Study: Area’s Winter Beach Bacteria Levels Similar to Mexico’s

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

The study, by the Southern California Coastal Water Research Project of Westminster, shows that contamination after a heavy rainstorm 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 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 operated by local, state and federal agencies.

The report marks the first time scientists have been able to provide a complete, regionwide picture of the extent of beach pollution.

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 research group’s study. “It’s a regionwide problem.”

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

Rainy Season Runoff Problems Stretch Far Although the study found the worst contamination at the mouths of storm drains and rivers, coastal waters were 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, 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 a major cause of high bacteria levels at beaches is fecal matter from bird droppings or other animal wastes. 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 could make swimmers sick with diarrhea, ear infections and skin rashes as well as more serious viruses and other illnesses.

Orange County beaches have been closed a record-breaking 37 times this year because of sewage spills. However, 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 sewage also comes from homeless people.

At Crystal Cove State Park, the state Department of Parks and Recreation was ordered earlier this month to get rid of septic systems beneath historic cottages. State water officials worried the antiquated tanks are sending untreated human waste into the fragile marine ecosystem.

In August, Weisberg’s group announced that enterovirus--the second-most-common human virus--was flowing into Newport Bay from at least one flood-control channel. The findings indicated that raw human waste is entering the long-polluted bay, most likely from leaking sewer lines, vagrants or illegal connections between sewer pipes and storm drains.

Tuesday’s 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 are designed to 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.”

Population Growth Adds to Difficulties

Environmental groups, including Heal the Bay in Santa Monica, have fought for over 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 region’s population grows. More people and pavement increase the volume of 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--often is seen all the way from Los Angeles to Santa Catalina Island, 26 miles offshore.

Under the U.S. Clean Water Act, local governments are held responsible for ensuring storm water contains no contaminants.

Some cities, especially in Los Angeles County, have already diverted some storm drains into sewers to keep the contamination out of the surf zone. But those diversion projects only operate during summer months, when runoff volumes are low.

During the wintertime, the problem is much more difficult. Fixing it could require costly filters in curbside catch basins and other solutions.