Narrative standards, on the other hand, require action only after problems are already visible. As of 2020, excess nitrogen and phosphorus accounted for nearly one-fifth of all stream miles impaired by water pollution, according to DEQ’s Integrated Report. This time, the Legislature mandated elimination of the numeric standard but added no requirement for DEQ to develop narrative standard rules. Fish and Wildlife Service since reduced water quality could affect threatened bull trout, arctic grayling and other sensitive aquatic species. “The law requires agencies to understand how gutting water pollution control standards would impact the state’s clean water resources, including threatened and endangered species, before making a decision.