Opinion ID: 446849
Heading Depth: 2
Heading Rank: 1

Heading: Insuring Attainment and Maintenance of the National Ambient Air Quality Standards for SO2

Text: 15 Section 110(a)(2)(B) of the Clean Air Act, 42 U.S.C. Sec. 7410(a)(2)(B), requires that EPA shall approve an implementation plan only if it determines that the plan will insure attainment and maintenance of the NAAQSs. On two grounds, Kamp argues that EPA's approval of the multi-point implementation plan is inconsistent with that requirement. Both of Kamp's arguments assume the accuracy of the multi-point technique. We are therefore presented with legal questions rather than highly technical disputes about the validity of the science underlying the multi-point method of emission regulation. Cf., e.g., Connecticut v. EPA, 696 F.2d 147, 157-59 (2d Cir.1982). 16 First, Kamp argues that the multi-point implementation plan creates an excessive risk that the NAAQSs will be violated. Kamp does not contest EPA's claim that the multi-point implementation plan produces expected rates of exceedance of no more than once per year. His objection is that an expected rate of exceedance of once per year is not enough to insure attainment and maintenance of the NAAQSs. Those standards require that there be no more than one exceedance of the maximum concentrations per year. See 40 C.F.R. Secs. 50.4(b), 50.5 (1983). Although over a ten-year period the multi-point system can be expected to allow no more than ten exceedances of each maximum concentration, there is no guarantee that the ten exceedances will occur exactly 365 days apart from each other. To the contrary, there is a 26% chance that in any given year there will be at least two exceedances bunched together. 4 In any year in which such bunching occurs, there will of course be a violation of a NAAQS. In sum, Kamp argues that because the multi-point implementation plan produces a 26% chance of violation in any given year, that plan does not insure attainment and maintenance of the NAAQSs. 17 We find no indication that Congress addressed this issue raised by Kamp. The Act does not define the requirement that the implementation plan must insure attainment and maintenance, nor does the legislative history elaborate on its meaning. See, e.g., H.R.Rep. No. 1146, 91st Cong., 2d Sess. 8 (1970) (stating only that the state plan must assure[ ] achieving [the] standard[s]), reprinted in 1970 U.S.Code Cong. & Ad.News 5356, 5363. We therefore review EPA's action to determine whether it is based on a reasonable interpretation of the Act. See Chevron, U.S.A., Inc. v. Natural Resources Defense Council, --- U.S. ----, 104 S.Ct. 2778, 2782-83, 81 L.Ed.2d 694 (1984). 18 EPA approved the implementation plan and rejected Kamp's argument on the ground that allowing a 26% probability of random bunching within any given 365-day period is not inconsistent with the statutory requirement that the plan insure attainment and maintenance of the NAAQSs. That is a reasonable position. We would be troubled if the implementation plan had an expected rate of exceedance greater than once per year. We would also be troubled if the implementation plan could be expected to produce twelve or fifteen exceedances in any given ten-year period. That is not our case, however. What causes the 26% chance of violation here is only the possibility that exceedances may occasionally bunch together in a 365-day period. Similarly, some years may go by without any exceedance. It is not unreasonable for EPA to conclude that accepting the 26% risk of exceedence in any given year comports with its obligation to approve only implementation plans which insure attainment and maintenance of the NAAQSs. 19 Our conclusion that EPA has interpreted the Clean Air Act in a reasonable manner is bolstered by prior administrative practice. See Udall v. Tallman, 380 U.S. 1, 17-18, 85 S.Ct. 792, 801-802, 13 L.Ed.2d 616 (1965). As we have noted, SO2 emissions have historically been regulated by the single-point method, which sets a fixed never-to-be-exceeded emission limitation that will insure that no exceedance will occur even on the day with the second-worst meteorological conditions expected in an average year. The federal implementation plan of 1978, which was retracted a month after its promulgation and which Kamp states that he prefers to the multi-point plan, used the single-point technique. As a theoretical matter, however, a single-point implementation plan generates the same possibility of bunching as does the multi-point plan. Under the single-point approach, if the worst atmospheric conditions occur no more than once during the year, there will be compliance with the NAAQSs. There is no guarantee, however, that the worst atmospheric conditions expected in an average year will occur only once. Although over a ten-year period there may be only ten days of the worst conditions, there will be a significant possibility--26% if the occurrence of the worst conditions is a truly random event, see supra note 4--that any given year will have two or more days of the worst conditions. When that happens, assuming the SO2 sources constantly emit up to the fixed, never-to-be-exceeded limit, there will necessarily be a NAAQS violation. Consequently, we find our conclusion that EPA acted reasonably confirmed by the fact that the multi-point implementation plan tends to be as protective of air quality as were plans approved under prior administrative practice. 20 Kamp raises a second argument based on the requirement that the multi-point implementation plan must insure attainment and maintenance of the NAAQSs. The multi-point plan allows the smelters to emit at high levels for a limited number of days each year. See supra pp. 1447-48 & n. 2. EPA admits that the levels are high enough that a NAAQS violation will occur if the high emissions twice coincide with a day having either the worst or the second worst weather conditions expected in an average year. In that sense, the high emissions exceed what Kamp calls the threshold of violation. Kamp argues that permitting emissions above the threshold of violation is inconsistent with EPA's obligation to insure attainment and maintenance of the NAAQSs. 21 We reject Kamp's argument. The concept of a threshold of violation, upon which the argument is based, has no foundation in the Clean Air Act. The Act requires simply that the state implementation plan insure attainment and maintenance of the NAAQSs. See 42 U.S.C. Sec. 7410(a)(2)(B). We have already indicated that the Arizona's multi-point plan complies with this requirement. It is therefore irrelevant that on some days emissions are at such a level that as a theoretical matter a NAAQS violation could occur in an average year. Furthermore, even if emissions were always below the threshold of violation as defined by Kamp, that requirement would not remove the possibility of NAAQS violations. There would remain the possibility that in the nonaverage years in which two days of the worst conditions bunch together, a NAAQS violation could occur. 22 We review to determine whether EPA has given a reasonable interpretation to the requirement that the attainment and maintenance of the NAAQSs be insured. We conclude that EPA's position, which risks only the possibility that exceedances may randomly bunch together, constitutes a reasonable interpretation of the Clean Air Act. 23