Swimmers and surfers at two of La Jolla's most popular beaches face bacteria warnings after San Diego County added La Jolla Cove and WindanSea Beach to its active advisory list.
The advisories were in effect as of Saturday, Oct. 3, according to the UCSD Guardian, which reported on the county's Beach & Bay Water Quality Monitoring Program data. The Children's Pool, which has carried a continuous advisory since 1997, remains under its own separate warning.
Black's Beach and La Jolla Shores were not under advisories as of Oct. 3.
The San Diego County Department of Environmental Health and Quality (DEHQ) issues advisories when water samples exceed 1,413 DNA copies of fecal bacteria per 100 milliliters. During an advisory, swimmers enter the water at their own risk. Closures, a more severe designation, bar swimming entirely.
Countywide, four beach closures and five advisories were in effect as of Oct. 3. Two closures at Border Field State Park and Tijuana Slough National Wildlife Refuge in Imperial Beach have been in place since October 2025.
Collapsed Tijuana pipeline drove sewage surge
The contamination traces to a major infrastructure failure south of the border. The Parallel Gravity Line, Tijuana's 10-mile main sewage pipeline, collapsed in two separate sections within two weeks in May 2026. The Mexican-owned line normally carries wastewater to the San Antonio de los Buenos treatment plant in Tijuana, which has a capacity of 18 million gallons per day, as KPBS first reported on June 1.
After the collapse, transboundary sewage flow from the Tijuana River into the Pacific Ocean jumped from roughly 10 million gallons per day to 34 million gallons within three days, according to data from the International Boundary and Water Commission (IBWC). The IBWC's update page confirms the U.S. section responded to a second pipeline break on Saturday, May 30, after an earlier break had been repaired around May 16.
The damage has not gone unnoticed. Patrick McDonough, senior attorney for San Diego Coastkeeper, told KPBS on June 1, after the pipeline collapsed, that his organization routinely receives email updates about ruptures in Tijuana's wastewater system that lead to spill events affecting local waters.
Health risks for La Jolla beachgoers
The DEHQ warns that sewage-contaminated water can cause cholera, dysentery, stomach flu and typhoid. Symptoms include diarrhea, rashes, eye irritation, coughing and congestion. Contaminated water can also carry rotavirus, polio and hepatitis A.
The advisories are disrupting organized water activities. Daniel Peterson, a UC San Diego fourth-year student and Triton Divers Club representative, told the UCSD Guardian that the club has to relocate when pollution levels spike.
"If there is a warning or the levels of pollution are too high, we do have to relocate," Peterson said. "If the water is too polluted … going in the water can cause … skin rashes and all sorts of other things."
La Jolla Cove has faced intermittent bacteria advisories since January 2026, according to lajolla.ca. The advisories will remain in effect until further notice.
Residents can check live beach water quality status at sdbeachinfo.com or by calling 619-338-2073.
