Lagoon systems: wastewater treatment plants in Mississippi
102 plants · 80% of the state · 49 MGD reported by 32 plants
Klarifi identifies 102 publicly owned wastewater treatment plants with lagoon systems in Mississippi, 80% of the 127 plants in the state (49 MGD reported by 32 plants). The largest is West Rankin Utility Authority WWTF in Richland at 10.32 MGD.
Lagoon systems treat wastewater in large earthen ponds over weeks of retention time, with or without mechanical aeration. They serve thousands of small towns because they are cheap to run, but they struggle with ammonia and nutrient limits, fill with sludge over decades and are the plants most often converted or upgraded when a permit is renewed.
The largest lagoons in Mississippi
| # | Facility | City | Avg flow (MGD) | NPDES permit | Expires | Violations (3y) |
|---|---|---|---|---|---|---|
| 1 | West Rankin Utility Authority WWTF | Richland | 10.32 | MS0061743 | Feb 2030 | 4 |
| 2 | Dcrua, Short Fork WWTF | Hernando | 6.5 | MS0062227 | Jun 2030 | 114 |
| 3 | Meridian POTW | Meridian | 5.41 | MS0020117 | Oct 2030 | 40 |
| 4 | Canton Mun Util-Beatties Bluff WWTF | Canton | 4.54 | MS0057517 | Dec 2030 | 375 |
| 5 | Harrison County Wastewater And Solid Waste Management Authority, East Biloxi Pot | Biloxi | 2.85 | MS0023159 | Mar 2029 | 0 |
| 6 | Laurel Potw, Number 1 | Laurel | 2.8 | MS0024163 | Apr 2031 | 0 |
| 7 | Natchez POTW | Natchez | 2.31 | MS0024252 | Mar 2028 | 0 |
| 8 | City Of Greenwood - Wastewater Treatment Plant | Greenwood | 2.12 | MS0023833 | Dec 2029 | 0 |
| 9 | Corinth POTW | Corinth | 2.02 | MS0061328 | Apr 2029 | 149 |
| 10 | Jackson POTW - Trahon And Big Creek WWTF | Jackson | 1.7 | MS0044059 | Jul 2026 | 24 |
| 11 | Morton POTW | Morton | 1.17 | MS0036234 | Nov 2029 | 53 |
| 12 | Bay Springs Industrial Park | Bay Springs | 0.98 | MS0034860 | Mar 2029 | 0 |
| 13 | Reynolds R. Ridgely Wastewater Plant | Columbus | 0.96 | MS0056472 | Dec 2030 | 2 |
| 14 | Saltillo POTW | Saltillo | 0.72 | MS0021733 | Mar 2025 | 21 |
| 15 | Desoto County Regional Utility Authority, Johnson Creek Wastewater Treatment Fac | Walls | 0.71 | MS0061271 | Jun 2030 | 3 |
| 16 | Batesville POTW | Batesville | 0.68 | MS0024627 | Sep 2028 | 9 |
| 17 | Florence POTW | Florence | 0.59 | MS0025275 | Dec 2028 | 35 |
| 18 | Waynesboro POTW | Waynesboro | 0.53 | MS0024228 | Jan 2028 | 30 |
| 19 | Pontotoc, City Of, Activated Sludge Facility | Pontotoc | 0.5 | MS0058581 | Apr 2024 | 13 |
| 20 | Amory POTW | Amory | 0.47 | MS0045489 | Apr 2030 | 226 |
| 21 | Metro Desoto Utilities | Olive Branch | 0.39 | MS0028479 | May 2029 | 210 |
| 22 | Houston POTW | Houston | 0.28 | MS0025071 | Oct 2027 | 1 |
| 23 | Water Valley POTW | Water Valley | 0.25 | MS0022331 | Jun 2029 | 42 |
| 24 | Como POTW | Como | 0.12 | MS0030104 | Oct 2026 | 114 |
| 25 | Inverness POTW | Inverness | 0.09 | MS0020320 | Apr 2031 | 45 |
Contacts and project signals for every plant on this list
Klarifi adds verified decision-maker contacts, permit limits, discharge monitoring data and the capital projects planned in each city, filterable by technology, size and compliance record.
Other technologies in Mississippi
Lagoon systems in other states
Lagoon systems 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.