Opinion ID: 492025
Heading Depth: 2
Heading Rank: 3

Heading: Failure to Promulgate a Zero Recommended Level for Vinylidene Chloride

Text: 18 NRDC does not dispute EPA's finding that vinylidene chloride is a possible--rather than a known or probable--human carcinogen. NRDC instead contends that Congress intended that EPA treat possible carcinogens no differently from known or probable ones. NRDC argues that EPA's regulatory scheme in effect imposes a requirement that a compound be found to be carcinogenic by a preponderance of the evidence before the agency will establish a recommended level of zero for it. Such a threshold requirement, NRDC contends, violates EPA's obligation to resolve uncertainty on the side of protecting public health. 19 We agree with NRDC that a preponderance-of-the-evidence threshold test would probably be inconsistent with Congress' directions in the Drinking Water Act. If the evidence established, for example, a 40% probability that a compound was carcinogenic, the agency's decision not to regulate would be difficult to square with the Drinking Water Act's instruction to the agency to establish a recommended level for each contaminant which, in its judgment, may have any adverse effect on health. Such a decision might well constitute an abuse of the discretion the agency is granted under the Drinking Water Act. But that situation in no way describes the instant case, and certainly there is no indication in the final rule that the agency has adopted a general policy not to establish a recommended level for a VOC unless a preponderance of the evidence demonstrates that it is a carcinogen. NRDC perhaps has taken too much to heart the agency's use of the word possible in its categorization of different VOCs. Although that label on its face could augur a preponderance-of-the-evidence test, the agency's explication of the Category II--compounds for which there is some equivocal evidence of carcinogenicity--makes it clear that the EPA has no such test in mind. Nor does the EPA's treatment of vinylidene chloride suggest that the agency employed a threshold preponderance-of-the-evidence test. The EPA here reasonably concluded that the evidence of vinylidene chloride's carcinogenicity was not even close to being in equipoise. The agency pointed out that no fewer than a dozen long-term animal studies had not demonstrated that vinylidene chloride has any carcinogenic effect. See 50 Fed.Reg. 46,888, J.A. 9. Against this data EPA weighed two studies that revealed a possibility of carcinogenic or protocarcinogenic effects, and it noted that the results in both of these studies had limitations that made their applicability to humans highly questionable. The agency therefore had adequate support for its conclusion that the evidence of TCE's carcinogenicity was sparse and equivocal. 20 Whether the EPA, having reached such a conclusion, properly declined to set a zero recommended level for vinylidene chloride involves essentially a question of statutory interpretation. The Drinking Water Act provides that the Administrator shall establish recommended levels for each contaminant which, in his judgment ... may have any adverse effect on the health of persons. 42 U.S.C. Sec. 300g-1(b)(1)(B). By its terms, the statute grants discretion to the Administrator to determine whether there is sufficient evidence to justify establishing a recommended level for a particular compound. Unless the agency must regulate as a carcinogen every VOC whose carcinogenicity it cannot conclusively disprove, an interpretation that would read the concept of administrative judgment out of the Act, the EPA has discretion not to treat a compound as a carcinogen notwithstanding some equivocal evidence to the contrary. See Environmental Defense Fund v. EPA, 598 F.2d 62, 88 (D.C.Cir.1978) (where evidence of a chemical's carcinogenicity is inconclusive, Administrator has discretion whether to regulate). EPA's decision not to establish a recommended level for vinylidene chloride based on the compound's carcinogenicity thus does not violate the statutory scheme of the Drinking Water Act. 21 Although EPA did not set a recommended level for vinylidene chloride based on the compound's carcinogenicity, the agency decided that the compound's other toxic effects did warrant the establishment of a recommended level. In then calculating the actual recommended level for vinylidene chloride, EPA divided by ten in order to take account of vinylidene chloride's possibly carcinogenic effects. NRDC argues that it was arbitrary and capricious for the agency to refuse to establish recommended level of zero based on vinylidene chloride's risk of carcinogenicity but then to take account of the very same risk in setting the recommended level for the compound. We disagree. A careful parsing of the statutory language provides ample support for EPA's action. The Drinking Water Act provides for promulgation of recommended levels in two steps. In the first, the Administrator determines whether a contaminant may have any adverse effect on the health of persons. If a contaminant may have an adverse effect (for example, in the case of vinylidene chloride, because of its noncarcinogenic risks), the Administrator is directed to set the recommended level at a level at which no known or anticipated adverse effects on the health of persons occur and which allows an adequate margin of safety. The statute thus leaves room for the EPA to consider in its actual setting of the recommended level risks other than those that catalyzed the preliminary decision to establish a recommended level. Here, the EPA did just that, concluding that the equivocal evidence of vinylidene chloride's carcinogenicity, although not sufficient to justify establishing a recommended level on that ground alone, was palpable enough to be accounted for at the adequate margin of safety stage. This is neither an unreasonable interpretation of the statute nor an unwise choice of policy. 22 Finally, NRDC argues that the promulgation of a non-zero recommended level for vinylidene chloride was an unexplained reversal of prior policy, and thus constituted arbitrary and capricious agency action under this court's decision in Greater Boston Television Corp. v. FCC, 444 F.2d 841 (D.C.Cir.1970), cert. denied, 403 U.S. 923, 91 S.Ct. 2229, 29 L.Ed.2d 701 (1971). NRDC points to EPA's 1979 promulgation of interim primary drinking water standards for trihalomethanes (THMs). See 44 Fed.Reg. 68,624 (1979). EPA regulated the THMs as carcinogens, having no safe threshold level, on the basis of no more than their structural similarity to a known carcinogen and positive evidence of mutagenicity. NRDC argues that comparable evidence warrants treatment of vinylidene chloride as a carcinogen in setting recommended levels. 23 We reject NRDC's claim because we cannot accept its premise that the EPA had a prior policy under which it would have set a recommended level of zero for vinylidene chloride. The agency's supposed policy arose in a proceeding very different from one at issue here, for compounds other than vinylidene chloride. That action scarcely establishes that the agency had a prior policy that would dictate promulgation of a zero recommended level for vinylidene chloride. Indeed, the rule under review was the first time EPA ever promulgated recommended levels for carcinogens under the Drinking Water Act. The agency thus had no prior policy from which to depart, and therefore it was not subject to additional procedural controls set by Greater Boston. In adopting the policy, EPA expressly recognized that it was a new policy in response to developments in cancer risk analysis. See 49 Fed.Reg. 46,294 (1984).