In a May 10 letter to the Montana Department of Environmental Quality, the EPA asserted that a measure the Montana Legislature passed in 2021 runs afoul of the Clean Water Act. The EPA said it’s concerned that the state’s repeal of numeric standards for nitrogen and phosphorus codified in Senate Bill 358 has led to degraded water bodies and lacks a grounding in science. The letter effectively puts numeric standards back in play for the DEQ’s permitting process.