On April 17, 2015, the Environmental Protection Agency (EPA or the Agency) promulgated national minimum criteria for existing and new coal combustion residuals (CCR) landfills and existing and new CCR surface impoundments. On August 21, 2018, the D.C. Circuit Court of Appeals issued its opinion in the case of Utility Solid Waste Activities Group, et al v. EPA, which vacated and remanded the provision that exempted inactive impoundments at inactive facilities from the CCR rule. In May 2023, EPA proposed regulations to implement this part of the court decision for inactive CCR surface impoundments at inactive utilities, or “legacy CCR surface impoundments”. This proposal included adding a new definition for legacy CCR surface impoundments. EPA also proposed to require such legacy CCR surface impoundments to follow existing regulatory requirements for fugitive dust, groundwater monitoring, and closure, or other technical requirements. Finally, EPA proposed requirements for CCR management units including a facility evaluation and to follow existing regulatory requirements for groundwater monitoring, corrective action, and closure for all CCR contamination (regardless of how or when that CCR was placed) at a regulated facility. After reviewing the public comments on the proposed rule, EPA will take final action.