A three-judge panel of the US Court of Appeals for the Fourth Circuit [official website] held [opinion, PDF] Wednesday that power company Dominion Energy did not violate the Clean Water Act [text, PDF] through its process of keeping a by-product of coal energy production called coal ash on site in a landfill and in settling ponds.

The Sierra Club sued Dominion Energy in 2015, arguing seepage of arsenic from coal ash stored at a Dominion Energy site was seeping into Virginia’s Elizabeth River and Deep Creek, and this was a violation of Clean Water Act prohibition against the unauthorized discharge of a pollutant “from a point source into navigable waters.”

In 2017, Judge John Gibney, Jr., of the US District Court for the Eastern District of Virginia found [opinion, PDF] that rainwater and groundwater were leaching arsenic from the coal ash in the landfill and settling ponds, and then polluting the groundwater, which carried the arsenic into navigable waters, and that the landfills and settling ponds constituted “point sources” as required by the Act.

The Fourth Circuit Wednesday disagreed in that these did not constitute “point sources” and therefore did not violate the Clean Water Act.

“At its core, the Act’s definition makes clear that some facility must be involved that functions as a discrete, not generalized, conveyance'” wrote the 3-0 panel, explaining that the coal ash holding ponds and landfills were rather, “like the rest of the soil at the site, static recipients of the precipitation and groundwater that flowed through them.”

The appeals court did agree with the district court that arsenic had in fact leached from the landfill and ponds into the waterways.

The Southern Environmental Law Center, which is representing the Sierra Club, said in a statement [press release] Wednesday that the decision was a disappointment, but it still did not affect “the lower court’s factual determination that arsenic is leaking from coal ash pits at Dominion’s Chesapeake facility and flowing directly into the Southern Branch of the Elizabeth River; nor does the decision alter the lower court’s determination that simply capping the ash in place is not an acceptable solution to this problem.”