Kelp accumulates bird droppings, then washes into the sea. Photo by Melinda Burns/SBN

It’s a question that led local officials in 2004 to initiate a $500,000 study of ground water, creek water and the ankle-deep water they call the “splash zone” at East and West beaches near Mission Creek.

Citizens’ groups such as Heal the Ocean have long suggested that the city’s aging sewer system was leaking into the ground water and travelling underground into the surf. But preliminary results from the study, which is funded in part by Heal the Ocean, suggest that city sewers are not to blame, the authors say.

Gulls pick through the kelp on the beach near Mission Creek. Photo by Melinda Burns/SBN

John Izbicki, a U.S. Geological Survey (USGS) hydrologist from San Diego who heads the study, said that hundreds of samples taken from 13 ground water wells, Mission Creek and the ocean for more than two years do not show that city sewers are polluting the ground water.

“So far, we have not found direct evidence of contamination on the beachfront or in Mission Creek from the sewer water,” Izbicki said. “One of the concerns was the main sewer line along West Beach. But we have not seen evidence of fecal bacteria contamination from that line.”

East Beach at Mission Creek is the second most polluted beach in the county. Photo by Melinda Burns/SBN

“We got very high concentrations of fecal bacteria,” Izbicki said. “Classicial microbiological thinking says that as that stuff sits on the beach, the bacteria should be dying. But they may be far more persistent than we thought.”

There are no studies linking guano with illness in humans. In addition to birds, other potential sources of beach water pollution could include dogs, seals and humans, Izbicki said. Fecal bacteria are present in the gut of all warm-blooded animals.

Hillary Hauser, executive director and co-founder of Heal the Ocean, said the group would be pleased if the study finds conclusively that city sewers are not the cause of ocean contamination.

“It’s what you don’t know that drives you nuts,” Hauser said. “But the jury’s still out as to what is going on in the ground water in this area.”

Birds have been found guilty in the past for polluting the ocean. In 2001, a DNA study performed by the University of Washington found that thousands of seagulls, attracted by the Tajiguas landfill, were the cause of fecal contamination at Arroyo Quemada Beach, then the No. 1 most contaminated beach in the county. The gulls sat on the beach for hours and the tide carried their guano into the water.

It had been previously thought that the landfill or nearby septic tanks were leaking into the ocean. But soon after a falconer began scaring away the birds from Tajiguas, Arroyo Quemada Beach began testing clean.

Today, Arroyo Burro beach is the most polluted in Santa Barbara County and East Beach at Mission Creek is a close second. In 2006, county data show, these two beaches tested unsafe for swimming at least 40 percent of the time.

Rebecca Bjork, the city’s wastewater system manager, said she has always been skeptical that city sewers were the cause.

“We kept saying, ‘We don’t think so,’ ” she said. “There’s not a strong mechanism for water to move out of a sewer line, unless something is causing it to be pressurized. It takes the route of least resistance.”

One exception, Bjork said, is that during big storms, city sewers have occasionally been overwhelmed because homeowners leave the caps off their private sewer lines or illegally connect roof drains to them.

To help solve the problem, the city last week inaugurated a new sewer line, 3,200 feet long, in the vicinity of Quarantina and Montecito streets, to act as a sewer bypass in heavy rains.

The USGS study of Santa Barbara’s beach and creek water quality is one of the most thorough in the state. Samples were taken from seven wells on West Beach; three near the skateboard park; and three in a residential neighborhood near Old Mission Creek, a tributary of Mission Creek that often tests high for fecal bacteria.

The scientists also tested the “swash zone” and travelled to and fro in a boat along the waterfront, sampling the surf. They studied how water was flowing into the beach and how it was draining out, and how the cycle was affected by rain. They captured data from a breach of the lagoon at Mission Creek, when polluted creek water poured into the surf.

“We go around the clock,” Izbicki said. “I’ve done a number of late-night stints, all through the night. We start following the tidal cycle down to the early morning.”

The results of the USGS study show that there is fecal contamination in some of the monitoring wells, indicating that it is present in shallow ground water. But the water is draining into the sewers, not moving towards the beach, Izbicki said.

The study is expected to be finished by the end of this year. It will not include recommendations.

“We can explain the consequences of certain decisions,” Izbicki said. “Ultimately, the beach is the responsibility of the citizens of Santa Barbara. It’s up to you all.”