Beach warning signs at Imperial Beach on July 14, 2022
Beach warning signs at Imperial Beach on July 14, 2022

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New technology revealed coastal waters in San Diego’s southernmost cities are likely contaminated by sewage from Mexico a lot more often in the touristy summer season than we ever knew before. But now the mayors of those cities want to go back to testing beach water quality the old way.

The county of San Diego’s rollout of the new technology and subsequent closing and abrupt reopening of beaches has confused beachgoers and drawn divisions between South Bay elected officials and their staff who are all fighting the same source of pollution: Sewage spilling from Tijuana over land and water borders into the U.S.

San Diego County is reportedly the first in the world to use this sensitive water quality test that counts bacteria by its DNA for routine beach monitoring. It revealed the Pacific Ocean off the shores of Imperial Beach through Coronado fail public health safety standards more often than previous technology could detect. At first, better and more rapid water quality results was something those cities supported. Sentiments changed. 

Coronado Mayor Richard Bailey points at the city’s beach area on a map on Monday, July 11, 2022. / Photo by MacKenzie Elmer

In a July 18 letter to the San Diego County Board of Supervisors, Mayors Richard Bailey of Coronado and Serge Dedina of Imperial Beach urged the county to return to the method that takes longer to return results but doesn’t trigger beach closures as often. 

“This test is tried and true and the public understands its operation and degrees of risk. In sum, it has been working,” the mayors wrote. 

Supervisor Nora Vargas, whose district includes Imperial Beach and the border, said it was advocates like Dedina who asked the county for improved pollution monitoring at beaches in the first place.

“If cities want to regress in water testing methods that potentially risk the health and safety of beachgoers, they can directly petition for a change to the old testing method at the state level,” Vargas said in an emailed statement Tuesday. 

Dedina’s co-signature on this letter demanding the county revert to using the old testing method conflicts with the opinion of the city’s staff. Imperial Beach’s environmental and natural resources director, Chris Helmer, has said they’re working with the county and support the new testing technology

Dedina has been one of the most vocal critics of the Tijuana border sewage spills, spearheading lawsuits against federal agencies responsible for border water issues and lobbying for and helping to secure millions of dollars from Congress to build bigger and better sewage treatment where the two nations meet. For years, he’s pointed to beach closures supported by failed water quality tests as evidence that the lives and businesses of Imperial Beach citizens were constantly at risk. 

Imperial Beach Mayor Serge Dedina speaks at a press conference in June 2021 about COVID-19 cross-border travel restrictions, with County Supervisor Nora Vargas in the background. / Photo by Adriana Heldiz

Now there’s a test that further supports those claims he’s long held to. The Imperial Beach shoreline was closed 81 percent of the month of May, according to the July letter from the mayors. 

Dedina says he felt the county blindsided him by dropping this new testing program without alerting all the stakeholders. 

“In nine years, I had not ever heard back from the county at all on any sort of update on the rapid testing,” Dedina said. “The next thing you know, there’s word the testing has happened, the beaches closed and with any attempt to communicate with the county, the door shuts.” 

The mayor said he feels Imperial Beach is being punished, in particular by Supervisor Vargas, who Dedina says has refused to accept meetings with him since February of 2021 after he co-signed a different letter criticizing the county’s COVID-19 vaccine rollout program. The letter was directed at the chair of the Board of Supervisors, Nathan Fletcher, and pointed to county data showing underserved groups and people of color had received fewer vaccine locations and doses despite having the highest infection rate. 

Before the rapid test rollout, and in lieu of better technology on the horizon, Dedina said the city worked closely with the county Department of Environmental Health to develop another kind of warning system when conditions were ripe for the ocean’s currents to sweep sewage from Tijuana northward. Imperial Beach lifeguards watched for signs of sewage – a smell or discolored water — and when the winds changed and southern swells came for Southern California, they’d notify the county. 

“The county discarded 25 years of best practices to review science and testing and figure out a system that works best. All of a sudden they said, your input is not required,” Dedina said. 

Following outrage over a series of beach closures during the new test rollout, the county abruptly changed its policy and opted for a new warning sign to be placed at beaches that fail the new water quality test and experience south swells or other signs of possible sewage contamination. That technically leaves the beaches open and the decision of whether to enter the water up to the public. 

Stephanie Kaupp, a Coronado resident who said she uses the beach but doesn’t recreate in the ocean water itself, is still disappointed in the mayors’ position.

“What happens if we rely on the old test which is less reliable and timely, now it’s left for the public to decide whether we should go in the water, but we can’t make an informed decision,” Kaupp said.

A beach in the city of Coronado. / Photo by MacKenzie Elmer

The mayors, according to their letter, want the county to ditch those warning signs as well saying they place “too great of a burden on public access and risk to public health.” Devonna Almagro, Vargas’ director of communications, said the warning system was a compromise after those same mayors petitioned to reopen beaches that were failing the new water quality tests. 

“If there wasn’t that system… and the water was contaminated, then those beaches would be closed,” Almagro said.                           

Bailey, the Coronado mayor, said in a follow up interview that he doesn’t believe the county should abandon testing waters with the new technology altogether, however. 

“We just don’t want to be the guinea pigs for the new test that might not have been thoroughly vetted in terms of public policy implications,” Bailey said. 

Two summer beach events in Coronado, including the California State Games junior lifeguard competition, were canceled earlier this month over concerns about the water quality. 

Imperial Beach from the border to Seacoast Drive has been closed since December of 2021. As of Thursday, beach contamination warnings along Coronado’s beaches lifted, save for one testing site at Avenida Lunar where the new test revealed bacteria levels twice as high as what’s safe under public health standards.

Join the Conversation


  1. Aside from the controversy at hand, I am concerned for the health of the lifeguards. Their job is to safeguard people in the ocean and to do so they have to enter the water to effect rescues, take preventive actions, and the like. Under the old system, the County legally closed the water to human contact and the lifeguard agencies were empowered, if they so chose, to prevent people from entering the water (Penal Code Section 409.5). Under the new system, lifeguards can’t enforce a closure, because the County has not closed the area (though the health hazard is at a level that they previously did close it). Therefore, the lifeguards are essentially forced to expose themselves as a routine of their job.

  2. Disappointed in the South Bay Mayors, instead of leading and demanding the state and Federal Government do something about the TJ river where we know the sewage is coming from they want to take the easy way out and ignore the problem. That is not the way to lead, and clearly is in keeping with their general attitude with governance, ignore the problem until it’s someone else who has to fix.

  3. Remember when the Mayor in Jaws wanted to keep the beach open on Amity Island during tourist season?

  4. Dedina and Bailey want the pollution problem to be handled like the COVID: stop testing and it will just go away. Wrong.

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