Pesticide monitoring in Montana's Columbia River Basin is finding an unsurprising result so far.
Researchers do not yet have all the details but said herbicides are the primary pollutant in early testing.
Rachel Malison, assistant research professor at the University of Montana and leader of the Pesticide Stewardship Partnership Program, said the plant-killing toxins come from various sources, including agricultural and residential users. She acknowledged the data is not surprising, given heavy herbicide use.
"We're not trying to throw up a big red flag for people yet," Malison noted. "We want to make sure we're looking into all the data and understanding it, but overall our message is, we want to have the best practices in place to help protect the waters the best we can."
The program started in October 2023 with grant funding from the U.S. Environmental Protection Agency. It aims to reduce toxins in the state's upper Columbia River Basin. Malison pointed out there is little data on pesticides in Montana's surface waters, adding it was a big part of why she wanted to do the work. They have taken samples from all 12 counties in the basin this year.
Malison explained it might surprise people to learn pesticide pollution from urban and suburban areas can be higher than from agriculture. She emphasized the program is not targeting any particular group, noting commercial pesticide users have to be licensed.
"In Montana, you actually have to take a lot of trainings and do recertifications, and be taught different methods," Malison outlined. "The basic homeowner doesn't have to have any of those trainings and can just buy it off the shelf and use it."
Malison and her team will keep rolling along with water sampling and monitoring in 2026, and will do more education and outreach.
"As we are getting data and results back, we're creating materials to help spread the messages and for people to understand how our actions on the land can influence the water," Malison underscored.
