Kennecott v. Environmental Protection Agency

The nonferrous-metals manufacturing industry discharged massive amounts of harmful pollutants. Pursuant to the Clean Water Act (CWA), the Environmental Protection Agency (EPA) (defendant) set effluent limitations for the nonferrous-metals manufacturing industry and based the limits upon what the EPA viewed as achievable technologies. The nonferrous-metals industry was generally subject to best available technology (BAT) requirements. The EPA spent more than five years collecting and studying data and considering public comments before setting effluent limits for the primary metals industry. The EPA used a waste-treatment process called lime, settle, and filtration as its model technology to set the effluent limits. The EPA collected data from six industries that used lime, settle, and filtration to compile the Combined Metals Data Base (CMDB). The EPA then used the CMDB to calculate effluent limitations for related industries that did not use lime, settle, and filtration, including the primary base metals industry. Kennecott (plaintiff) petitioned for a review of the nonferrous-metals rulemaking, arguing that the EPA’s data was flawed. Kennecott argued that the CMDB database was limited and because the CMDB plants differed significantly from primary metals plants, the EPA should have used data submitted by the primary metals industry for its calculations. Kennecott also argued that the EPA did not obtain enough samples over a long enough period, so the data did not accurately reflect achievable concentrations. The EPA contended that it did not require long-term data to predict long-term performance and used well-established statistical methods to factor in variability. The EPA also claimed that there was evidence to show that the treatability of wastewater depends on the solubility of the pollutants, not on pollutant concentrations, so the wastewaters in the CMDB industries and those of the primary base metals industry were comparable.