OSWER/OSRTI Washington, DC 20460


## N ATIONAL 

## P RIORITIES 

## L IST 

## (NPL)

***Final Site*** March 2010 

### SALTCHUCKMINE Outer Ketchikan County, Alaska

 Site Location: Salt Chuck Mine is located on Prince of Wales Island, in the Tongass National Forest at the northern end of Kasaan Bay.

 Site History: The Salt Chuck Mine site is an inactive former gold, silver, and copper mine. The site contains large volumes of mine tailings, including 100,000 cubic yards of saturated tailings in Salt Chuck Bay adjacent to the former mill site. The most intense mining and milling activity occurred from 1915 to 1941 when approximately 326,000 tons of ore were mined. The upland area of the site is owned by the U.S. Forest Service and consists of approximately 45 acres including the following source areas: a large pit connected to the main adit, two shafts, a tunnel, and 13 waste rock dumps. The impacted tidelands are owned by the State of Alaska.

 Site Contamination/Contaminants: Contaminants in the sources, surface water and sediments include copper, mercury, polychlorinated biphenyls (PCBs) and benzo-a-anthracene. Concentrations of all of these contaminants in upland sources exceed EPA cleanup guidelines for soil and mercury. Copper concentrations in the Bay exceed EPA risk assessment guidelines. Copper and mercury detected in clam tissues in the Bay exceed the consumption guidelines for mercury in fish tissue issued by the Alaska Department of Health and Social Services.

 Potential Impacts on Surrounding Community/Environment: Sediments and surface water in Kasaan Bay and Lake Ellen Creek have been contaminated by mercury and copper. Kasaan Bay is used by the Kasaan Tribe (several hundred people) as a commercial and subsistence fishery and shell fishery. Heavy metals from tailings both in the upland and in the Bay are impacting water quality and sediments both in the Bay and Lake Ellen Creek, which drains into the bay. The contamination affects salmon and shellfish in areas where both are harvested intensively by the local native community.

 Response Activities (to date): The Forest Service completed a draft site evaluation looking at potential cleanup alternatives in 2007. The Forest Service is finalizing this document and plans to conduct a focused cleanup action of upland debris and contaminated soils in 2011.

 Need for NPL Listing: The State of Alaska Department of Environmental Conservation (ADEC) has requested that EPA proceed with listing the site on the NPL because of the magnitude and location of contamination source areas upland and in the Bay, and because of the impacts on Kasaan Bay and the subsistence and commercial fisheries and shell fisheries that support the local native population. ADEC indicated that NPL listing of the site is the only option that will ensure that the entire site will be addressed in a timely and comprehensive manner. EPA received a letter of support for placing this site on the NPL from the State.

[The description of the site (release) is based on information av ailable at the time the site was evaluated with the HRS. The d escription may change as additional information is gathered on the sources and extent of contamination.]

For more information about the hazardous substances identified in this narrative summary, including general information regardi ng the effects of exposure to these substances on human health, please see the Agency for Toxic Substances and Disease Registry (ATSDR) ToxFAQs. ATSDR ToxFAQs can be found on the Internet

at http://www.atsdr.cdc.gov/toxfaq.html or by telephone at 1-888-42-ATSDR or 1-888-422-8737.