Opinion ID: 628244
Heading Depth: 2
Heading Rank: 2

Heading: Reasonableness of Excluding Biodegradation in Setting the TC Regulatory Level for Chloroform

Text: The petitioners argue that EPA's decision not to account for biodegradation of chloroform in its subsurface transport model is arbitrary and capricious because the decision is unsupported by the administrative record, inconsistent with other EPA action, and in violation of EPA policy regarding verification of model results. The petitioners also claim that EPA failed to consider regulatory alternatives before deciding not to account for biodegradation. We reject each of these claims. EPA decided not to take account of biodegradation in its revised TC because the Agency did not have adequate information at this time to include biodegradation in the model. EPA, Responses to Public Comments on Subsurface Fate and Transport Model Used in the Toxicity Characteristic Rule, at 2-33 to 2-37 (EPA Responses ); see also 55 Fed.Reg. 11,823-24 (1990). The petitioners claim that EPA improperly failed to consider the extensive data they submitted on biodegradation rates--see Comments of API and NFPA (September 26, 1986), at VII-12 to VII-16; id. at Attachment 10 (citing articles submitted by API and NFPA); Comments of API and NFPA (June 5, 1988), at 10-14--because similar data were not available for other organic constituents. EPA did reject the petitioners' data in part because similar data were not available for most of the constituents regulated under the TC. See EPA Responses at 2-33 ([o]nly a few of the chemicals affected by this rulemaking were included [in the biodegradation data submitted by the petitioners], and most of the data was for aerobic conditions). However, EPA gave another reason for deciding not to factor biodegradation into its model: Biodegradation rates in the subsurface are known to vary considerably across the United States, but there are insufficient data to quantify this variability.... At present, the Agency does not have sufficient data correlating biodegradation rates with subsurface conditions (e.g., pH, temperature) to accurately model anaerobic degradation in the subsurface. Id. API and NFPA have never contested, before the Agency or this Court, EPA's finding that the submitted data failed to account for pH and temperature variations in different subsurface environments throughout the United States. In light of the substantial deference due to an Agency's expert scientific judgment, see Natural Resources Defense Council v. Thomas, 824 F.2d 1211, 1216 (D.C.Cir.1987), we hold that this deficiency in the data warranted its rejection by the Agency. API and NFPA also claim that EPA failed to consider the following three alternative approaches to biodegradation: (1) adoption of a single, conservative biodegradation rate based on evidence submitted by API and NFPA; (2) use of that evidence to calculate a reasonable range of biodegradation rates for chloroform by using a Monte-Carlo mathematical technique; and (3) deferral of regulation of chloroform until EPA has developed the data it believed necessary to account for biodegradation. The failure to consider legitimate alternatives may render an agency decision arbitrary and capricious. See Yakima Valley Cablevision v. FCC, 794 F.2d 737, 746 (D.C.Cir.1986). However, EPA adequately considered and rejected each of the alternatives that the petitioners raised below. Thus, the Agency did not act in an arbitrary or capricious manner by failing to adopt one of the suggested alternatives. API and NFPA first suggest that EPA should have adopted a single, conservative biodegradation rate from within the range suggested by the petitioners' studies. But as we have already discussed, EPA reasonably concluded that it could not rely upon these studies. Thus, the Agency was justified in setting the biodegradation rate to the single, conservative rate of zero. See EPA, Background Document for EPA's Composite Model for Landfills Sec. 6.2.4, at 79 (noting that under the revised TC the biodegradation coefficient was set to zero). The second alternative, the use of a mathematical model known as the Monte Carlo technique, was not raised by the petitioners' in any of its comments to the Agency. Thus, EPA was not obligated to address this alternative. 42 U.S.C. Sec. 7607(d)(7)(B); Northside Sanitary Landfill v. Thomas, 849 F.2d 1516 (D.C.Cir.1988), cert. denied, 489 U.S. 1078, 109 S.Ct. 1528, 103 L.Ed.2d 833 (1989). In any case, EPA did explain that the Monte Carlo technique requires reliable nationwide data, which were lacking for biodegradation. See supra p. 448. The third and final alternative that API and NFPA suggested was for EPA to defer setting a regulatory level for chloroform. EPA chose to defer regulation of certain constituents based on reliable studies suggesting that the constituents had an unusual sensitivity to hydrolysis, one of the processes that affects subsurface attenuation. 55 Fed.Reg. 11,822-23 (1990). However, EPA found that there were insufficient reliable data showing an unusual sensitivity of chloroform, or any other constituent, to biodegradation rates in an anaerobic environment. See EPA Response at 2-33. Thus, EPA reasonably decided that deferral was not warranted based on the information submitted by the petitioners. The petitioners also maintain that EPA acted in an inconsistent manner by deferring regulation of some constituents, but declining to defer regulation of chloroform. But the distinction in the record discussed immediately above explains why EPA decided to treat differently chloroform and other constituents. The Agency had data demonstrating that certain constituents were highly sensitive to a particular model parameter or assumption, but it did not have sufficient data to remedy the inaccuracy resulting from that sensitivity. In other words, EPA had data indicating that there was a special problem and that more data were necessary to address it. In contrast, EPA had no reliable data indicating that the regulatory level for chloroform would be greatly affected by the development of a biodegradation parameter. Thus, EPA reasonably decided that there was no need to defer in anticipation of additional data regarding the biodegradation of chloroform. Finally, the petitioners contend that EPA's failure to use the biodegradation data they submitted violated the Agency's own policy that model results must be compared to available measurements, and any significant discrepancies should be discussed. 51 Fed.Reg. 34,048 (1986). But EPA's decision to reject the petitioners' biodegradation studies is not inconsistent with the announced policy of comparing the groundwater transport model to available empirical measurements. As we have noted, supra p. 448, EPA did consider the petitioners' data but found it lacking on a number of levels--most prominently, its failure to account for variations in subsurface pH and temperature. Having reasonably rejected these studies, the agency was not obligated under its policy to compare the model to the results reported in the studies. Thus, based on the record evidence available at the time of the decision, EPA did not act in an arbitrary or capricious manner by deciding not to account for biodegradation as an attenuating mechanism in establishing the regulatory level for chloroform. The petitioners may seek to have EPA revise the rule if and when appropriate new data are available. 5 U.S.C. Sec. 553(e); 42 U.S.C. Sec. 6974. IV. APPLICATION OF THE TC TO METALLIC SUBSTANCES The petitioners contend that EPA acted unlawfully in making the TCLP more sensitive to lead and other inorganic constituents than was the Agency's earlier leaching procedure, the EP. The Agency failed, they claim, (1) to give adequate notice of the scope of the TCLP; (2) to reconcile its conflicting views about the scope of the TCLP; (3) to provide an adequate statement of the basis and purpose of the TCLP rule; and (4) to act in accordance with its congressional mandate. Our review of these contentions indicates that EPA's promulgation of the TCLP was reasonable and proper. A. Notice The petitioners contend that EPA failed to provide adequate public notice, as required under 5 U.S.C. Sec. 553(b)(3), that the TCLP would be more sensitive than the EP to lead and other inorganic constituents. The petitioners rely most heavily upon a passage in the Regulatory Impact Statement that accompanied the proposed TCLP: The existing and proposed regulations do not differ in their treatment of metals. Thus, any impact of the proposed regulation on the municipal sector would be due solely to the additional organic [i.e., non-metallic] compounds. 51 Fed.Reg. 21,661. On initial inspection, this passage might indicate that the new TCLP would not differ from the EP in its sensitivity to lead and other metals. EPA, however, presents a number of persuasive reasons why this reading would be inaccurate. First, in context the passage is seen to refer only to the number of metallic constituents covered by the TCLP, not to the sensitivity of the test with respect to those constituents. It makes sense to view the passage this way because the TCLP added 25 new organic constituents not previously regulated under the EP, but added no new metals. Second, even if the passage were read to refer to the relative sensitivity levels of the old and new leaching procedures, the preceding paragraph indicates that any such comparison is limited to the effect of the new TCLP on sewage sludge generated by the municipal sector and does not extend to inorganic constituents generally The petitioners also cite several passages indicating that EPA's primary purpose in developing the TCLP was to improve the regulation of organic constituents only. For example, in initially proposing the TCLP, EPA explained that [t]he acetic acid models primarily the leaching of metals from an industrial waste. The impetus behind development of the [TCLP] was the need also to address the leaching of organic compounds. .... EPA's intent, then, was to develop an improved leaching test method suitable for use in evaluating wastes containing organic toxicants. 51 Fed.Reg. 21,653 As EPA notes, however, this passage hardly indicates that inorganic constituents would be immune from more stringent regulation. In fact, on the same page of the Federal Register, EPA notes that among the [o]ther objectives [of the TCLP] were ... that it also model the mobility of inorganic species. Id. Four pages earlier, EPA states that the TCLP has been developed to address the mobility of both organic and inorganic compounds.... Id. at 21,649. In addition, EPA notes that it gave express notice of the terms of the TCLP as ultimately adopted. The petitioners concede that EPA adopted the TCLP test in substantially the same terms as proposed, but contend that the substance of the proposal changed dramatically and in a manner inconsistent with the Agency's description of the test. In essence, the petitioners seem to argue that the Agency statements discussed above somehow misled them into thinking that the test would not regulate metals more stringently--despite the petitioners' actual knowledge of the terms of the proposed TCLP. As noted above, however, the Agency's statements did not indicate that the new test would treat metals in the same way as had the EP. Finally, EPA notes that a number of industry groups submitted comments criticizing the increased sensitivity of the TCLP to inorganic constituents. Such submissions are not dispositive on the question of notice, see Shell Oil Co. v. EPA, 950 F.2d 741, 750-51 (D.C.Cir.1991), but they are at least probative evidence that the notice given was adequate. Id. at 757. Taken together with the portions of the TCLP proposal quoted above, it appears that the Agency gave adequate public notice of the character and scope of the TCLP. B. Reasonableness Second, the petitioners contend that the adoption of the TCLP was arbitrary and capricious because EPA incorrectly assumed that the TCLP would yield the same results as had the EP with respect to metals, such as lead. For its part, EPA need only repeat that it never assumed that the TCLP and the EP would yield the same results for inorganic constituents. Again, as noted above, EPA made it clear when it initially proposed the TCLP that the new test would affect the regulation of both organic and inorganic constituents. The petitioners also contend that adoption of the TCLP is inconsistent with EPA's later decision, see 55 Fed.Reg. 22,660 (1990), to retain the EP for the purpose of evaluating lead and other metals following treatment. EPA responds that it retained the EP for inorganic constituents following treatment because data used to develop the treatment standards for these wastes were based on EP toxicity leachate data whereas similar data based upon the TCLP were not yet available. Id. This explanation for EPA's limited retention of the EP certainly seems to be reasonable. In an area implicating the Agency's scientific expertise, as does this, we require no more of it. See Thomas, 824 F.2d at 1216 (Happily, 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).