After nearly 70 years of sediment contamination in a Presidio lake, Caltrans was ordered to pay more than $13 million for cleanup and to divert runoff to prevent further harm.
The settlement was reached earlier this month after nearly a decade of research, documentation and pleas for help by the Presidio Trust to Caltrans, the entity responsible for the contamination of Mountain Lake. The trust had discovered the contamination in 2000.
The lawsuit was a last resort, according to the trust’s assistant general counsel, Andrea Andersen.
“The Department of Justice sent two letters to try and work this out before a lawsuit was filed,” she said. “But we were unsuccessful.”
As a result of the settlement, Caltrans will pay $13.5 million to dredge the lake, replace the overflow pipeline and cover legal costs.
Caltrans also must develop a permanent solution to prevent further roadway runoff into the lake, according to Eileen Fanelli, environmental remediation program manager with the trust.
“But that is a longer project,” she said. “We’ll proceed with remediation of the lake and implement an interim solution while they find a new way to catch the sediment, particulates and contaminants.”
The Presidio Parkway was built in 1938 by the California Highway Commission, according to the lawsuit, which was filed in January 2009. The department eventually became Caltrans in 1978.
As a result of the 1938 construction, runoff from the roadway inadvertently caused lead, zinc and copper to settle in the lake over the course of several decades. The contamination was discovered in 2000 when the trust ran tests of the lake. The results showed alarming levels of contamination in the sediment.
Both Presidio and Caltrans officials said the contaminated sediment is most likely the result of lead-based fuel that was used in cars until the 1970s.
Caltrans spokesman Steve Williams said the agency will work with all parties to clean up the lake.
“The majority of it is from the emissions from vehicles from back when the freeway was built in the 1930s,” Williams said.
Mountain Lake is located on the southern end of the Presidio near Park Presidio Boulevard and Lake Street. It is roughly 4 acres, with a maximum depth of 12 feet.
Now that Caltrans is being held responsible, cleanup can move forward, according to Fanelli. Sediment dredging is expected to begin in 2013 and will last one year. Though trust officials hope the lake will still be accessible during the work, some trails and beaches might be restricted at times.