Settling CERCLA defendants in relation to violations of §107(a) of CERCLA at the Butte priority soils operable unit must remove contaminated mine tailings in numerous locations in and near Butte, Montana; capture and treat certain contaminated groundwater; construct stormwater retention basins to protect surface waters from contaminated runoff; pay EPA $3.5 million for past costs, $11.2 million in future oversight costs, and $20.5 million to Montana to undertake certain remedial and restoration actions; and implement stormwater control and operation and maintenance activities; the consent decree also requires certain federal agencies to pay $10 million of EPA's past costs to resolve a defendant's counterclaims.