EPA Announces Open Comment Period for Proposed Plan to Address Carson River Mercury Superfund Site, Nevada’s Sole Superfund Site

 U.S. EPA News Release:

EPA Announces Open Comment Period for Proposed Plan to Address Carson River Mercury Superfund Site, Nevada’s Sole Superfund Site

October 13, 2021

Media Contact: Josh Alexander, (415) 214-5940, alexander.joshua@epa.gov

DAYTON, NEVADA — The U.S. Environmental Protection Agency (EPA) will begin accepting public comments on its Proposed Plan related to mercury and the Carson River Mercury Superfund site on October 15. The Plan aims to reduce human exposure to mercury from a section of the Carson River site known as Operable Unit 2.

The 30-day public comment period for the Proposed Plan ends on November 15, 2021. Comments may be sent via email to Bain.Andrew@epa.gov. Comments may also be provided by calling and leaving a voicemail at 1-800-231-0775. EPA will review and consider all public comments regarding cleanup at the site.

The Proposed Plan, a recorded presentation discussing the Plan, a summary brochure, and the Administrative Record (site files) will be available by October 15, 2021, at: http://epa.gov/superfund/carsonrivermercury.

Printed versions of the Proposed Plan and summary brochure can also be accessed in hard copy at:

•     Churchill County Library, 553 S. Maine Street, Fallon, NV 89406

•     Dayton Valley Branch Library, 321 Dayton Valley Road, Dayton, NV 89403

•     Nevada State Library, 100 N. Stewart Street, Carson City, NV 89701

•     Silver Stage County Library, 3975 Silver Stage Place, Silver Springs, NV 89429

Background on Carson River Mercury Site:

In 1859, miners discovered large natural deposits of gold and silver, also known as the Comstock Lode, in Carson City, Virginia City, and Dayton, Nevada. From about 1860-1890, miners used mercury to process gold and silver ore at approximately 236 mills. This mining process released an estimated 14 million pounds of mercury into the environment.

In 1990, the Carson River Mercury Superfund Site was added to the EPA’s National Priorities List, which consists of some of the most toxic Superfund sites in the country. The Site covers about 330 square miles and in five counties and affects more than 130 river miles in Northwestern Nevada. Historic mill sites in Carson City, Virginia City, Dayton, Washoe Valley, and Pleasant Valley have mercury contamination, and waterways located next to mill sites spread mercury into the floodplain of the Carson River. EPA’s site investigation has found significant amounts of mercury in soil, sediments (earthen materials that settle to the bottom of a water body), fish and wildlife.

Currently, the site has been divided by EPA into two operable units to better manage cleanup actions. Operable Unit 1 consists of the old mill sites and tailings. Operable Unit 2 includes the Carson River and adjacent floodplain from the New Empire area to the Carson Sink.

For more information on EPA’s Superfund Program, please visit: https://www.epa.gov/superfund.

Learn more about EPA’s Pacific Southwest Region. Connect with us on Facebook and on Twitter.