During more than 200 years occupying the Presidio, the U.S. Army left behind not only batteries and barracks. Years of dumping trash, construction debris, and various chemicals created over a dozen waste dumps spread across the park. Even though the military turned over the Presidio to the Park Service in 1994, the agency still had the responsibility of cleaning up the toxic landfills they had left behind. The Army removed underground fuel tanks and then decided to leave the rest up to the Presidio Trust. The Trust is a public & private hybrid caring for the Presidio’s interior lands: restoring historic buildings, caring for the historic forests, and cleaning up the Presidio’s waste dumps.
Under the guidance of the state Department of Toxic Substances Control, the landfills began being removed in 2003. So far, four landfills have been remediated, removing 164,500 tons of soil in about 8,000 truck loads. Although gone from the Presidio, the waste has been taken to a different type of landfill that can handle their toxic mix, a hazardous waste disposal site in Kings County California. There are eight more landfills to clean up, but they should be done by 2010. Some landfills are being excavated while others may be capped, the cheaper alternative that leaves the dump in place and covers it with an impenetrable barrier. A public advisory group, the Remediation Advisory Board, serves as the community’s watchdog over the cleanup.
The Presidio’s coastal bluffs are arguably the wildest place left in San Francisco. Taking a walk on its towering sand dunes and steep cliffs amidst the soundtrack of the crashing waves lends a sense of rugged adventure. The natural history of San Francisco is of course the story of every large city in the world that was built on its natural resources. Dune ecosystems once covered one third of San Francisco, and the coastal cliffs ringed the city from the Ocean Beach all the way around to Telegraph Hill. If it were not for the Army base, the Presidio and much of the rest of the Golden Gate Recreation Area would no doubt have been a maze of concrete. The Remediation Program has opened the way for Trust and Park Service employees to repaint the landscape with native plants and historic forest species.
The first Presidio bluffs site to be cleaned up was Battery Crosby in 2005, and the work has since continued north towards the Golden Gate Bridge. More removal is slated for the next decade. Only a few years into the restoration, bumblebees buzz on seaside daisy while a Bewick’s wren flits in and out of newly opened coastal ravines and freshwater seeps. An amazing new trail called the Batteries to Bluffs Trail was installed in 2007, allowing access along the vertical cliffs and hidden beaches. Visitors can see seabirds rafting beyond the waves, and get an eyeful of the serpentine rock that underlays this habitat. The scaly green state rock is a manifestation of California’s location on top of a subduction zone, where an ocean plate is being pushed under a continental one and scraped materials have been squeezed back up through a fault zone. Although impressive, these habitats are fragmented and the Park Service still has much work to do managing invasive plants in the surrounding area, and protecting threatened or endangered species such as the San Francisco lessingia, Presidio clarkia, and Franciscan thistle. From this view at the narrow mouth of the Golden Gate one ponders the pioneers and immigrants that first crossed this point, entering the enormous bay that was to become their home. It is amazing that in this thriving metropolis, we can still share a little space with wildflowers and wildlife.
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