Idaho NPDES permit search
Status, expiry and violations for 94 municipal wastewater permits · issued by IDEQ as IPDES permits
In short
How do I look up an NPDES permit in Idaho?
Search this page by permit number or plant name for a municipal plant’s permit status, expiry date and violations. For the official file, search DEQ’s list of issued permits or DEQ’s IPDES public permits page. EPA’s ECHO database shows the monitoring results and violations of every permit. The 99 industrial permits in Idaho are listed in Klarifi with a free account.
Links to official sources checked September 2026.
Effective
16
Administratively continued
77
Expired
1
Plants with effluent violations, 3 years
69
Where to find official Idaho NPDES records
Idaho Department of Environmental Quality (IDEQ) runs the NPDES program in Idaho under authorization from EPA Region 10, as the Idaho Pollutant Discharge Elimination System (IPDES). It issues and enforces the permits and keeps the official file: applications, permits, fact sheets and monitoring reports. IDEQ website ↗
permits · permit documents
Set “Filter by Type” to IPDES, type the facility name or permit number and open the document link in that row.
permits · applications
Coverage under general permits: pick the general permit, or type the facility name or coverage number, and open its notice of intent.
permits · DMRs · inspections · violations · enforcement
EPA’s Enforcement and Compliance History Online. Search water facilities by permit number, name or city; the Detailed Facility Report lists inspections, violations and enforcement actions, and Effluent Charts plot monitoring results against the permit limits.
- Permit numbers
- IPDES keeps EPA’s numbers. General permits are numbered like IDR100000 (construction stormwater), and each coverage under one gets its own number, such as IDR053201.
- Discharge monitoring reports
- Through EPA’s NetDMR or NeT, depending on the permit, with other reports through DEQ’s IPDES E-Permitting System.
Industrial and commercial NPDES permits in Idaho
Most NPDES permits are not held by municipal plants. EPA’s permit database lists 99 individual permits in force for industrial and commercial facilities in Idaho (manufacturers, food processors, mines, power plants, landfills), 7 of them major dischargers, plus 278 facilities covered by a general permit, mostly for stormwater. 32 of the individual permits recorded at least one effluent violation in the last three years.
| Facility | Permit | Status | Expires | Effluent violations |
|---|
Unlock 99 industrial permits in Idaho
Search every industrial and commercial discharger in Idaho by name or permit number, with permit status, expiry and violation history. Free with a Klarifi account.
Industrial and commercial NPDES permits in Idaho: permits in force (effective or administratively continued) held by facilities EPA does not class as publicly owned treatment works or federal facilities. Source: EPA ICIS-NPDES via Klarifi, October 2026.
Violations at Idaho wastewater plants
69 of the 94 municipal plants on this page recorded at least one effluent violation, a monitored value above a permit limit, in the last three years, and 75 had a violation of any kind, including late or missing monitoring reports. Each plant’s page shows its own count. EPA’s enforcement records list 102 formal cases naming Idaho wastewater plants, 15 of them since fiscal year 2020, with $1.2 million in penalties assessed. Enforcement cases in Idaho →
Permit renewals by year
An NPDES permit runs for five years. To keep discharging, a plant must apply for renewal at least 180 days before the expiry date, and the renewed permit usually arrives with tighter effluent limits, new monitoring requirements or a compliance schedule. That is why the year a permit expires is the year a plant starts budgeting for upgrades: nutrient removal, disinfection, capacity or controls.
Largest permit holders in Idaho
| Facility | City | Avg flow (MGD) | Design (MGD) | NPDES permit | Status | Expires | Violations (3y) |
|---|---|---|---|---|---|---|---|
| West Boise WWTP | Garden City | 50.91 | 24 | ID0023981 | Effective | Jun 2027 | 10 |
| Pocatello City WWTP | Pocatello | 6.38 | 12 | ID0021784 | Administratively continued | Aug 2017 | 8 |
| Nampa WWTP | Nampa | 10.69 | 11.76 | ID0022063 | Administratively continued | Oct 2021 | 27 |
| Rexburg WWTP | Rexburg | 3.22 | 6 | ID0023817 | Effective | Mar 2028 | 41 |
| Emmett WWTP | Emmett | 1.68 | 5.7 | ID0020311 | Administratively continued | Jan 2007 | 2 |
| Lewiston WWTP | Lewiston | 3.36 | 5.7 | ID0022055 | Administratively continued | Jan 2021 | 0 |
| Page WWTP | Smelterville | 2.04 | 4.3 | ID0021300 | Administratively continued | Sep 2018 | 1 |
| Ketchum Sun Valley WWTP | Ketchum | 1.14 | 4 | ID0020281 | Administratively continued | Jul 2017 | 0 |
| Moscow STP | Moscow | 1.84 | 4 | ID0021491 | Effective | Jan 2031 | 0 |
| Kuna North WWTP | Meridian | 1.3 | 3.5 | ID0028355 | Administratively continued | May 2014 | 5 |
Idaho NPDES permits: questions
NPDES permit search in other states
Sources and methodology
Flow, permit and violation figures come from the EPA's ICIS-NPDES discharge monitoring records. Population served comes from the Clean Watersheds Needs Survey 2022. Treatment structures are identified by Klarifi's review of aerial imagery, and capital improvement projects are extracted from published municipal budget documents. Violations are counted over the last three years of monitoring reports.
Data refreshed October 12, 2026.
Wastewater terms: NPDES permit · POTW · Significant industrial user · MGD · FOG · Equalization tank · all terms