The 50 largest wastewater treatment plants in Kentucky
Ranked by average flow · 144 MGD combined · 86% of the state's reported flow
Derek R Guthrie WQTC MSD in Louisville is the largest publicly owned wastewater treatment plant in Kentucky by reported average flow, treating about 55.21 million gallons per day. The 50 plants below treat 144 MGD between them, 86% of the flow reported by all 195 plants in the state, and serve about 690,811 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 | Derek R Guthrie WQTC MSD | Louisville | 55.21 | 109,588 | KY0078956 | Apr 2031 | 16 |
| 2 | Rwra Max Rhoads WWTP | Owensboro | 7.68 | 43,157 | KY0020095 | Dec 2021 | 1 |
| 3 | Valley Creek Wastewater Treatment Plant | Elizabethtown | 6.45 | 30,361 | KY0022039 | Oct 2023 | 1 |
| 4 | Richmond Otter Creek STP | Richmond | 5.92 | 49,761 | KY0107107 | Dec 2030 | 4 |
| 5 | Strodes Creek STP | Winchester | 4.5 | 19,276 | KY0037991 | Sep 2026 | 1 |
| 6 | Hopkinsville Hammond Wood STP | Hopkinsville | 3.67 | 33,426 | KY0066532 | Sep 2030 | 2 |
| 7 | Bee Creek WWTP | Murray | 3.39 | 18,935 | KY0072761 | Sep 2028 | 2 |
| 8 | Berea Municipal Utilities WWTP | Berea | 3.37 | 14,666 | KY0079898 | Nov 2030 | 0 |
| 9 | London STP | London | 3.07 | 22,319 | KY0021270 | May 2030 | 19 |
| 10 | Morehead WWTP | Morehead | 2.83 | 16,051 | KY0052752 | Dec 2030 | 0 |
| 11 | Henderson South STP #2 | Robards | 2.69 | 3,188 | KY0100293 | Jun 2012 | 0 |
| 12 | Waste Water Treatment | Corbin | 2.61 | 19,507 | KY0020133 | Jan 2031 | 28 |
| 13 | Middlesboro STP | Middlesboro | 2.56 | 10,756 | KY0072885 | Oct 2030 | 0 |
| 14 | Radcliff STP | Radcliff | 2.42 | 23,001 | KY0022390 | Nov 2029 | 1 |
| 15 | Greenup County Environmental Commission Wastewater Treatment Plant | Russell | 1.91 | 39,869 | KY0048348 | May 2030 | 0 |
| 16 | Maysville STP | Maysville | 1.87 | 9,947 | KY0020257 | Jul 2031 | 0 |
| 17 | Harrodsburg WWTP Expansion | Harrodsburg | 1.84 | 8,802 | KY0027421 | Dec 2027 | 69 |
| 18 | Mount Sterling Hinkston Creek STP | Mt Sterling | 1.82 | 13,115 | KY0104400 | Dec 2027 | 14 |
| 19 | Fort Knox WWTP | Fort Knox | 1.82 | 24,015 | KY0112721 | Sep 2030 | 2 |
| 20 | Tompkinsville STP | Tompkinsville | 1.76 | 2,329 | KY0020702 | Mar 2027 | 122 |
| 21 | Paris STP | Paris | 1.74 | 10,698 | KY0090654 | Mar 2030 | 6 |
| 22 | Hazard, City Of | Hazard | 1.6 | 8,820 | KY0020079 | Aug 2030 | 8 |
| 23 | Leitchfield STP | Leitchfield | 1.42 | 5,876 | KY0022934 | Nov 2030 | 1 |
| 24 | Winchester Municipal Utilities | Winchester | 1.3 | 6,938 | KY0108740 | Jan 2031 | 1 |
| 25 | Greenville STP | Greenville | 1.19 | 6,102 | KY0020010 | Mar 2030 | 29 |
| 26 | Morganfield WWTP | Morganfield | 1.16 | 5,601 | KY0021440 | May 2031 | 26 |
| 27 | Carrollton Regional WWTP | Carrollton | 1.15 | 8,811 | KY0104931 | Mar 2027 | 0 |
| 28 | Mount Washington STP | Mt Washington | 1.15 | 19,466 | KY0033804 | Nov 2030 | 0 |
| 29 | Harlan STP | Harlan | 1.09 | 6,137 | KY0026093 | Jun 2031 | 7 |
| 30 | La Grange STP | La Grange | 1.02 | 10,110 | KY0020001 | Nov 2027 | 5 |
| 31 | Red River WWTP | Stanton | 0.9 | 8,606 | KY0034428 | Feb 2031 | 4 |
| 32 | Cynthiana STP (new) | Cynthiana | 0.87 | 6,845 | KY0105856 | Jun 2026 | 0 |
| 33 | Hickman East STP | Hickman | 0.84 | 2,210 | KY0028436 | Aug 2025 | 219 |
| 34 | Benton STP | Benton | 0.79 | 5,068 | KY0021172 | Sep 2029 | 9 |
| 35 | Ky State Reformatory | La Grange | 0.79 | 1,600 | KY0040126 | Nov 2022 | 45 |
| 36 | Williamstown/dry Ridge WRF | Williamstown | 0.75 | 5,810 | KY0109991 | Dec 2030 | 12 |
| 37 | Paintsville Municipal Water Works-Paintsville WTP | Paintsville | 0.75 | 4,980 | KY0020630 | Nov 2030 | 2 |
| 38 | Caveland Environmental Auth | Horse Cave | 0.74 | 8,516 | KY0091561 | Mar 2027 | 5 |
| 39 | Columbia/adair County STP | Columbia | 0.72 | 4,085 | KY0024317 | Apr 2031 | 2 |
| 40 | Walton STP | Walton | 0.72 | 3,510 | KY0039756 | Nov 2029 | 1 |
| 41 | Liberty STP | Liberty | 0.7 | 2,227 | KY0026352 | Sep 2030 | 32 |
| 42 | Paducah/mccracken County Jsa - Woodlawn | Paducah | 0.7 | 4,262 | KY0025828 | Jul 2027 | 24 |
| 43 | Prestonsburg STP | Prestonsburg | 0.67 | 8,187 | KY0027413 | Aug 2031 | 2 |
| 44 | Eminence STP | Eminence | 0.67 | 3,241 | KY0026883 | Sep 2030 | 5 |
| 45 | Jackson STP | Jackson | 0.65 | 2,966 | KY0021288 | Apr 2030 | 24 |
| 46 | New Marion WWTP | Marion | 0.65 | 3,062 | KY0113247 | Jun 2027 | 359 |
| 47 | Irvine STP | Irvine | 0.64 | 4,527 | KY0025909 | Feb 2031 | 49 |
| 48 | Vine Grove STP | Vine Grove | 0.58 | 4,520 | KY0024988 | Aug 2031 | 22 |
| 49 | Dawson Springs STP | Dawson Springs | 0.57 | 2,363 | KY0023868 | Jan 2030 | 89 |
| 50 | Hodgenville STP | Hodgenville | 0.56 | 3,598 | KY0026379 | Jan 2023 | 2 |
Treatment technology for each plant is shown with a free Klarifi account. Create one →
Largest plants in Kentucky: 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 · Filter press · FOG · 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 Kentucky (2026).” Updated October 26, 2026. https://klarifi.io/facilities/kentucky/largestNeed a custom cut of the data for a state, a county or a list of plants? Email info@klarifi.io.