Debates over the reach of the Clean Water Act (“CWA”) have been ongoing for decades. At stake is whether a discharge of a pollutant from a point source to a “navigable water,” defined as “waters of the United States” (“WOTUS”), requires the discharger to obtain a National Pollutant Discharge Elimination System (“NPDES”) permit. The first two sections of this article explore two recent WOTUS developments: U.S. Supreme Court review of the “groundwater conduit” theory of CWA jurisdiction, and a proposed revision to the definition of WOTUS. The third section provides a brief summary of WOTUS-related developments for additional context

1. The “Groundwater Conduit” Theory Heads to the Supreme Court

The question of whether a NPDES permit is required for discharges of pollutants to groundwater that ultimately reach jurisdictional waters is being considered in the October 2019 Term by the U.S. Supreme Court.

The CWA prohibits the discharge of a pollutant into “navigable waters,” defined under the act as “the waters of the United States, including the territorial seas,” from a “point source” without a NPDES permit.  A “discharge” is defined as “any addition of any pollutant into navigable waters from a point source.” 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.” Whether a discharge to groundwater that makes its way to a jurisdictional surface water is a discharge requiring a NPDES permit has long been debated.

On February 19, 2019, the  Supreme Court granted certiorari in County of Maui v. Hawai’i Wildlife Fund (Supreme Court Case No. 18-260) on one question: “Whether the CWA requires a NPDES permit when pollutants originate from a point source but are conveyed to navigable waters by a nonpoint source, such as groundwater?”  There is a split in the circuits on this question.

The Sixth Circuit has held in two separate decisions that a NPDES permit is not required for pollutants leaching from coal ash ponds at power plants that migrated through groundwater to navigable waters. These decisions declined to apply decisions of the Fourth and Ninth Circuits requiring NPDES permits for pollution from a pipeline spill discharging several thousand gallons of gasoline to groundwater that eventually reached navigable waters (Fourth Circuit) and for the placement of treated wastewater into injection wells that was proven, via dye tracer tests, to reach the Pacific Ocean (the Maui case in the Ninth Circuit).

EPA had filed an amicus brief in Maui before the Ninth Circuit, supporting the view that the Maui discharges required a permit if the discharges reached jurisdictional surface waters through groundwater with a direct hydrological connection to that surface water. On April 15, 2019,  EPA issued an “Interpretive Statement” reversing that position, effectively siding with the Sixth Circuit and stating that releases of pollutants to groundwater are “categorically excluded from CWA jurisdiction…because Congress explicitly left regulation of discharges to groundwater to the states and to EPA under other statutory authorities.”

Recently, the County of Maui considered an offer of settlement from the environmental plaintiffs – which would have removed the case from the Supreme Court docket – but ultimately rejected the offer. Maui has been briefed before the Supreme Court but is not yet scheduled for argument.

The Maui case raises interesting policy and administrative law questions about judicial deference to agency interpretations. One such question is whether, in considering the issues in Maui, the Court might rely on the Chevron doctrine of deference to reasonable agency interpretations of ambiguous statutes to defer to EPA’s April 15, 2019 Interpretive Statement excluding groundwater from the jurisdictional waters of the United States under the CWA. In another case that it recently decided, Kisor v. Wilkie, the Supreme Court declined to overturn the related Auer doctrine of affording judicial deference to agency interpretations of their own regulations. Notably, in separate concurring opinions, Justices Roberts and Kavanaugh emphasized that the Kisor opinion did not affect the Chevron doctrine.

2. What is a “Water of the United States”? Recent Regulatory Developments

Our prior blog posts (available here, here, here, and here) have explored developments around the 2015 (Obama administration) “WOTUS Rule” describing which bodies of surface water are considered “waters of the United States” subject to CWA jurisdiction. At the time of the issuance of the 2015 rule, EPA and the Army Corps of Engineers (“ACOE”) (collectively, the “Agencies”) estimated that it would result in 2.84-4.65% more positive assertions of jurisdiction over US waters. Opponents, including agricultural interests, fear that the rule leaves open too great of a space for regulators or courts to determine that certain ditches or depressions are included in jurisdictional waters.

On February 14, 2019, the Agencies published for comment a proposed Replacement WOTUS Rule  (the “Proposed Rule”). Some key provisions of the Proposed Rule include:

• The preamble to the Proposed Rule emphasizes the importance of the states’ autonomy to regulate their waters, and the need for regulatory clarity on which waters are jurisdictional under the CWA.
• The Proposed Rule emphasizes the reasoning in Justice Scalia’s plurality opinion in Rapanos v United States, which made a “direct hydrological connection” to traditional navigable waters a critical factor in determining whether a water body was subject to CWA jurisdiction. By contrast, the 2015 WOTUS Rule emphasized Justice Kennedy’s concurring opinion in that case, which provided that a “significant nexus” to a traditional navigable water was required for a water body to be jurisdictional.
• Under the Proposed Rule, tributaries, which are subject to CWA jurisdiction, must convey perennial or intermittent flow downstream to a traditional navigable water, where “perennial” means surface water flowing continuously year-round during a typical year, and “intermittent” means surface water flowing continuously during certain times of a typical year — not merely in direct response to precipitation.
• Under the Proposed Rule, wetlands subject to CWA jurisdiction must abut or have a direct hydrological surface connection to other Waters of the United States in a typical year.
• The Proposed Rule specifies which ditches are subject to CWA jurisdiction.
• The Proposed Rule limits CWA jurisdiction over lakes and ponds to those that are traditionally navigable waters, or that contribute perennial or intermittent flow to a traditional navigable water.

3. The Context: A Short Timeline of Key WOTUS Definition Developments Since 2015:

• In October 2015, the Sixth Circuit issued a nationwide stay of the 2015 WOTUS Rule.
• In February 2017, the President issued Executive Order 13788, ordering EPA and the Army Corps of Engineers (the Agencies) to review the 2015 WOTUS rule and to issue a proposed rule rescinding or revising the 2015 WOTUS Rule as appropriate and consistent with the law.
• In June 2017, the Agencies proposed a rule to rescind the 2015 WOTUS Rule, with the intention of issuing a replacement rule in the future. A supplemental proposal to “clarify, supplement and seek additional comment” on this proposed rule was issued in July 2018.
• On February 6, 2018, the Agencies issued a rule to delay the implementation of the 2015 WOTUS Rule until at least 2020. This “Suspension Rule” was immediately challenged in court.
• On February 28, 2018, the Sixth Circuit vacated its nationwide stay of the 2015 WOTUS Rule, pursuant to a Supreme Court decision holding that the federal district courts, rather than appellate courts, had original jurisdiction under the CWA to hear challenges to the WOTUS Rule.
• On June 8, 2018, the Southern District of Georgia enjoined the implementation of the 2015 WOTUS Rule in the 11 states that had challenged it before that court: Georgia, Alabama, Florida, Indiana, Kansas, North Carolina, South Carolina, Utah, West Virginia, Wisconsin, and Kentucky. These 11 states join 13 states that are subject to a similar injunction imposed by a federal court in North Dakota in 2015. Thus, as of this ruling, the 2015 WOTUS Rule was enjoined in 24 states, and would be effective in 26 states (plus the District of Columbia and U.S. Territories), but for the Suspension Rule.
• On August 16, 2018, the District of South Carolina enjoined the Suspension Rule nationwide. Thus, as of that ruling, the WOTUS rule was effective in 26 states (plus the District of Columbia and U.S. Territories) and enjoined in the remaining 24 states.
• In September 2018, the Southern District of Texas and the District of North Dakota issued separate injunctions that collectively enjoined the 2015 WOTUS Rule in Texas, Mississippi, Louisiana, and Iowa. Thus, as of these rulings, the 2015 WOTUS Rule was effective in 22 states (plus the District of Columbia and U.S. Territories) and enjoined in 28 states.
• On November 26, 2018, the Western District of Washington vacated the Suspension Rule.
• On December 4, 2018, the District of South Carolina vacated the Suspension Rule nationwide.
• In March 2018, the Agencies abandoned their defense of the Suspension Rule, filing motions to dismiss their appeals of the orders vacating that rule.
• On February 14, 2019, the Agencies issued the Proposed Rule. The comment period closed on April 15, 2019.

EPA is now reviewing the estimated 500,000 comments that were filed on the Proposed Rule. We are tracking further developments and will provide updates.