Wastewater Treatment Plants in Tennessee
227 facilities · 320 MGD combined flow
Klarifi tracks 227 publicly owned wastewater treatment plants in Tennessee with a combined average flow of 320 MGD, serving about 2,612,175 residents. 45 plants treat more than 1 MGD and 4 more than 10 MGD; 92 use lagoon systems and 15 have digesters or biogas infrastructure. The largest is Metro Central Wastewater Treatment Plant in Nashville at 88.2 MGD. 16 NPDES permits expire this year and 41 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. Showing facilities 1–200 of 227 by average flow — browse the rest with the page links below.
227 plant locations in Tennessee; dot size follows average flow.
NPDES permits and renewals in Tennessee
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 Tennessee
| Facility | City | Avg flow (MGD) | Design (MGD) | NPDES permit | Expires | Technology | Violations (3y) |
|---|---|---|---|---|---|---|---|
| Metro Central Wastewater Treatment Plant | Nashville | 88.2 | — | TNL020575 | Dec 2030 | Clarifiers | 62 |
| Moccasin Bend Wastewater Treatment Plant | Chattanooga | 36.67 | — | TNR053775 | Jun 2030 | Clarifiers, Aerated lagoons, Uncovered lagoons, Biogas silos | 53 |
| Whites Creek Wastewater Treatment Plant | Nashville | 21.51 | 37.5 | TN0024970 | Oct 2025 | Clarifiers, Aerated lagoons, Biogas balloons | 39 |
| Nashville Dry Creek STP | Madison | 12.69 | 24 | TN0020648 | Oct 2025 | Clarifiers, Biogas silos, Biogas balloons | 34 |
| City Of Cookeville Department Of Water Quality Control (wwtp) | Cookeville | 9.62 | 14 | TN0024198 | Jun 2027 | Clarifiers, Uncovered lagoons, Carrousels / oxidation ditches | 27 |
| Kingsport STP | Kingsport | 8.68 | 12.4 | TN0020095 | Dec 2028 | Clarifiers, Biogas silos, Biogas balloons | 36 |
| City Of Franklin Wastewater Treatment Plant | Franklin | 7.12 | 16 | TN0028827 | Dec 2026 | Clarifiers, Carrousels / oxidation ditches, Biogas silos | 44 |
| Cleveland Utilities Wastewater Treatment Plant | Charleston | 6.59 | 21.6 | TN0024121 | Apr 2027 | Clarifiers, Aerated lagoons | 43 |
| Johnson City STP | Johnson City | 5.49 | 16 | TN0024244 | Sep 2026 | Clarifiers | 23 |
| Sevierville (mccroskey Island) STP | Sevierville | 5.32 | 4.8 | TN0063959 | Apr 2030 | Clarifiers, Uncovered lagoons, Carrousels / oxidation ditches | 115 |
| City Of Columbia Wastewater Treatment Plant | Columbia | 5.06 | 10 | TN0056103 | Oct 2028 | Clarifiers | 68 |
| Turkey Creek WWTP (morristown Stp) | Morristown | 4.87 | 7.5 | TN0023507 | Oct 2029 | Clarifiers, Biogas silos | 22 |
| Harpeth Valley Utility District STP | Nashville | 4.76 | 10 | TN0074748 | Feb 2030 | Clarifiers, Carrousels / oxidation ditches | 4 |
| Hallsdale-Powell U.D.-Melton Hill Lk | Knoxville | 4.48 | 9.7 | TN0078905 | Sep 2028 | Clarifiers, Aerated lagoons, Carrousels / oxidation ditches | 44 |
| Oak Ridge STP | Oak Ridge | 4.1 | 30 | TN0024155 | Dec 2028 | Clarifiers | 35 |
| West Knox Ud Melton Lake WWTP | Knoxville | 3.94 | 10 | TN0080721 | Mar 2028 | — | 13 |
| City Of Spring Hill STP | Spring Hill | 3.65 | 5 | TN0075868 | Dec 2028 | Clarifiers, Carrousels / oxidation ditches | 42 |
| Collierville Northwest STP | Collierville | 3.38 | 6 | TN0078841 | Jan 2028 | Clarifiers, Carrousels / oxidation ditches, Biogas balloons | 3 |
| Denzil Bowman Wastewater Treatment Plant (greeneville Stp) | Greeneville | 3.34 | 7 | TN0021229 | Oct 2030 | Clarifiers, Carrousels / oxidation ditches | 28 |
| Dyersburg STP | Dyersburg | 3.12 | 9.45 | TN0023477 | Dec 2027 | Clarifiers, Aerated lagoons | 20 |
| Knob Creek Waste Water Plant | Johnson City | 3.07 | 4 | TN0024236 | Sep 2026 | Carrousels / oxidation ditches | 17 |
| Humboldt Utilities Authority | Humboldt | 3.04 | 5 | TN0062588 | Aug 2027 | Aerated lagoons | 7 |
| Shelbyville Wastewater Treatment Plant | Shelbyville | 3.04 | 6.5 | TN0024180 | Jan 2029 | Clarifiers, Carrousels / oxidation ditches | 22 |
| Crossville STP | Crossville | 2.61 | 3.5 | TN0024996 | Dec 2026 | Clarifiers, Carrousels / oxidation ditches | 26 |
| Jackson Energy Auth- Middle Fk | Jackson | 2.45 | 8 | TN0075876 | May 2027 | — | 6 |
Tennessee plants by treatment technology
All 227 plants in Tennessee
Wastewater treatment 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.