Oskaloosa NE WWTP
2295 235th St., Oskaloosa, IA 52577 · Mahaska County · Publicly Owned Treatment Works
- Average flow
- 0.69 MGD
- Design flow
- 3 MGD
- NPDES permit
- IA0038539
- Administratively continued
- Permit expires
- March 2026
- Population served
- 5,214
- CWNS 2022
Oskaloosa NE WWTP is a publicly owned wastewater treatment works in Oskaloosa, Mahaska County, Iowa treating an average of 0.69 million gallons per day against a permitted design capacity of 3 MGD, serving about 5,214 residents. It discharges under NPDES permit IA0038539 (administratively continued), which expires in March 2026, with 51 recorded violations in the last three years. EPA has recorded 1 formal enforcement action naming the plant, the latest in December 2025.
Treatment technology
3 treatment structures and unit processes identified at Oskaloosa NE WWTP.
Available with a free Klarifi account
See the full treatment train at Oskaloosa NE WWTP: structures, unit processes and planned upgrades, with exact unit counts.
Compliance snapshot (last 3 years)
- Total violations
- 51
- Effluent violations
- 51
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 Oskaloosa NE WWTP in EPA's ICIS system.
- Formal actions
- 1
- 1 since FY2020
- Penalties assessed
- $3,000
- all cases
- EPA inspections
- 0
- none on record
Latest case · Dec 2025
City of Oskaloosa Biosolids ESA CWA 309G2E AO For Class I Penalties - Biosolids Expedited Settlement
Administrative order · CWA, NPDES Permit Violations · Final Order With Penalty · Penalty $3,000
EPA's description of the case:
“Facility land applied biosolids above the 40 CF 503.13 ceiling limits.”
Source: EPA ECHO, civil enforcement case 07-2025-0110.
Full case history with a free Klarifi account
Every action against Oskaloosa NE WWTP with dates, milestones, violation types and EPA's complete case summaries, plus inspections and informal actions.
Key contacts
4 verified contacts for Oskaloosa NE WWTP, with validated emails and direct phone numbers.
Unlock 4 verified contacts (1 more than shown)
Names, validated emails and direct phone numbers for decision-makers at Oskaloosa NE WWTP, plus the full compliance history and discharge data.
Nearby wastewater treatment plants in Iowa
University Park · 2 mi away
—
Oskaloosa · 4 mi away
0.71 MGD
Beacon · 4 mi away
0.03 MGD
Oskaloosa · 5 mi away
—
Rose Hill · 8 mi away
—
Leighton · 9 mi away
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New Sharon · 10 mi away
0.14 MGD
Fremont · 12 mi away
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Oskaloosa NE 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 March 28, 2025.
Wastewater terms: POTW · MGD · NPDES permit · Inflow and infiltration · Significant industrial user · WWTP · all terms