Wastewater Treatment Plants in Mississippi
127 facilities · 70 MGD combined flow
Klarifi tracks 127 publicly owned wastewater treatment plants in Mississippi with a combined average flow of 70 MGD, serving about 170,643 residents. 16 plants treat more than 1 MGD and 1 more than 10 MGD; 102 use lagoon systems and 1 have digesters or biogas infrastructure. The largest is West Rankin Utility Authority WWTF in Richland at 10.32 MGD. 7 NPDES permits expire this year and 20 next year.
Every plant below links to a profile with average and design flow, treatment technology, the NPDES permit and its expiry, a three-year compliance snapshot and the capital projects planned in its city.
127 plant locations in Mississippi; dot size follows average flow.
NPDES permits and renewals in Mississippi
Every plant discharges under an NPDES permit that is renewed every five years, usually with tighter limits. The renewal year is the year a plant budgets for upgrades.
Largest wastewater treatment plants in Mississippi
| Facility | City | Avg flow (MGD) | Design (MGD) | NPDES permit | Expires | Technology | Violations (3y) |
|---|---|---|---|---|---|---|---|
| West Rankin Utility Authority WWTF | Richland | 10.32 | 29.1 | MS0061743 | Feb 2030 | Clarifiers, Uncovered lagoons | 4 |
| Dcrua, Short Fork WWTF | Hernando | 6.5 | 8 | MS0062227 | Jun 2030 | Clarifiers, Uncovered lagoons, Carrousels / oxidation ditches | 114 |
| Meridian POTW | Meridian | 5.41 | 13 | MS0020117 | Oct 2030 | Clarifiers, Aerated lagoons, Uncovered lagoons | 40 |
| Canton Mun Util-Beatties Bluff WWTF | Canton | 4.54 | 8 | MS0057517 | Dec 2030 | Clarifiers, Uncovered lagoons, Carrousels / oxidation ditches | 375 |
| Jcua - West Jackson County WWTP | Pascagoula | 4.4 | 5 | MS0045446 | Dec 2029 | Clarifiers | 16 |
| West Biloxi Wastewater Treatment Plant | Biloxi | 4.07 | 11.7 | MS0030333 | Jun 2028 | Clarifiers | 1 |
| Harrison County Wastewater And Solid Waste Management Authority, East Biloxi Pot | Biloxi | 2.85 | 10 | MS0023159 | Mar 2029 | Clarifiers, Aerated lagoons, Uncovered lagoons | 0 |
| Laurel Potw, Number 1 | Laurel | 2.8 | 7.4 | MS0024163 | Apr 2031 | Clarifiers, Uncovered lagoons, Carrousels / oxidation ditches | 0 |
| Hcua, Long Beach And Pass Christian | Pass Christian | 2.4 | 7 | MS0043141 | May 2030 | Clarifiers, Carrousels / oxidation ditches | 0 |
| Natchez POTW | Natchez | 2.31 | 5 | MS0024252 | Mar 2028 | Clarifiers, Uncovered lagoons | 0 |
| City Of Greenwood - Wastewater Treatment Plant | Greenwood | 2.12 | 6.32 | MS0023833 | Dec 2029 | Uncovered lagoons | 0 |
| Corinth POTW | Corinth | 2.02 | 6 | MS0061328 | Apr 2029 | Clarifiers, Uncovered lagoons, Carrousels / oxidation ditches | 149 |
| Brookhaven POTW | Brookhaven | 1.73 | 3 | MS0024147 | Feb 2031 | Clarifiers, Carrousels / oxidation ditches | 1 |
| Jackson POTW - Trahon And Big Creek WWTF | Jackson | 1.7 | 4.5 | MS0044059 | Jul 2026 | Clarifiers, Uncovered lagoons, Carrousels / oxidation ditches | 24 |
| Clarksdale POTW | Clarksdale | 1.31 | 5 | MS0020311 | Apr 2028 | Clarifiers, Biogas silos | 154 |
| Morton POTW | Morton | 1.17 | 2.97 | MS0036234 | Nov 2029 | Aerated lagoons, Uncovered lagoons | 53 |
| Aberdeen East WWTP | Aberdeen | 0.98 | 4 | MS0055581 | Jul 2024 | — | 5 |
| Bay Springs Industrial Park | Bay Springs | 0.98 | 1 | MS0034860 | Mar 2029 | Clarifiers, Uncovered lagoons | 0 |
| Reynolds R. Ridgely Wastewater Plant | Columbus | 0.96 | 10 | MS0056472 | Dec 2030 | Clarifiers, Uncovered lagoons | 2 |
| Indianola POTW | Indianola | 0.78 | 2.25 | MS0024619 | Oct 2028 | — | 719 |
| Diamondhead Water Sewer District | Diamondhead | 0.75 | 2.5 | MS0046078 | Feb 2028 | Clarifiers | 0 |
| Saltillo POTW | Saltillo | 0.72 | 0.98 | MS0021733 | Mar 2025 | Clarifiers, Uncovered lagoons, Carrousels / oxidation ditches | 21 |
| Desoto County Regional Utility Authority, Johnson Creek Wastewater Treatment Fac | Walls | 0.71 | 2 | MS0061271 | Jun 2030 | Clarifiers, Uncovered lagoons, Carrousels / oxidation ditches | 3 |
| Tunica County Utility District | Robinsonville | 0.69 | 3 | MS0048691 | Nov 2029 | Clarifiers, Carrousels / oxidation ditches | 30 |
| Batesville POTW | Batesville | 0.68 | 2.1 | MS0024627 | Sep 2028 | Clarifiers, Uncovered lagoons, Carrousels / oxidation ditches | 9 |
Mississippi plants by treatment technology
All 127 plants in Mississippi
Wastewater treatment 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.