EPA Issues 2020 WOTUS Rule and Supreme Court holds groundwater may be jurisdictional

Last week brought two major developments under the Clean Water Act.  EPA published the 2020 Waters of the United States (WOTUS) Rule, which attempts to define the scope of waters subject to regulation under the CWA.  Among other things, the 2020 WOTUS Rule excludes groundwater from the definition of “waters of the United States.”  But just days later, the United States Supreme Court held in County of Maui v. Hawaii Wildlife Fund that, in certain circumstances, discharges to groundwater are subject to CWA permitting requirements.

2020 WOTUS Rule

The 2020 WOTUS Rule, which is distinct from the repealed 2015 WOTUS Rule, attempts to clarify the definition of “waters of the United States” by limiting it to four categories:

  1. territorial seas and traditional navigable waters;

  2. perennial and intermittent tributaries that contribute surface water flow to such waters;

  3. certain lakes, ponds, and impoundments of jurisdictional waters; and

  4. wetlands adjacent to other jurisdictional waters.

 The 2020 WOTUS Rule excludes from the definition of ‘‘waters of the United States’’ all waters or features not mentioned above. In addition to this general exclusion, the final rule expressly excludes:

  • groundwater;

  • ephemeral features;

  • diffuse stormwater runoff and directional sheet flow;

  • most ditches;

  • prior converted cropland;

  • artificially irrigated areas;

  • artificial lakes and ponds;

  • water-filled depressions constructed upland or in non-jurisdictional waters;

  • stormwater control features;

  • groundwater recharge, water reuse, and wastewater recycling structures; and

  • waste treatment systems.

Whether the 2020 WOTUS rule will survive judicial challenge remains to be seen, but its categorical exclusion of groundwater appears to have been indirectly overruled by the Supreme Court within days.

County of Maui v. Hawaii Wildlife Fund

This case involved a challenge to the County’s discharge of wastewater into four groundwater wells.  Once discharged, the wastewater travelled approximately a half-mile underground before it reached the Pacific Ocean.  The main question was whether the wastewater discharge required a permit under the CWA. The Supreme Court held that a CWA permit is required when either (1) there is a direct discharge from a point source into navigable waters or (2) where there is a “functional equivalent” of a direct discharge.  The analysis of whether a “functional equivalent” discharge exists is highly-fact specific, and courts must consider factors such as:

  • the distance between the point source and the navigable water;

  • the time that pollutants travel;

  • any dilution or chemical changes to the pollutant between the point source and the navigable water;

  • the amount of pollutant discharged from the point source and the amount entering a navigable water.

A County of Maui-type analysis might apply not just to direct injection via a well but also to situations such as seepage from an impoundment that moves through groundwater to a navigable water.  The main takeaway from the case is that discharges of pollutants to groundwater with the potential to reach navigable waters are likely now subject to a CWA “functional equivalent” inquiry. 

Chris Smith