The Idaho Conservation League (ICL) released its seventh annual Idaho Wastewater Treatment Plant Report.
The report is based on 2023 data with the seventh annual assessment finding that 58% of all sewage facilities in Idaho failing to comply with Clean Water Act (CWA) standards for harmful bacteria, chemicals, toxic metals, or other substances at least once during 2023.
For comparison, the sixth annual assessment found a compliance rate of 57% during 2022.
11 of the 112 sewage treatment plants spread across Idaho were responsible for more than half of all violations reported statewide (approximately 63%).
All 11 of these worst-performing facilities were located in relatively small communities. A similar trend was also identified in ICL’s 2022 assessment.
Since ICL began publishing these reports in 2016, many of the same facilities have consistently failed to meet their CWA permit requirements, according to the report.
Conversely, 47 cities and towns across the state reported no discharge violations in 2023.
Many treatment facilities, in particular ones serving the municipalities of Nez Perce, Kuna, Mullan, Emida, Smelterville, and Craigmont, made string improvements to reduce or even eliminate their discharge violations from 2022 to 2023.
42% of treatment facilities operated in 2023 without any violations.
ICL reviewed discharge data for all 112 municipal wastewater treatment plants with NPDES or IPDES permits. This data covered the past year (January 2023 through December 2023), and accessed the information at the U.S. Environmental Protection Agency’s (EPA’s) Enforcement and Compliance History Online website.
The ICL review found that 65 facilities had violated their discharge permits during 2023. In total, these facilities reported 458 discharge violations. This was down from 2022 when 520 individual violations were reported.
The data revealed a large variability in total recorded discharge violations among facilities. 35 facilities had three or less discharge violations. Three facilities accounted for 32% of all violations and 11 facilities accounted for 62% of all violations.
