The San Diego Regional Water Quality Control Board issued the investigative order to the owners and operators of municipal stormwater sewer systems and publicly owned sewage collection systems and treatment works after monitoring by the Southern California Coastal Water Research Project (SCCWRP) revealed high concentrations of human fecal matter in 12 locations sampled during storms in 2016-17.
“The adoption of the investigative order continues the Water Board’s efforts to focus on outcomes that restore and protect human and environmental health,” said David Gibson, Executive Officer of the San Diego Water Board. “Identifying and eliminating or reducing sources of human fecal waste is the best approach to ensuring our waters are safe and support many beneficial uses.”
The SCCWRP study of the Lower San Diego watershed also detected the presence of norovirus, a pathogen that can cause gastrointestinal illness. The risk of disease is elevated for individuals engaging in water-contact recreational activities after storms – most notably surfers, who spend considerable time in the water regardless of season. While the region’s beaches are among the cleanest in the state, water quality deteriorates during storms and wet weather, when stormwater infrastructures often fail to fully capture and treat urban runoff.
Besides the potential health risks, beach closures due to poor water quality harm the state economy.
Millions of tourists and residents, for instance, visit California’s beaches annually to swim, kayak, dive or surf, generating more than $10 billion per year.
Under the order, which was released for public review and comment in May 2018, the agencies have six months to produce an investigation workplan and are required to submit a final report quantifying actual and suspected sources of human fecal discharges within five years. The extended time frame was established primarily because of the large number of agencies involved (10) and the fact the recurring discharges appear to originate from diffuse sources throughout the Lower San Diego River Watershed, an area that extends from the inland community of Lakeside to Ocean Beach, a distance of 24 miles. Based on the best available information, these potential sources include:
- Overflows and leakage from publicly owned sewer collection systems
- Discharges and leakage from private pipelines
- Faulty septic systems on residential properties
- Homeless encampments located near the Lower San Diego River and its tributaries
Once the origin and transport pathways of the discharges are established, the Board will evaluate the effectiveness of existing pollutant control programs and can pursue abatement and remediation measures to improve water quality in the watershed and downstream beach coastal areas. The directive also will lead to a better understanding of the potential health risks and the transport pathways into the Lower San Diego River, through Mission Valley, past Mission Bay and into Ocean Beach.
The mission of the San Diego Water Board is to protect and restore the chemical, physical and biological integrity of waters in the region. To learn more about the monitoring and assessment program, visit our website here.