NPDES permits in Iowa
678 permits held by publicly owned wastewater treatment plants · issued by Iowa DNR
Effective
526
Administratively continued
151
Expired
1
Total tracked
678
Iowa Department of Natural Resources (Iowa DNR) runs the NPDES program in Iowa under delegation from EPA Region 7, issuing and enforcing the discharge permits listed here. Klarifi tracks 678 permits held by publicly owned treatment plants in the state, with status, expiry, design flow and three-year compliance for each. Agency website →
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.
Permit renewals by year
2029: 96 permits
2030: 121 permits
2031: 65 permits
Largest permit holders in Iowa
| Facility | City | Avg flow (MGD) | Design (MGD) | NPDES permit | Status | Expires | Violations (3y) |
|---|---|---|---|---|---|---|---|
| Water Pollution Control Facility | Cedar Rapids | — | 86.95 | IA0042641 | Effective | Aug 2030 | 15 |
| Iowa City, City Of (south) STP | Iowa City | — | 43.3 | IA0070866 | Effective | Jul 2030 | 11 |
| Davenport Wastewater Treatment Plant | Davenport | — | 40 | IA0043052 | Administratively continued | Jun 2026 | 0 |
| City Of Sioux City STP | Sioux City | — | 28.73 | IA0043095 | Effective | Jan 2031 | 10 |
| Burlington, City Of (wwtp) | Burlington | — | 28.3 | IA0043079 | Effective | Jan 2027 | 4 |
| Coralville WWTP | Coralville | — | 22.56 | IA0020788 | Effective | Mar 2026 | 1 |
| Cedar Falls City Of STP | Cedar Falls | — | 21.6 | IA0036633 | Effective | Dec 2029 | 0 |
| Fort Dodge City Of STP | Fort Dodge | — | 21.6 | IA0044849 | Effective | Dec 2030 | 0 |
| Council Bluffs City Of STP | Council Bluffs | — | 17.9 | IA0036641 | Effective | Aug 2031 | 0 |
| Marshalltown City Of STP | Marshalltown | — | 17.44 | IA0038610 | Effective | Oct 2027 | 8 |
| Clinton WWTP | Clinton | — | 17 | IA0035947 | Effective | Jun 2031 | 12 |
| City Of Muscatine Water & Resource Recovery Facility | Muscatine | — | 16.9 | IA0023434 | Effective | Mar 2030 | 20 |
| Fairfield City Of STP | Fairfield | — | 16.1 | IA0035076 | Effective | May 2026 | 28 |
| City Of Boone Water Pollution Control | Boone | — | 15.1 | IA0058076 | Effective | Nov 2029 | 3 |
| Newton City Of STP | Newton | — | 13.1 | IA0027723 | Effective | Apr 2031 | 3 |
| Ottumwa City Of STP | Ottumwa | — | 12.5 | IA0058611 | Effective | Feb 2031 | 1 |
| Iowa Great Lakes Sanitary District WWTP | Milford | — | 10.26 | IA0059765 | Administratively continued | Aug 2026 | 15 |
| North Liberty WWTP | North Liberty | — | 10.05 | IA0032905 | Effective | Apr 2031 | 0 |
| Osceola WWTP South | Osceola | — | 9.84 | IA0041815 | Effective | Oct 2029 | 165 |
| Fort Madison City Of STP | Fort Madison | — | 9.3 | IA0027219 | Effective | Dec 2029 | 5 |
| Indianola Water Resource Recovery Facility | Indianola | — | 9.1 | IA0053405 | Effective | Aug 2027 | 5 |
| Atlantic City Of STP | Atlantic | — | 8.1 | IA0029025 | Effective | Feb 2030 | 5 |
| Estherville WWTP | Estherville | — | 8 | IA0023744 | Administratively continued | Dec 2025 | 69 |
| Storm Lake WWTP | Storm Lake | — | 8 | IA0032484 | Effective | Oct 2029 | 3 |
| Perry WWTP | Perry | — | 7.88 | IA0032379 | Effective | May 2030 | 4 |
NPDES permits in Iowa: 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 September 11, 2026.