A sewage spill in a San Ysidro treatment plant may have caused millions of gallons of sewage to flow through the Tijuana River into a public beach.
Typically, surfers and swimmers are notified of any potential contamination in public waters.
However on April 4, a spill in San Ysidro made its way to Imperial Beach unbeknownst to the surfers who frequent the beach, according to our media partners VoiceofSanDiego.org, who broke the story.
The spill was caused by a software malfunction in the treatment plant, an engineer for International Boundary and Water Commission told NBC San Diego.
Raw sewage and runoff water spilled in the plant for three hours before any of the workers realized, the plant's engineer said.
The spill flooded parts of the plant’s system, which filters about 25 million gallons of Tijuana sewage. As a result of the sewage spill, the filtration system shut down, allowing that water to flow unfiltered into the Tijuana River.
The river discharges just south of Imperial Beach. Up to 7 million gallons of untreated water per day flowed from the plant for five days, the VOSD article explained.
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County authorities tested the water and determined it was not contaminated.
“The spill itself was from the plant into the Tijuana River," said county spokesman Gig Conaughton. "It was actually cleaner than the water that’s in the river. There’s no reason to report that and it’s not what we typically do. We’re told about it and we make sure the beaches are okay.”
However some surfers reported smelling and tasting the contamination.
"It's like a really raspy taste, and you could see the foam and the brown in the water," said surfer Anthony Marsh. "It's pretty disgusting."
When a shift in the currents caused some of that unfiltered sewage to stream through the Tijuana River and into Imperial Beach, the county notified the public that the flows could impact them.
The beach was closed Wednesday – yet swimmers and surfers were in the water for nearly a week after the initial spill in San Ysidro.
Yet Serge Denina with the conservation organization Wildcoast said the IBWC should have told the public about the plant's 2 million gallon spill when it happened.
"It's bad enough to have polluted water," Denina said. "it's worse when federal agencies and international agencies don't do their job."
The county should have also worked with the IBWC to notify the public, said the Surfrider Foundation’s Mark West in a statement.
“Tragically, neither the IBWC nor county water officials deemed it necessary to alert the public of the sewage spill and malfunction,” West said.
"The closing of the beach yesterday was the first time ocean goers would have been made aware of the Tijuana River sewage contamination which started on April 4th.”
IBWC subcontracts the facility through Veolia Water. The company will be investigating the spill to determine what caused it and potentially install an alarm system which would notify workers of spills.
The federal agency that runs the cross-border treatment plant says it did notify state and county officials about the spill.
An agency spokesperson said she's trying to improve that process, to send email alerts to groups like "Wildcoast" whose members are actually on the beach, every day.