Three water quality experts, speaking at the City of Malibu’s Water Quality Symposium, dispute the notion that poor water
quality in the Malibu Lagoon and Surfrider Beach is due to human waste.
By Knowles Adkisson / The Malibu Times
Three scientists presented evidence last week at the City of Malibu’s Water Quality Symposium that septic system runoff may not be responsible for contamination in the Civic Center Area.
The Malibu City Council had voted three days earlier to approve a Memorandum of Understanding with the Los Angeles County Regional Water Quality Board to build centralized wastewater treatment facilities in the central area of Malibu. The basis for the MOU was the water board’s position that runoff from septic systems in the Civic Center was causing contamination in Malibu Lagoon and Surfrider beach. The findings by the scientists, if they turn out to be correct, would cast doubt on that position.
The water board is scheduled to vote on July 14 whether to approve the MOU.
Water quality experts John Izbicki, Eric Dubinsky and Randal Orton gave presentations before a capacity audience at city hall June 30 in which they pointed to bird and other animal waste and upstream rock formations as the potential culprits responsible for poor water quality in the area. However, Mark Gold, president of local environmental group Heal the Bay and a frequent critic of Malibu septic systems, also presented evidence he said demonstrated that septic systems are, in fact, largely responsible for water contamination.
Izbicki, a research hydrologist for the United States Geological Survey (USGS), presented evidence from a recent USGS study commissioned by the city and overseen by him. After analyzing approximately 450 samples taken from Malibu Lagoon and Surfrider Beach in July 2009 and April 2010, Izbicki found that “indicators of human fecal material and contamination within groundwater … are very low, actually effectively absent.”
While fecal indicator bacteria were present in the water, Izbicki speculated the bacteria originated from birds or other animal species.
Gold, who in May questioned the thoroughness of the USGS study because samples were taken only during two two-week periods, presented evidence collected by Heal the Bay since 1998 that, he said, pointed to human waste as the origin of the contamination.
Izbicki acknowledged that “it is possible that we could have sampled improperly and just missed the wastewater.”
To account for that possibility, Izbicki said he and his team compared water imported to Malibu for human use with native water in the lagoon and near the beach. High levels of wastewater were found in the native samples, he said, but they did not have human bacteria in them, which would seemingly rule out septic systems as the source of contamination.
Dubinsky, a bacteria specialist with the Lawrence Berkeley National Laboratory, raised the possibility in his presentation that bacteria originating from bird or other animal waste had latched onto kelp and other local organic matter and was regenerating on its own in the environment.
In a panel discussion at the end of the day, Gold said the majority of beaches in California that were similar to Surfrider Beach did not share its contamination problems.
“I do find it very compelling that the vast majority of open ocean beaches [unlike Malibu’s] really meet fecal bacteria standards a hundred percent of the time,” Gold said.
Gold asked why, even if the bacteria had regenerated to form regrowth, it could not be determined whether the regrown bacteria emanated from human or non-human animals. Dubinsky responded that bacteria capable of regrowing in the environment are versatile and can survive in both nature and in living organisms, making it difficult to determine their origin.
“Some bacteria can grow in the environment and also in human guts,” Dubinsky said.
The least expected explanation for the contamination came during a presentation by Orton, the resource conservation manager for the Las Virgenes Municipal Water District. Orton presented recent results from a study done by the water district that in 2009 found contamination in Malibu Creek was the result of exposure at its headwaters to a hazardous, petroleum-rich rock formation called the Monterey formation.
Above-average levels of more than 20 water quality parameters throughout the length of Malibu Creek, Orton said, “cannot be explained by reference to pure urban runoff, or any other source of the urban watershed.”
Orton also said the excessive amounts of algae in the creek, which make it difficult for fish species to survive due to low dissolved oxygen levels, could be a by-product of the elevated nutrient levels resulting from exposure to the rock.
The purpose of the symposium was to bring together experts from various scientific fields to examine water quality issues in Malibu. The evidence presented at the symposium could have an affect on future negotiations between the city and state agencies regarding water quality issues.