For Immediate Release: Tuesday, September 26, 2023


Will Tiedemann, Conservation Associate, (208) 345-6933 x 228

Abby Urbanek, Communications Manager, (208) 345-6933 x 214

Report finds 57% of Idaho’s sewage treatment plants are violating pollution discharge limits

BOISE, ID – The Idaho Conservation League’s (ICL) sixth annual study of Idaho’s wastewater treatment plants found in 2022, more than 57% of all sewage facilities in Idaho failed to comply with Clean Water Act standards for the discharge of harmful bacteria, chemicals, toxic metals, and other substances. During 2022, there were 520 violations of the Clean Water Act among wastewater treatment plants in Idaho.

Municipal wastewater treatment plants are on the front line for protecting water quality and human health. Properly built and operated, well-maintained sewage treatment plants are critical for keeping our rivers and lakes fishable, swimmable, and safe. Yet, the majority of these plants are violating their pollution discharge limits.

“Statewide the overall picture is troublesome, with just 43% of treatment facilities operating last year without any violations,” said Will Tiedemann, Conservation Associate with ICL. “This is an abysmal rate for something so essential as clean water, and is unacceptable to be coming from facilities that are meant to protect us.”

There is a significant range in the performance of facilities across Idaho. In 2022, some facilities reported zero violations while others reported upwards of 40 or 50 violations. 

Other findings:

  • 11 of the 119 sewage treatment plants spread across Idaho were responsible for more than half (51%) of all violations reported statewide. All 11 of these worst-performing facilities were located in relatively small rural communities. 
  • 3 facilities (Driggs, Jerome, and Kuna) accounted for a quarter of all violations in 2022.
    • City of Driggs WWTP: The Driggs wastewater treatment facility had 53 total violations in 2021 and 53 violations again in 2022. The facility also had the second largest pollutant discharge over limits in 2022 at 36,457 pounds of ammonia. 
    • City of Jerome WWTP: The Jerome facility dealt with significant new effluent issues, with 18 violations in 2022. 
    • City of Kuna WWTP: The City of Kuna’s “North” wastewater treatment facility jumped from three discharge violations in 2021 to 16 in 2022. The facility also discharged the fourth most pollutants over limits in 2022 (7,301 pounds of ammonia). 
  • 52 cities or towns across the state reported no discharge violations in 2022.
  • Many treatment facilities—in particular, ones serving the municipalities of Blackfoot, Firth, Wilder, Tensed, Marsing, and Kendrick—made strong improvements to reduce or even eliminate their discharge violations from 2021 to 2022. 

ICL issued its first Wastewater Treatment Plant report in 2017. The annual report compiles and examines discharge permit violations for every Idaho facility, and reports on their record of meeting legal standards pursuant to the Clean Water Act. ICL has presented these reports at meetings and conferences to mayors, city officials, regulating agencies, and the general public to bring attention to these important issues. 

Along with reviewing violations from Idaho’s wastewater treatment plants, ICL’s report provides concrete suggestions for ways to engage local leaders to act to improve sewage treatment plants with violations.

“This report serves as a springboard for advocacy when it comes to clean water, highlighting the facilities that are doing their job and those that need to change,” continued Tiedemann. “Everyone deserves clean water. We encourage Idahoans and local leaders who live in areas with facilities that have violations to act now by contacting their city or local government to learn more, provide feedback, and demand action.”

ICL will continue to track each facility’s compliance, particularly those with poor track records. Review ICL’s 2023 Wastewater Treatment Plant Report in its entirety at