Oxidation ditches: wastewater treatment plants in Ohio
113 plants · 14% of the state · 107 MGD reported by 112 plants
Klarifi identifies 113 publicly owned wastewater treatment plants with oxidation ditches in Ohio, 14% of the 837 plants in the state (107 MGD reported by 112 plants). The largest is Upper Mill Creek Water Reclamation Facil in West Chester at 8.34 MGD.
Oxidation ditches are ring-shaped activated sludge reactors with long retention times, common at plants between 0.5 and 10 MGD. They are recognisable from the air by their looped channels and rely on surface aerators or brush rotors, which are frequent replacement and energy-efficiency projects.
The largest oxidation ditch plants in Ohio
| # | Facility | City | Avg flow (MGD) | NPDES permit | Expires | Violations (3y) |
|---|---|---|---|---|---|---|
| 1 | Upper Mill Creek Water Reclamation Facil | West Chester | 8.34 | OH0072087 | Dec 2023 | 33 |
| 2 | Beavercreek WRRF | Dayton | 7.3 | OH0025381 | Nov 2030 | 47 |
| 3 | Findlay WPCF | Findlay | 7.22 | OH0025135 | Oct 2029 | 1 |
| 4 | North Regional Wastewater Treatment Plan (0857143037) | Dayton | 7.07 | OH0049646 | Feb 2027 | 47 |
| 5 | Mason WWTP No 2 | Mason | 5.56 | OH0020494 | May 2026 | 1 |
| 6 | Lower East Fork Regional WWTP | Milford | 5.43 | OH0049379 | Oct 2026 | 4 |
| 7 | French Creek WWTP | North Ridgeville | 4.98 | OH0044512 | Oct 2027 | 5 |
| 8 | Fairborn Water Reclamation Center | Huber Hts | 3.48 | OH0025062 | Nov 2026 | 0 |
| 9 | Niles WWTP | Niles | 3.43 | OH0026743 | Sep 2028 | 9 |
| 10 | Kenton WWTP | Kenton | 2.3 | OH0025925 | Feb 2029 | 5 |
| 11 | Piqua WWTP | Piqua | 2.18 | OH0027049 | Aug 2027 | 3 |
| 12 | Oxford WWTP | Oxford | 2.04 | OH0026930 | Dec 2028 | 5 |
| 13 | Southwest Licking W & Sd Gale Rd Envir Ctrl Fac | Hebron | 1.87 | OH0113964 | Jan 2028 | 0 |
| 14 | City Of Salem - Wastewater Plant | Salem | 1.71 | OH0027324 | May 2027 | 5 |
| 15 | Bellefontaine WWTP | Bellefontaine | 1.62 | OH0024066 | Jan 2027 | 18 |
| 16 | Springboro WWTP | Springboro | 1.58 | OH0027472 | Apr 2028 | 0 |
| 17 | Minster WWTP | Minster | 1.52 | OH0026573 | Oct 2027 | 18 |
| 18 | O'Bannon Creek Regional WWTP | Loveland | 1.5 | OH0048089 | Sep 2026 | 7 |
| 19 | Urbana WPCF | Urbana | 1.42 | OH0027880 | Nov 2025 | 3 |
| 20 | Clyde WWTP | Clyde | 1.28 | OH0024686 | Dec 2027 | 16 |
| 21 | Nine Mile Creek WWTP | New Richmond | 1.22 | OH0049361 | Nov 2030 | 3 |
| 22 | Jackson WWTP | Jackson | 1.2 | OH0020834 | Jun 2026 | 3 |
| 23 | Amherst Wpcc | Amherst | 1.19 | OH0021628 | Jan 2026 | 10 |
| 24 | Greenville WWTP | Greenville | 1.19 | OH0025429 | Sep 2028 | 5 |
| 25 | Celina WWTP | Celina | 1.17 | OH0020320 | Mar 2028 | 3 |
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 Ohio
Oxidation ditches in other states
Oxidation ditches in Ohio: 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.