Montana regulators last week addressed federal disapproval of new state guidance for nutrient pollution in rivers and lakes.
The standards apply to wastewater treatment plants and other entities that release nutrients that in excessive amounts can cause harmful algal blooms.
The Montana Department of Environmental Quality has formally responded to a letter the U.S. Environmental Protection Agency sent in May that questioned the effectiveness of a new Montana law that rolled back nutrient standards based on a strict hard-number limit.
The state is establishing more flexible criteria using measurements that include visuals, also called narrative standards. At a meeting of the DEQ’s nutrient advisory group, regulator Amy Steinmetz said the state’s response references initial talks with the federal agency.
"EPA stated that both numeric and narrative criteria can be used in permits, impaired waters lists and total maximum daily loads informed by the science to protect against the adverse effects of nutrient pollution," she said.
