Opinion ID: 501652
Heading Depth: 1
Heading Rank: 4

Heading: plume rise

Text: 134 Dispersion of pollutants is greater when a lot of exhaust is combined in a single stack rather than ejected through several. Thus one key indicator of dispersive effect is plume rise, the distance the exhaust is carried above the top of the stack. We deal here with EPA regulation of such stack combinations. The phenomenon occurs both as (1) a stack originally constructed combining exhaust that might have been handled with several stacks and as (2) a stack built to replace several separate stacks. 135 Section 123(a) bars credit not only for too tall stacks but also for any other dispersion technique. In its 1982 Regulations, EPA expressed a narrow definition of the practices to be denied credit under this language, and expressly excluded several, including combining the exhaust gases from several stacks into one stack. 47 Fed.Reg. 5868/3 (1982). The Sierra Club court read EPA's explanation of the definition as in essence a weighing of the likelihood that [the various practices] would be used as dispersion techniques ... and the burden, both on enforcement agencies and on industry, of attempting to differentiate legitimate from illegitimate uses. 719 F.2d at 462. The environmental petitioners challenged the definition's exclusion of certain practices, including stack combination. They advocated a definition depending on intent: if a source adopted a practice in order to obtain a less stringent emission level or to avoid imposition of a harsher one, the practice would be regarded as a dispersion technique. Sierra Club Brief (Sierra Club litigation) at 36. 136 The court agreed with Sierra Club that the agency's conception of dispersion technique was unduly restricted, and held that the words ... sweep broadly enough to encompass at least the meaning urged by petitioners; the use of devices, alterations to the stack, or other techniques when they are significantly motivated by an intent to gain emissions credit for greater dispersion. Sierra Club, 719 F.2d at 462. The court acknowledged the agency's authority to exempt entire categories of practices on either of two grounds--administrative necessity or the de minimis character of the effects. But it concluded that the agency had fall[en] far short of demonstrating either. Id. at 463. In its remand to the agency, however, the court left open the possibility that the agency could develop classes of plant improvements that are clearly legitimate or clearly illegitimate so as to reduce substantially the number of cases in which a full-scale examination of the motivation for the change will be required. Id. at 463-64. 137 The agency responded to the court's remand by amending its definition of dispersion technique to include 138 any technique which attempts to affect the concentration of a pollutant in the ambient air by ... (iii) Increasing final exhaust gas plume rise by manipulating source process parameters, exhaust gas parameter, stack parameters, or combining exhaust gases from several existing stacks into one stack; or other selective handling of exhaust gas streams so as to increase the exhaust gas plume rise. 139 40 C.F.R. Sec. 51.1(hh)(1) (emphasis added). NRDC challenges the agency's new intent-based test, arguing that Congress intended to cover all features having dispersive effects, at least to the extent they may exceed normal dispersion. See NRDC Brief at 62 n. 121. 140 NRDC urged this court four years ago to adopt a definition of dispersion technique based on a source's motivation. This court accepted NRDC's view. The environmental petitioners could then have made their current argument in favor of an effects test. Since res judicata (claim preclusion) bars relitigation not only of matters determined in a previous litigation but also ones that a party could have raised, Tutt v. Doby, 459 F.2d 1195, 1197 (D.C.Cir.1972), NRDC is barred. To accept NRDC's invitation to reopen the issue would be to ignore the concern for finality that underlies res judicata and create incentives for future strategic gamesmanship. We decline. 141 Nor does the presence of other parties on the brief open up reconsideration of the matter. 42 U.S.C. Sec. 7607(b)(1) (1982) requires that any petition for review of such regulations as these be filed within 60 days after their appearance in the Federal Register. Contentions in favor of an effects test over one of intent were obviously ripe at the time of initial promulgation in 1982. No party offers the slightest excuse for failure to raise these contentions in the challenges to that set of rules. While we have recently suggested a number of implicit qualifications to apparently iron time limits on challenges to agency rules, National Labor Relations Board Union v. FLRA, 834 F.2d 191, 195-97 (D.C.Cir.1987), nothing in that case suggests that a party, fully on notice as to the potential impact of rules upon its interests, is free to sit back while the matter is subject to prolonged and complex litigation, and then challenge remanded rules on the basis that the court's first ruling did not go far enough. Any such interpretation would make a travesty of Congress's efforts to bring litigation of agency rules to a timely conclusion and to protect the likely reliance of affected parties. 142 Thus the only issue properly before us is whether the agency properly responded to our remand in Sierra Club. It endeavored to do so by creating bright line rules with which to discern whether a source's decision to use a single stack was significantly motivated by a desire to achieve a higher degree of pollution dispersal. These are expressed in the subparts of 40 C.F.R. Sec. 51.1(hh)(2)(ii). Subpart (A) exempts stacks originally designed and constructed with combined gas streams, and subpart (B) exempts stack mergers occurring as part of a change in operations comprising an installation of pollution controls and a net reduction in allowable emissions of a pollutant. Subpart (C) provides a laxer test, based on grandfathering precepts, for stack mergers occurring before July 8, 1985 (the date of the rules' appearance in the Federal Register). For them, exemption applies if the merger occurred either as part of a change in operations that included installation of emissions control equipment or was carried out for sound economic or engineering reasons. NRDC objects to each of these classes of exemptions. We address them in turn. 143
144 A person with only the notoriously risky little knowledge of our air pollution control laws might suppose that the pollution effects of this exclusion must be de minimis. After all, we are talking only of post-1970 stacks, and original-design post-1970 stacks should be attached to post-1970 plants, which in turn should be subject to NSPS emissions rates. If SIPs are unlikely to impose stricter controls than NSPS, then nothing would be at stake. 145 NRDC asserts, however, that as many as 56 post-1970 plants are not covered by NSPS, and it appears that of these 25 have a combined stack as part of their original design. ICF Inc., Final Analysis of the Proposed Stack Height Regulations, June 1985, Appendix D, reprinted in NRDC Brief, Addendum B. EPA appears not to contest the point, and indeed has not invoked the de minimis concept to justify its decision. Accordingly, we plunge ahead on the premise that something of moment is at issue. 146 The agency provides three arguments in support of this exemption. Each of them appears to us, for one reason or another, to misfire. While we do not by any means find that the EPA's conclusion is in violation of statutory authority, we are unable to conclude that it rests upon reasoned decisionmaking. See SEC v. Chenery Corp., 332 U.S. 194, 196, 67 S.Ct. 1575, 1577, 91 L.Ed. 1995 (1947) (We may not supply a reasoned basis for the agency's action that the agency itself has not given.); Greater Boston Television Corp. v. FCC, 444 F.2d 841, 851 (D.C.Cir.1970), cert. denied, 403 U.S. 923, 91 S.Ct. 2229, 29 L.Ed.2d 701 (1971) (the court must intervene if the agency has not genuinely engaged in reasoned decisionmaking). 147 First, EPA rests on the text of our opinion in Sierra Club and on concepts of ordinary language. It notes that original design characteristics do not increase plume rise, so that, it says, they cannot be dispersion techniques. 50 Fed.Reg. at 27,903. It cites Sierra Club 's references to dispersion techniques as alterations to the stack, changes in stack dimensions, and improvements in support of this reading of the statutory language. EPA Brief at 60, citing 719 F.2d at 462-64. 148 We think the observations of Sierra Club on the subject are highly inconclusive. The passages cited by the EPA appear to have been merely mentioning examples, not attempting an exhaustive list. Elsewhere the court used potentially more inclusive language. See 719 F.2d at 462 (noting that the statutory term would reach the use of devices ... when they are significantly motivated by an intent to gain emissions credit for greater dispersion). 149 So far as ordinary language is concerned, clearly nothing inherently prevents the term dispersion technique from encompassing a practice adopted during the facility design phase. Moreover, the statute itself does not use the term increase, with its connotation of change from the levels produced by an existing condition. That term appears only in the EPA's definition of dispersion technique. 40 C.F.R. Sec. 51.1(hh)(1)(iii) (any technique which attempts to affect the concentration of a pollutant in the ambient air by ... [i]ncreasing final exhaust gas plume rise by ... selective handling of exhaust gas streams). 150 Second, the EPA argues that treatment of original design stacks as dispersion techniques raises insuperable administrative difficulties, namely determining what stack configuration a firm would have adopted in lieu of a unified stack. Indeed, EPA could not necessarily assume that the size of the plant's units would have been the same. Cf. Sierra Club, 719 F.2d at 462 (endorsing exemption of a class of practices if the agency could demonstrate that attainment of the statutory goals is impossible). As articulated by EPA, however, these difficulties do not seem enough standing alone. NRDC has suggested one plausible solution, that of using average plume rise as of 1970 as a proxy for normal plume rise. NRDC Brief at 62 n. 121. Indeed, the agency's August 1984 draft of the current regulations would have established assumptions as to normal plume rise for source categories through a comparative analysis of stack parameters. Rebuttal Comments 61, J.A. 865. EPA's rejection of both these alternatives is unexplained, leaving the claim of undue enforcement difficulty inadequately supported. 151 Finally, the agency asserts that stacks are often merged pursuant to original facility design for legitimate economic or engineering reasons. It points out, for instance, that it is less expensive to build one large stack than three smaller stacks, and also less costly to fit one stack with pollution control equipment than to install such equipment in multiple stacks. 50 Fed.Reg. at 27,903. EPA suggests that because there are legitimate nondispersion-related reasons for merging gas streams, and mergers for the purpose of increasing plume rise are only a theoretical possibility, its decision to exempt all originally designed merged streams is justified. 152 The difficulty with this argument is that, given other data in the record, it appears not to satisfy EPA's own test of intent to obtain dispersion benefits. NRDC points to evidence indicating that power plants have long realized that merged gas streams can significantly increase plume rise, and that firms have purposefully designed plants to take advantage of this increased dispersion since the early 1960s. A.J. Clarke, The Application of Air Pollution Research to Power Station Design, Phil. Transactions (Roy.Soc.London), Nov. 13, 1969, at 265, 269-72, J.A. 862 n. 25. Thus the record, viewing it most favorably to the EPA position, appears to suggest dual purposes, each alone sufficient to explain sources' selection of the single-stack option. 153 Conceivably EPA might rest on the view that the existence of a sufficient non-dispersion motive exonerates a practice, i.e., establishes its failure to meet the Sierra Club intent test. Although the language of Sierra Club is ambiguous, and the matter was not at issue, the court appears likely to have contemplated a different view--that the presence of dispersion intent as a sufficient motive, or as a motive crucial (in combination with others) to tilt the decision in favor of a single stack, would render the device a dispersion technique. See 719 F.2d at 463 (suggesting that the EPA could not find a lack of dispersion intent for an entire class of techniques unless it could demonstrate that there is in fact no or little incentive to implement these techniques because the potential reduction in emissions limitations would not be worth the cost). But in fact the EPA appears to have rejected the narrower test. See 50 Fed.Reg. 27,902/3 (a pure 'but for' test runs the risk of creating exclusions that effectively swallow the rule itself). Thus, so far as we can grasp it, the EPA believes a source characteristic should be presumed a dispersion technique if dispersion purposes alone provide a sufficient motivation, regardless of the strength of other purposes. If so, EPA's findings of legitimate nondispersionary purposes are not enough, by its standards, to exonerate an original-construction single stack. 154 To sum up: EPA relies on (1) a notion of increase that it never tries to substantiate; (2) administrative difficulties that it asserts without negating the solutions proposed by others and itself; and (3) the existence of a sufficient alternative purpose, which (assuming it is substantiated) is not enough under its own apparent view of the law. The total is three flawed reasons. While in some cases they might form a tenuous sort of tripod, here they seem to us to fail. According to NRDC's undisputed claim this issue accounts for a large fraction of the dispersed emissions at stake. It is fair to demand more, loath as we are to prolong the agony of this process. 155 Obviously we owe the agency deference if it affords a reasoned explanation, consistent with what Congress has clearly required or (in the absence of a clear mandate) with a reasonable interpretation of the statute. Chevron U.S.A. Inc. v. NRDC, 467 U.S. 837, 842-44, 104 S.Ct. 2778, 2781-83, 81 L.Ed.2d 694 (1984). The present record, however, does not appear to bring us to that point.
156 As noted, this rule exempts stack mergers effected as part of a change in operation that includes the installation of pollution controls and is accompanied by a net reduction in the allowable emissions of a pollutant. This exclusion only applies to the emission limitation for the pollutant affected by the change in operations. 40 C.F.R. Sec. 51.1(hh)(2)(ii)(B). NRDC argues that this exemption is potentially too lenient by noting the hypothetical possibility that a source could use merger credit for increment expansion purposes under the prevention of significant deterioration (PSD) program, 42 U.S.C. Sec. 7470 et seq., thus enabling the source to meet PSD requirements at reduced expense. NRDC does not spell out the objection in any detail. Mere allusion to such a hypothetical is not enough to persuade us that the exemption represents an abuse of the Administrator's discretion. 157
158 Such mergers qualify for exemption if a source can demonstrate that its merger was accomplished as part of a change in operation to install pollution control equipment or for good economic or engineering reasons. 40 C.F.R. Sec. 51.1(ii)(2)(ii)(C). The rule creates a presumption of intent to gain emissions credit in two cases: (1) where there was an increase in the emission limitation after the merger; or (2) where there was no emission limitation in existence before the merging but the quantity of pollutants actually emitted increased in comparison to the pre-merger levels. Id. 159 NRDC attacks EPA's retroactivity analysis, claiming that the agency has not supported its decision to apply a more lenient rule to pre-1985 mergers than to post-1985 mergers. First, it maintains that before 1985 there was no well established practice of allowing credit for dispersion resulting from stack merger. NRDC finds evidence of a more severe approach in EPA's 1976 Guidelines and the 1979 proposed regulations. It substantiates the former solely with one letter from a regional EPA administrator disapproving credit for a particular merger, and the latter with quotation of the proposal's vague language (other selective handling of exhaust gas streams so as to increase the exhaust gas plume rise). NRDC Brief at 60, 61 n. 119. The agency asserts the existence of a uniformly permissive rule, pointing to three 1980 guidance documents which uniformly took the view that merging of separate stacks into a single stack 'is generally not considered a dispersion technique' absent other factors. 50 Fed.Reg. 27,903/2. We find the evidence in this regard to be somewhat inconclusive. 160 Second, NRDC argues that the agency erred in not requiring a demonstration of reliance. The agency responds that it is infeasible to require a demonstration of actual reliance when the reliance in question is upon general agency guidance rather than a specific formula or rule. EPA Brief at 66. The point is well taken. Thus, for us, the question comes down to whether the agency's rule for pre-1985 sources is sufficiently protective of the statutory purpose. 161 NRDC asserts that the regulations provide large loopholes for mergers that were significantly motivated by an intent to gain increased dispersion credit. As to mergers accompanying installation of pollution control equipment, it suggests that a source might intentionally install equipment for one pollutant in order to secure the right to increase emissions of another. On the facts, this seems most improbable. The rule applies only to pre-1985 mergers, and we doubt many source owners had the foresight to anticipate EPA's exemption and slip through its supposed loophole before its promulgation. Further protection is added by EPA's presumption of a significant dispersion motive where the merger was accompanied by a relaxation of emissions limits or an increase in emissions. 162 As to the exemption for mergers made for sound economic or engineering reasons, NRDC objects not on the basis of that language itself but by reference to language in a Guidance document later published by EPA, Implementation of Stack Height Regulations--Exceptions From Restrictions on Credit for Merged Stacks at 3 (October 28, 1985). In a separate suit brought by NRDC before this court we declined substantive review of that document on the ground that the guidelines represent tentative agency positions that may be modified in subsequent agency proceedings, and do not represent final agency action subject to judicial review under 42 U.S.C. Sec. 7607(b) (1982). NRDC v. Thomas, No. 85-1488 and consolidated cases (D.C.Cir. Aug. 3, 1986). NRDC has brought nothing to our attention that would increase their finality. 163 Accordingly, the substantive review now appropriate reveals no illegality in EPA's rules for pre-1985 stack mergers.