Nutrients in Montana’s Water

Summer time algal blooms, pond scum, and river choking weeds – all are problems because of human caused amounts of nutrients in water. The culprits are phosphorus and nitrogen, nutrients that come from various “end of pipe” (point) sources such as sewage treatment plants, factory farms, and industrial facilities, along with “non-point” sources, such as agriculture, urban runoff, and forestry.

Montana’s waters are increasingly facing a threat from nutrient pollution. This pollution, in the form of excess nitrogen and phosphorus, enters waterways from fertilizers, animal manure, sewage treatment facilities, laundry detergents, stormwater runoff, and septic tanks. It can cause algal growth (algal blooms) that negatively impacts stream health and aquatic life, and has serious impacts to human health at high levels, especially infants and other vulnerable populations.

What is Montana Doing About Nutrient Pollution?

Montana was one of the first states to adopt “numeric” nutrient pollution limits, which created a numeric standard for the measurable amount of pollution that can be discharged into our rivers and streams. The numeric limits were approved by the U.S. Environmental Protection Agency (EPA) as an effective way to address nutrient pollution. Unfortunately, in 2021, due to industry pressure, the Montana Legislature repealed the numeric limits on pollution, and directed the Montana Department of Environmental Quality (DEQ) to draft implementation rules for the new law that includes “narrative” limits and an “adaptive management” approach to regulate these pollutants.

As part of its duties under the Clean Water Act, the EPA was required to review the changes to Montana law. Recognizing the increased pollution concerns and conflict with the federal Clean Water Act, the U.S. Environmental Protection Agency (EPA) rejected several aspects of the legislation that repealed Montana’s numeric standard. However, even though numeric limits are currently the law, Montana is continuing to develop a set of regulations that would allow for narrative limits and an adaptive management approach. These regulations are currently being developed by the nutrient working group at DEQ.

MEIC has been at the forefront of advocating for strong water quality protection laws since our founding. We also are a vigilant “watch dog” to assure the laws are complied with, and that permitting activity protects Montana’s most valuable, shared resource. We are working closely with our conservation partners and monitoring the nutrient working group and proposed regulations to assure that they protect Montana’s water.

Learn more:

Clark Fork Coalition Nutrient Page

Montana DEQ – Nutrient Working Group

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