On February 1, 2018, the U.S. Court of Appeals for the Ninth Circuit issued a highly anticipated decision in Hawai’i Wildlife Fund v. County of Maui, No. 15-17447 (9th Cir. Feb. 1, 2018). The court held that the County of Maui (County) is required to obtain a Clean Water Act (CWA) permit to dispose of recycled water via discharge into groundwater that is hydrologically connected to the ocean.

The case has broad implications for water supply and wastewater treatment agencies across the West because it would require certain types discharges to groundwater to be regulated under the CWA’s National Pollutant Discharge Elimination System (NPDES)—thereby importing all the CWA’s surface water–related requirements (including the ability for private citizens to bring enforcement lawsuits) into the groundwater setting.

Portrait photo of Andre Monette
Andre Monette, member of the Environmental & Natural Resources practice group in Best Best & Krieger LLP’s Washington, DC, office.

The discharges at issue in the Ninth Circuit case emanate from the Lahaina Wastewater Reclamation Facility on the northwest coast of Maui (between Lahaina and the Kapalua airport). The facility is the principal municipal wastewater treatment plant for West Maui. It receives approximately 4 million gallons of sewage per day from a collection system serving approximately 40,000 people. That wastewater is treated and used as recycled water for irrigation throughout the area, including on nearby golf courses. Excess recycled is injected into wells at the facility.

While the County initially considered building an ocean outfall to dispose of excess recycled water directly into the ocean, it decided against that because of potential harm to coastal waters. Instead, the County installed two wells in 1979 as part of the original plant design, and two more were installed in 1985 as part of an expansion project. The County uses the wells to dispose of a large portion of the recycled water it produces at the plant, approximately 3 to 5 million gallons per day.

In June 2013, the U.S. Environmental Protection Agency (EPA), the Hawaii Department of Health, the U.S. Army Engineer Research and Development Center, and researchers at the University of Hawaii conducted a study on three of the four wells to gather data on the hydrological connections between the injected recycled water and the coastal waters.

The study involved placing tracer dye into the wells and monitoring submarine seeps off the nearby beach. The study concluded that a hydrogeologic connection exists between two of the three wells tested and the nearby coastal waters. Eighty-four days after injection, tracer dye introduced into two of the wells began to emerge from the seafloor along North Kaanapali Beach, near Kahekili Beach Park, about a half-mile southwest of the treatment plant. According to the study, 64 percent of the treated wastewater injected into the two wells eventually makes it to the ocean.

In 2012, after prior reports that recycled water from the Lahaina treatment plant was discharging to the ocean, four environmental advocacy groups filed suit under the CWA against the County. The lawsuit alleged that the discharges to groundwater were effectively to surface waters and subject to the CWA’s NPDES program. The Federal District Court for the District of Hawaii agreed, holding that that the groundwater was acting as a conduit for the discharges, making them within the CWA’s NPDES requirements.

The County appealed to the Ninth Circuit Court of Appeals. There, a three-judge panel agreed with the lower court, holding that any time there is a “fairly traceable” connection between a discharge to groundwater and discharges from the groundwater to a surface water, the original discharge will be subject to the CWA’s NPDES program.

The court’s decision represents a major departure from past application of the CWA. The plain text of the CWA provides that any discharge of a pollutant from a pointsource to waters of the United States requires an NPDES permit. The term “waters of the United States” has been defined broadly by the courts and EPA but does not include groundwater. As a result, discharges to groundwater on their own do not trigger NPDES requirements.

These discharges are not unregulated, however. Under state law, most states regulate the quality of groundwater and the use of groundwater from both a supply and a quality perspective. Federal law does as well, in the form of the Safe Drinking Water Act, the Resource Conservation and Recovery Act, and the Comprehensive Environmental Response, Compensation, and Liability Act (also known as the Superfund act).

The Ninth Circuit noted this aspect of the CWA. Instead, like the lower court, the Ninth Circuit held that discharges through groundwater could be subject to NPDES requirements, even if the intermediary water body was not subject to the same requirements. The court compared the discharges at issue in Maui to cases involving the aerial application of pesticides. In those cases, and famously in a related case involving the Navy’s discharge of explosive ordinance during live fire exercises in Puerto Rico, courts have held that discharges to air over water are subject to the NPDES program.

If the court’s decision stands, it will have major implications for water supply, wastewater, and flood control projects. One example is groundwater recharge. Underground storage of water allows agencies to have a place to put water while reducing losses from evaporation. To protect the raw water from saltwater intrusion, some projects also rely on injecting recycled and potable water into groundwater basins to create a barrier between saltwater and freshwater. Under the “fairly traceable” standard, if an agency puts water containing elevated TDS, nitrogen, chlorine, or any other “pollutant” into the ground as part of a groundwater recharge project and that pollutant migrates to any “waters of the United States,” the discharge would require an NPDES permit.

Requiring an NPDES permit puts existing and future recharge projects at risk because it can be difficult to develop appropriate or attainable permit requirements. Traditionally, the CWA imposes effluent limitations that apply at the end of the pipe that the water discharges from. A discharge that moves through another medium can change during that journey in ways that are hard to quantify. Thus, what leaves a groundwater aquifer and enters a surface water can be very different than what was discharged into the groundwater in the first place. The CWA has strict requirements that were developed to apply to discharges to surface water that will be difficult to manage in the groundwater setting.

Similar cases are pending in North Carolina, Ohio, Kentucky, New York, Tennessee, and Virginia. If these courts adopt the Ninth Circuit’s rationale, it will expand the reach of the CWA to a whole range of activities that it currently does not cover. For those in the water supply, wastewater, or flood control industries, it would mean greater regulation by the federal government and exposure to private lawsuits from environmental groups.

The fact that so many other courts are considering the issue also raises the potential that the Supreme Court may weigh in. As of March 2018, the County of Maui has asked the Ninth Circuit to reconsider its decision. If that request is denied, it is likely that the County will ask the Supreme Court to take the case.

Andre Monette is a member of the Environmental & Natural Resources practice group in Best Best & Krieger LLP’s Washington, DC, office. You can reach him at andre.monette@bbklaw.com.