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Montana is rolling out new rules for algae-causing pollution that can go into waterways

An algal bloom
Dmitrii Bykanov
An algal bloom

The Montana Department of Environmental Quality Friday published draft rules for the release of nutrients from facilities like feedlots or wastewater treatment plants that produce it in their waste.

The DEQ monitors the nutrients nitrogen and phosphorus. In large amounts, these can cause algae growth that uses up oxygen, kills aquatic animals and clogs waterways. A state report found that, in 2020, 35 percent of the river miles it studied were impaired by nutrient pollution.

For the last 10 years, the DEQ has used strict numeric standards to monitor the amount of nutrients in waterways. Many facilities acquired exceptions, called variances.

lawmakers passed a bill to repeal the numeric standards in 2021. Now, the state is using narrative standards, which can include visual identifiers in waterways, and regulators have been working to finalize the new program.

“We’re looking at a suite of metrics really instead of just two and that suite of data is what’s gonna tell us [if we are] meeting the water quality standard or not,” said DEQ Water Quality Division Administrator Lindsey Krywaruchka.

Kelly Lynch is the Executive Director of the Montana League of Cities and Towns, a group that has long opposed numeric nutrient standards and said they are too difficult for cities to comply with when it comes to wastewater treatment and disposal.

Lynch says the new program is an improvement, but still lacks flexibility when it comes to ranges for dissolved oxygen and other metrics.

“The problem is that if you fall even one bit, one number, one tenth of a number outside those thresholds, you are immediately considered to be in exceedance of the standard and in violation of the standard,” she said.

On the other side of the issue are conservation groups like Upper Missouri Waterkeeper that argue the state is moving away from the most effective way of regulating nutrient pollution.

“We think it’s indefensible as a matter of science,” said Upper Missouri Waterkeeper Executive Director Guy Alsentzer.

The Department of Environmental Quality will hold a public hearing on the new draft rules on June 10.

The comment period also ends on June 10.

You can email your comments to or mail them to:

Department of Environmental Quality
Water Quality Planning Bureau
PO Box 200901
Helena, MT 59620

Kayla writes about energy policy, the oil and gas industry and new electricity developments.