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Even though San Diego beaches are failing water quality tests after public health officials implemented a new, more sensitive testing technology, the County of San Diego is leaving them open. 

At least, open to interpretation.

Summer beach closures cascaded over Imperial Beach and Coronado like never before after May 5, when the County of San Diego deployed a first-in-the-nation water quality test that counts bacteria by its DNA. That triggered backlash from elected officials concerned about losing access to beaches over the Fourth of July holiday.

Then, the county abruptly reopened them. 

By July 1, the county announced it would post new, blue signs at beaches warning there may be sewage in the water that could cause illness. While warning beach goers about the water, the county stipulated that it would only close beaches when there was a “known” source of sewage contamination, like a reported spill, or when the often-contaminated Tijuana River flowed into the Pacific Ocean.

Elise Rothschild, an environmental health specialist and formerly director at the county Environmental Health Department, said that was done so the public could make their own decisions about whether to enter the water.

 “We don’t have the authority to close the beaches” otherwise, she said. 

Coronado Mayor Richard Bailey argues that there’s another explanation for the county’s decision to warn of sewage in the water while allowing people to swim in it.  

“I think it’s because (the county doesn’t) believe in the integrity of their own test and methodology, and don’t want to face the public backlash that would ensue if the beaches closed half the year,” Bailey said. “They close the beaches all the time. That’s their job.” 

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

The county of San Diego began using a more sensitive water quality test along its coastline by May 5. The test looks for the presence of the Enterococcus bacteria, which is found in the gut of warm-blooded mammals, including humans. Find Enterococcus and there’s a good chance feces are also in the water, which means there could be harmful viruses present as well. COVID-19, for instance, can be tracked by looking for the virus shed in feces. 

By May 10, tests showed the shore water in Coronado was too dirty for human contact under public health standards established by the state. The county shut down the beaches.

Coronado’s beaches closed four more times in the ensuing weeks, alarming elected leaders there because the city faced the prospect of shuttered beaches during the holiday weekend. 

Bailey decried the sudden closures on the local news, telling Voice of San Diego it got to the point where he told the county he’d personally rip the closure signs from the sand.

“It’s unprecedented for our community. It’s unprecedented for public access to the shore. It’s unprecedented for economic development,” Bailey said. “This could have catastrophic effects for Coronado.”

Initially, Bailey blamed the new water quality test because, prior to its rollout, beaches in Coronado typically only faced closures after a huge winter storm or a major sewage spill from Tijuana over the border. While Imperial Beach, located closer to the border, can face closures year round due to contamination, Coronado’s beaches rarely do in the summertime.  

The pressure from beach communities mounted.

Beaches in Coronado and Imperial Beach were closed the morning of June 29 when water quality tests again showed bacteria levels exceeded state health standards. The morning of July 1, the county lifted the closure, but not because tests showed bacteria levels had fallen below the state’s threshold. 

Water quality tests taken hours before county officials lifted the closure show bacteria levels were still three times state health standards. Yet the county reopened the beach, replacing the closure signs with bright blue ones that issued a new warning: “Beach water may contain sewage and may cause illness,” it read. It was the first time the county had ever posted such a notice. 

“We are sampling South County daily because of the concern down there, so we are giving the public updated daily information for them to make their own decision,” said Rothschild of the Department of Environmental Health, which issues beach advisories and closures. 

That flummoxed Bailey. He wants the beach open but now can’t help but wonder whether the sudden reopening means the county isn’t standing behind its new water quality test.

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

“Here in Coronado, it’s created a lot of confusion because at the end of the day, the only question that matters is: ‘Is the water safe or not?’” Bailey said. 

Some members of the public are confused. Karl Bradley, a member of a citizen’s board that keeps tabs on the Tijuana River sewage problem said during a Thursday meeting that he wants to bring the county in to explain.

“I know they have different colored signs out there but I don’t know if one sign means, go in the water, and one sign doesn’t,” Bradley said. 

Cameron Kaiser, deputy director of the county’s Public Health Department, said the new testing technology is indeed indicating that bacteria levels in the water are exceeding state health standards more frequently than before.

“This test is superior and more sensitive,” Kaiser said. “It’s picking up stuff we couldn’t see before.” 

But the county is letting the public choose whether to swim in the water anyway, taking the position that it can’t close beaches based on the results of water quality tests alone.

“The County’s policy is to close beaches when there’s known sewage contamination,” wrote spokeswoman Donna Durckel in an email.   

In South Bay, everybody knows where the pollution is coming from, said Chris Helmer, the city of Imperial Beach’s environmental and natural resources director.

“It’s Punta Bandera,” Helmer said.

Punta Bandera is the name of a broken down wastewater treatment plant in Tijuana that’s spilling millions of gallons of untreated sewage pumped from Tijuana sewers straight into the Pacific Ocean virtually nonstop.

A Scripps Institution of Oceanography study recently confirmed the link between Punta Bandera and sewage contamination on Southern California beaches in the summertime. In the Northern Hemisphere’s summer, storms from the Southern Hemisphere push ocean currents northward that pick up sewage from Punta Bandera and carry it along the coast.

Helmer said the new test’s results only further confirm the Scripps study.

“What we’re asking is that the county take the lead on explaining the justifications for their signs, the science and reasons why beaches close,” Helmer said. “If beaches closed from known pollution sources south of the border, tell the public where those are. Be the spokesperson for beach water quality, not Imperial Beach or Coronado.”

Rothschild, from the county, wouldn’t confirm whether Punta Bandera sewage plumes count as “known” sewage, repeating that the county depends on an official report, like notifications from the border agency the International Boundary and Water Commission, which alerts the region of a sewage spill over the land border. The last report of a known spill from IBWC was April 28, well before the slew of beach closures after the sensitive test launched. 

As for the closures between May 5 and June 29, the county said it closed those beaches based on the test result and because south swell conditions or odors and discolored water were apparent. But since July 1, the policy changed, and those two conditions now trigger the new warning or regular beach advisory. 

Bailey said he wants the County Board of Supervisors to direct the public health department to continue testing beach water the previous way – under the test that is less sensitive but historically had rarely issued beach advisories or closures at Coronado in the summer. 

He pointed to data obtained from the county showing tests at the same beach under both methods showed drastically different results. 

“There’s a huge disconnect between the two. If that’s the case then the county has been doing it wrong for the past 25 years,” Bailey said. 

That differs from Imperial Beach’s stance.

“We’re very supportive of the new test in Imperial Beach,” Helmer said. “We’re not asking the county to change it.”

The county didn’t develop this test on its own. It worked for years in concert with the California Department of Public Health and the Southern California Coastal Water Research Project on research and development of the new digital droplet polymerase chain reaction (or ddPCR) test, which the U.S. Environmental Protection Agency approved for San Diego County’s use in May of 2021. San Diego is the first in the country to use it and it could soon be deployed in other cities. 

Before the more sensitive test, the county used one that required 24 hours to determine water quality. Bacteria in water samples had to be taken back to a lab and grown, then counted. 

That essentially meant the county could tell the public today how safe the ocean was yesterday. Beach community leaders asked for a faster test, and after years of development, the county gave them one.

Under the previous method, tests generally showed unsafe water quality in South County during the rainy wintertime season, when the sewage-plagued Tijuana River swelled with stormwater and contamination, spilling along Imperial Beach just miles from Coronado. 

The county’s new blue warning signs are, potentially, temporary. Rothschild, from the county Environmental Health Department, said the signs will be used until September and then the county will assess how the public interacted with them. She said that the county hasn’t yet set up a public survey or another method to measure that impact.

As of 7:30 a.m. Tuesday, water quality in Coronado at the sampling site off Avenida Lunar was technically safe for human contact, according to county data. But not at the Imperial Beach pier, which failed a water quality test that same day. An advisory is posted warning the public bacteria levels exceed health standards there – but swimmers are still free to get in the water. 

Join the Conversation


  1. Mayor Bailey would be wise to stop complaining. As this article notes, the blue signs are a completely new phenomenon, which seem aimed at allowing beaches that would normally (based on objective contamination levels) be closed to remain open. Ms. Rothschild is wrong that the Environmental Health Department doesn’t have the authority to close the area. California Penal Code section 409.5 states, “If the calamity creates an immediate menace to the public health, the local health officer may close the area where the menace exists pursuant to the conditions set forth in this section.” Various individuals have the authority to enforce the closure, including police and full-time lifeguards. But they lack that authority unless the local health officer declares the area closed. What has changed here is an unwillingness by the County to issue that declaration.

    1. Looks like a majority of the County Board of Supervisors don’t want to rock the tourism industry boat, even if it puts visitors at risk.

  2. The job of a journalist goes beyond simple reporting and quoting people. A journalist also has the responsibility to sort things out in a focused way that identifies and explains the issues. Unfortunately, the Elmer article simply shuffles the confusion around by merging science, politics and regulatory authority into a obscure discussion that simply leaves the reader hanging. For example, references are made to the violation of “state health standards” as the reason beaches were initially closed, yet there is no tie-in between those state standards and the county’s new testing regime. This article is twice as long as it needs to be, full of political fluff and seriously lacking when it comes to sorting out the confusion.

  3. First of all, the old methodology was not wrong; science is just getting better. Cigarettes cause lung cancer. Seat belts save lives. Noise disruptions from aircraft flying overhead can cause a plethora of medical issues, including hyper-tension and heart failure, according to a growing body of results from clinical studies. It is not just tourism dollars versus health consequences, but tourism dollars is a major consideration. And tourism is a big component of the San Diego economy at about 30 percent. But tourism in general pays low wages that are becoming increasingly out of step with the costs of living in San Diego. During the pandemic, there was an unprecedented decrease in tourism dollars, and yet San Diego is still here. During that same period, the environment related health benefitted substantially. Maybe it is time to begin looking more closely at health as the independent variable and tourism as the dependent variable.

    1. Instead of weighing “health consequences” against “tourism dollars”, why doesn’t Congress, the EPA, and other responsible regulatory agencies finally allocate the remaining funds to actually fix the wastewater system so that both will benefit? It’s raw sewage! And it continues unabated while everybody is alarmed by the results of new DNA tests on the water. The water is exactly the same as it was before May 1. Devising a new test to detect the same bacteria and putting up different signs doesn’t change anything – it’s only a matter of measuring the amount of untreated sewage that spews into our ocean from Tijuana, unabated, at all times of the year, and in which direction it is flowing. It needs to be addressed with a real solution that requires actual construction of physical infrastructure, not more expensive and wasteful studies, reports, and tests to prove that there is a problem with the sewage being discharged into our ocean from Tijuana.

  4. Coronado Mayor Bailey comes across like his Amity counterpart, Larry Vaughn, in Jaws, Disregard or dispute the experts’ findings, anything to keep those beaches open to keep the money flowing.

  5. UC San Diego used RNA testing to detect the SARS-CoV-2 virus in their campus building wastewater. The test was very sensitve, and could detect the virus from a single person’s poop at the building’s main sewer pipe. The problem was that the test couldn’t distinguish the difference between 1-2 infected people pooping vs 10-20 infected people pooping. I wonder if this DNA test has a similar limitation, very sensitive, but with limited dynamic range.

  6. Interesting. The new blue warning signs won’t have much effect on tourism this summer, since by the time they get to the beach, visitors will have already incurred the cost of travel, local hotel rooms, etc. But NEXT summer may be a bummer for IB and Coronado.

  7. I am a visitor staying for a month in Coronado this summer. This has been extremely disappointing. We won’t be back next summer. It instead will pick beaches further north.

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