Opinion ID: 588800
Heading Depth: 2
Heading Rank: 6

Heading: EPA's Actions Regarding Perchloroethylene

Text: 58 Perc is a man-made volatile organic chemical used principally as a solvent in the dry cleaning business and also as a degreasing agent in industry. Because of its past disposal in landfills, perc has leached into groundwater and poses a potential contamination threat to drinking water supplies. EPA Office of Drinking Water, Tetrachloroethylene (perchloroethylene) Occurrence in Drinking Water, Food, and Air at i-iii (1983), reprinted in J.A. at 1484. 59 Perc has long been a subject of the EPA regulatory consideration, with the Agency proposing that it regulate perc as a Category I contaminant in 1985. At that time, the EPA recognized that perc had been classified in Group C, which usually results in the EPA assigning the chemical to Category II, but remarked that a 1985 study by the National Toxicology Program (NTP) suggested that perc should be placed in Category I. National Primary Drinking Water Regulations; Volatile Synthetic Organic Chemicals, 50 Fed.Reg. 46,880, 46,887-88 (1985). In light of the NTP study, the EPA deferred final action on perc until it could consider additional comments. Id. at 46,888. 60 Nothing further occurred concerning perc until 1989 when the EPA proposed the rule at issue here. In the proposed rule, the EPA reviewed perc's classification history and explained that no scientific consensus had yet developed as to whether perc should fall within Group B2 or C. Proposed Rule, 54 Fed.Reg. at 22,091. Accordingly, the EPA proposed two alternatives for setting an MCLG for perc: The EPA could take a limited view of the evidence and treat perc as a Group C contaminant with an MCLG of 0.01 mg/l; or, as it preferred, the EPA could treat perc as a Group B2 chemical with an MCLG of zero. Id. 61 In the Final Rule, the EPA admitted that it was still deliberating about whether to classify perc in Group B2 or C. Final Rule, 56 Fed.Reg. at 3,541. However, the Agency felt compelled by a consent order, see id. at 3,531, to promulgate a final perc standard by December 31, 1990; therefore, the EPA concluded that based on its careful review of the comments received in response to the May, 1989 notice and the Agency's evaluation of scientific evidence available since the proposal, it remains the EPA's view that there is strong evidence of carcinogenicity through ingestion and that [perc] is a Category I chemical for purposes of establishing an MCLG under the SDWA. Id. at 3,541. After promising that its action would not prejudice the on-going review of perc's proper classification as a Group B2 or C contaminant, the EPA then went on to answer comments attacking the scientific studies it had relied upon in placing perc in Category I. Id. at 3,541-42. 62 IFI filed a timely petition for judicial review of the perc standard, and this court granted the motion by the HSIA to intervene in support of IFI.
63 Attacking the EPA's regulation of perc for alleged procedural defects, IFI argues that the EPA has since 1985 followed a clear, consistent policy of placing Group A and B contaminants in Category I and Group C contaminants in Category II for purposes of establishing SDWA MCLGs. 2 According to IFI, perc is now, and has been throughout this rulemaking, classified in Group C, despite an aborted EPA proposal to reclassify perc as a Group B2 contaminant. The EPA has a legal obligation to follow its own procedures. Vitarelli v. Seaton, 359 U.S. 535, 539-40, 79 S.Ct. 968, 972-73, 3 L.Ed.2d 1012 (1959). If an agency action is based upon a defined procedure, even though generous beyond the requirements that bind such agency, that procedure must be scrupulously observed. Id. at 546-47, 79 S.Ct. at 976 (Frankfurter, J., concurring & dissenting). IFI asserts that if the EPA had followed its past practice, it would have placed perc in Category II and assigned it a non-zero MCLG. Therefore, IFI contends, the EPA acted arbitrarily and capriciously when it placed perc, a Group C contaminant, in Category I with a resulting MCLG of zero. 64 We are not convinced that the EPA failed to follow its procedures when it placed perc in Category I and assigned it an MCLG of zero. Perc's classification group has not been definitively determined. While a 1985 Health Assessment Document assigned perc to Group C, we find that the EPA reopened this designation based on a subsequent NTP study. See Hazardous Waste and Superfund Programs; Amendment to Preambles, 56 Fed.Reg. 643, 643-44 (1991) (discussing history of the EPA's effort to place perc in a group and stating that the EPA is continuing its deliberations concerning the weight-of-evidence classification for [perc].). 65 The EPA was careful to note in the proposed rule that a scientific consensus had not developed on whether perc should be classified in Group B2 or C, and that consequently it would fully consider both approaches before promulgation. Proposed Rule, 54 Fed.Reg. at 22,091. The EPA asserts that the categorization of perc in the Final Rule will have no effect on the separate effort to classify perc. Moreover, when the EPA completes its classification, the Agency represents that it may reconsider perc's categorization. Brief for Respondent at 61-62. As such, IFI overstates its case by contending that the EPA has forced a Group C contaminant into Category I or that the EPA preordained a zero MCLG in the proposed rule. More accurately, the EPA has placed a Group C-B2 contaminant in Category I and assigned it an MCLG of zero, without waiting for a final classification. 66 The determinative question, then, is whether the EPA violated its own regulations by assigning perc to a category before it had completed perc's classification. National Conservative Political Action Committee v. FEC, 626 F.2d 953, 959 (D.C.Cir.1980) (Agencies are under an obligation to follow their own regulations, procedures, and precedents, or provide a rational explanation for their departures.). The EPA contends that its action did not violate agency procedures since the SDWA-specific contaminant categories do not follow in lockstep the agency-wide, weight-of-the-evidence cancer classification groups. Brief for Respondent at 63 (The cancer classification thus does not dictate the drinking water category, or vice versa.). As examples, the EPA lists three contaminants that are classed in Groups A or B, but were placed in SDWA Category II for the Final Rule because there were studies showing these contaminants did not pose a high risk from the ingestion of drinking water. Final Rule, 56 Fed.Reg. at 3,532, 3,535-37 (discussing categorization of asbestos, cadmium, and chromium). Additionally, the EPA relates that styrene, like perc, did not have a cancer classification and was therefore categorized, like perc, based on available scientific evidence. Id. at 3,532, 3,540-41. 67 We note that the examples of deviations the EPA provides us occurred in this rulemaking, thereby diminishing their value as rebuttal evidence to IFI's charge that the EPA departed from its past practice in this rulemaking. Moreover, the record indicates that the EPA devised the three-category approach in 1985 to complement the agency-wide classification system that had been proposed in 1984 and would become final in 1986--the categories and classifications are thus not the total strangers the EPA would suggest. See 1985 Proposed Rule, 50 Fed.Reg. at 46,948; see also Cancer Risk Assessment Guidelines, 51 Fed.Reg. 33,992, 33,999-34,000 (1986) (Cancer Guidelines) (promulgating as a final rule the cancer risk classification system first proposed in 1984). In fact, when the EPA discussed the possible MCLGs for perc in the May 1989 Proposed Rule, it spoke in terms of whether perc fell within Group C or B2. Proposed Rule, 54 Fed.Reg. at 22,091. 68 However, IFI has not directed us to anything within the EPA's procedures prohibiting the Agency from assigning an SDWA Category when the cancer classification for a contaminant is unresolved. Accordingly, this petition is distinguishable from those cases requiring the invalidation of agency actions that conflict with or depart from the plain meaning of an agency's regulations. See, e.g., Exportal Ltda. v. United States, 902 F.2d 45, 49-50 (D.C.Cir.1990) (rejecting agency interpretation of its own regulation that conflicted with plain meaning of the regulation). 69 Instead, we believe this petition turns on whether the EPA reasonably interpreted its categorization procedures as allowing it to place an unclassified contaminant in a category based on a review of the scientific evidence. As explained by the Agency when it established the SDWA Categories, Category I includes those chemicals which have sufficient human or animal evidence of carcinogenicity to warrant their regulation as probable human carcinogens. 1985 Proposed Rule, 50 Fed.Reg. at 46,948. The EPA interpreted this as making the critical inquiry not whether the Agency has completed its classification process, but rather whether a review of the scientific evidence leads to a determination that the contaminant is a probable human carcinogen. 70 We find this interpretation of the categorization procedures permissible and fully consonant with the dictates of notice-and-comment rulemaking. Chemical Manufacturers Ass'n v. EPA, 919 F.2d 158, 170 (D.C.Cir.1990) ( '[A]n agency's interpretation of its own regulations will be accepted unless it is plainly wrong.'  (quoting General Carbon Co. v. Occupational Safety and Health Review Comm'n, 860 F.2d 479, 483 (D.C.Cir.1988))). When the EPA proposed an MCLG for perc, it furnished a full opportunity for comment on perc's carcinogenicity based on publicly available scientific studies. Proposed Rule, 54 Fed.Reg. at 22,091. It also advised the public that [b]ecause no scientific consensus yet exists, it is necessary for the Agency to make a judgment based on a reasonable weighing of evidence from the data at hand. Id. So despite the proposed rule's discussion of classifying perc in Group C or B2, IFI cannot complain that it was denied an opportunity to comment on the studies relied on by the EPA, or that it was unaware that a finding of probable human carcinogenicity based on a reasonable weighing of evidence would result in perc being placed in Category I. Therefore, we are satisfied that the EPA acted in an entirely permissible manner without depriving the petitioner of its right to notice and comment in this rulemaking. 71 Finally, we reject IFI's contention that the studies relied on by the EPA do not support a finding that perc is a probable human carcinogen. Faced with a similar dispute regarding the 1985 categorization of trichloroethylene, we upheld the EPA's action, noting that [h]appily, it is not for the judicial branch to undertake comparative evaluations of conflicting scientific evidence. Our review aims only to discern whether the agency's evaluation was rational. NRDC v. EPA, 824 F.2d at 1216. 72 We apply that standard here and find that IFI has not shown that the EPA acted irrationally. The Agency responded to comments such as those now iterated by IFI and provided a detailed discussion of its reasons for placing perc in Category I. Final Rule, 56 Fed.Reg. at 3,541-42. For example, the Agency noted that [i]ndications of cancer activity were seen in mice and rats, in both sexes, by inhalation and oral exposure. Id. at 3,542. The EPA acknowledged the controversy surrounding the occurrence of mouse liver tumors, mononuclear cell leukemia in rats, and male rat kidney tumors, but concluded that these events were relevant for consideration in the overall weight of evidence for potential [perc] human health hazards and that the totality of the animal evidence is judged by EPA to be sufficient to view [perc] as a Category I contaminant. Id. Critical to this conclusion was the EPA's belief that although there may be other plausible mechanistic explanations for the reported occurrences of cancer, the experimental animal evidence identifies the potential for a carcinogenic response in humans unless there is evidence to the contrary; that is, lack of key information does not support the use of the uncertainties to discount the sufficient level of animal evidence. Id. In sum, the EPA considered a variety of animal evidence suggesting the carcinogenicity of perc. Though other factors may also have played a role in causing carcinogenic responses, the EPA's methodology has consistently been to accept findings of carcinogenicity absent contrary findings. NRDC v. EPA, 824 F.2d at 1217. Therefore, we will not disturb the EPA's regulation of perc as a Category I contaminant. 3