Activated sludge and clarifiers: wastewater treatment plants in Tennessee
85 plants · 37% of the state · 283 MGD reported by 80 plants
Klarifi identifies 85 publicly owned wastewater treatment plants with activated sludge and clarifiers in Tennessee, 37% of the 227 plants in the state (283 MGD reported by 80 plants). The largest is Metro Central Wastewater Treatment Plant in Nashville at 88.2 MGD.
Activated sludge is the standard mechanical process for cities: aeration basins where bacteria consume organic matter, followed by clarifiers that settle the biomass out. These plants are identified by their circular or rectangular clarifiers and by the suspended-growth process code, and they are the main market for blowers, diffusers, clarifier mechanisms and instrumentation.
The largest activated sludge plants in Tennessee
| # | Facility | City | Avg flow (MGD) | NPDES permit | Expires | Violations (3y) |
|---|---|---|---|---|---|---|
| 1 | Metro Central Wastewater Treatment Plant | Nashville | 88.2 | TNL020575 | Dec 2030 | 62 |
| 2 | Moccasin Bend Wastewater Treatment Plant | Chattanooga | 36.67 | TNR053775 | Jun 2030 | 53 |
| 3 | Whites Creek Wastewater Treatment Plant | Nashville | 21.51 | TN0024970 | Oct 2025 | 39 |
| 4 | Nashville Dry Creek STP | Madison | 12.69 | TN0020648 | Oct 2025 | 34 |
| 5 | City Of Cookeville Department Of Water Quality Control (wwtp) | Cookeville | 9.62 | TN0024198 | Jun 2027 | 27 |
| 6 | Kingsport STP | Kingsport | 8.68 | TN0020095 | Dec 2028 | 36 |
| 7 | City Of Franklin Wastewater Treatment Plant | Franklin | 7.12 | TN0028827 | Dec 2026 | 44 |
| 8 | Cleveland Utilities Wastewater Treatment Plant | Charleston | 6.59 | TN0024121 | Apr 2027 | 43 |
| 9 | Johnson City STP | Johnson City | 5.49 | TN0024244 | Sep 2026 | 23 |
| 10 | Sevierville (mccroskey Island) STP | Sevierville | 5.32 | TN0063959 | Apr 2030 | 115 |
| 11 | City Of Columbia Wastewater Treatment Plant | Columbia | 5.06 | TN0056103 | Oct 2028 | 68 |
| 12 | Turkey Creek WWTP (morristown Stp) | Morristown | 4.87 | TN0023507 | Oct 2029 | 22 |
| 13 | Harpeth Valley Utility District STP | Nashville | 4.76 | TN0074748 | Feb 2030 | 4 |
| 14 | Hallsdale-Powell U.D.-Melton Hill Lk | Knoxville | 4.48 | TN0078905 | Sep 2028 | 44 |
| 15 | Oak Ridge STP | Oak Ridge | 4.1 | TN0024155 | Dec 2028 | 35 |
| 16 | City Of Spring Hill STP | Spring Hill | 3.65 | TN0075868 | Dec 2028 | 42 |
| 17 | Collierville Northwest STP | Collierville | 3.38 | TN0078841 | Jan 2028 | 3 |
| 18 | Denzil Bowman Wastewater Treatment Plant (greeneville Stp) | Greeneville | 3.34 | TN0021229 | Oct 2030 | 28 |
| 19 | Dyersburg STP | Dyersburg | 3.12 | TN0023477 | Dec 2027 | 20 |
| 20 | Shelbyville Wastewater Treatment Plant | Shelbyville | 3.04 | TN0024180 | Jan 2029 | 22 |
| 21 | Crossville STP | Crossville | 2.61 | TN0024996 | Dec 2026 | 26 |
| 22 | Gatlinburg STP | Gatlinburg | 2.24 | TN0020117 | Aug 2030 | 17 |
| 23 | Manchester STP | Manchester | 2.15 | TN0025038 | Feb 2029 | 40 |
| 24 | Lewisburg STP | Lewisburg | 2.1 | TN0022888 | May 2028 | 24 |
| 25 | Dickson STP | Dickson | 2 | TN0066958 | Dec 2026 | 21 |
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
Activated sludge and clarifiers in other states
Activated sludge and clarifiers 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.