Nevada Governor Brian Sandoval has agreed with the US Environmental Protection Agency's (EPA) recommendation to add the toxic Anaconda copper mine site near Weed Heights in Lyon County to the Superfund National Priorities List (NPL).
Under the latest proposal, $31m would be available to help clean-up the abandoned mine.
Sandoval said: "The shared goal of the state of Nevada, the EPA and representatives of Lyon County has always been to fully clean-up the site in a timely manner.
"Based on assurances given to the local officials during the EPA's visit to the site, the state will concur with the proposed designation and a plan for a rapid, comprehensive site clean-up will proceed."
Located 80 miles south-east of Reno, the Anaconda mine in Yerington is already a federal Superfund site.
Adding the site to the National Priority List will make it eligible for federal money to pay for 90% of the amount needed to begin clean-up of the contaminated waste ponds.
Sandoval added that the agency must develop and implement a contingency plan of necessary interim actions to prevent a release of Arimetco draindown fluids to the environment in case it fails to secure enough federal funds to close the Arimetco portion of the site permanently.
Yerington Mayor George Dini said: "Today's decision is a direct result of collaborating toward a shared goal of fully cleaning up the site in an efficient and responsible manner."
Recently, Sandoval and the EPA signed an agreement to address issues at the Anaconda mine.