Opinion ID: 628244
Heading Depth: 2
Heading Rank: 1

Heading: Accuracy of the Toxicity Characteristic as Applied to Chloroform

Text: Taking the same tack as AMC and EEI in their challenge to the TCLP's application to mineral wastes, API and NFPA contend that EPA's failure to consider biodegradation violates the congressional mandate to insure that [the TCLP] accurately predicts the leaching potential of wastes which pose a threat to human health and the environment when mismanaged. 42 U.S.C. Sec. 6921(g). They point to EPA's acknowledgement that biodegradation as a mechanism was neglected, i.e., the biodegradation coefficient was set to zero in the TC for chloroform. EPA, Background Document for EPA's Composite Model for Landfills Sec. 6.2.4, at 79. API and NFPA cannot prevail under Chevron for reasons similar to those already discussed with respect to the statutory challenge of AMC and EEI, supra pp. 444-446. The statutory mandate for improved accuracy focuses explicitly on the extraction procedure and the choice of leaching medium, but makes absolutely no mention of the DAF or particular attenuation mechanisms. See 42 U.S.C. Sec. 6921(g). The petitioners cannot plausibly maintain that this statutory directive evinces a clear congressional intent to consider biodegradation as an attenuating mechanism in determining the regulatory level for chloroform under the TC. Thus, because congressional intent on the precise question at issue is unclear, EPA's approach survives Chevron scrutiny if it constitutes a reasonable construction of the statute. Chevron, 467 U.S. 837, 104 S.Ct. 2778. As we have already concluded, supra pp. 444-446, EPA reasonably responded to the congressional call for improved accuracy by changing the TCLP to include two leaching fluids and eliminating an exception to the rule that large solid pieces of waste must be reduced to particles prior to testing.