The Montana Department of Environmental Quality (DEQ) has completed a draft water quality assessment for a segment of the Gallatin River.
DEQ completed the assessment after hearing concerns from local groups and receiving a petition to assess the Gallatin River.
“We were concerned when we heard about algae in the Gallatin and as a result we funded a five-year monitoring effort that started in 2019. We knew we would not be able to complete a statewide assessment this year and we wanted to make sure we could still investigate these specific concerns, so we provided the solution of an individual waterbody assessment to be able to identify any potential issues and help determine solutions,” said Greg Olsen, interim water quality division administrator at DEQ. “The data we have collected over multiple years has been crucial to our analysis and we appreciate our partnership with the Gallatin River Task Force to help monitor the river and provide additional data through a collaborative effort.”
This assessment of the Gallatin River indicates that the river is impaired due to exceeding thresholds for algae in 25 percent of the samples. The assessment is based on an evaluation of all readily available data collected within the past 10 years, including water quality monitoring performed by DEQ and the Gallatin River Task Force.
Excess algae is often caused by an exceedance of thresholds for Total Nitrogen and Total Phosphorus. In this instance, the data do not show an exceedance of those thresholds. DEQ will need to determine what is causing excess algae in the Gallatin River and then develop a Total Maximum Daily Load (TMDL) or standards, as needed, to reduce the pollutants causing excess growth.
A TMDL defines the amount of certain pollutants the waterbody can hold without impacts to water quality and beneficial uses of the river.
“The health of Montana’s waters is vital to our communities and DEQ has invested resources and staff time to better understand the Gallatin’s ecosystem,” said Olsen. “We’re committed to continuing to work with our local partners on solutions.”
DEQ is seeking comment on the draft assessment and hosting a public meeting on July 14, 2022 in Big Sky, Mont. The hybrid meeting will include a presentation and opportunity for questions. Attendees can access the meeting by telephone, in-person or online.
What: A hybrid presentation on the draft Gallatin River assessment.
When: Thursday, July 14, 2022 at 6 p.m.
Where: The hybrid meeting will have both an online and in-person option.
• The in-person meeting will be held in Big Sky, Mont. at the Base Big Sky Community Organization (285 Simkins Drive)
• To access the online or phone option, please visit: https://deq.mt.gov/News/publiccomment-folder/news-article40
Written and electronic public comment will be accepted through August 22, 2022. Once the public comment closes, DEQ will review comments and make any necessary updates to the assessment.
To view the assessment and provide comment, visit: https://deq.mt.gov/News/publiccomment-folder/news-article40
In the meantime, DEQ has prioritized the lower Gallatin as a focused watershed. Focused watersheds receive additional funding and prioritization for restoration projects.
Past projects in the Gallatin area have included stabilizing streambanks and creating wetlands to help reduce nitrogen loading and to reduce sediment in the river.