For Immediate Release: Wednesday, September 7, 2022


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

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

Report finds 75% of Idaho’s sewage treatment plants are violating pollution discharge limits

BOISE, ID – The Idaho Conservation League’s (ICL) fifth annual study of Idaho’s wastewater treatment plants found more than 75% of plants failed to comply with Clean Water Act permits for the discharge of harmful bacteria, chemicals, toxic metals, and other substances. During the three-year review period (2019-2021), there were 1,385 violations 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. 

While municipal wastewater treatment plants discharge a variety of pollutants, ammonia, E. Coli, and suspended solids are among some of the most common. 

“Nearly 8 out of every 10 sewage treatment plants discharged pollutants at levels higher than legally allowed,” said Will Tiedemann, Conservation Associate with ICL. “That means they are harming or endangering the water we, our families, our pets, and Idaho’s wildlife drink, swim, and recreate in – something that we will not overlook.”

There is a wide variation in the number of violations that facilities reported. While some facilities reported few violations, others reported well over 80 violations. 

Other main findings:

  • 10 of the 112 facilities were responsible for more than half of all violations reported statewide. All 10 of these worst performing facilities were located in relatively small rural communities.
  • Five facilities — Driggs, Nezperce, Wilder, Plummer, and Genesee — have been on ICL’s “Top 10 Polluters” list for almost a decade.
  • 28 cities or towns reported no discharge violations during the three-year period of our review.
  • Seven facilities — Eastern Idaho, Fairfield, Franklin, Fruitland (Snake River), Greenleaf, Hayden, and Twin Falls — improved their performance to zero violations for our review of the 2019-2021 period.

Facilities reporting violations need to carefully evaluate the causes for their violations and then identify and implement solutions.

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. 

“We write these reports so Idahoans and local leaders can ideally come together to fix these problems,” continued Tiedemann. “This report provides concrete suggestions for ways to engage local leaders to act to improve sewage treatment plants with violations.”

ICL will continue to track each facility’s compliance, particularly those with poor track records.