To embed, copy and paste the code into your website or blog: On February 11, three environmental groups — Sierra Club, Alliance for Affordable Energy, and PennEnvironment, Inc. — filed a petition for review in the D.C. Circuit Court of Appeals (D.C. Circuit) challenging the U.S. Environmental Protection Agency’s (EPA) recent final rule titled, “Hazardous and Solid Waste Management System: Disposal of CCR; A Holistic Approach to Closure Part B: Alternate Demonstration for Unlined Surface Impoundments,” 85 Fed. Reg. 72,506 (Nov. 12, 2020). Commonly called “Part B,” the rule allows owners and operators to submit demonstrations showing their clay-lined impoundments are adequately protective of human health and the environment. Part B is the second of two rulemakings comprising EPA’s “Holistic Approach to Closure” amendments to the coal combustion residuals (CCR) rule. Environmental groups filed a similar challenge to the “Part A” rule in the D.C. Circuit in November 2020. That case,