The Idaho Conservation League's fifth annual report on discharges from sewage treatment plants finds three-quarters violated Clean Water Act standards between 2019 and 2021.
However, those violations aren't equally distributed: just 10 facilities were responsible for more than half of them.
Will Tiedemann, conservation associate for the Idaho Conservation League, said the facilities are in rural towns, which have the fewest resources.
"There's less money, there's less support and funds to be able to adequately maintain and equip these treatment plants to do the work they need to do," Tiedemann explained. "That can be a big challenge, " Tiedemann.
Pollutants such as ammonia and E. coli were the most common. Tiedemann pointed out the violations pose a potential threat to human and wildlife health. Despite the large number of infractions, the report mentioned there were 28 cities and towns with no violations, and seven improved over the three-year period.
Tiedemann noted Idaho has received funds from coronavirus aid passed by Congress, which could help towns facing issues with their wastewater treatment plants. However, some rural communities could be pushed to the bottom of the list because of their small population size.
Tiedemann emphasized members of small communities could also have greater influence on their leaders.
"Maybe the converse point of being a small town is that every citizen's voice matters just that much more when they are these smaller towns," Tiedemann remarked. "Speaking to your local officials - speaking to your mayors, any kind of city boards, county commissioners, things like that - maybe can have a bigger effect,"Tiedemann.
He added the report comes at an interesting time, as Idaho takes over Clean Water Act enforcement from the U.S. Environmental Protection Agency. He stressed the public has an opportunity to help the state develop what compliance with the act will look like.
