CPC International, Inc. v. Train

The Environmental Protection Agency (EPA) (defendant) promulgated regulations under the Federal Water Pollution Control Act Amendments of 1972 (FWPCA) that a new plant in the corn wet milling industry should achieve an average of daily values for 30 consecutive days of an effluent level that does not exceed 20 pounds of five-day biochemical oxygen demand (BOD5) and 10 pounds of the total amount of suspended solids (TSS) per 1,000 standard bushels of corn produced (MSBu). This standard was to be reached using deep bed filtration. The EPA used the Clinton corn plant treatment facility, which used deep bed filtration, to support the new source standards. The EPA synthesized a model corn wet milling plant and corresponding treatment facility using data from the corn wet milling industry and other industries that encounter similar wastewater to base the new BOD5 standard on. The EPA also used data of industry performance results and the Clinton plant’s production of modified starches to consider increased waste loads generated by the production of modified starches. The EPA concluded that the new TSS standard could be met based on the use of deep bed filtration in other industries but lacked support from results within the corn wet milling industry. The EPA asserted that deep bed filtration was a demonstrated technology in other industries and could be transferred to the corn wet milling industry with a similar success rate of BOD5 and TSS effluent level reduction. Representatives of the corn wet milling industry (representatives) (plaintiffs) denied the EPA’s assertions and sought a direct review of the regulations. The representatives argued that the EPA did not properly consider the increased waste loads generated by the production of modified starches when calculating the effect of BOD5 using the model plant. The representatives also argued that results from other industries indicated that deep bed filtration would not remove TSS efficiently or consistently enough to meet the new TSS standard and that data from several other industries was unusable because it was measured on a different scale and unclear whether deep bed filtration was being used or not.