Opinion ID: 588800
Heading Depth: 2
Heading Rank: 4

Heading: Regulation of DBCP

Text: 26 The pesticide DBCP was widely used in the continental United States until 1979, when the EPA banned it because of health risks. DBCP was marketed by a number of companies, including petitioners Dow, Shell, and Occidental. Because DBCP in runoff water will migrate through soil, it may leach into aquifers used for drinking water. In 1985, the EPA concluded that the 27 available data indicate that DBCP has non-carcinogenic and carcinogenic effects in animals. Based on potential adverse health effects and occurrence and potential occurrence in drinking water, EPA is proposing to regulate DBCP. The [MCLG] will be based upon carcinogenic effects and an [MCLG] of zero is proposed. 28 1985 Proposed Rule, 50 Fed.Reg. at 46,989. Four years later, the EPA noted 29 that the epidemiology data base is inadequate to refute or demonstrate that DBCP causes tumors in humans. EPA believes there are sufficient data to conclude that DBCP is carcinogenic in animals since the compound has been shown to be carcinogenic in both rats and mice. EPA therefore has classified DBCP in Group B2: probable human carcinogen. 30 Proposed Rule, 54 Fed.Reg. at 22,083. The Final Rule reiterated this analysis, Final Rule, 56 Fed.Reg. at 3,545, placing DBCP in Category I with an MCLG of zero and an MCL of 0.0002 mg/l. Id. at 3,528 (Table 3).
31 Petitioners Dow, Shell, and Occidental argue that the EPA did not adequately explain its action in setting the MCLG and MCL for DBCP. Petitioners also assert that the EPA failed to address their comments and improperly rejected data presented by them. Petitioners focus on the EPA's response to human epidemiological studies submitted during the comment period, claiming that the EPA rejected human epidemiological evidence on DBCP without any explanation. Brief for Petitioners at 33. 32 Petitioners refer primarily to two epidemiological studies, the Hearn and Wong studies, of workers exposed to DBCP in the work environment. Id. at 13. Shell presented these studies in comments submitted to the EPA in 1986. See Comments of Shell Oil Co. (May 8, 1986), reprinted in J.A. at 859. Shell and Dow presented them again in 1989 in response to the Proposed Rule. See Comments of Shell Oil Co. and The Dow Chemical Co. (Aug. 19, 1989), reprinted in J.A. at 172. Shell and Dow stated that the studies do[ ] not show any statistically significant increase in either overall cancer rates or any specific cancer type in workers exposed to the chemical. Id. at 204. 33 Petitioners assert that the EPA made only one response to the evidence--that it believe[d] the epidemiology data base is inadequate to refute or demonstrate that DBCP causes tumors in humans[.] Brief for Petitioners at 34 (quoting Final Rule, 56 Fed.Reg. at 3,545). A conclusory statement, of course, does not in itself provide the satisfactory explanation required in rulemaking. State Farm, 463 U.S. at 43, 103 S.Ct. at 2866. The EPA maintains, however, that petitioners ignore many of its responses to the epidemiological data. See Brief for Respondent at 34-36. The EPA points to a report it prepared in 1987 in response to Shell's 1986 comments. See EPA Final Report: Review of the Epidemiologic Literature on the Carcinogenic Effects of DBCP (Mar. 5, 1987), reprinted in J.A. at 1852. That report contained the following assessment of the Hearn study: 34 The limited number of years of follow-up and the limited statistical power are two serious limitations to this study. Continued follow-up is essential to firmly conclude that there is no or little excess risk of cancer in workers with DBCP exposure. The absence of more definitive exposure data limits the utility of this study for risk assessment. 35 Id. at 16-17, reprinted in J.A. at 1868-69. Regarding the Wong study, the report stated: 36 No qualitative or industrial hygiene data are available to indicate the extent and level of exposure to [DBCP]. However, the authors suggest that the exposure was relatively low compared to exposure to [other] brominated chemicals. As such, this study offers very limited evidence about the potential risks associated with DBCP, since the exposure levels are unknown and are likely to be extremely low. 37 Id. at 18, reprinted in J.A. at 1870. The EPA, then, found that both the Hearn and Wong studies presented insufficient exposure data. 38 We conclude that the EPA adequately addressed the human epidemiological data on DBCP. The data was collected from workers exposed to DBCP primarily through inhalation in the workplace, not from individuals exposed to DBCP through ingestion of drinking water. In response to studies of the effects of the chemical on animals, the EPA emphasized that toxicity may depend on dosing route ..., [therefore] inhalation data should not be relied upon in a risk assessment for oral exposure. EPA, Response Document (revised July 19, 1989) at 4-127, reprinted in J.A. at 1104. This is particularly true where, as here, the EPA has assessed the inhalation studies and has concluded that they fail to provide adequate exposure data. 39 Dow, Shell, and Occidental raise several other challenges to the EPA's rulemaking on DBCP. First, they contest the EPA's reliance on animal studies on the ground, among others, that the EPA did not adequately respond to petitioners' comments. These comments had questioned the EPA's use of studies that reviewed the effects of DBCP on animals when inhaled into the lungs. See id. at 4-125, reprinted in J.A. at 1102. The EPA responded that [i]nhalation toxicity data on DBCP were evaluated but played no critical role in EPA's risk assessment for DBCP in water. Id. at 4-127, reprinted in J.A. at 1104 (emphasis added). 40 Shell and Dow also commented that some experiments on which the EPA relied involved extremely high doses of DBCP and that in these experiments the tumors tended to develop at the site of contact. Comments of Shell Oil Co. and The Dow Chemical Co. at 10-11, reprinted in J.A. at 184-85. The EPA responded that its analysis of DBCP was an exhaustive survey that was not limited to one particular type of study: 41 Based on positive animal data in two species (rats and mice) by three routes of exposure (oral, inhalation and dermal), including site of contact and distant site tumors, DBCP is considered to have a sufficient level of evidence for carcinogenicity in animals. 42 EPA Drinking Water Criteria Document for DBCP (Mar. 1988) at V-88, reprinted in J.A. at 1613 (emphasis added). Considering the EPA's responses, we cannot agree with petitioners' assertion that the EPA has given no indication of how it evaluated the evidence Petitioners submitted as to the reliability of certain of the animal studies[.] Brief for Petitioners at 34. We conclude that the EPA adequately responded to the commentary and sufficiently justified its reliance on animal studies. 43 Petitioners also maintain that the EPA failed to respond adequately to data demonstrating that DBCP naturally degrades over time. Petitioners noted that DBCP has an approximate half-life of six years and is no longer being introduced into the environment. Comment/Response Document on 1989 Proposed Rule at 9-14, reprinted in J.A. at 1464 (citation omitted). We agree with the EPA that petitioners have failed to establish the relevance of DBCP degradation to the MCL level. If DBCP concentration has already naturally degraded to levels below the MCL in many water sources, then plants using this water will not have to treat for DBCP. As the EPA explained in its response to the natural degradation commentary, [o]ccurrence is a different issue than the level at which the MCL is set. Id. at 9-15, reprinted in J.A. at 1465. While it is true that the Agency's rule may require the construction of costly treatment facilities in order to handle a hazard that will soon cease to exist, we cannot quarrel with its conclusion that this is nevertheless required by the Act. 44 Finally, petitioners argue that the EPA did not establish that the MCL for DBCP was feasible in light of the high costs to drinking water systems that will have to lower the DBCP concentration to no more than 0.0002 mg/l. The SDWA mandates an MCL that is as close to the [MCLG] as is feasible. 42 U.S.C. § 300g-1(b)(4). The Act also requires the EPA, in making this feasibility determination, to tak[e] cost into consideration. Id. § 300g-1(b)(5). Petitioners argue that the EPA erred in its cost analysis by, inter alia, focusing on the cost estimates for large water systems as opposed to small ones. 45 We begin with the meaning of feasible as used in the Act. The statute states: 46 [T]he term feasible means feasible with the use of the best technology, treatment techniques and other means which the [EPA] finds ... are available (taking cost into consideration). For the purpose of [§ 300g-1(b)(4) ], granular activated carbon is feasible for the control of synthetic organic chemicals[.] 47 Id. The EPA's projected cost of treatment for DBCP is based on the use of granular activated carbon technology. See Final Rule, 56 Fed.Reg. at 3,577 (Table 30 and n. 1). Because DBCP is a synthetic organic chemical, the use of granular activated carbon is per se feasible under section 300g-1(b)(5). We therefore conclude that the EPA adequately explained why the prescribed treatment was feasible within the meaning of the statute.