Southland Leads U.S. in Beach Closings, Warnings : Environment: O.C. bucks trend with number of incidents declining by more than half in 1993. Researchers point out that areas with frequent testing have the most alerts.

Beaches across the United States were closed to swimmers or posted with health warnings more than 2,400 times last year, with one-third of them occurring in Southern California, according to an annual report released Wednesday by a national environmental group.

In California, beach closures and advisories resulting from high bacteria counts more than doubled to 1,397 in 1993, compared to 609 the year before, according to the Natural Resources Defense Council report.

But Orange County bucked the trend, posting 61 closures--largely due to sewage overflow and runoff in Dana Point--compared to 139 in 1992, the report says.

“One difference that sort of stands out,” said Bob Merryman, the county’s director of environmental health, “is that there was a significant decrease in the incidents that were caused by line blockages in the sewer lines. The sewage treatment plants, generally speaking, are doing a little bit better job in maintaining their systems.”

That trend appears to be continuing: as of this month, he said, the county has experienced 29 beach closures, compared to 47 at the same time last year. “Even if we have two or three more closures and they are minor,” Merryman said, “the number will be significantly lower than last year’s.”

The large number of health advisories in California does not mean that the region has the nation’s most contaminated beaches. Instead, most of the disparity is attributed to local health agencies that test more frequently and are quicker to warn the public than their counterparts elsewhere.

Nearly all of California’s increase was attributed to numerous health advisories in San Diego County, where heavy winter storms caused sewer system breakdowns or washed large volumes of runoff to sea. San Diego County posted 727 warnings last year--by far the most in the nation--including some in January and February that lasted several weeks and encompassed much of the county’s coastline.

“The blame should not lie with those whose numbers are high,” said NRDC attorney Everett DeLano in Los Angeles. “This does not mean that San Diego beaches are more heavily polluted than Los Angeles County’s, rather that San Diego is doing a better job of protecting the public and closing the beaches when they should be closed.”

In Los Angeles County, beaches were closed or posted with warnings 59 times--an increase from 37 in 1992, according to the report. About half were along a 20-mile stretch of Santa Monica Bay from Topanga Canyon Boulevard to the Palos Verdes Peninsula.

Ventura County is the only Southern California county that does not routinely test its beaches for bacteria. It posted health warnings four times last year because of an oil spill in late December.

In most cases, the warnings were triggered by high coliform bacteria counts, which indicate that the water has been contaminated by human sewage or animal waste from spills or river runoff.

But since there are no national standards, how frequently beaches are tested for coliform bacteria and under what conditions they are closed to the public varies widely from state to state--even county to county--and from year to year.

For instance, eight states, including Oregon, Washington and most of the Gulf Coast, do not monitor coastal water and issue no public warnings. But health agencies in Los Angeles, Orange and San Diego counties sample a large number of beaches weekly and issue public advisories because of strong interest from swimmers, surfers and environmental groups.

In Orange County, water officials this week unveiled what they hope will be a natural remedy to the pollution that has caused popular Aliso Beach to be closed frequently over the decades: catch basins of native plants along Aliso Creek to trap and filter damaging spills before they reach the ocean.

“We can deal with the pollution in the creek,” said Michael Dunbar, district general manager for the Laguna Beach-based South Coast Water District, “before it gets to the public beach.”

In San Diego, Dan Avero, deputy environmental health director for the county, said its high number of advisories is at least partially a result of its frequency of water tests and its policy of posting warnings after rain.

“Some jurisdictions don’t have the funding to do routine monitoring. We probably do more sampling and monitoring than any other jurisdiction,” he said. “We take a cautious approach in deciding to go out with the advisories. Our priority is to protect public health and we want to make sure the water is safe for people to swim in.”

Some of San Diego County’s health warnings--187 last year--were triggered at Imperial Beach by persistent problems with sewage flowing up the Tijuana River from Mexico. Frequent storm-related sewage spills also occurred near Oceanside.

Each day that a beach was posted with an advisory is counted as one occasion. At Del Mar Beach on Camp Pendleton, for example, health warnings were issued from Jan. 16 through March 6, amounting to 50 advisories.

The coliform tests used by most counties to determine whether to post warnings are not considered a highly accurate way to measure the real health risks to swimmers and surfers.

While coliform can indicate the presence of raw human sewage, which could spread diseases such as hepatitis and dysentery, it also may point to bird droppings or other animal wastes that are not considered a serious disease threat. But since no reliable means exist to determine the source of the coliform, most health departments in Southern California close beaches as a precaution until the counts are normal.

The environmentalists say their report is evidence that Congress, which is debating reauthorization of the Clean Water Act, should incorporate more stringent controls on urban runoff and set uniform standards for when states monitor and close beaches. The debate in Congress is expected to last through next year.

“It’s not the numbers that are at issue. What this report really attempts to show is that there are still beach closings. It’s an indicator that our waters are not clean,” DeLano said.

Times staff writer David Haldane contributed to this report.