Study Identifies 2 Likely Causes of Beach Closings

Scientists who spent more than a year studying the pollution that forced the 1999 Huntington Beach closures said Thursday they have identified two possible culprits: bird waste from a nearby marsh and sewage from a sanitation outfall.

The long-awaited report represents the most exhaustive examination of Huntington Beach’s shore contamination problem, which kept the city’s landmark beaches off limits for much of the summer of 1999 and dealt a blow to its “Surf City” tourist economy.

The exact cause of the high bacteria counts recorded at the beaches has remained a mystery ever since, but the group of 11 scientists Thursday presented what they considered their best theories:

* Birds living in the Talbert Marsh produced waste with a strong strain of bacteria that does not die easily. The marsh acts as a “incubator” for the bacteria, which eventually wash into the surf.

* The Orange County Sanitation District releases partially treated sewage from an underwater outfall four miles off the coast. Normally, this sewage stays away from beaches. But the report suggests that heated water from a nearby power plant actually draws the effluent to the surface, polluting the beach.

* Studies showed that high tide causes ocean water to rush 2 1/2 miles inland along the Talbert Channel. When the tide subsides, it pulls pollutants out to sea.

The scientists who wrote the report ruled out broken sewer lines as a cause for the fouled water but said more study is needed to determine exactly how to prevent the pollution from coming back.

The study marks the latest chapter in an environmental whodunit that began in June 1999 when officials first began seeking the cause of the rising beach bacteria levels. Local and state agencies have spent more than $5 million on the probe, doing everything from placing red dye in the water to detect tide patterns to checking miles of sewer lines for leaks.

“What this study shows is that it’s not a quick fix,” said city spokesman Richard Barnard.

Indeed, scientists pointed out that the bacteria from bird waste at the Talbert Marsh raise questions about whether the effort to protect such marshland ecosystems conflicts with the goal of clean ocean water.

“Marshes have always been thought to be cleansers,” said Stanley Grant, a researcher at UC Irvine. “What this study showed was, surprise, they are not. That on the contrary, the water coming out has more bacteria than when it comes in.”

Not all findings in the report were unchallenged. The Orange County Sanitation District took issue with the scientists’ theory that effluent from the agency’s outfall contributed to the beach closings.

“We don’t find the same conclusion to be true,” said district spokeswoman Lisa Lawson. “We will be doing further studies to see if this theory is acceptable or not acceptable.”

Study authors expressed concern Thursday about the way officials administer beach closings.

Because of a time lag between when water is tested and when unsafe bacteria levels are detected, Grant said, beach closure postings are inaccurate about half the time. Often by the time beaches are closed, the pollution has dissipated.

It’s “almost like navigating the freeway with SigAlert info that is a day old,” he said.

But since the study began, the county has acquired new technology that allows officials to analyze water samples much more quickly.

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Times staff writer Seema Mehta contributed to this report.