Groundwater Conduit Theory and Its Impact on Superfund Sites, Waste Management Units

The Legal Intelligencer

(by Alana Fortna)

The Clean Water Act regulates the discharge of pollutants into “waters of the United States” pursuant to National Pollutant Discharge Elimination System (NPDES) permits issued by the U.S. Environmental Protection Agency (EPA) or an authorized state agency. This is not a new concept. However, what has come to be known as “the groundwater conduit theory” is disrupting the long-standing understanding of what is and what isn’t covered by the Clean Water Act. This new theory also creates questions for companies and attorneys dealing with Superfund sites and waste management units regulated under RCRA. This article discusses the circuit split on this theory and what I view as potential implications for Superfund sites and waste management units depending on how the U.S. Supreme Court rules.

Several federal cases have addressed the issue of the indirect discharge of pollutants into jurisdictional waters via groundwater transport, and the Supreme Court may weigh in on this question soon. This is an important issue with far-reaching ramifications because it is generally understood that all groundwater that is not otherwise removed (i.e., pumped for drinking water supply) will eventually discharge to a surface water. The Clean Water Act prohibits discharges of pollutants from a “point source” without a NPDES permit, 33 U.S.C. Section 1342. A “point source” is defined as “any discernible, confined and discrete conveyance, including but not limited to any pipe, ditch, channel, tunnel, conduit, well, discrete fissure, container, rolling stock, concentrated animal feeding operation, or vessel or other floating craft, from which pollutants are or may be discharged.” Based on this definition, discharges into and through groundwater have not been considered point source discharges because they are not the typical “end of the pipe” discharges. Recent case law out of the U.S. Courts of Appeal for the Fourth, Ninth and Sixth Circuit has resulted in a circuit split on coverage under the Clean Water Act.

In Upstate Forever v. Kinder Morgan Energy Partners, 887 F.3d 637 (4th Cir. 2018), the Fourth Circuit evaluated Clean Water Act coverage for a discharge from a ruptured pipeline in South Carolina. The court interpreted the Clean Water Act to prohibit indirect discharges from point sources to navigable waters as long as the discharge is “sufficiently connected to navigable waters.” To be sufficiently connected, there must be a “direct hydrological connection” between the point source and the navigable waters. In Hawaii Wildlife Fund v. County of Maui, 886 F.3d 737 (9th Cir. 2018), the Ninth Circuit addressed discharges to wastewater treatment plant wells that eventually reached the Pacific Ocean. The Ninth Circuit similarly found Clean Water Act liability based on indirect discharges but further limited coverage to instances where “the pollutants are fairly traceable from the point source to a navigable water such that the discharge is the functional equivalent of a discharge into the navigable water” and the pollutants that reach the surface water are more than “de minimis.” The Sixth Circuit diverged from both the Fourth and Ninth circuits by holding that both courts expanded Clean Water Act coverage beyond what was envisioned. The Sixth Circuit reviewed two cases involving discharges from coal ash ponds and held that a discharge for purposes of the Clean Water Act occurs only where the pollutant is added to jurisdictional waters “by virtue of a point-source conveyance,” see Kentucky Waterways Alliance v. Kentucky Utilities, 905 F.3d 925 (6th Cir. 2018) and Tennessee Clean Water Network v. Tennessee Valley Authority, 905 F.3d 436 (6th Cir. 2018). The decisions of the Fourth and Ninth circuits have been appealed to the Supreme Court. The Supreme Court has granted the petition from the Ninth Circuit case as to the following question: “Whether the Clean Water Act requires a permit when pollutants originate from a point source but are conveyed to navigable waters by a nonpoint source, such as groundwater.” The Supreme Court has not yet ruled on the petition from the Fourth Circuit case, which asks the court to consider whether the Clean Water Act “also applies to discharges into soil or groundwater whenever there is a ‘direct hydrological connection’ between the groundwater and nearby navigable waters.”      

If the Supreme Court agrees to hear both appeals from the Fourth and Ninth circuits, the decisions could have an impact on companies and attorneys involved in Superfund site cleanups and waste management units at operating facilities. With regard to Superfund sites, a decision that affirms the Fourth and Ninth circuits could create future liability at a site where a company has already invested significant time and expense in a remedial investigation and design work. If a company has not achieved complete source control, then it could arguably face additional liability under the Clean Water Act for contamination that is migrating from the source area into groundwater and ultimately to a navigable water. The issue becomes more complicated when it is a large Superfund site with multiple source properties contributing the same contaminants of concern. Who shoulders the liability under the Clean Water Act? How do the companies establish that they are not the source of the discharge from the groundwater to the surface water? Is there a plausible way to apportion the liability when you have a commingled plume? These are questions that are not easily answered and could be very costly to answer. Moreover, remediation activities at Superfund sites take time and are subject to an established procedure under the regulatory scheme. Depending on how the Supreme Court rules, this procedure could be disrupted by citizen suit challenges. Environmental groups who disagree with the agency’s approach to the remediation or who think the remediation work is taking too long could attempt to influence the remedial action through a Clean Water Act citizen suit.

Similarly, the requirements for design, operation and closure of hazardous waste management units at operating facilities are regulated under RCRA. Specific regulations have been developed for various types of hazardous waste management units under Subtitle C of RCRA in 40 CFR parts 264, 265 and 266. The regulatory requirements are intended to protect human health and the environment from the risks posed by hazardous waste. Closure decisions that are made pursuant to solid waste regulations under RCRA (or state law by delegation) can be challenged by citizen groups under the Clean Water Act. This is problematic because there is more certainty under RCRA versus the Clean Water Act. In this regard, the Clean Water Act prohibits unpermitted discharges regardless of the level of pollutants or any evaluation risk. For a RCRA citizen suit, the plaintiff has the heavy burden of establishing an “imminent and substantial endangerment.” Because RCRA is based on level of risk, it does not necessarily follow that the only remedy will be source removal. Rather, there are likely multiple remedial alternatives that can abate a RCRA violation or be approved as a final remedy at a Superfund site. If the Supreme court establishes liability under the Clean Water Act for scenarios involving hazardous waste management units, then companies closing such a unit could face citizen suits where the environmental group argues that the only appropriate remedy is elimination of the discharge (i.e., removal of the source).

In short, how this case law develops is relevant not only from a NPDES permitting standpoint, but also from a remediation and waste management standpoint. Depending on how the groundwater conduit theory progresses, it could lead to substantial uncertainty for companies dealing with remediation at Superfund sites or closure of a hazardous waste management unit.  Babst Calland Clements & Zomnir will continue to monitor this case law for purposes of evaluating its potential impact on these regulatory schemes.

Alana Fortna is a shareholder in the environmental and litigation groups of Babst Calland Clements & Zomnir. She represents clients in large-scale cost recovery actions under CERCLA and state law statutes, actions seeking injunctive relief under RCRA, and citizens’ suits brought under various federal statutes and regulatory programs including the Clean Water Act and the Clean Air Act. Contact her at

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