Fighting Beach Pollution in the Lab
With stately multimillion-dollar homes, miles of shade-dappled bridle trails and a private beach below steep bluffs, Hope Ranch is a place of uncommon wealth and serenity. But like other California coastal communities, it has wrestled for years with a mysterious problem that may be rooted in runoff from its own land.
County officials have posted dozens of health warnings on the beach since 1998. And parents routinely shoo their children away from a tiny creek that drains the 1,900-acre enclave and empties onto the shoreline.
Residents had hoped they had the problem under control several years ago after fixing a septic system and taking measures to keep horse manure out of the creek.
But when surfers and swimmers later got sick, the community turned to the emerging science of microbial source tracking to try to pin down the elusive origin of the pollution. In recent years, a growing number of government agencies and local communities have used the technology to pinpoint whether they need to fix sewage systems, relocate wildlife or capture waste from livestock.
Rather than simply confirming the presence of fecal bacteria, the tracking methodology often uses genetic fingerprinting to detect what species produced it. Without knowing the origin of such pollution, experts say, stopping it can be a matter of guesswork. A community could waste millions of dollars upgrading a sewer system, for example, if it later turns out that the pollution comes from ranch lands or from seabirds flying overhead.
Scientists using microbial source tracking in San Luis Obispo County identified birds, humans, cattle and dogs as contributors to bacterial pollution that restricted shellfish harvesting in Morro Bay. And they discovered that decaying sewer pipes in Avalon on Catalina Island were polluting the shoreline with human bacteria.
Beach pollution poses a persistent threat to one of the state’s most valuable assets. Although government officials cannot precisely quantify the health effects, polluted runoff in seaside communities is widely believed to cause numerous illnesses each year among beachgoers and put popular stretches of the coast off-limits to residents and tourists.
The State Water Resources Control Board requires health warnings to be posted when bacteria levels exceed standards for swimming and other water contact.
Records show that from 2000 through 2004, warnings were posted for the equivalent of 150 miles of beach for 10 days each year on average -- mostly in Los Angeles, Orange and San Diego counties. In addition, sewage spills and leaks from 2001 through 2004 caused beach closures that annually averaged the equivalent of about 65 miles of beach for the same duration.
As is the case at many beaches, the bacterial pollution in San Diego’s Mission Bay was long presumed to be human. Yet it continued even after the city spent about $130 million on sewer and storm drain upgrades between 1985 and 1996.
Fearing that more costly work might be needed, officials arranged two microbial source tracking studies in 2002 and concluded that bird droppings were the primary pollutant. The city now is changing its bayside irrigation to avoid washing bird waste from the grass into the water.
“Any technique that gives you reliable answers on how you spend public funds is worthwhile,” said Deborah Castillo, spokeswoman for the city’s storm water program. “The beauty of this study was we were able to target the problem and be specific about how we approached a solution.”
Most microbial source tracking tries to match the bacterial strains removed from water to a host species. These genetic fingerprinting techniques are largely dependent on collecting a “library” of samples for comparison.
Other methods test for the presence or absence of signature genes carried by specific warm-blooded animals, especially humans. Experts say detecting human waste is important because it generally is considered more likely to contain pathogens that can produce illnesses.
Many Southern California beaches are near creeks and storm drains, which collect runoff from residential developments, agricultural land and open space.
“In a watershed with ... residents, pets, rodents, birds, urban wildlife and all the sewer lines and septics, God knows what we have got,” said Mansour Samadpour, the owner of a consulting company who pioneered a genetic fingerprinting technique and has performed about 170 pollution studies, using a library that now exceeds 120,000 samples.
“Then you get into an estuarine environment with marine mammals and an abundance of birds,” he added. “And you have beaches where humans swim, and humans become sources” of fecal bacteria....
“These are complex issues.”
Santa Barbara County -- with its popular beaches, tourist economy and environmental activism galvanized by a disastrous oil spill in 1969 -- has become a laboratory of sorts for pollution tracking.
Several years ago, Rincon Point -- a surfing spot renowned for its perfectly peeling waves -- also became known for excessive bacteria in its lagoon and along its cobbled beach. After surfers complained to Heal the Ocean, the environmental group teamed with county health officials for a study in 1999.
The report, based on tests by Samadpour while at the University of Washington, pointed to septic tanks from neighboring homes as the most likely source of human fecal pollution.
“The study was useful in the political sense because the community started looking more at bringing a sewer into the area,” said Dan Reid, the county’s project manager.
The community, which has about 75 homes, decided to obtain sewer hookups from Carpinteria, but the project has been stalled by litigation by three residents. Their attorney, Eric Kitchen, said the sewer was unnecessary because residents repaired their septic systems after the study, and the water quality has been consistently good.
One of the county’s most frequently closed beaches was at Arroyo Quemado Creek, where environmentalists suspected that a nearby county landfill was to blame for pollution. But a DNA study prepared in 2001 with lab work by Samadpour concluded that most pollution was the result of droppings from seagulls that congregated in the lagoon after feeding at the landfill.
After the county hired falconers in 2002, the birds of prey soon scared away most gulls from the landfill and the beach water quality began meeting pollution standards.
“The results were overnight,” said Mark Schleich, deputy public works director.
The U.S. Environmental Protection Agency reports that about 13% of the country’s surface waters violate fecal bacteria standards -- and that much of the pollution comes from runoff.
To protect swimmers, fishermen and others, California for many years has required local governments to measure indicators of fecal contamination on popular beaches.
“The method the state mandates is very limited,” said Jill Zachary, Santa Barbara’s clean water manager. “It tells you the presence of bacteria -- but it could be a bird, raccoon, cat, skunk, a cow or a human. It does not tell you the source.”
Although microbial source tracking represents a considerable improvement, government experts say it has limitations. In cases involving several sources of pollution, scientists still cannot precisely quantify how much is coming from each source.
Tests by the Southern California Coastal Water Research Project Authority in 2003 found that the most accurate microbial tracking methods could identify the dominant fecal pollutant about three out of four times.
“If I am going to Las Vegas and you tell me I have a 75% chance, I am a rich man,” said Stephen B. Weisberg, executive director of the authority. “But if I spend $20,000 for a cleanup and I am wrong 25% of the time, lots of people will be angry with me.”
The EPA has not given its stamp of approval to any microbial tracking methods but has provided guidance to public agencies considering them.
“It is not quite ready for prime time ... for regulatory usage, even though people are trying to use it that way,” said Terry Flemming, the EPA’s regional beach coordinator. “On the other hand, we are asking people to find and fix sources [of pollution], and that puts people in a quandary.”
Residents of Hope Ranch, a community of more than 700 homes, have worked on their own to unravel a pollution mystery that has touched two of their most valuable recreational amenities: their private beach and 30 miles of bridle trails.
The equestrian lifestyle drew retired Arizona architect Ed Sands and his wife to the ranch in 1998, when they built a Spanish-style home with a corral and a stable in the frontyard.
“It became one of the last refuges of the old California style,” said Sands, president of the 100-member horse owners association. “There are very few places where horses have access to the beach.”
However, pollution from Las Palmas Creek that empties onto the beach prompted a homeowners group to obtain a study, which found evidence of contamination from horses, with some human waste. Residents say the community spent about $50,000 to upgrade the septic system at its beach bathhouse and took measures to better control and dispose of manure.
But a few years ago, Kenneth Young and seven buddies who were surfing near the creek mouth came down with sinus or respiratory illnesses.
“We said, ‘Let’s find out what’s coming out’ ” of the creek, said Young, a movie industry caterer who heads the homeowner association’s beach committee.
Later, the committee raised about $20,000 for a study by four UC Santa Barbara graduate students advised by associate professor Patricia Holden.
“Overall, Hope Ranch is an environmentally conscious community, and everyone wants the creek water to be clean,” Holden said.
Among other things, the study is using tracking techniques to learn whether the creek and beach waters contain human waste or bacteria commonly found in the feces of herbivores, such as horses. The results are expected this spring.
Depending on what the study finds, Young and Sands acknowledge that it eventually could lead to septic system repairs or more restrictions on horse owners.
Stressing their desire for coexistence, however, they want to adopt solutions that will protect the beach and preserve the equine ambience that contributes to property values.
“It puts the ‘ranch’ in Hope Ranch,” Sands said.
