NRECA welcomed revisions by the Environmental Protection Agency to a 2015 rule regulating containment of coal ash from electric generation.

The final Coal Combustion Residual (CCR) Phase 1 rule gives utilities more time to begin closing CCR surface impoundments and to reflect a new risk-based approach to overseeing coal ash facilities authorized by Congress in the Water Infrastructure Improvements for the Nation (WIIN) Act.

"EPA's final rule will avoid unintended consequences as the agency incorporates new regulatory authority provided by Congress," said NRECA CEO Jim Matheson.

Without the extension, power plants could have been forced to permanently close CCR units or coal ash ponds that might otherwise be permitted under new risk-based criteria.

The revisions also confirm that a state authorized to administer the CCR rule can certify compliance through a permit. Further certification by a qualified professional engineer is not necessary.

The share of co-op electricity coming from coal was at 41 percent in 2016, the latest data shows.