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Press Release

Caltrans to Pay $10 Million to Remediate the Presidio’s Mountain Lake and to Re-route Highway 1 Drainage to Avoid Future Contamination

For Immediate Release
Office of Public Affairs
Proceeds of Settlement to Fund Remediation of Mountain Lake Lead Contamination Caused by the Operation of Highway 1

WASHINGTON -- Federal officials announced a civil settlement with the state of California Department of Transportation (Caltrans) resolving claims brought by the Presidio Trust and the U.S. Army resulting from Caltrans’ construction and operation of Highway 1 (also known as Park Presidio Boulevard) through the Presidio of San Francisco. Under the settlement, Caltrans is required to pay $5.5 million toward the remediation of Mountain Lake sediment contamination, fund and construct runoff diversion projects to eliminate future discharges to Mountain Lake, and reimburse a portion of the United States’ legal costs. The total settlement is valued at $13.5 million.

The settlement resolves the United States’ claims for breach of a 1938 permit that authorized Caltrans to build Highway 1 through the Presidio and required Caltrans to repair any damage caused by construction and operation of the highway. The United States filed an action in federal court in January 2009 alleging that runoff from Highway 1 has contaminated Mountain Lake sediment with lead, copper, zinc and other substances, and that highway drainage facilities are in need of repair or replacement. Under the terms of the settlement, Caltrans will pay $5.5 million to the United States for remediation of Mountain Lake, $4 million for re-configuring the Mountain Lake overflow pipeline, $500,000 for the Presidio’s legal costs, and will fund and construct a run-off diversion project, at an estimated cost of $3.5 million, so that contaminants from Highway 1 will no longer enter Mountain Lake.

“Today marks a step forward to preserve and protect Mountain Lake, which is one of the city’s only natural lakes and is an integral part of San Francisco’s treasured Presidio,” said Ignacia S. Moreno, Assistant Attorney General for the Environment and Natural Resources Division at the Department of Justice. “After decades of lead and other contamination of Mountain Lake, today’s settlement will fund both the cleanup and the infrastructure to protect this natural resource long into the future.”

The Presidio is located within the Golden Gate National Recreation Area and features significant natural, historic, scenic, cultural and recreational resources. Mountain Lake lies at the southern edge of the Presidio and is one of the few natural lakes in San Francisco and the only lake within the Presidio. Mountain Lake attracts migratory birds, resident wildlife and frequent human visitors, and fronts a neighborhood park, playground and a small beach. A walking path and trail surrounds a large part of Mountain Lake, which is accessible by foot and bicycle.

“The Trust is working closely with regulators to ensure that the cleanup of Mountain Lake is protective of human health and the environment,” said Eileen Fanelli, Environmental Remediation Manager for the Presidio Trust. “This settlement with Caltrans will allow us to stay on schedule and complete the remediation of lake sediment by 2013.”

The settlement is subject to a 30-day public comment period that begins with the posting of a notice in the Federal Register. The consent decree will be available for viewing at .

Updated April 5, 2024

Press Release Number: 11-1484