Latest court ruling further underscores circuit split on groundwater conduit theory.

By Joel C. Beauvais and Stacey L. VanBelleghem

The US District Court for the Central District of Illinois has held that power plant owners are not liable under the Clean Water Act (CWA) for discharges of pollutants from coal ash disposal facilities through groundwater to waters of the US. The November 14 ruling is the latest in a series of recent defeats of CWA citizen suits premised on the so-called “groundwater conduit” theory.

Plaintiffs in Prairie Rivers Network v. Dynegy Midwest Generation, LLC initiated a CWA citizen suit against the owners of the Vermilion Power Station, a retired coal-fired power plant in Illinois. Plaintiffs alleged that defendants unlawfully discharged pollutants into groundwater from unpermitted seeps in their coal ash disposal facility and this groundwater was hydrologically connected to the Middle Fork of the Vermillion River. The district court relied on prior US Court of Appeals for the Seventh Circuit precedent (outside the coal ash context), holding that the CWA does not govern discharges of pollutants into groundwater, even if there is a hydrologic connection between the groundwater and waters of the US. Unlike other recent cases evaluating CWA liability from coal ash facility seepage into groundwater, this court did not address whether the coal ash facility was a “point source” under the CWA, given the existing circuit court precedent on the groundwater conduit theory.

If plaintiffs appeal this decision and the Seventh Circuit upholds it, this will further underscore a clear circuit split on whether the CWA governs discharges of pollutants from a point source to groundwater that is hydrologically connected to waters of the US. As summarized in Latham’s September 27, 2018 blog, the Ninth Circuit and Fourth Circuit have each squarely held that the CWA governs discharges of pollutants from point sources into hydrologically connected waters, although these cases were not in the context of coal ash disposal facilities. The Fourth Circuit has foreclosed these citizen suits against coal ash facility owners on other grounds — that the impoundments are not a point source under the CWA. In contrast, the Sixth Circuit has rejected the groundwater conduit theory of liability under the CWA, while also holding that coal ash disposal facilities are not point sources.

Petitions to review both the Ninth and Fourth Circuit (non-coal ash) decisions are currently pending before the Supreme Court. The Court may soon decide whether it will take up one or both of these cases. Meanwhile, the US Environmental Protection Agency (EPA) issued a request for comment on the groundwater conduit issue earlier this year, and has yet to announce whether it will issue a rulemaking or guidance clarifying the agency’s position. While the Central District of Illinois’ recent decision adds to the growing body of favorable case law for owner/operators of coal ash disposal facilities, the ultimate outcome remains to be determined. Stakeholders will be watching closely both the appeal of this decision and further proceedings before the Supreme Court and EPA.