Southwestern Electric Power Co. v. EPA, No. 15-60821 (5th Cir. 2019)Annotate this Case
The Fifth Circuit vacated portions of the EPA's final rule updating effluent limitation guidelines (ELGs) for legacy wastewater and for combustion residual leachate and remanded for agency reconsideration. The court held that the EPA acted arbitrarily and capriciously by setting a Best Available Technology Economically Available (BAT) limit for legacy wastewater equal to the outdated best practicable control technology currently available (BPT) standard of surface impoundments.
The court held that the leachate rule conflates the BAT and BPT standards in a way not permitted by the statutory scheme, and the agency's proffered justifications for the leachate rule were not supported by the factors set forth under the Clean Water Act for determining BAT. Therefore, the BAT determination for leachate failed Chevron step one. In the alternative, the leachate regulation failed at Chevron step two because it rests on an impermissible interpretation of the Clean Water Act.