Lagoon systems: wastewater treatment plants in Tennessee
92 plants · 41% of the state · 120 MGD reported by 72 plants
Klarifi identifies 92 publicly owned wastewater treatment plants with lagoon systems in Tennessee, 41% of the 227 plants in the state (120 MGD reported by 72 plants). The largest is Moccasin Bend Wastewater Treatment Plant in Chattanooga at 36.67 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 Tennessee
| # | Facility | City | Avg flow (MGD) | NPDES permit | Expires | Violations (3y) |
|---|---|---|---|---|---|---|
| 1 | Moccasin Bend Wastewater Treatment Plant | Chattanooga | 36.67 | TNR053775 | Jun 2030 | 53 |
| 2 | Whites Creek Wastewater Treatment Plant | Nashville | 21.51 | TN0024970 | Oct 2025 | 39 |
| 3 | City Of Cookeville Department Of Water Quality Control (wwtp) | Cookeville | 9.62 | TN0024198 | Jun 2027 | 27 |
| 4 | Cleveland Utilities Wastewater Treatment Plant | Charleston | 6.59 | TN0024121 | Apr 2027 | 43 |
| 5 | Sevierville (mccroskey Island) STP | Sevierville | 5.32 | TN0063959 | Apr 2030 | 115 |
| 6 | Hallsdale-Powell U.D.-Melton Hill Lk | Knoxville | 4.48 | TN0078905 | Sep 2028 | 44 |
| 7 | Dyersburg STP | Dyersburg | 3.12 | TN0023477 | Dec 2027 | 20 |
| 8 | Humboldt Utilities Authority | Humboldt | 3.04 | TN0062588 | Aug 2027 | 7 |
| 9 | Tullahoma STP | Tullahoma | 2.2 | TN0023469 | Jul 2027 | 6 |
| 10 | Elizabethton WWTP | Elizabethton | 1.8 | TN0023515 | Aug 2031 | 18 |
| 11 | Newport Utilities Board Wastewater Treatment Plant | Newport | 1.56 | TN0020702 | Mar 2030 | 9 |
| 12 | Smithville STP | Smithville | 1.47 | TN0065358 | Sep 2027 | 1 |
| 13 | Lenoir City STP | Lenoir City | 1.43 | TN0020494 | Jul 2031 | 11 |
| 14 | City Of Pulaski Wastewater Treatment Plant | Pulaski | 1.4 | TN0021687 | Oct 2027 | 2 |
| 15 | Arlington STP | Arlington | 1.27 | TN0078603 | Nov 2027 | 99 |
| 16 | Martin STP | Martin | 1.21 | TN0062545 | May 2030 | 20 |
| 17 | Lexington Utilities- Waste Water Treatment Plant | Lexington | 1.13 | TN0024341 | Oct 2028 | 6 |
| 18 | Munford Sewer Department Lagoon | Munford | 1.04 | TN0062499 | Dec 2030 | 10 |
| 19 | Selmer STP | Selmer | 1 | TN0062308 | Dec 2029 | 118 |
| 20 | Jefferson City STP | Jefferson City | 0.88 | TN0021199 | Dec 2029 | 5 |
| 21 | Sparta Electric And Public Works Dba Sparta Wastewater Treatment Plant | Sparta | 0.84 | TN0061166 | Sep 2027 | 24 |
| 22 | City Of Savannah | Savannah | 0.82 | TN0061565 | Sep 2028 | 23 |
| 23 | Town Of Livingston | Livingston | 0.8 | TN0021873 | Jun 2030 | 18 |
| 24 | Trenton WWTP | Trenton | 0.64 | TN0078271 | Jan 2027 | 0 |
| 25 | Tiptonville - City Lagoon | Tiptonville | 0.63 | TN0026409 | Aug 2030 | 73 |
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 Tennessee
Lagoon systems in other states
Lagoon systems in Tennessee: 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.