The 50 largest wastewater treatment plants in Mississippi
Ranked by average flow · 85 MGD combined · 99% of the state's reported flow
West Rankin Utility Authority WWTF in Richland is the largest publicly owned wastewater treatment plant in Mississippi by reported average flow, treating about 12.02 million gallons per day. The 50 plants below treat 85 MGD between them, 99% of the flow reported by all 134 plants in the state, and serve about 149,577 people. Every plant links to its profile with permit and compliance data. Treatment technology is shown with a free Klarifi account.
| # | Facility | City | Avg flow (MGD) | Population | NPDES permit | Expires | Violations (3y) |
|---|---|---|---|---|---|---|---|
| 1 | West Rankin Utility Authority WWTF | Richland | 12.02 | — | MS0061743 | Feb 2030 | 4 |
| 2 | Meridian POTW | Meridian | 7.57 | — | MS0020117 | Oct 2030 | 39 |
| 3 | Dcrua, Short Fork WWTF | Hernando | 6.26 | — | MS0062227 | Jun 2030 | 114 |
| 4 | West Biloxi Wastewater Treatment Plant | Biloxi | 5.57 | — | MS0030333 | Jun 2028 | 1 |
| 5 | Jcua - West Jackson County WWTP | Pascagoula | 5.09 | 18,515 | MS0045446 | Dec 2029 | 16 |
| 6 | Canton Mun Util-Beatties Bluff WWTF | Canton | 4.91 | — | MS0057517 | Dec 2030 | 372 |
| 7 | Reynolds R. Ridgely Wastewater Plant | Columbus | 3.85 | — | MS0056472 | Dec 2030 | 2 |
| 8 | Laurel Potw, Number 1 | Laurel | 3.18 | — | MS0024163 | Apr 2031 | 0 |
| 9 | Harrison County Wastewater And Solid Waste Management Authority, East Biloxi Pot | Biloxi | 2.95 | 37,000 | MS0023159 | Mar 2029 | 0 |
| 10 | City Of Greenwood - Wastewater Treatment Plant | Greenwood | 2.49 | — | MS0023833 | Dec 2029 | 0 |
| 11 | West Point Potw, West | West Point | 2.3 | — | MS0020788 | May 2027 | 11 |
| 12 | Natchez POTW | Natchez | 2.14 | — | MS0024252 | Mar 2028 | 0 |
| 13 | Brookhaven POTW | Brookhaven | 2.06 | 12,423 | MS0024147 | Feb 2031 | 1 |
| 14 | Jackson POTW - Trahon And Big Creek WWTF | Jackson | 1.88 | 14,931 | MS0044059 | Jul 2026 | 24 |
| 15 | Clarksdale POTW | Clarksdale | 1.76 | 20,550 | MS0020311 | Apr 2028 | 99 |
| 16 | Cleveland POTW | Cleveland | 1.56 | — | MS0020567 | Jan 2030 | 25 |
| 17 | Morton POTW | Morton | 1.49 | 3,365 | MS0036234 | Nov 2029 | 57 |
| 18 | Aberdeen East WWTP | Aberdeen | 1.37 | — | MS0055581 | Jul 2024 | 5 |
| 19 | Saltillo POTW | Saltillo | 1.26 | 2,376 | MS0021733 | Mar 2025 | 9 |
| 20 | Amory POTW | Amory | 1.1 | — | MS0045489 | Apr 2030 | 227 |
| 21 | Waynesboro POTW | Waynesboro | 1.07 | — | MS0024228 | Jan 2028 | 30 |
| 22 | Indianola POTW | Indianola | 1 | — | MS0024619 | Oct 2028 | 719 |
| 23 | Jackson County Utility Authority, POTW 6c | Moss Point | 1 | — | MS0021521 | Aug 2030 | 8 |
| 24 | Diamondhead Water Sewer District | Diamondhead | 0.98 | — | MS0046078 | Feb 2028 | 0 |
| 25 | Bay Springs Industrial Park | Bay Springs | 0.96 | — | MS0034860 | Mar 2029 | 0 |
| 26 | Batesville POTW | Batesville | 0.85 | 7,813 | MS0024627 | Sep 2028 | 9 |
| 27 | Pontotoc, City Of, Activated Sludge Facility | Pontotoc | 0.82 | — | MS0058581 | Apr 2024 | 13 |
| 28 | Desoto County Regional Utility Authority, Johnson Creek Wastewater Treatment Fac | Walls | 0.76 | 21,000 | MS0061271 | Jun 2030 | 3 |
| 29 | Tunica County Utility District | Robinsonville | 0.73 | — | MS0048691 | Nov 2029 | 32 |
| 30 | Pearl River County Utility Authority, Neal Road POTW | Picayune | 0.7 | — | MS0061174 | Nov 2028 | 0 |
| 31 | Pearl River Wastewater Treatment Plant | Philadelphia | 0.56 | — | MS0053503 | Mar 2030 | 39 |
| 32 | Houston POTW | Houston | 0.53 | — | MS0025071 | Oct 2027 | 0 |
| 33 | Florence POTW | Florence | 0.42 | — | MS0025275 | Dec 2028 | 32 |
| 34 | Water Valley POTW | Water Valley | 0.4 | — | MS0022331 | Jun 2029 | 42 |
| 35 | Metro Desoto Utilities | Olive Branch | 0.38 | — | MS0028479 | May 2029 | 214 |
| 36 | Pearl River County Utility Authority, Poplarville POTW | Poplarville | 0.31 | — | MS0020494 | Oct 2027 | 1 |
| 37 | Shaw POTW | Shaw | 0.31 | — | MS0024953 | Jun 2031 | 14 |
| 38 | Lucedale POTW | Lucedale | 0.27 | — | MS0044504 | Aug 2028 | 17 |
| 39 | Harrison County School District | Gulfport | 0.27 | 9,121 | MS0061191 | Apr 2029 | 3 |
| 40 | Chickasaw Trail WWTP | Byhalia | 0.23 | — | MS0060046 | Dec 2030 | 67 |
| 41 | Long Beach Industrial District Park | Long Beach | 0.22 | — | MS0022373 | Sep 2027 | 13 |
| 42 | Hancock Co Port & Harbor Commission | Bay Saint Louis | 0.21 | — | MS0059501 | Jul 2031 | 0 |
| 43 | Como POTW | Como | 0.18 | — | MS0030104 | Oct 2026 | 77 |
| 44 | Nicholson Water And Sewer Association Inc | Picayune | 0.17 | — | MS0033871 | Nov 2027 | 1 |
| 45 | New Harmony WWTP | Philadelphia | 0.17 | — | MS0058645 | Mar 2030 | 70 |
| 46 | Neshoba County | Philadelphia | 0.11 | — | MS0043478 | Mar 2028 | 50 |
| 47 | Lafayette County Industrial Park | Oxford | 0.1 | — | MS0043079 | Oct 2029 | 14 |
| 48 | Harrison County Utility Authority, Tradition Development | Gulfport | 0.09 | 2,483 | MS0057011 | Aug 2030 | 1 |
| 49 | Glen Allan Utility District | Glen Allen | 0.09 | — | MS0047601 | May 2031 | 45 |
| 50 | Mississippi Investors Ix Llc, Beaver Dam Crossing Sewer Treatment Plant | Mchenry | 0.08 | — | MS0061182 | May 2029 | 18 |
Treatment technology for each plant is shown with a free Klarifi account. Create one →
Largest plants 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 October 26, 2026.
Wastewater terms: WWTP · POTW · MGD · NPDES permit · Equalization tank · Centrate · all terms
Cite this page
Journalists, researchers and educators are welcome to quote these figures. Please credit Klarifi as the source and link to this page.
Klarifi. “Largest wastewater treatment plants in Mississippi (2026).” Updated October 26, 2026. https://klarifi.io/facilities/mississippi/largestNeed a custom cut of the data for a state, a county or a list of plants? Email info@klarifi.io.