Environment & Science

Malibu's fecal bacteria problem could have many sources, geological survey says

A surfer enters the water before tribal elder Mati Waiya from the Chumash Nation conducts the dedication ceremony for the iconic Malibu Surfrider Beach to become the first 'World Surfing Reserve' (WSR), in Malibu on October 9, 2010.
A surfer enters the water before tribal elder Mati Waiya from the Chumash Nation conducts the dedication ceremony for the iconic Malibu Surfrider Beach to become the first 'World Surfing Reserve' (WSR), in Malibu on October 9, 2010.
Mark Ralston/AFP/Getty Images

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People in the Southland crowd Surfrider Beach and Malibu Lagoon; local lore advises them to close their mouths in those waters so they’ll avoid eye infections and sickness. Preliminary findings from the U.S. Geological Survey are shedding new light on the sources of that pollution. That's clouding plans for cleanup.

Malibu's idealized by surfers, swimmers, birdwatchers, even musicians. U.S. Geological Survey hydrologist John Izbicki describes Malibu Lagoon conditions as ideal, too – except he's talking about the Petri dish-like growing conditions for bacteria.

"That lagoon during the summer months is essentially at human body temperature," Izbicki says. "It's nutrient rich. The bacteria like to be associated with fine grain sediments at the bottom of the lagoon. It's constantly being inoculated by fecal material from birds."

Another suspected source of bacteria are Malibu's septic systems. They're often blamed when that area fails health standards for fecal indicator bacteria. Those bacteria don't necessarily cause sickness, but where they are, waterborne illness usually shows up, too.

Izbicki and a team of USGS scientists took samples in July of 2009 and last April. He traced bacteria using molecular and genetic markers, and chemicals from people. "Caffeine being one. Bisphenol A, which is a plasticizer, common in wastewater discharges," Izbicki says. "We can actually identify where water has been based on the presence of these chemicals."

If a septic system spills bacteria, it's in water that moves underground. So where water quality experts could blame tanks, it would make sense to find caffeine and tracer chemicals in that groundwater.

Izbicki's still finalizing his data – and he says he hasn’t found that material so far. "During the summer, the lagoon had very, very high bacteria concentrations. And they're actually far, far higher than we got in groundwater," Izbicki says. "Effectively, during both the summer sampling period and the April sampling period we had very, very little bacteria in groundwater. So, the high bacteria concentrations in the lagoon had to be from some other source."

Regulators at the regional water quality control board say that doesn't change a cleanup order they issued for Malibu a year-and-a-half ago. The civic center area has four years to hook up to a wastewater treatment system. Malibu Knolls, Serra Retreat and the colony have eight years to phase out septic tanks.

The regional board's chair, Fran Diamond, says plenty of evidence and other sampling points to problems with septic systems – problems that the board's phaseout aims to solve. "And that was all based on many, at least six if not more peer-reviewed studies that proved to the state board and the regional board that this was an appropriate action and it was based on sound science," Diamond says.

Malibu's already agreed to build a wastewater treatment plant under terms for the commercial area septic ban. That plant will also treat recycled water.

Diamond says that could benefit residential areas of Malibu too. "We're really concerned about contamination of our groundwater, we have to protect our groundwater and make sure all future uses are protected," Diamond says.

Still, negotiations continue over exactly how the ban will work in residential areas. Heal the Bay's Mark Gold points out that the city of Malibu helped pay for Izbicki's research.

Gold says he can't comment on a preliminary abstract of a study without data – but, he adds, that doesn't stop other people from jumping to conclusions about what Izbicki's said so far. "The big concern that I have about what's being said about the study is the extrapolation – looking at two discrete time periods during a relatively dry year and saying that's the condition of Malibu Lagoon all of the time," Gold says.

View Malibu Septic Hearing Nov. 5, 2009 in a larger map

Malibu's mayor, John Sibert, defends the study. He expects that it could change plans for septic bans in some neighborhoods – perhaps by shrinking the area in which homeowners must kick in for sewers, or by shrinking the assessments the property owners would have to pay. "We have had a lot of dogma about what is the cause of bacteria in the ocean and the lagoon and it's important to start to understand where it actually does come from because you can't fix it if you don't know what causes it."

Izbicki's study isn't likely to be the last word on the way all that fecal bacteria gets into Malibu waters. The small city, regulators and environmentalists will have a little more time to argue about what to do next.