A group litigating variances to Montanaâs water quality standards petitioned the Environmental Protection Agency Monday claiming a new state law runs counter to the agencyâs authority to approve or disprove changes under the Clean Water Act and is a risk to the stateâs waterways. Upper Missouri Waterkeeper filed the petition following the signing of Senate Bill 358 into law by Gov. Greg Gianforte. The new law repeals numeric standards for ânutrients,â namely nitrogen and phosphorus, that are discharged into the stateâs waterways from water treatment plants and in...