County Will Broaden Warnings to Swimmers

In a change that acknowledges a new health risk in Southern California, Los Angeles County authorities have decided to warn swimmers and surfers that beaches may be unsafe after rainstorms.

The risk comes from chemicals and other pollutants washed off city streets and through the many open-air storm drains that empty into the ocean. Scientists and the U.S. Environmental Protection Agency consider the urban runoff a potential threat to human health, although the degree of danger is still in debate.

County health officials, who have yet to announce the new warning policy, are still trying to decide some details, such as how much rain constitutes a “storm” and how to best inform the public.

Rather than post warning signs on the beaches, health officials have decided to publicize the danger through the media during the rainy season. The officials said they do not have enough evidence to justify posting warning signs.

A spokesman for the county Department of Health Services confirmed the new policy Tuesday but said it will be submitted to the Board of Supervisors before being released.

Until now, health officials have alerted the public about contaminated surf only after sewage spills. In the last month, the health department has twice ordered warning signs posted on beaches throughout Los Angeles County because sewage overflowed into Ballona Creek, which empties into the Pacific near Marina del Rey.

But reports from scientists about the contamination found in ordinary urban runoff helped spur a change in thinking about what constitutes a threat to public health.

Pressure from city officials in Los Angeles, which was the source of the sewage overflow, also apparently contributed to the change. When health officials blamed sewage for contaminating the beaches earlier this month, city officials protested loudly and produced test results that they said proved that runoff was to blame.

Despite the decision to warn the public about storm runoff, county health officials continued to insist that they made the right decision in blaming Los Angeles sewage for the beaches being closed on two different weekends in the last month.

But the change signals at least partial, if grudging, acceptance of the increasing evidence that urban storm runoff carries dangerous bacteria and other pollutants with it into the ocean.

High Concentration

An EPA study of urban runoff nationally found in 1983 that the water gushing down storm drains can carry a much higher concentration of dirt, grit and other suspended solids than even the discharge from some sewage treatment plants.

Harmful chemicals and toxic metals, such as lead and cadmium, attach to these particles and ride them into the ocean. Currents can then wash the contaminants toward the beaches, where they become caught in the tumbling surf.

Locally, scientists know the most about flows down the concrete channels of the Los Angeles River, which collects runoff from the entire San Fernando Valley, central Los Angeles and most of the San Gabriel Valley. A recent study by the Southern California Coastal Water Research Project found metals such as silver, lead, zinc and chromium, as well as oil, grease and traces of DDT, in the runoff that reaches San Pedro Bay.

In Ballona Creek, which collects runoff from West Los Angeles, tests have picked up more oil and grease, perhaps because the flood control channels that feed the creek flow near the San Diego Freeway or because of illegal dumping. “We see a lot of petroleum products going down Ballona Creek,” said Henry Schafer, a researcher at the water research project, a joint-powers agency of Los Angeles and other local cities.

Organic Contamination

In addition to the metals and other residues, storm runoff carries organic contamination from yard and animal waste--and illegal sewage connections, some city officials suspect--and apparently led to high bacteria counts along local beaches during recent storms.

“The one thing that’s sure is storms do introduce more bacterial contamination onto beaches than any other sources,” said Jack Anderson, director of the research project.

The debate has been over whether the bacterial contamination found in the ocean is from human waste rather than animal droppings or soil. Only the bacteria from human waste is considered a health threat.

City biologists, who test the waters of Santa Monica Bay for sewage pollution daily, contend that the storm runoff carries sufficient bacteria to threaten human health.

Lack Evidence

But county health authorities, who have less experience with testing the ocean waters, said they still lack the evidence necessary to justify posting warning signs on the beaches after every storm.

Plans are under way to conduct special tests in Santa Monica after storms this winter, but funds are limited, said Jack Petralia, acting director of environmental health for Los Angeles County.

County officials are also limited by their laboratory, which takes longer to process seawater samples than other laboratories.

During the beach closure two weeks ago, the beaches were closed on Sunday. They actually were safe for swimming again on Tuesday morning. But health officials could not reopen them until Thursday afternoon when test results became available.