Chronic Sewage Spills in San Diego

The fundamental problem with sewage in San Diego County is twofold: we have old and easily clogged or damaged infrastructure, and we have insufficient treatment. 

As infrastructure ages, pipes can corrode and break easily with the pressure of water flowing through them. This happened during San Diego County’s second largest sewer spill in March 2007, when a corroded sewer main that runs under Buena Vista Lagoon burst. The resulting sewage spill lasted three days and discharged 7.3 million gallons of untreated sewage into the lagoon. Nearly 1,700 fish died as a result of the sewage overwhelming the lagoon’s ecosystem.

Similarly, pipes that are not inspected and maintained frequently can get blocked and damaged by tree roots and grease that we pour down the drain.  Tree roots and grease are very common causes of spills in the system. According the State Water Resource Control Board, grease and tree roots cause about 79 percent of all spills in California’s municipal sewer systems.

Historically, the City of San Diego and Camp Pendleton wear the crown for major sewage spill culprits, but other agencies (e.g. Hale Avenue Resource Recovery Facility (HARRF) in Escondido, Oceanside) all experience spills that impact wildlife and public health. 

When sewage spills into San Diego’s water, it contains a mixture of substances, such as nutrients (nitrogen and phosphorus), pathogens (bacteria and viruses) and a suite of chemicals.

Nitrogen and phosphorus are important elements for photosynthetic organisms to thrive. However, when concentrations in water get too high, it results in excessive growth of photosynthetic organisms. This disrupts the amount of oxygen in the water available to aquatic animals. In some cases, it leads to large amounts of dead fish. Some forms of nitrogen and phosphorus are toxic to animals. 

San Diegans contribute too. We flush more than bodily wastes down the drain. Cosmetics and hair products wash off us. Our bodies only partially absorb medications we consume. These pharmaceuticals and personal care products flow through our drains to our sewer pipes. Our current wastewater technology does not remove these substances, and they are discharged into our coastal waters. A recent study conducted by the Southern California Coastal Water Research Project (SCCWRP) found that seawater and sediment in the vicinity of and effluent from the Point Loma treatment plant (and three others in Southern California) had measurable levels of common pharmaceuticals like ibuprofen, naproxen, and gemfibrozil (lipid-controlling medication) among others. Fish living in the vicinity of the plant also had measurable levels of a wide range of pharmaceuticals and personal care products like laundry detergent, antibiotics, sun block and flame retardants.

[1] State Water Resources Control Board, 2009. Statewide Sanitary Sewer Overflow Reduction Program Annual Compliance Report, Executive Director’s Report, May 2009. Appendix 4. 25 pgs. Data is from January 2007 through Arpil 2009.