In a mixed decision, a federal appeals court has ruled that the Obama administration’s rule to regulate coal ash does not go far enough in some areas but did not give environmentalists the full win they were seeking.

Environmental groups challenged the Obama-era 2015 rule because, they said, certain provisions weren’t stringent enough. Industry groups, focusing on other provisions, contended that they were too expansive.

In sum, the U.S. Court of Appeals for the District of Columbia Circuit’s Aug. 21 decision in the case, Utility Solid Waste Activities Group v. EPA, gave neither side all that it wanted.

The decision, by a three-judge panel of the appellate court, comes amid efforts by the Trump administration to roll back the Environmental Protection Agency’s 2015 rule intended to regulate coal ash and other residual materials from coal-fired power plants.

The court noted that in 2012, U.S. coal-fired power plants produced about 110 million tons of solid waste as residuals. It added, “That waste contains myriad carcinogens and neurotoxins.”

The waste material is typically stored “in aging piles or pools that are at varying degrees of risk of protracted leakage and catastrophic structural failure,” the decision said.

‘Green’ groups view the appellate court’s opinion, on balance, as a victory. “With this ruling, the court has delivered a win for communities and for public health—EPA and utilities can no longer ignore the clear dangers posed by unlined coal ash ponds or poorly lined ponds.”  Lisa Hallowell, senior attorney with the Environmental Integrity Project, said in a statement.

The Utility Solid Waste Activities Group, an industry organization, “is still reviewing the decision,” the group’s executive director, Jim Roewer, said in an Aug. 22 email.

Wyn Hornbuckle, a U.S. Dept. of Justice spokesman, said via email on Aug. 24, "We're reviewing the ruling."

In its ruling, the court agreed with environmental groups that EPA erred in failing to mandate that unlined surface impoundments for the residual materials be closed and in exempting inactive impoundments at inactive electric power plants from its regulations.

The court also sided with environmental organizations in ruling that the agency shouldn’t have classified clay-lined impoundments as being lined.

The court ruled against industry groups on several of its challenges, for example, determining that EPA does have the authority to regulate inactive impoundments and that the agency did provide enough public notice that it intended to apply aquifer-location criteria to existing impoundments.

The court also found, however, that EPA did arbitrarily decide to regulate residual piles 12,400 tons or greater and remanded that decision to the EPA, a win for industry.

Further complicating the coal ash regulations, the Trump Administration in July released amendments to the Obama-era coal ash regulation.

Those revisions, published in the Federal Register on July, would, among other things, give states greater authority to set disposal requirements that meet needs to specific sites, including changing groundwater performance standards.

--With Pam Radtke Russell

Story updated on 8/24/18 with Dept. of Justice statement