposed to adopt a continuous SO, emission limitation of 0.30 lb/MMBtu. Compliance would be determined on a 30-day rolling average and would be phased in between 1995 and 1999. Because of the uncertainty in determining the improvement in visibility expected as a result of reducing emissions at the NGS, EPA solicited comments on three alternative control Strategies for NGS: a. A continuous SO, emission limitation of 0.50 Ib/MMBtu. Compliance would be determined on a 30-day rolling average and would be phased in between 1995 and 1999. b. A continuous SO, emission limitation of 0.10 Ib/MMBtu. Compliance world be determined on a 30-day rolling average and would be phased in between 1995 and 1999. c. AJanuary 10, 1991 proposal submitted by SRP under which it would test alternative control technologies, and if one of the technologies met a minimum removal efficiency at a set cost, the NGS would install that technology and operate it in the wintertime. ’ The SRP owns 21.7 percent of the NGS project for its own use and benefit, and 24.3 percent for the use and benefit of the United States in accordance with the NGS project agreements. The term "NGS participants” is used in this notice to refer to the parties which have rights and responsibilities associated with the operation of NGS and includes the owners, the operators, and the U.S. Bureau of Reclamation (for the United States). | 12 If none of the technologies met the test criteria, NGS would reduce its emissions by 70 percent (0.30 Ib/MMBtu emission limit) measured on an annual basis by the year 2000. In addition, EPA requested comment on whether another emission limitation or a different averaging period may be more appropriate. 2. Attribution As part of the February 8, 1991 proposal, EPA reopened the comment period on its September 5, 1989 preliminary finding that several episodes of wintertime impairment in the GCNP was reasonably attributable to NGS. The EPA noted both in the September 1989 and the February 1991 notices that the finding was not based on any single analytical technique in the NPS report on WHITEX, but rather-on the collection of techniques performed by the NPS using WHFTEX and other data. In detail, EPA explained that all of the techniques used by the NPS support the conclusion that NGS is a source of visibility impairment in the Grand Canyon during certain wintertime episodes. Also, in some detail, EPA discussed the National Academy of Science’s (NAS’) review of the WHITEX study and discussed other visibility studies performed subsequent to WHITEX. The National Research Council of the NAS reviewed and reported on the scientific methods used in the WHITEX report. The NAS report, entitled "Haze in the Grand Canyon: An Evaluation of the Winter Haze Intensive Tracer Experiment" (October 1990), 3 contained a qualitative assessment of WHITEX which supported ; EPA’s finding that, on some days, NGS is a source of visibility : impairment in the GCNP.* Further, the NAS found that the "rate : of SO, emissions from NGS is easily large enough to serve as the ee * The report found, for example, that the detection at Hopi Point (GCNP) of the unique tracer released from NGS in the WHITEX study “is an unambiguous indicator that air parcels containing NGS emissions did impinge on the GCNP on several occasions.” Executive Summary at p. 3. 13 source of the sulfur measured in the GCNP."° However, the report also found that the data base and data analyses techniques in the WHITEX report were not, Standing alone sufficient to ascertain the quantitative NGS contribution to haze at any given time. The NAS report has been placed in the rulemaking docket.'° The SRP has conducted another Study known as the Navajo Generating Station Visibility Study (NGSVS). That study attempted to measure the degree of contribution by the NGS to visibility impairment in the GCNP during the 1989-1990 winter season and to assess the level of improvement expected as a result of reducing the SO, emissions at NGS. The SRP Submitted a draft report describing that study and its results! during the public comment period on EPA’s February 8, 1991 proposal. The NGSVS concluded that NGS emissions were present at Hopi Point less frequently than during the WHITEX period. In addition, the NGSVS concluded that on days when NGS emissions were present, visibility impairment at Hopi Point associated with those emission was substantially less than the amount calculated in the NPS report on WHITEX. However, results indicate that NGS was responsible for a significant quantity of sulfate and haze during specific visibility impairment episodes in GCNP. 3. BART Analysis In light of its attribution finding, EPA conducted an analysis in accordance with the BART Guidelines (EPA-450/3-80-009b) and 40 CFR 51.301(c)(4)(iii)."2 That analysis included consideration of the following: the costs of compliance, the energy and non-air * The NAS report at p. 33. '° Additional copies of this report are available from the National Academy Press, 2101 Constitution Avenue, NW., Washington, DC 20410. ? Sonoma Technology, Inc., "Navajo Generating Station Visibility Study,” Draft Number 2, April 16, 1991. '2 U.S. EPA, "Draft Report on Best Available Retrofit Technology (BART) Analysis for the Navajo Generating Station in Page, Arizona,” January 1990. A copy of this document has been placed in Docket A-89-02A. 14 quality environmental impacts, any existing pollution control technology in use at the facility, the remaining useful life of the source, and the degree of improvement in visibility anticipated to result from application of controls. Considering the requirements found in the BART Guidelines, EPA divided its analysis into two major parts. In the first part, EPA identified the SO, emission controls that are readily available to the source, the costs of such controls, and other impacts of installing and operating the controls. In the second part of the analysis, EPA attempted to define the source-impairment relationship which was then used to predict the improvements in visual air quality that can reasonably be expected to occur as a result of installing and operating the controls defined in the control technology analysis. Because EPA was faced with some uncertainties in each of the parts of the analysis, EPA bounded its results by giving low and high estimates. A detailed discussion of this analysis for NGS was provided in EPA’s February 8, 1991 proposal. To estimate the cost of controlling the SO, emissions at NGS, EPA used the Integrated Air Pollution Control System (IAPCS) cost model to predict the capital and operating cost estimates for 0.10, 0.30, and 0.50 Ib/MMBtu control levels.’ The results from the IAPCS indicated that wet flue gas desulfurization (FGD) achieving a 0.30 Ib/MMBtu emission limit for all three units, the control level that was proposed by EPA, was estimated to have total capital cost requirements of between $245.9 million and $402 million with total levelized annual costs (including amortized capital, interest, operating, and maintenance costs) estimated to be between $91.9 million and $128.3 million.'* In its February 8, 1991 proposal, EPA also estimated the potential costs to residential electricity customers serviced by the si Integrated Air Pollution Control System Costing Program, Version 3.0, copyright PEI and Associates, Inc., 1989. 14 All dollar amounts were measured in 1988 dollars. Camid SUP aay ; } ; j % : 15 NGS participants as well as the potential costs to Central Arizona Project (CAP) customers. One of the more complicated tasks in the BART analysis was defining the relationship between the SO, emissions at NGS and the visibility impairing sulfate in the GCNP. This relationship had to be addressed in order to estimate the degree of improvement in visibility that could be anticipated to result from the use of the alternative SO, control systems. Because of the complex terrain in and around the GCNP, EPA defined the source/impairment relationship using the ratio of SO, emissions at NGS to Sulfate in the GCNP attributable to NGS as found in the final WHITEX report. Using this ratio, EPA then applied a linear rollback model. However, in light of the uncertainties Surrounding these analyses EPA considered a broad range of source-impairment relationships. In addition, EPA developed and applied 4 nonlinearity factor to the rollback model to estimate the improvements in visibility that would result from reductions in SO.,,. Because no single standard method exists for measuring improvements in visibility, the EPA employed two of the most widely used techniques to define the improvements in visibility expected to occur in the GCNP. One of the methods used to estimate the visibility improvements in the GCNP was analyzing the changes in contrast expected to occur as a result of reducing SO, emissions at NGS. The EPA stated in the proposal that this method is particularly relevant because human observers use contrast to make judgments of how atmospheric clarity changes with pollutant concentration. The contrast is defined as the percent difference between the brightness of a scenic element end its background. The second technique was to analyze the seasonal average visual range change (see 56 FR 5182 Table 1). Although not specifically addressed in the BART analysis, the proposal noted that EPA suspected that NGS emissions may contribute to visibility impairment in the GCNP during other seasons of the year and in other Class I areas in the region. Thus, 16 EPA sought comment on any other potential visibility impairments caused by NGS. The EPA also noted in the proposal that it was not required as a part of its analysis to estimate monetary benefits associated with improving visibility in the GCNP. However EPA evaluated the monetary benefits in developing a part of the preliminary Regulatory Impact Analysis (RIA) (as required by Executive Order 12291) for the proposed rule. 4. Control of Particulate Matter and Nitrogen Oxides In the February 8, 1991 proposal, EPA noted that two other pollutants emitted by NGS, NO, and PM, are known to contribute to visibility impairments in some circumstances.’* The current emissions of NO, and PM from NGS were not identified as significantly contributing to the visibility impairment in the Grand Canyon. However, EPA expressed concern based upon its technical judgment regarding the behavior of the pollutants as potential contributors to visibility impairment as a general matter, upon the amount of the pollutants emitted by NGS, upon the proximity of NGS to the GCNP, and upon the characteristics of the NGS plume, as shown by WHITEX and other studies, that increased emissions of these pollutants could result in impairment in the GCNP. The EPA noted that although the NGS is not subject to any NO, emission limitations, SRP has stated that NGS currently emits NO, at a rate of 0.4 to 0.5 Ib/MMBtu. Therefore, EPA proposed an NO, emission limit consistent with NGS’ existing emission rate, as well as the rate at other similar plants, of 0.5 Ib/MMBtu. The EPA noted that PM emissions for the NGS are currently limited in two ways. The Arizona SIP has both an emission rate limitation of 0.06 lb/MMBtu and an opacity limit of 40 percent for NGS. The SRP has stated that NGS currently emits PM at a rate of 0.03 Ilb/MMBtu with an opacity of between 10 and 15 percent. Thus, the opacity limit of 40 percent is well above the NGS existing 'S See, e.g., BART Guidelines at p. 12-13. a a oe 17 emissions. Therefore, EPA proposed a 20 percent Opacity limitation consistent with current NGS emissions in order to preclude any visibility deterioration that would be caused by an increase in PM emissions. The EPA requested comments on whether NO, and PM emission limits would be appropriate for NGS. 5. Compliance Schedule The EPA proposed to require that the emission limitation be achieved in three phases. Specifically, EPA proposed that the final emission limitation would need to be met on one unit by January 1, 1995; on two units by January 1, 1997; and on all three units by January 1, 1999. The EPA solicited comments on whether the phased-in compliance schedule proposed was appropriate as a matter of law or policy, and, as noted, requested comment on the January 1991 SRP proposal that a final emission limitation not become effective before January 1, 2000. 6. Use of Seasonal Controls Part of the SRP proposal called for the use of seasonal controls. Therefore, EPA solicited comment on the use of seasonal controls. In the February 8, 1991 notice, EPA noted that such controls would have to be both technically and legally justified before they could be used. 7. Other Issues In the February 8, 1991 proposal, EPA also specifically Solicited comments on the following: a. Use of continuous emission monitoring systems for compliance determinations. b. Plant-wide averaging of the emission limitations. c. Other available technologies which can reduce SO, emissions at NGS to achieve the proposed or alternative limits and which may require less capital investment and/or Operating expenses than those technologies evaluated in the BART analysis. In addition to soliciting written comments during the comment period, EPA held a public hearing on March 18 and 19, 1991 in 18 Phoenix, Arizona. A copy of the transcript of the hearing is in Docket A-89-02A. As a result of the comment period and public hearing, EPA received over 400 comments on its proposal. All the comments have been placed in Docket A-89-02A. Because of the differences in technical opinions expressed and data analyses submitted to EPA during the comment period, EPA sponsored a technical review meeting on April 25 and 26, 1991. The EPA invited the NGS participants and the environmental groups who submitted technical information to EPA to send technical representatives to the meeting to discuss the interpretation of the available data. The meeting was open to the public, and a summary of that meeting is included in Docket A-89-02A. E. New information After the Close of the Initial Comment Period After the comment period closed on April 19, 1991, at the recommendation of EPA, representatives of SRP, Grand Canyon Trust (GCT), and EDF met to discuss alternative approaches to EPA’s February 8, 1991 proposal. In August 1991, the outside parties reached agreement and together recommended that EPA adopt an alternative control for NGS consisting of a 0.10 Ib/MMBtu SO, emission limitation (approximate to a 90 percent control level) based on a rolling annual average and phased in by unit in November 1997, November 1998, and August 1999. In addition, under the agreement, NGS would shift its maintenance schedule such that 6 unit-weeks of planned maintenance would occur between November | and March 15 each year. Under specific conditions, the Administrator of EPA may allow NGS to shift the maintenance schedule outside of that period or not to conduct scheduled maintenance in a given year. Representatives of EPA participated in many of the meetings with the parties and provided technical assistance. Representatives of the State of Arizona also attended several of the meetings and provided additional technical support. New technical materials and cost information, including adjustments of the potential control costs, were exchanged between the parties and EPA. Summaries of the meetings and significant conversations in which EPA was 19 involved and copies of the new material and information which were submitted to or developed by EPA have been included in Docket A- 89-02A. The outside parties memorialized their agreement in an MOU which they submitted to EPA along with recommended regulatory requirements for EPA’s final rulemaking action. The SRP estimated (in 1992 dollars) a capital cost of $430 million and a total levelized annual cost of $89.6 million for the parties’ recommended alternative. In comparison, SRP estimated a capital cost of $510 million and a total levelized annual cost of $106 million to meet the alternative EPA proposed in February 1991. Noting that the alterative incorporated in the MOU would provide more visibility protection for the GCNP at a lower cost for NGS and its customers, EPA, on August 8, 1991, reopened the comment period on its February 8, 1991 proposed action (56 FR 38399, August 13, 1991). In the notice, EPA stated that it was giving serious consideration to the control option recommended by the outside parties and incorporated in an appendix to the notice a memorandum from EPA’s Office of General Counsel concluding that the outside parties’ legal rationale in support of their recommended control option was meritorious. The EPA reopened the commend period until September 9, 1991. Where addresses were available, commenters on the February 8, 1991 proposal were notified by mail of the reopened comment period in order to facilitate their ability to comment. The EPA received 21 comments during the supplemental comment period. Eighteen of the commenters supported the alternative incorporated in the MOU, and three opposed it. The SRP, GCT, EDF, the Wilderness Society, the National Wildlife Federation, and the Sierra Club conditionally withdrew their prior comments which were inconsistent with the MOU and associated documents. II. Today’s Actions In today’s action EPA is promulgating its final determination on the attribution to NGS of certain visibility impairment episodes in 20 GCNP and is promulgating Federal revisions to the visibility implementation plan for Arizona to address those impairment episodes. As discussed below, EPA has concluded that certain visibility impairment episodes in GCNP are traceable to NGS and that NGS is a dominant contributor to certain visibility impairment episodes. The EPA finds today that a 0.10 lb/MMBtu SO, emission limitation (approximately a 90 percent emission reduction) based on a rolling annual average and phased in by unit in November 1997, November 1998 and August 1999 in addition to scheduled winter maintenance at NGS affords greater visibility improvements than the alternative advanced in EPA’s February 1991 proposal. In particular, it will reduce by two-thirds the amount of pollution allowed under the proposed rule. In addition, EPA finds that the final rule will be significantly less costly than the proposal. Consequently, EPA further concludes that today’s final action will provide a greater degree of “reasonable progress" toward the national goal of remedying such impairment than would be provided by the February 1991 proposal (see section 169A(b)(2) of the Act, 42 U.S.C. 7491(6)(2)). In EPA’s August 1991 supplemental notice requesting comment on the rulemaking alternative largely adopted in final form today, the Agency noted that SRP, GCT, and EDF had recommended that the legal rationale in support of this alternative be the requirement in section 169A(b)(2) of the Act that implementation plan revisions addressing visibility impairment achieve “reasonable progress" toward the national visibility goal. The supplemental notice also indicated that EPA’s Office of General Counsel had reviewed the matter and concluded, subject to any significant points that may be raised in the reopened comment period, that EPA could rely on the reasonable progress provisions as the basis for this alternative. No significant adverse comments addressing the legal basis were received. Accordingly, EPA is adopting this rationale as discussed in the supplemental notice. Today’s action is based upon the material in the docket including EPA’s review and consideration of all comments received ee a Ty ee ee 21 during the comment periods and at the public hearing. The agreement between GCT, EDF, and SRP and _ associated recommendations to EPA, largely adopted in final form today, also are in the docket. The EPA has responded to all of the significant comments received. Some responses are provided later in today’s notice. Additionally, EPA has prepared a document accompanying today’s action. "Response to Public Comments: Proposed Revisions to Arizona Visibility FIP for Navajo Generating Station," which responds to comments. This document has been placed in Docket A-89-02A. A. Impairment Traceable to NGS The EPA regulations promulgated on December 2, 1980 ({r]equire the control of impairment that can be traced to a single existing stationary facility or small group of existing Stationary facilities . . ." (45 FR 80085). Accordingly, EPA’s regulations currently cover existing sources where the impairment is traceable or “reasonably attributable” to that source by visual observation or other techniques deemed appropriate by the State (Phase I impairments). The EPA, acting for the State under section 110(c) of the Act, deems the techniques in the WHITEX report, the NGSVS report, and other data and analyses in the docket as appropriate techniques for determining reasonable attribution in this case for the following reasons. 1. The unique tracers, deuterated methane used in the WHITEX study and perfluorocarbons used in the NGSVS, injected into the emissions of NGS were observed in substantial quantities at Hopi Point during periods of episodic visibility impairment. 2. The NGS is the predominate source of SO, in the region. 3. SO, released by a power plant converts into sulfates through chemical transformation in the atmosphere. 4. Meteorological data show that the NGS plume easily can, and frequently does, travel to GCNP. 5. The data and analyses in the docket show that sulfates are the major contributor to visibility impairment in GCNP. 22 The EPA recognize that NGS is not the only source of visibility impairment at GCNP. Under the applicable statutory provisions and regulations, however, this is not determinative’® (see generally section 169A of the Act and 40 CFR 51.300 307). Moreover, even though WHITEX and NGSVS contain some scientific uncertainty, they are technically adequate for the regulatory purposes at hand, as they both showed that episodes of visibility impairment in the GCNP can be reasonably attributed to NGS. Accordingly, EPA concludes today that certain visibility impairment episodes of the GCNP are traceable to NGS, and NGS is a dominant source of those impairments. Notwithstanding that other sources also may contribute to those impairment episodes at GCNP. EPA concludes that the addition of emissions controls at NGS alone will result in a Significant improvement in visibility at GCNP and will make “reasonable progress" toward meeting the national visibility goal. B. Control Technology As part of the BART analysis '’ for the February 1991 proposal, EPA reviewed the available control technologies as well For example, under section 169A(b)(2) of the Act, EPA is authorized to require visibility implementation plans containing “emission limits, schedules of compliance and other measures” necessary to make reasonable progress toward meeting the national visibility goal (see also 40 CFR 51.302(c)). The national visibility goal, in turn, calls for the remedying of “any” manmade visibility impairment in Class I areas (see section 169A(a)(1) and 40 CFR $1.300(a)). As noted, EPA’s regulations implementing section 169A address visibility impairment that is reasonably attributable to a single source or small group of sources and deferred action on complex problems such as regional haze (see generally, 45 FR 80084 (December 2, 1980)). Accordingly, as provided in the 1980 regulations, EPA may remedy through emission limits, schedules of compliance, or other measures “any” visibility impairment that is reasonably attributable to an existing stationary source or small group of sources (see also section 169A(c) of the Act and so CFR 51,303 (authorizing an exemption from control requirements only where a plant does not “by itself or in combination with other sources” omit pollution "which may reasonably be anticipated to cause or contribute to significant impairment of visibility" in any Class I area and affirms by negative inference, EPA’s broad rulemaking authority)). U.S. EPA "Draft Report on Best Available Retrofit Technology (BART) Analysis for the Navajo Generating Station in Page, Arizona,” January 1990. iinet 23 as the environmental impact of the use of such technologies and the estimated costs of installing and operating such equipment. In today’s action, EPA is not requiring the use of any particular control technology. Rather, EPA is establishing an emission limitation and NGS has the discretion to select and install the type of control system which best meets its needs. The available information in the docket indicates that a wet FGD system will be the economically proven control technology for meeting the 0.10 lb/MMBtu emission limitation at NGS. As a result of new information provided by SRP, EPA has revised and updated its cost estimates for the installation and operation of a wet FGD system. The revised estimated Capital cost and total levelized annual cost to meet the emission limitation EPA proposed in February 1991, in 1992 dollars, are $510 million and $106 million, respectively. The estimated capital cost and the total levelized annual cost, in 1992 dollars, to meet the emission limitation promulgated today, are $430 million and $89.6 million, respectively. Although not considered in these cost estimates, EPA expects that NGS will be able to recoup a portion of the control costs by the sale of marketable allowances which it will receive as part of the allowance trading program that EPA is establishing under Title IV of the Act. Based on the information submitted during the comment period by SRP and Nevada Power Company (NPC) and the above cost figures, EPA has estimated that the average SRP and NPC customers electric bills will increase approximately $1.72 and $1.57 per month, respectively. The customers of the other utilities will have smaller increases in their electric bills. | Commenters representing CAP customers submitted information showing that water costs would increase between $4.10 and $4.50 per acre foot based on EPA’s February 1991 proposal. Since the cost figures for the final action are lower than the figures used for these estimates, the increase in water costs for the CAP customers is expected to be less than $4.10 to $4.50 per acre foot. 24 C. Control Strategy The EPA has adopted the combination of a higher level in control; compliance phased in by unit in 1997, 1998 and 1999; an annual averaging period; and scheduled winter maintenance as a control strategy for NGS -- the alternative recommended to the EPA by GCT, EDF, and SRP and identified in EPA’s August 1991 supplemental notice - because it better addresses the visibility effects of concern at a lower cost than the proposal in EPA’s February 1991 notice. As highlighted here and elsewhere, the control strategy for NGS must be viewed as a whole and not as severable parts. The EPA has carefully weighed the relevant Statutory and regulatory considerations and concluded that, taken in its entirety, today’s control strategy for NGS will provide a greater degree of reasonable progress toward the national goal at a lower cost than EPA’s February proposal. Essentially, the SO, emissions from NGS can contribute to two types of visibility impairment. The major impact of NGS is its dominant single source impact during certain episodic visibility impairment events, usually during the winter. This impact has been observed in winter studies (WHITEX and NGSVS) as well as intense aerosol monitoring within the canyon since 1988.'* The other concern addressed by the control strategy in today’s action is the less intense impairments which occur at the GCNP during seasons other than winter, and occur at other nearby mandatory Class I Federal areas.’® The lower level of NGS SO, emissions required by the 0.10 lb/MMBtu emission limitation adopted today will afford GCNP greater protection from episodic events than an emission limitation ’See Docket A-89-02A, specifically items IV-D-164 and IV-D-375. See, e.g., Latimer, Douglas, "Haze Impacts on the Golden Circle of National Parks of Sulfur Dioxide Emission from Navajo Generating Station: Haze Puff Model Calculations for 1988-90." 25 which allows significantly more SO, emissions but is averaged over a shorter period, such as the 0.30 Ib/MMBtu emission limitation proposed by EPA in its February 1991 notice. The probability of high NGS contribution to severe episodic sulfate impairment events is limited by the known design reliability of current technologies which will achieve the required 0.10 Ib/MMBtu emission limitation as well as the scheduled winter maintenance requirement. Thus, EPA believes that despite the use of an annual averaging time, the Significant increase in control level, expected reliability of the control technology, and winter maintenance, taken together will, for the most part, prevent continuation of severe winter episodes caused by NGS. At the same time, the annual average lowers the costs of compliance. With respect to the long-term potential visibility impacts on the Golden Circle area (the other Class I areas in the Colorado Plateau), there is little doubt that the lower emission rate over a year’s average will reduce NGS’ contribution to sulfate formation and thus to sulfate-caused impairment more than the control level proposed by EPA in February 1991. Given NGS’ central location in relation to many Class I areas, no matter what meteorological events occur over a multi-year period, it is likely that the sulfates originating from NGS and transported to Surrounding Class I areas will be reduced in proportion to the difference in emission limitations, i.e., to one-third of the levels in the February 1991 proposal. Further, during the comment period on the February 1991 proposal, EPA received technical information Suggesting that NGS contributes to visibility impairment at GCNP in non-winter seasons.” For the reasons just discussed, the significant lower emission rate required today will, over the long-term, curb NGS’ contribution to any visibility impairment in the GCNP during seasons other than winter to a greater degree than EPA’s proposed option. See Docket A-89-02A, item IV-D-171, and season control discussion below. 26 Accordingly, the control scheme adopted today for NGS is appropriate for addressing the winter episodic visibility impairment observed at the GCNP and will also reduce any long-term, long- range impairment that NGS emissions may contribute to during other seasons at GCNP and at other nearby Class I areas.” D. Emission Limitation After reviewing the option recommended by SRP, EDF, and GCT in their MOU, EPA has determined that such a control Strategy will provide a substantially greater degree of emissions reduction, and a correspondingly greater degree of visibility improvement at a substantially lower cost than the alternative proposed in February 1991.” For these reasons, EPA also concludes that this option will make additional reasonable progress towards attainment of the national visibility goal in comparison to the February 1991 proposal. Thus, in today’s action EPA is promulgating an SO, emission limitation of 42 ng/J (0.10 lb/MMBtu) heat input to be phased in by unit in November 1997, November 1998, and August 1999, with compliance determined on a rolling annual average basis. 21 As noted, section 169A of the Act establishes a national visibility goal, not an air quality standard or a specific emission standard. While the objective is to attain the goal, EPA’s only mandate from Congress is to make reasonable progress toward the goal. For these reasons, EPA has more flexibility in selecting a centrol strategy to meet the visibility reasonable progress requirements than it does when a health-based air quality standard or specific emission standard must be met. Thus, in determining reasonable progress, EPA, by law, must consider the costs of compliance, the time necessary for compliance, and the energy and non-air quality environmental impacts of compliance (see section 169A(g)(1) of the Act). Consideration of the pertinent statutory scheme and these specific factors has informed several aspects of today’s action. Thus, for the policy and legal reasons stated, an annual rolling average emission limitation is acceptable for this case. Moreover, while this emission limitation is not expected to interfere with attainment of any other requirement of the Act, its adoption does not relieve NGS of any responsibility for meeting any air quality standard, emission standard, or other requirement of the Act. 2 In the August 1991 supplemental notice, EPA published and requested comment on the parties’ August 8, 1991 MOU and associated documents. During the public comment period, the parties further clarified their agreement and submitted a revised version of their MOU and recommended regulatory requirements to EPA, both documents dated August 22, 1991. a 27 Under today’s final action, compliance with the annual rolling average will be determined by computing a weighted plant-wide average of the SO, emission rate based on the daily SO, emission rate and the electric energy generated for the previous 365 "boiler operating days" for each unit.~ The EPA was concerned that the plant-wide average reflects the actual release of emissions at the plant. Therefore, after discussion with representatives of SRP, GCT, and EDF, EPA settled on a methodology that appropriately weights the emissions from each unit before calculation of the plant- wide average. The EPA has used the daily electric energy generated as a weighting factor because that information is readily available for each unit and in this case is proportional to the heat input to the boilers. Specifically, compliance will be determined as follows: 1. For each unit that has accumulated at least 365 boiler operating days since the passage of the starting date applicable to it, the plant must measure and record the SO, emission rate and the electric energy generated on each boiler operating day. The SO, emission rate will be computed using the date from the required continuous emission monitoring system for the unit and using method 19, appendix A, 40 CFR part 60. The electric energy generated, in megawatt-hours, will be recorded from the megawatt- hour meter for the unit. 2. For each unit, the previous 365 boiler Operating days will be identified. 3. For each such day, the product of the SO, emission rate and the electric energy generated wil! be computed. 3 A “boiler operating day” is specific for each steam-generating unit at NGS and is defined as a 24-hour calendar day (the period of time between 12:01 a.m. and 12:00 midnight in Page, Arizona) during which coal is combusted at that NGS unit for the entire 24 hours.” This definition is consistent with the definition for “boiler operating day” in 40 CFR 60.41a: "a 24-hour period during which fossil fuel is combusted in a steam-generating unit for the entire 24 hours.” The EPA notes that the set of previous 365 boiler operating days for each unit will be unique to that unit and thus the same set of calendar days probably will not be used for all three units in determining compliance. 28 4. The 365 products for each unit will be added. 5. The electric energy generated for the 365 boiler operating days for each unit will be added. 6. The sums of the product of the SO, emission rate and the eiectric energy generated will be divided by the sum of the electric energy generated to produce a plant-wide weighted annual average SO, emission rate for comparison with the emission limitation to determine compliance. Recording and computation of the daily electric energy generated and SO, emission rates will commence on: 1. November 19, 1997 for the first unit. 2. November 19, 1998 for the second unit. 3. August 19, 1999 for the third unit. The NGS has the discretion to determine which of its three units will be controlled first and second. In the discussion below, EPA has recognized that certain difficulties encountered during the first year of operation of a control system or the catastrophic failure of a control system may, based on EPA’s judgment, warrant a limited exclusion from compliance with the emission limitation. However, as discussion below indicates, the control system, as a general matter, must be optimally operated consistent with good engineering practices to keep emissions at, or below, the emission limitation. For each unit, in determining compliance with the annual average emission limitation during the first year. of operation of the control equipment installed to comply with this emission limitation, periods during which one of the followin; conditions are met will be excluded: 1. Equipment or systems do not meet designer’s or manufacturer’s performance expectations. 2. Field installation including engineering or construction precludes equipment or systems from performing as designed. The periods during the first year to be excluded will be determined by the Administrator based on periodic reports of eee 29 compliance with this emission limitation which must identify the times proposed for exclusion and provide the reasons for the exclusion, including the reasons for the Outage of the control system. The report also must describe the actions taken to avoid the outage, to minimize its duration, and to reduce SO, emissions at the plant to the extent practicable while the control System was not fully operational. Whenever the time to be excluded exceeds a cumulative total of 30 days for any control system, the NGS owner or operator must file a report within 15 days addressing the history of, and prognosis for, the performance of the control equipment. In addition to the foregoing, the Administrator will exclude from the compliance determination for a unit any periods of emissions from a unit for which the Administrator finds that the control equipment is out of service because of catastrophic failure of any control system which occurred for reasons beyond the control of the NGS participants and operators and could not have been prevented by good engineering practice. The Administrator will not exclude the period if the equipment failure was a consequence of a lack of appropriate maintenance; of intentional or negligent conduct or omissions of the NGS participants or operators or the control System design, construction, or operating contractors. The final regulation requires that all equipment needed to comply with this regulation to be optimally operated consistent with good engineering practice to keep emissions at or below the emission limitation. The regulation also requires that following any control system outages, the system must be returned to full operation as expeditiously as practicable. The final regulation provides that continuous emission monitors must be installed to determine compliance with the emission limitation. This equipment must meet the specifications listed in appendix B of 40 CFR part 60, the quality assurance procedures in appendix F of 40 CFR part 60, and the requirements for estimating emission rate in ng/J or (Ib/MMBtv) set out in method 19, appendix 30 A, 40 CFR part 60.% The NGS is required to report emissions and maintain records in accordance with the procedures in 40 CFR 60.7. In addition, EPA is establish [Text truncated at 120,000 characters. The full text is on the page linked above.] --- Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/brief%3Amicro_IA40386019_1069%3A2. Public record. Not legal advice.