A federal judge has given the U.S. Environmental Protection Agency 60 days to set a date for finalizing a coal-ash regulation. In an Oct. 29 memorandum, Reggie Walton, a district judge for the District of Columbia, said EPA must submit a proposal to the court for setting a release date for the controversial rule. The EPA proposed the regulation in 2010.

Environmental groups have argued that coal ash should be designated a hazardous waste under the Resource Conservation and Recovery Act (RCRA). But construction groups contend that designation would stigmatize its reuse as a "green" component in concrete and other building materials.

The judge's action stems from a lawsuit that several environmental and public-health organizations filed in 2012. The suit claims EPA has failed to fulfill its obligations under RCRA to review and revise its waste regulation. Walton noted that while EPA may be obligated to review and finalize its rule, there is no guarantee the agency will designate coal ash as a hazardous material.