The United States Environmental Protection Agency named the Silver Bow Creek/Butte area and the Anaconda Smelter Superfund sites as two of the 21 top priorities in the nation for cleanup.
The sites on the list will be targeted for immediate and intense attention.
For the Silver Bow Creek/Butte area, the EPA has taken steps to accelerate negotiations and set a deadline for an agreement to ensure stormwater controls along Silver Bow and Blacktail creeks as well as review the water treatment plant for the Berkeley Pit.
At the Anaconda Smelter site, the EPA has directed Atlantic Richfield to complete lead and arsenic sampling and cleanup of commercial and residential properties including another 1,000 homes over the next three years.
The EPA also directed Atlantic Richfield to begin testing school grounds for lead and school interiors for lead and arsenic in the next few months.
Butte and Anaconda were the only two Montana sites to make the list.
New Jersey was the only state with more sites on the priority list with three listed.