The U.S. federal government, on request of the EPA, has filed a lawsuit against the City and Country of San Francisco over "its repeated and widespread failures to operate its two combined stormwater-sewer systems and sewage treatment plants in compliance with the law and its permits, and in a manner that keeps untreated sewage off the streets and beaches of San Francisco", informs Courthouse News.
The complaint states that the City’s combined sewer overflows (CSOs) discharge “billions of gallons of combined sewage each year onto the beaches of San Francisco and into San Francisco Bay and its tributaries”, and that the City fails to “adequately plan and prepare for, respond to, report, or provide public warnings for releases, overflows and backups of combined sewage and other pollutants to homes, yards, streets, and sidewalks”.
In response to the lawsuit, representatives from the San Francisco Public Utility Commission (SFPUC) said the litigation is "unfortunate", emphasizing the city's ongoing efforts to address infrastructure needs exacerbated by climate change and evolving water quality challenges. They argue that collaborative efforts, rather than legal recourse, are key to resolving regulatory concerns and effecting meaningful change.
Most of San Francisco is served by a combined sewer system that collects and treats both wastewater and stormwater in the same network of pipes, unlike other coastal cities in California which have separate sewer and stormwater systems. According to the SFPUC, their extensive system of underground storage, transport, and treatment boxes minimizes the frequency and volume of CSOs when extreme storm exceed the capacity of the system, and when discharges do occur, they consist overwhelmingly of stormwater. On average, discharges occur 10 times per year, while the average number of storms per year is 30.
The SFPUC argues that “San Francisco, and indeed every other combined sewer system in the country, cannot capture, treat and disinfect all of the stormwater from every storm”, due to the technical complexity, lack of feasibility, extremely high costs, and negligible environmental benefits. It has requested a “variance” for its bayside discharges – this is an available regulatory tool that would modify discharge requirements for a specific timeframe – while the City implements projects to protect water quality in San Francisco Bay for approximately $2.36 billion over the next 15 years.
The projects proposed by the SFPUC “represent the highest attainable water quality condition that can be cost-effectively achieved”, including $1.5 billion to reduce nutrients in the effluent of its Southeast WWTP and green infrastructure to divert stormwater into the ground.
Environmental advocacy groups like San Francisco Baykeeper contend that the city's wastewater treatment plants remain overwhelmed during heavy storms, leading to significant sewage and trash discharge into the bay. Baykeeper itself threatened to sue last March. “San Francisco is dumping raw sewage and trash directly into the Bay at a magnitude that’s almost incomprehensible,” said Baykeeper managing attorney Eric Buescher in a statement.
Baykeeper mentions estimates from SFPUC documents: “In a typical year, the agency discharges 1.2 billion gallons of combined stormwater runoff and sewage, which contains feces, bacteria, viruses, chemicals, and trash. In a wet year, the volume of discharge can exceed 2 billion gallons”, adding that 6% of its total discharge is sewage.
