# Opposition Brief — Appalachian Power Co. v. Environmental Protection Agency > Briefs, arguments, decisions, and more. URL: https://www.frixlaw.com/law-library/documents/brief%3Amicro_IA40386014_1199%3A7 ## Record - **Collection:** Supreme Court brief - **Document type:** Opposition Brief - **Published:** January 1, 2001 - **Citation:** 532 U.S. 903 ## Text Supreme Court, U.S. FILED (a) 9 VAN 4 2001 Nos. 00-632 and 00-633 IN THE Supreme Court of the Anited States STATE OF MICHIGAN, et al., Petitioners, Vv. U.S. ENVIRONMENTAL PROTECTION AGENCY, et al., Respondents. STATES OF OHIO AND INDIANA, Petitioners, V. U.S. ENVIRONMENTAL PROTECTION AGENCY, et al, Respondents. On Petitions for a Writ of Certiorari to the United States Court of Appeals for the District of Columbia Circuit BRIEF IN OPPOSITION FOR CONSOLIDATED EDISON COMPANY OF NEW YORK, INC., KEYSPAN GENERATION LLC, PECO ENERGY COMPANY, AND PSEG POWER LLC PATRICK M. RAHER JOHN G. ROBERTS, JR.* JoDY M. FOSTER HOGAN & HARTSON L.L.P. 555 Thirteenth Street, N.W. Washington, D.C. 20004 (202) 637-5810 *Counsel of Record Counsel for Respondents SPO CLERK ' ; i QUESTION PRESENTED Whether this Court should grant certiorari to consider the Court of Appeals’ correct determination that the Environ- mental Protection Agency did not abuse its discretion or violate the federalist structure of the Clean Air Act when it considered a cost factor in the determination of significant contribution under Section 110(a)(2)(D) of the Act. (i) il PARTIES TO THE PROCEEDINGS AND RULE 26.1 STATEMENTS The following is a list of the parties filing this brief in opposition, together with their statements pursuant to S. Ct. R. 26.1. These parties were intervenors below in support of affirmance and are respondents in this Court pursuant to S. Ct. R. 12.6: Consolidated Edison Company of New York, Inc., states that its parent corporation is Consolidated Edison, Inc., a publicly held corporation. Consolidated Edison Company has no affiliates or subsidiaries that have issued shares or debt securities to the public. KeySpan Generation LLC states that its parent corpo- ration is MarketSpan Corporation, d/b/a KeySpan En- ergy, a publicly held company. An affiliate of KeySpan Generation LLC, The Houston Exploration Company, has also issued shares or debt securities to the public. PECO Energy Company states that its parent company, Exelon Corporation, has issued stock to the public. no other affiliates or subsidiaries of the Company have is- sued shares or debt securities to the public. PSEG Power LLC (formerly Public Service Electric & Gas Co.) states that its parent company, Public Service Enterprise Group Incorporated, has issued stock to the public. No other affiliates or subsidiaries of PSEG Power have issued shares or debt securities to the public. ill TABLE OF CONTENTS QUESTION PRESENTED ...........scscsscsssssseseeesessseenseneeeees i PARTIES TO THE PROCEEDINGS AND RULE 26.1 STATEMENTS............::scccceseeseseeeseeeeees il UTI TIN caiccccccccesaseccnsasscscsssesssscscccssccosssossocsocses 2 COUNTERSTATEMEN T .........c.ccscssccscccscsscseerscrsescessess 3 REASONS FOR DENYING THE WRIT................:00000+ 5 I. THE DECISION BELOW DOES NOT CONFLICT WITH DECISIONS OF THIS COURT OR OTHER DECISIONS OF TR BU, CIEE cecntasntcecsctnsncntescsansacccccosccssescessess 5 A. The Decision Below Does Not Conflict With Decisions Of This Court Addressing EPA’s Authority To Consider Cost Factors Under CAA as scensiensonsdianstned 6 B. The Decision Below Does Not Conflict With D.C. Circuit Decisions Addressing EPA’s Authority To Consider Cost Factors Under CAA EI a aL ES oe 7 II. THE DECISION BELOW CORRECTLY AFFIRMED EPA’S DISCRETION TO CONSIDER COST FACTORS IN THE DETERMINATION OF SIGNIFICANT iV TABLE OF CONTENTS—Continued Ill. EPA’S SIGNIFICANT CONTRIBUTION DETERMINATION DOES NOT VIOLATE FEDERALISM OR INTERSTATE EQUITY CONCERNS ............::06+: 14 A. EPA's Significant Contribution Determination Does Not Ignore the Significance of States' Boundaries in Determining their Reduction IN isin schicinadincebcasdeniinnshdesineiitiinnisaduacntanhesiol 15 B. The Federalism Structure of the CAA Does Not Require EPA to Adopt a Proportional Interpretation of States’ Emission Reduction Obligations under SE TD snctnticnesinititinpnnaciutiticicenntiis 17 C. EPA's Significant Contribution Determination Does Not Raise Interstate Equity Issues Requiring this SE ITI ncinchincatilinislidbindedaplaiteisépiniscibaieannabe 19 CUA S sisctnnitnictitstinaniaissninninentiiatemmmaniinsinnntaonetn 21 Vv TABLE OF AUTHORITIES Page CASES: American Trucking Ass'n v. EPA, 175 F.3d 1027, modi- fied on reh'g, 195 F.3d 4 (D.C. Cir. 1999), cert. granted, 120 S.Ct. 2003, 2193 (2000) .....ssccrssccscccorcreserensesers 2 Association of Am. Railroads v. Surface Transp. Bd., 161 F.3d 58 (D.C. Cir. 1998).....cccscscsessseesesserssreseeneeeeneenees 11 Chevron U.S.A., Inc. v. Natural Resources Defense Council, Inc., 467 U.S. 837 (1984).....:cccccesssseesesssnreseeeeeenees 11 Illinois v. City of Milwaukee, 406 U.S. 91 (1972)... 15 Lead Indus. Ass'n v. EPA, 647 F.2d 1130 (D.C. Cir.), cert. denied, 449 U.S. 1042 (1980)........ccccesesseeeseneetseereeeeetees 6 New York v. EPA, 852 F.2d 574 (D.C. Cir. 1988), cert. denied, 489 U.S. 1065 (1989).......sescscssseseeseseeeneeeseennennenees 11 NRDC v. EPA, 824 F.2d 1146 (D.C. Cir. 1987) (en banc) .......... 8 OSG Bulk Ships, Inc. v. United States, 132 F.3d 808 (D.C. Cir. 1998)......:ccsssssscsssscssssescsceressssnenesssseazecenersnneneenees 11 South Terminal Corp. v. EPA, 504 F.2d 646 (1st Cir. 1974) ....csecscscssesssssececsssssssssssscscscsensssesseensocsnssenscasasseasacnseasseeces 7 Train v. NRDC, 421 U.S. 60 (1976)......:ccccscesscssreseeceerseereeeenees 5,6 Union Electric Co. v. EPA, 427 U.S. 246 (1976)......0-s0+0 5, 6,7 Virginia v. EPA, 108 F.3d 1397 (D.C. Cir.), modified on reh'g, 116 F.3d 499 (D.C. Cir. 1997)......sessssessesesseeereeeeressees 15 vi TABLE OF AUTHORITIES—Continued Page STATUTES: The Clean Air Act, 42 U.S.C. §§ 7401-7671q (1994 & DUI TS BOT csctcinsnetsentiinaiaintianiitateiainastanianaiiaia neds te 2 CAA S BOR, GRGDG. 6 DODD viiscceciicetelete iii 6 CAA § 109(b), 42 U.S.C. § 7409(b) .o.....cccccccscssssesssenecseeen 7 CAA § 190, 43 CGC, Gai rsscicstitsitiictistahnnietiincdigeaeresttil 6 CAA § 110(a)(2)D), 42 U.S.C. § 7410(a)(2)(D)........ passim CAA § 132, 4B WE. 6 FUG cssiiinstisicltlitacceens es 8 | CAA § 181(b)(2)(A), 42 U.S.C. § 751 1(6)(2)(A) oeceeeceesseees 13 CAA § 184, 42 U.S.C. § 75116 ....ccccccccosccsscsccsscoseocsccseccecose 13 RULES AND REGULATIONS: i. CH, BR. BB .nnoccsessninsininensipamnsiuansiniapibinisetanpsediiadmaima aaamiiae eat 2 4S Fo. Rag, FA331 Gat, D, UC ccccncescststinctnniciitanistuiatataaiises 13 63 Fed. Reg. 57,356-537 (Oct. 27, 1998). ........cccccsccsseseseeee passim OTHER AUTHORITY: Robert L. Stern, et al., Supreme Court Practice (7th ed. SDDS ) .cocsvecsacenanensontipnisigngisinentniasiaaitiniadiiimaiiamatianaieien ae 10 IN THE Supreme Court of the Anited States Nos. 00-632 and 00-633 STATE OF MICHIGAN, et al., Petitioners, Vv. U.S. ENVIRONMENTAL PROTECTION AGENCY, et al., Respondents. STATES OF OHIO AND INDIANA, Petitioners, V. U.S. ENVIRONMENTAL PROTECTION AGENCY, et ai., Respondents. On Petitions for a Writ of Certiorari to the United States Court of Appeals for the District of Columbia Circuit BRIEF IN OPPOSITION FOR CONSOLIDATED EDISON COMPANY OF NEW YORK, INC., KEYSPAN GENERATION LLC, AND PSEG POWER LLC Respondents Consolidated Edison Company of New York, Inc., Keyspan Generation LLC, and PSEG Power LLC respectfully request that the Court deny the petitions for certiorari filed in this case by the State of Michigan, et a/. in No. 00-632 (“Michigan”) and by the States of Ohio and Indiana in No. 00-633 (“Ohio and Indiana”). We refer to these petitioners collectively as “Petitioning States.” 2 INTRODUCTION This case meets none of the criteria warranting an exercise of this Court’s certiorari jurisdiction. See S. Ct. R. 10. It implicates no conflict among the circuits and raises no important unsettled questions of law. To the contrary, this case involves the ordinary exercise of discretion by the Environmental Protection Agency (“EPA”) in implementing a statutory provision of the Clean Air Act (“CAA”), 42 U.S.C. §§ 7401-7671q (1994 & Supp. III 1997), requiring States to address the interstate transport of air pollution. The rule at issue, 63 Fed. Reg. 57,356-537 (Oct. 27, 1998), which is referred to as the “NOx SIP Call,” requires certain states to revise their State Implementation Plans (“SIPs”) to reduce emissions of nitrogen oxides (NOx) that impact ozone attainment problems in downwind areas. In an attempt to transform this typical administrative rule- making case into one worthy of this Court’s review, Peti- tioning States argue that the Court of Appeals decision in this case conflicts with holdings of the D.C. Circuit in other CAA cases, including American Trucking Ass'ns v. EPA, 175 F.3d 1027 (“ATA”), modified on reh’g, 195 F.3d 4 (D.C. Cir. 1999), cert. granted, 120 S. Ct. 2003, 2193 (2000). Peti- tioning States’ attempt to manufacture certworthy issues from superficial similarities in these cases is misguided. Far from implicating important jurisprudential conflicts, this case involves an unremarkable affirmation of agency discretion consistent with well-settled law. Petitioning States also argue that this case raises important federalism and interstate equity issues relating to the inter- State transport of air pollution that require this Court’s review. While the CAA provision at issue certainly does implicate issues of federalism and interstate equity, the D.C. Circuit correctly determined that EPA’s rulemaking. was properly responsive to these concerns. Petitioning States do 3 not provide any compelling arguments for devoting this Court’s scarce resources to further review of these matters. Respondents filing this opposition provide the Court with an important perspective on the rule at issue in this case: that of electric generating companies in downwind states who view the NOx SIP Call as a soundly reasoned, technologi- cally and economically feasible, necessary step to address the complex and persistent problem of interstate transport of ozone. Over the last decade electric generators in downwind states have invested many millions of dollars in control technolo- gies to improve air quality and assist in their states’ efforts to attain the national ozone standard. The beneficial health impacts of these emission control efforts, however, have been largely thwarted by imported NOx from upwind sources in the South and Midwest that are not subject to as strict emis- sion control requirements and can produce electricity using higher-emitting, cheaper fuel sources. Their transported emissions intermingle with other airborne emissions and significantly increase downwind states’ ozone levels. By requiring upwind states to control their sources not only to prevent local air pollution but to prevent—as the CAA requires—significant contribution to ozone attainment problems downwind, the NOx SIP Call will remedy this gross inequity and its resulting adverse health impacts. COUNTERSTATEMENT As Petitioning States explain, Michigan at 4-5, Ohio and Indiana at 3-4, Section 110(a)(2)(D) of the CAA, 42 U.S.C. § 7410(a)(2)(D), requires states to prevent air pollution sources located within their boundaries from significantly contributing to air quality attainment problems in downwind states. Pursuant to its expressly delegated authority to implement that provision, EPA promulgated the NOx SIP 4 Call, requiring certain states in the eastern half of the United States to revise their state air quality plans to eliminate amounts of NOx emissions that EPA had determined were “significantly contributing” to downwind ozone attainment problems. While Petitioning States characterize EPA’s calculation of “significant contribution” in the NOx SIP Call as one based solely on cost considerations, see Michigan at 6-7, Ohio and Indiana at 4, EPA’s determination of significant contribution was in fact a two-step process based primarily on air quality factors and only secondarily on cost considerations. In the first step, the agency identified states that were “sig- nificantly contributing” to downwind attainment problems, using air quality modeling that determined whether the NOx emissions of a state, when combined with emissions from other states, were a significant factor in the formation of ozone in downwind states. See 63 Fed. Reg. at 57,381. Only after having thus identified, on the basis of air quality factors alone, the states that were significantly contributing to ozone attainment problems downwind did EPA use a cost-based methodology to calculate the amounts of NOx emissions that these states could permissibly emit without violating the Section 110 prohibition on significant contribution. Jd. Because air quality modeling is not well-adapted to quan- tify precise emissions impacts,! in this second step EPA identified a set of cost-effective control technologies and then, using state-specific NOx inventory information, mod- eled the air quality impacts of applying these technologies to the covered states. Finding that the resulting levels of NOx emissions would significantly reduce ozone formation in l Air quality models, particularly broad regional scale models such as those used in the NOx SIP Call, are excellent tools for identifying directional trends and relative impacts, but are not regarded as well-suited for determining precise quantities of emissions impacts. 5 downwind states, EPA established those levels as state- specific “NOx budgets”—for each state, the total amount of NOx emissions that could be emitted consistent with Section 110’s prohibition on significant contribution to transport. Specifically, EPA’s NOx emission budgets were based on the NOx emissions levels that would be permitted in these states under uniform application to their NOx inventories of certain NOx pollution controls that EPA had determined could be cost-effectively implemented at $2,000 per ton or less. See 63 Fed. Reg. at 57,365. The Court of Appeals upheld EPA’s consideration of this cost factor in its determination of significant contribution under Section 110(a)(2)(D). It also rejected challengers’ arguments that the CAA requires state-specific quantifica- tions of significant contribution and that the SIP Call Rule impermissibly denied states their rights under the CAA to determine their implementation strategies. REASONS FOR DENYING THE WRIT I. THE DECISION BELOW DOES NOT CONFLICT WITH DECISIONS OF THIS COURT OR OTHER DECISIONS OF THE D.C. CIRCUIT In an attempt to manufacture a case for certiorari where none exists, Petitioning States argue that the decision below conflicts with holdings of this Court and with prior decisions of the D.C. Circuit regarding EPA’s discretion to consider costs in implementing the CAA. See Michigan at 7-8, 20-21; Ohio and Indiana at 14-15. Specifically, Petitioning States point to two of this Court’s cases, Union Electric Co. v. EPA, 427 U.S. 246 (1976), and Train v. NRDC, 421 US. 60 (1976), addressing EPA’s authority to consider economic factors when evaluating the adequacy of a state’s SIP sub- mittals under CAA Section 110, 42 U.S. § 7410, and to two D.C. Circuit decisions, Lead Indus. Ass’n v. EPA, 647 F.2d 6 1130 (D.C. Cir.), cert. denied, 449 U.S. 1042 (1980), and ATA, 175 F.3d 1027, holding that EPA lacks authority to consider costs when setting National Ambient Air Quality Standards (“NAAQS”) under CAA Section 109, 42 U.S.C. § 7409. A. The Decision Below Does Not Conflict With Deci- sions Of This Court Addressing EPA’s Authority To Consider Cost Factors Under CAA Section 110. The decision below does not conflict with the Section 110 precedents of this Court cited by Petitioning States. In both Union Electric, 427 U.S. at 257 & n.5, and Train, 421 U.S. at 90-91, the Court addressed arguments about EPA’s authority under provisions of Section 110 other than Sec- tion 110(a)(2)(D) to consider claims of economic and tech- nological infeasibility—i.e., to use cost considerations to excuse a State’s failure to comply with EPA’s interpretation of the requirements of Section 110. These cases are distin- guishable first because they involve challenges to agency action arising under, and interpreting, different provisions of Section 110 than the one at issue in this case. More impor- tantly, the underlying principle of these cases—that EPA may not rely on cost factors to allow states to impede CAA compliance—does not conflict with the decision below upholding EPA’s use of a cost factor in its determination of how states must comply with ane 110(a)(2)(D)’s trans- port prohibition. Indeed, in Union Electric this Court expressly addressed EPA’s authority to consider costs in the context of facilitat- ing rather than hampering compliance with Section 110. As Petitioning States acknowledge, Michigan at 9 n.4, the Court indicated that, in evaluating whether a SIP includes provi- sions for attaining the NAAQS “as expeditiously as practica- ble” as required under Section 110(a)(2)(A)(i), EPA “may consider whether it is economically or technologically 7 possible for the state plan to require more rapid progress than it does.” Id. (citing Union Electric, 427 U.S. at 265, n.13). EPA’s use of a cost factor in determining significant contri- bution in the NOx SIP Call is consistent with the principle that the agency may consider costs in the context of facili- tating state compliance with Section 110's air quality goals. 2 B. The Decision Below Does Not Conflict With D.C. Circuit Decisions Addressing EPA’s Authority To Consider Cost Factors Under CAA Section 109. Contrary to Petitioning States’ assertions, the D.C. Cir- cuit’s holding in the ATA and Lead Industries cases—that EPA is prohibited from considering costs when establishing the NAAQS under Section 109—does not conflict with the decision below upholding EPA’s authority to consider cost factors in determining significant contribution under Section 110(a)(2)(D). Sections 109 and 110 are different statutory sections with different purposes. Section 109 requires EPA to set NAAQS that, “based on [statutory] criteria and allow- ing an adequate margin of safety, are requisite to protect the public health.” 42 U.S.C. § 7409(b). Section 110 is a very lengthy section with many different provisions detailing the many obligations of states with respect to their air quality implementation plans. EPA is charged with responsibility for implementing both sections, of course, but the statutory 2 Another circuit has also concluded that cost considerations are permissible in enforcing Section 110’s requirements where those considerations are employed to achieve, not impede, compliance with Section 110’s air quality goals. See South Terminal Corp. v. EPA, 504 F.2d 646, 676 (1st Cir. 1974) (observing, with respect to EPA regional transportation control plan imposed as a Federal Implementation Plan under Section 110, that “[e]conomic consid- erations may play some role *** in EPA’s selection among alternative means to achieve its mandated clean air goal”). 8 standards that EPA must interpret in defining the agency’s and the states’ obligations under the two sections are entirely unrelated to each other. Thus, the decision below does not present an issue similar to the one before this Court in ATA. Indeed, the Court of Appeals expressly noted that the NOx SIP Call case only concerned whether EPA could permissibly consider cost in its implementation of Section 110(a)(2)(D) and did not raise issues as to whether the agency was required to consider costs or was permitted to use a cost/benefit criterion in selecting its final rule, Michigan App. at 15a-16a, issues that are raised in ATA. 3 Certainly, the judges who authored the opinion below would be surprised to learn that the decision conflicts with prior D.C. Circuit precedent. The opinion provides a lengthy analysis of how the decision is derived from the “settled law of this circuit.” Michigan App. at 20a-22a. In particular, the opinion focuses on a prior case upholding EPA’s authority to consider costs when regulating hazardous air pollutants under Section 112 of the CAA, 42 U.S.C. § 7412, to achieve an “ample margin of safety” to protect public health, see Michi- gan App. at 20a (citing NRDC v. EPA, 824 F.2d 1146, 1163 (D.C. Cir. 1987) (en banc)). The Court of Appeals observed that NRDC, along with several other cases, stands for the principle that unless there is “clear congressional intent to 3 Indeed, the lack of conflict between the D.C. Circuit’s hold- ings is evidenced by the fact that the decision below issued only ten months after the ATA decision, with parts of both decisions authored by the same judge; clearly, Circuit Judge Williams did not perceive any conflict between the two cases. Further, petitions for rehearing were rejected by the D.C. Circuit. See Michigan App. at 55a-58a. 9 preclude consideration of cost,” an agency is not barred from considering it. Jd. Applying the NRDC standard, the D.C. Circuit concluded that EPA’s consideration of cost factors in the significant contribution determination was permissible, stating that “there is nothing in the text, structure or history of § 110(a)(2)(D) that bars EPA from considering cost in its application.” Jd. at 22a. There is nothing about this holding that remotely warrants this Court’s intervention. There is no conflict between it and the other cited cases addressing EPA’s authority to consider costs under Sections 109, 110, or 112. Indeed, the CAA precedents are consistent with each other. They indicate that EPA’s authority to consider cost factors when implementing the CAA must be determined on a case-by-case basis through analysis of congressional intent, as revealed by the text of the statutory provision under which the agency acts and other appropriate indicia, as well as the factual circumstances of the specific consideration of costs at issue. In reality, Petitioning States do not seek from this Court a “resolution” of the Section 109 and Section 110 precedents, but rather a modification of earlier holdings with which they disagree. See, e.g., Michigan at 21 (advocating that this Court “resolve” alleged conflict by flipping the D.C. Cir- cuit’s prior holdings and deciding that EPA must consider costs under Section 109 but cannot consider them under Section 110); see also Ohio and Indiana at 14-15 (advocating that this Court hold that EPA may consider costs under both Sections 109 and 110, but only as a secondary factor to health concerns under Section 109 and to air quality concerns under Section 110). Given Petitioning States’ failure to demonstrate any con- flicts between the decision below and other CAA cases addressing EPA’s authority to consider costs, as well as the 10 lack of identity between the issues in this case and those in ATA, this Court should deny the request of Ohio and Indiana to defer consideration of the certiorari petitions until after resolution of the ATA cases. See Ohio and Indiana at 16 n.8, 17. Even were this Court persuaded that there is some tension in D.C. Circuit precedents regarding EPA’s authority to consider costs in implementing the CAA, it is well-settled that this Court does not sit to resolve intracircuit conflicts. The established principle, as Justice Harlan once wrote, is that “decisions between different panels of the same Court of Appeals will not be considered to present a reviewable conflict, since such differences of view are deemed an intramural matter to be resolved by the Court of Appeals itself.” Robert L. Stern, et al., Supreme Court Practice 176 (7" ed. 1993) (quoting Hon. John M. Harlan, Manning the Dikes, 13 Record of N.Y.C. Bar Ass’n 541, 552 (1958)). The en banc process is the established means of identifying and settling any intracircuit conflicts. Petitioning States also attempt to argue that, because EPA actions under the CAA that have nationwide scope can only be reviewed by the D.C. Circuit, conflicts among D.C. Circuit CAA decisions are “on par” with conflicts between different circuits. Michigan at 19. They offer no support for this theory, which is inconsistent with the very reason the CAA provides nationwide jurisdiction in the D.C. Circuit in the first place. II. THE DECISION BELOW CORRECTLY AF- FIRMED EPA’S DISCRETION TO CONSIDER COST FACTORS IN THE DETERMINATION OF SIGNIFICANT CONTRIBUTION The issue before the D.C. Circuit was not whether EPA’s consideration of a cost factor under Section 110(a)(2)(D) is the correct way to determine significant contribution, but 11 whether it is a permissible one. Neither the CAA nor its legislative history detail how Congress intended the phrase “contribute significantly” to be interpreted.* Thus, as estab- lished under Chevron’s familiar two-step framework, the question for a reviewing court is whether the agency action is based on a permissible construction of the statute. Chevron U.S.A., Inc. v. Natural Resources Defense Council, Inc., 467 U.S. 837, 842-843 (1984). EPA’s interpretation is reviewed with great deference and upheld if reasonable. See, é.g., Association of Am. Railroads v. Surface Transp. Bd., 161 F.3d 58, 64 (D.C. Cir. 1998) (court engaging in Chevron step-two analysis affords “significant leeway” to agency interpretation); OSG Bulk Ships, Inc. v. United States, 132 F.3d 808, 814 (D.C. Cir. 1998) (court accords “great defer- ence to the particular way in which the agency chooses to implement a statute that it is empowered to administer’). Deference to EPA’s interpretation is indeed at its zenith in this case due to the highly technical nature of the significant contribution determination and the complex statute in which it is embedded. See New York v. EPA, 852 F.2d 574, 580 (D.C. Cir. 1988) (court accords great deference to decisions within agency’s “area of special expertise, at the frontiers of science”), cert. denied, 489 U.S. 1065 (1989). 4 Petitioning States Michigan ef al. argue that the “plain lan- guage” of Section 110(a(2)(D), and the legislative history associ- ated with it, make clear that “[t]he word ‘significantly’ goes to the level of the impact and cannot reasonably be interpreted to allow the consideration of economic efficiency.” Michigan at 13. As they note, the 1990 Amendments changed the transport prohibition from a prohibition on interstate pollution that “prevent[ed] attain- ment” downwind to the current significant contribution standard. While Petitioning States see this change as indicating that the word significantly goes to the level of impact, it is just as plausible that the amendment from “prevent” to “significantly contribute” reflects congressional awareness that it is difficult, if not impossi- ble, from an air-quality perspective alone to quantify the role of particular upwind states in determining downwind attainment. 12 The record in this case more than substantiates the Court of Appeals’ judgment that EPA’s consideration of costs in implementing the transport prohibition was permissible and reasonable. As detailed above, the court concluded, based on well-established precedent, that nothing in the CAA pre- cludes EPA from considering cost when making a remedial determination under its authority to issue SJP Calls. Further, the D.C. Circuit recognized that EPA exercised its discretion to consider costs under Section 110(a)(2)(D) in an appropri- ate manner. Indeed, the court stated that “[i]n some contexts, ‘significant’ begs a consideration of costs,” Michigan App. at 19a, and detailed at length its reasons for concluding that the determination of significant contribution under Section 110(a)(2)(D) was a circumstance that warranted considera- tion of costs, see id.at 19a-22a. Petitioning States assert that EPA’s determination of sig- nificant contribution relied on an “arbitrary, unbounded” standard. See Ohio and Indiana at 9-12; see also Michigan at 23 n.13. Petitioning States are wrong. As the Court of Appeals recognized, EPA’s consideration of cost in its significant contribution determination was a reasonable decision, given the complexities of ozone transport, to design a solution based on determining whether downwind attain- ment problems could be addressed by eliminating at least the amounts of NOx emissions that could be most cost- effectively eliminated. See Michigan App. at 14a-1Sa. Moreover, EPA’s air quality evaluation of the cost method- ology included modeling and comparative analysis of the downwind impacts of the cost-effective state NOx budgets as well as of more stringent control measures. See 63 Fed. Reg. at 57412-13. Thus, EPA’s use of a cost factor was neither arbitrary nor unbounded but rather reflected a complex, reasoned approach to identifying and addressing significant contribution. CMP REPASE ER IS Se eC Te SHAAN HELEN NH NDR ee