EPA is proposing to add two abandoned mine sites to its Superfund list.

2 California Hazardous Waste Sites Proposed for NPL

EPA is proposing that the abandoned sites New Idria Mercury Mine in San Benito County and the Blue Ledge Mine in Siskiyou County be added to the National Priorities List.

The U.S. Environmental Protection Agency is proposing to add two abandoned mines that discharge toxic pollutants to California waterways to the Superfund National Priorities List.

The New Idria Mercury Mine site located in San Benito County affects waterways leading to the San Joaquin River and San Francisco Bay. Blue Ledge Mine in Siskiyou County discharges into streams in the Rogue River-Siskiyou National Forest and ultimately the Applegate Reservoir, a popular recreation area.

“Abandoned mines have left behind a toxic legacy that continues to threaten the health of people and natural resources of California.” said Jane Diamond, director of EPA’s regional Superfund program. “Listing these two sites will enable the EPA to reduce risks to the environment and ensure protection of important water resources.”

New Idria is an abandoned mercury mine approximately 64 miles southeast of Hollister, Calif. Past mining operations have resulted in mercury contamination and acid mine drainage in San Carlos Creek, Silver Creek, and a portion of Panoche Creek, at levels toxic to aquatic organisms. Environmental impacts extend more than 15 miles to creeks and wetland areas, endangered species habitat, and ultimately the San Joaquin River and the San Francisco Bay.

The Blue Ledge Mine is located on privately owned land surrounded by the forest, approximately three miles south of the Oregon-California border. Copper, cadmium, other metals, and acid mine drainage from past copper and zinc mining operations have contaminated sediments and surface water at levels that are toxic to aquatic organisms. Impacts include the absence of fish for more than three miles downstream and potential negative impacts to fisheries all the way to the Applegate Reservoir, nearly eight miles downstream.

In 2006, EPA performed an emergency response action to stabilize waste rock that was releasing into Joe Creek, just downstream from Blue Ledge Mine. In 2010, the U.S. Forest Service (USFS) received $12.4 million in American Reinvestment and Recovery Act funds plus $1.4 million from the ASARCO Environmental Trust to place the waste rock into an on-site repository. This work began last summer.

To date, there have been 1,627 sites listed on the NPL since 1980, 128 of which are in California. Nationally, cleanup is under way or complete at 1,100 of the 1,627 sites.

With all Superfund sites, EPA tries to identify and locate the parties potentially responsible for the contamination. For sites without financially viable potentially responsible parties, listing makes the sites eligible for federal funds that will enable completion of the cleanup.

Source: U.S. EPA

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