The U.S. Environmental Protection Agency (EPA) announced on July 8 that it has completed a seven-year, $20 million cleanup of residential and commercial properties in Eureka, Nev.

Since 2012, EPA removed more than 56,000 cubic yards of arsenic- and lead-contaminated soil. Eureka’s lead smelting industry in the late 1800s led to widespread soil contamination, noted EPA.

“On behalf of EPA staff and contractors, I’d like to extend my gratitude to the community for their collaboration and patience as we worked together on this enormous task,” said EPA Pacific Southwest Regional Administrator Mike Stoker in a statement. “Removing soil contaminated with heavy metals protects the health of local Eureka residents.”

After EPA and the Nevada Division of Environmental Protection (NDEP) detected high levels of lead and arsenic in surface soils in 2012, EPA began a comprehensive assessment throughout Eureka, sampling 287 parcels in town. Over the course of six construction seasons, EPA cleaned up 183 properties, placed rock covers over four historic smelter locations, replaced landscaping and installed fencing. The work cost $20 million.

“NDEP appreciates the collaborative relationship formed between the EPA, NDEP and Eureka County to make this project a success,” said Greg Lovato, NDEP administrator, in a statement. “The cleanup activities conducted by the EPA and the future long-term management of the remedy by NDEP and Eureka County will reduce future exposure to lead and arsenic in this community for generations.”

The work at the Eureka smelter sites included excavation and disposal of contaminated soils at an onsite repository. In addition, EPA installed drainage controls and fencing around one of the large slag piles, while NDEP and Eureka County installed drainage controls and fencing around a second large slag pile.

EPA worked closely with NDEP, Eureka County and the Nevada State Historic Preservation Office (NSHPO) during the seven-year effort. Eureka County and NDEP provided logistical and technical support, while NSHPO ensured compliance with historic preservation requirements.

Institutional controls will be managed by both Eureka County and NDEP. The Institutional Control Plan, which provides guidelines to help ensure properties are not re-contaminated, was approved by the Board of Eureka County Commissioners and NDEP.