Clean Water Act Permitting Reaches Groundwater

Discharging pollutants to navigable waters has required an NPDES permit under the Federal Clean Water Act for nearly 50 years.  Now, pollutants discharged to land that seep in groundwater to navigable waters are also subject to (sometimes) NPDES permit requirements.

The Maui municipal wastewater plant collects and treats about 4 million gallons per day and pumps it into four 200-foot wells.  If the treated wastewater were discharged directly into the ocean, a Clean Water Act NPDES permit would clearly be required, but in this case, the discharge wells were located about a half mile from the Pacific Ocean, so no permit was sought.  The Hawaii Wildlife Fund sued, claiming a permit is required because the wastewater pollutants travel in groundwater to the ocean.

The District Court found the discharge from the wells to the ocean was “functionally one into navigable water,” and the Ninth Circuit affirmed that a permit is required when “pollutants are fairly traceable from the point source to a navigable water.”  On April 23, 2020, the Supreme Court affirmed with a different standard, holding that a permit is required when a discharge is the “functional equivalent of a direct discharge” from a point source into navigable waters.

In a split decision, the Supreme Court found the Ninth Circuit’s “fairly traceable”  analysis too broad, potentially encompassing pollutants that reach navigable waters from miles away and years after discharge.  However, the “functionally equivalent” standard offers little improvement in clarity.  While there would be little dispute over circumstances at the ends of the spectrum (a discharge pipe mere feet from navigable waters on the one hand, and a discharge pipe hundreds of miles from the nearest navigable waters on the other), there is fertile ground for differing interpretations of the vast area in between.  The Court identified a number of “potentially relevant factors” that may inform an assessment of how functionally equivalent a transmission through groundwater is to a point source discharge.  They include, among other things: transit time, distance traveled, the nature of the material through which the pollutant travels, the extent of dilution or chemical alteration during transit, and the amount of pollutant that reaches navigable waters relative to the amount discharged.  The Court remanded the matter to the Ninth Circuit to apply the new standard.

The decision came just days after the Environmental Protection Agency and the U.S. Army Corps of Engineers released the final rule redefining Waters of the U.S. (“WOTUS”), which replaced the 2015 Rule that sought to codify multiple Supreme Court Decisions, including the contentious Rapanos decision, but which set off a cascade of legal challenges.  Pursuant to a Trump Executive Order seeking to narrow the reach of the CWA, federal agencies repealed the Obama-era rule and replaces it with a new rule that takes effect June 20, 2020.  Lawsuits are already being filed.

The decades-long theme of waiting for clarification on CWA jurisdiction continues.