Thief River Falls WWTP
803 Barzen Ave S, Thief River Falls, MN 56701 · Pennington County · Publicly Owned Treatment Works
- Average flow
- 6.93 MGD
- Design flow
- 2.99 MGD
- NPDES permit
- MN0021431
- Administratively continued
- Permit expires
- August 2026
- Population served
- 8,749
- CWNS 2022
Thief River Falls WWTP is a publicly owned wastewater treatment works in Thief River Falls, Pennington County, Minnesota treating an average of 6.93 million gallons per day against a permitted design capacity of 2.99 MGD, serving about 8,749 residents. It discharges under NPDES permit MN0021431 (administratively continued), which expires in August 2026, with 29 recorded violations in the last three years. EPA has recorded 1 formal enforcement action naming the plant, the latest in March 2025.
Treatment technology
Treatment structures and unit processes at Thief River Falls WWTP.
Treatment structure data not yet analyzed for this facility.
Compliance snapshot (last 3 years)
- Total violations
- 29
- Effluent violations
- 9
Based on NPDES Discharge Monitoring Reports. Full violation history, parameters and discharge data available in the Klarifi platform.
EPA enforcement history
Federal civil enforcement cases, compliance inspections and informal actions recorded for Thief River Falls WWTP in EPA's ICIS system.
- Formal actions
- 1
- 1 since FY2020
- Compliance actions
- $50,500
- required by EPA orders
- EPA inspections
- 2
- latest Jul 2022
Latest case · Mar 2025
THIEF RIVER FALLS-TREATMENT PLANT | AOC
Administrative order · SDWA, National Drinking Water Regulations · Final Order No Penalty · Compliance actions $50,500
EPA's description of the case:
“The final order of this AOC was sent 3/14/2025”
Source: EPA ECHO, civil enforcement case 05-2025-1039.
1 informal enforcement action (notices of violation and similar), the latest in Dec 2022.
Full case history with a free Klarifi account
Every action against Thief River Falls WWTP with dates, milestones, violation types and EPA's complete case summaries, plus inspections and informal actions.
Key contacts
Decision-makers at Thief River Falls WWTP.
No verified contacts on file yet
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Nearby wastewater treatment plants in Minnesota
Saint Hilaire · 7 mi away
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Thief River Falls · 10 mi away
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Viking · 13 mi away
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Plummer · 15 mi away
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Red Lake Falls Township · 16 mi away
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New Folden Township · 17 mi away
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Goodridge · 19 mi away
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Middle River · 21 mi away
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Thief River Falls WWTP: frequently asked questions
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 26, 2026; facility record last updated October 10, 2026.
Wastewater terms: POTW · MGD · NPDES permit · Inflow and infiltration · Equalization tank · Centrate · all terms