Sewage does not reach Malibu Creek, but Heal the Bay scientists say the spill would have been worse if it happened on a rainy day.
By P.G. O’Malley/Special to The Malibu Times
Just two months after a leak in a high-pressure pipeline sent untreated sewage sludge from the Malibu Canyon Tapia wastewater facility into Malibu Creek, the line failed again. Only quick action from Heal the Bay, followed by crews from Las Virgenes Municipal Water District, kept sewage from once again contaminating the creek.
Water district Facilities Manager David Lippman admitted that the incident, which occurred early morning on Dec. 8, came as a surprise. Lippman said the high-pressure sludge line had been thoroughly inspected in the area of the first leak, and after external corrosion was found a 50-foot section of ductile iron pipe was replaced with PVC plastic. In October, some 500 gallons of sludge made its way into Malibu Creek, which was dammed and the contaminated water pumped.
Asked about the cause of the second leak, Lippman said he hadn’t had time to investigate.
“We’ve concentrated all our energies on clean-up. Now that that’s complete, we’re proceeding to investigate this second incident and what can be done to keep this from happening again.”
It was a Heal the Bay Stream Team doing routine water sampling that spotted both sewage spills. This time the team reported the leak to the Tapia plant, which immediately shut down the flow of sludge. The team also notified authorities at Malibu Creek State Park and lifeguards at Surfrider Beach.
“If this happened on a day like this, with this rain,” said Heal the Bay scientist Shelley Luce on Monday, a week after the spill, “there would be effects all the way downstream.”
As it was, the district reported that sludge was stopped just 20-30 feet short of Malibu Creek in the dry streambed that runs along the creek channel.
“This second occurrence calls the whole system into question,” Luce said.
But Dennis Dickerson, executive officer of the Los Angeles Regional Water Quality Control Board, indicated the water district had responded as it should, this time taking the failed pipe out of service and routing sludge through a parallel line.
Noting that the pipe in question is only 10 years old and could typically be expected to last four to five times that long, Dickerson said, “I was out there and I’ve seen the photographs. It’s pretty clear the problem is corrosion. The cause of the corrosion is what’s in question.”
The Tapia wastewater facility treats sewage from 85,000 households in the Conejo Valley, a process that produces reclaimed water, which is either discharged into Malibu Creek or sold for irrigation, and sludge, which is processed at the district’s composing facility on Las Virgenes Road in north Malibu Canyon. Although the sewage is fed to the Tapia facility by gravity, because the compost facility is 350 higher than the Tapia plant, the sludge has to be pumped under pressure, circumstances that Dickerson said is a likely factor in the pipe’s failure.
“If sections of the pipe are corroded and the pipe is under pressure, over time it will break through.” Dickerson insisted that finding answers was a “high priority” for the water board and that one outcome of the two spills coming so close together is that the district may be faced with installing automated shut-off equipment to stop sludge flow if pipeline pressure drops.
Lippman was quick to point out that the line is only in service four hours a day, and that someone from the facility drives Las Virgenes Canyon Road at least twice during the time the sludge is moving. Asked if there were any alternatives to high-pressure pumping, he said the sludge could be removed by truck, but given the present volume of sewage being processed, this would mean 25-30 truck trips a day.
Lippman said specialized equipment would be used to inspect the interior of the metal pipe, which is buried eight feet underground.
“We had every indication from our engineering and corrosion consultants that the other sections of the failed pipe were sound,” Lippman said. “We want to be methodical and correct about determining where the corrosion is coming from and determining a repair strategy so this doesn’t happen again.”
Luce, who has routinely testified about inadequate water quality safeguards in regard to the Ahmanson Ranch development upstream of the district’s facilities, expressed concern about the fact that the 3,050-home project will initially use the Tapia plant to process its wastewater, routing its sewage down Las Virgenes Road.
“Imagine adding 200,000 gallons more a day to what Tapia now handles,” Luce said. “We can’t have concentrated sewage pipes bursting.”