NPDES permits in Mississippi
127 permits held by publicly owned wastewater treatment plants · issued by MDEQ
Effective
112
Administratively continued
13
Expired
2
Total tracked
127
Mississippi Department of Environmental Quality (MDEQ) runs the NPDES program in Mississippi under delegation from EPA Region 4, issuing and enforcing the discharge permits listed here. Klarifi tracks 127 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: 38 permits
2030: 24 permits
2031: 8 permits
Largest permit holders in Mississippi
| Facility | City | Avg flow (MGD) | Design (MGD) | NPDES permit | Status | Expires | Violations (3y) |
|---|---|---|---|---|---|---|---|
| West Rankin Utility Authority WWTF | Richland | 10.32 | 29.1 | MS0061743 | Effective | Feb 2030 | 4 |
| Meridian POTW | Meridian | 5.41 | 13 | MS0020117 | Effective | Oct 2030 | 40 |
| West Biloxi Wastewater Treatment Plant | Biloxi | 4.07 | 11.7 | MS0030333 | Effective | Jun 2028 | 1 |
| Harrison County Wastewater And Solid Waste Management Authority, East Biloxi Pot | Biloxi | 2.85 | 10 | MS0023159 | Effective | Mar 2029 | 0 |
| Reynolds R. Ridgely Wastewater Plant | Columbus | 0.96 | 10 | MS0056472 | Effective | Dec 2030 | 2 |
| Canton Mun Util-Beatties Bluff WWTF | Canton | 4.54 | 8 | MS0057517 | Effective | Dec 2030 | 375 |
| Dcrua, Short Fork WWTF | Hernando | 6.5 | 8 | MS0062227 | Effective | Jun 2030 | 114 |
| Laurel Potw, Number 1 | Laurel | 2.8 | 7.4 | MS0024163 | Effective | Apr 2031 | 0 |
| Hcua, Long Beach And Pass Christian | Pass Christian | 2.4 | 7 | MS0043141 | Effective | May 2030 | 0 |
| City Of Greenwood - Wastewater Treatment Plant | Greenwood | 2.12 | 6.32 | MS0023833 | Effective | Dec 2029 | 0 |
| Corinth POTW | Corinth | 2.02 | 6 | MS0061328 | Effective | Apr 2029 | 149 |
| Clarksdale POTW | Clarksdale | 1.31 | 5 | MS0020311 | Effective | Apr 2028 | 154 |
| Jcua - West Jackson County WWTP | Pascagoula | 4.4 | 5 | MS0045446 | Effective | Dec 2029 | 16 |
| Natchez POTW | Natchez | 2.31 | 5 | MS0024252 | Effective | Mar 2028 | 0 |
| Jackson POTW - Trahon And Big Creek WWTF | Jackson | 1.7 | 4.5 | MS0044059 | Administratively continued | Jul 2026 | 24 |
| Aberdeen East WWTP | Aberdeen | 0.98 | 4 | MS0055581 | Administratively continued | Jul 2024 | 5 |
| Jcua POTW 2c | Gautier | — | 4 | MS0043010 | Effective | Apr 2027 | 5 |
| Brookhaven POTW | Brookhaven | 1.73 | 3 | MS0024147 | Effective | Feb 2031 | 1 |
| Cleveland POTW | Cleveland | — | 3 | MS0020567 | Effective | Jan 2030 | 25 |
| Jackson County Utility Authority, POTW 6c | Moss Point | 0.6 | 3 | MS0021521 | Effective | Aug 2030 | 8 |
| Tip H. Allen Water Treatment Plant | Canton | — | 3 | MS0042455 | Effective | Feb 2027 | 368 |
| Tunica County Utility District | Robinsonville | 0.69 | 3 | MS0048691 | Effective | Nov 2029 | 30 |
| Morton POTW | Morton | 1.17 | 2.97 | MS0036234 | Effective | Nov 2029 | 53 |
| Diamondhead Water Sewer District | Diamondhead | 0.75 | 2.5 | MS0046078 | Effective | Feb 2028 | 0 |
| Pearl River County Utility Authority, Neal Road POTW | Picayune | 0.65 | 2.4 | MS0061174 | Effective | Nov 2028 | 0 |
All 127 plants in Mississippi →
NPDES permits in Mississippi: 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.