The San Diego Regional Water Quality Control Board (Water Board) filed a complaint on September 4, 2018 against the United States Section of the International Boundary Water Commission (IBWC), alleging violations of the Clean Water Act (CWA) related to contamination in the Tijuana River. Relying on a 1944 U.S./Mexico treaty, the complaint alleges that the IBWC is responsible for addressing waste entering the U.S. from Mexico along the Tijuana River watershed.

The Tijuana River crosses the border into California through a flood conveyance channel operated by the IBWC, feeds the Tijuana River Estuary—a coastal wetland home to multiple species protected under the California Endangered Species Act—and eventually flows into the Pacific Ocean. The IBWC constructed and maintains a wastewater treatment plant and a supporting system of concrete channels, detention basins and pump stations to capture and treat waste flows entering the U.S. from Mexico. And, in 2014, the Water Board issued a National Pollutant Discharge Elimination System (NPDES) permit to the IBWC, allowing discharge of treated water into the Pacific Ocean.

The Water Board alleges numerous violations of the NPDES permit and the CWA. Specifically, the IBWC’s delinquent maintenance and operation of the water treatment facilities have allowed untreated wastes to enter the waters of the United States, impacting the Tijuana River and Estuary, and the Pacific Ocean. The complaint lists eleven discharge events from the wastewater collection system between April 2015 and February 2018. Testing of some of the alleged spill events show water quality exceedances for fecal coliform and enterococcus bacteria, and the presence of contaminants including mercury, chloroform, dichlorobenzene, copper, nickel, zinc, oil, ammonia grease, and suspended solids. Each of these listed substances are pollutants under the CWA and may only be discharged pursuant to a permit. Additionally, the IBWC allegedly failed to test three of the discharge events as required by its NPDES permit, so the full extent of the claimed contamination is unknown.

The Water Board contends that the contamination has impaired the beneficial uses of the impacted waters. Six miles of the river and the estuary have been listed as impaired water bodies as a result of continuing pollution. Additionally, beaches along the city of Imperial Beach near the Tijuana Estuary were closed over 200 days in 2015 and approximately 150 days in both 2016 and 2017 to protect the public from dangerous pollutants.

In its prayer for relief, the Water Board requests the court enter a judgment declaring that the identified releases were violations of the CWA and the NPDES permit and ordering IBWC to take all necessary actions to comply with the CWA and the NPDES permit. The Water Board also seeks attorney fees and costs pursuant to CWA Section 505(d), 33 U.S.C. § 1365(d), which allows recovery of litigation costs, including reasonable attorney fees, to any prevailing or substantially prevailing party.

The Water Board’s lawsuit comes only six months after a similar suit was filed by the City of Imperial Beach, City of Chula Vista, and the San Diego Unified Port District against the IBWC for the same Tijuana River-related pollution. In that case, the court recently held plaintiffs could maintain their claims under the CWA, but had failed to state a claim for violation of the Resource Conservation and Recovery Act because the complaint did not allege that the IBWC was actively involved in or had control over the waste disposal as required under Ninth Circuit precedent. Both lawsuits are before Judge Jeffery Miller in the U.S. District Court for the District of Southern California.