Study Finds Widespread Runoff Peril on the Coast

More than half of Southern California’s shoreline--from Santa Barbara to San Diego--is unsafe for swimming after rainstorms because of bacteria carried to the ocean by urban runoff, according to a scientific study released Tuesday.

The study, by the Southern California Coastal Water Research Project, shows that contamination after a heavy rain is pervasive and extreme: Most bacteria counts registered very high, even at beaches far from storm drains and 36 hours after the rain had ended.

The bacteria counts found at beaches throughout Southern California were comparable to the levels found at Mexican beaches.

“In summer, there’s a marked difference between our beaches and the Mexican beaches. But after a rainstorm, you can’t tell them apart,” said Stephen Weisberg, director of the scientific group, which is based in Westminster and operated by local, state and federal agencies.

This is the first time scientists have been able to provide a complete, regionwide picture of the extent of beach pollution.

Contrary to popular perception that runoff pollution is mostly a problem for Santa Monica Bay, beaches in all five coastal counties registered similar bacteria counts.

“There was not one area that was noticeably worse than the others,” said Rachel Noble, a USC microbiologist who conducted the tests and led the study. “It’s a regionwide problem.”

County health agencies have long advised swimmers to stay out of the ocean after storms. But many surfers and others mistakenly believe that the only unhealthy waters are around river mouths and storm drains, and that even there they are dirty only immediately after rain.

The study found the worst contamination at the mouths of storm drains and rivers, but coastal waters were still heavily polluted miles from such outlets.

“I’m not surprised that we saw bacterial hits, but it’s the intensity of the hits, far from the drains, that is unusual,” Weisberg said. “Some of these places are pretty darn far.”

The study shows how dramatically the region’s rainy weather contamination differs from the summertime problem.

In the group’s summer test, only about 5% of the shoreline violated bacteria standards, and most of those areas only marginally. But in the winter, the bacteria counts skyrocketed.

In the winter, “not only is the problem pervasive, but it’s . . . typically well in excess of the [bacteria] threshold,” Weisberg said. “That shows there’s lots of bad water.”

In the past, some local officials have suggested that a major cause of high bacteria levels at beaches is bird droppings or other animal wastes that do not pose much of a health risk. But Noble said most of the beaches tested positive for fecal coliform, total coliform and enterococcus bacteria, which means human feces are likely to be present, too.

Human sewage can make swimmers sick with diarrhea, ear infections and skin rashes, as well as more serious viruses and other illnesses.

No one is certain how sewage winds up in urban runoff. The waste is supposed to remain in sewer pipes that flow into treatment plants. But leaks, septic tanks built too close to the shore, overflows and illegal sewer connections apparently let large amounts of sewage flow untreated into streets and curbside drains. Some pollution also comes from homeless people.

The report is based on samplings of ankle-deep water from 254 sites in five counties, from Point Conception to Punta Banda, Mexico, taken on Feb. 20--a day and a half after a heavy rain.

The beaches tested represent all ocean waters accessible to swimmers along 690 miles of shoreline, from rocky coves to sandy beaches.

Fifty-eight percent of the samples exceeded bacteria standards. That is 10 times more than the violations found during a similar summertime survey.

“This indicates in a very scientifically rigorous way that storm water is a problem we need to deal with,” Noble said. “On either side of the border, we have storm water issues that need to be addressed.”

City and county agencies are wrestling with ways to curb Southern California’s runoff problem, which is believed to be the worst in the nation.

“There’s no question that it’s certainly a daunting challenge,” said Dennis Dickerson, executive officer of the Los Angeles Regional Water Quality Control Board, which is responsible for enforcing runoff rules in Los Angeles and Ventura counties.

“But I do think it’s possible to substantially change the runoff problem we have after storms. We are already seeing some significant improvements with regard to the measures that are being taken by various cities.”

Environmental groups, led by Santa Monica-based Heal the Bay, have fought for more than a decade to get local and state officials to do more to solve the runoff problem.

“This demonstrates as a region we’ve done a horrible job of preventing storm water pollution,” said Mark Gold, executive director of Heal the Bay.

David Beckman, a senior attorney at the Natural Resources Defense Council in Los Angeles, said the problem is getting worse as the population grows and additional pavement that increases the runoff.

Officials have long suspected that runoff problems are extreme throughout the region after rainstorms. From the air, brown, turbid water--a sign that lighter fresh water is sitting atop heavier salt water--is often seen all the way from Los Angeles to Santa Catalina Island, 26 miles offshore.

Under the federal Clean Water Act, local governments are responsible for ensuring that storm water runoff contains no contaminants. The Natural Resources Defense Council and Heal the Bay recently won a lawsuit that will force the Los Angeles regional board to set enforceable runoff limits for contaminants, including regulations for coliform bacteria, due in 2002.

The regional board recently adopted controversial standards that require new major projects in Los Angeles County to capture runoff. Most cities in the county, as well as builders and developers, have opposed the new standards.

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Bacteria at the Beach

Ocean water was tested for bacteria at 254 sites from Point Conception, Calif., to Punta Banda, Mexico, on Feb. 20, a day and a half after a rainstorm. Fifty-eight percent of the sites exceeded health standards for bacteria. The beaches tested represent all ocean waters that are accessible to swimmers along 690 miles of shoreline.

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Type of site % exceeding health standard

Beach at mouth of storm-water outlet: 87%

Beach 100 yards from outlet: 67%

Sandy beach: 62%

Rocky beach: 34%

All beaches: 58%

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Source: Southern California Coastal Water Research Project