Oxidation ditches: wastewater treatment plants in Indiana
95 plants · 22% of the state · 91 MGD reported by 91 plants
Klarifi identifies 95 publicly owned wastewater treatment plants with oxidation ditches in Indiana, 22% of the 434 plants in the state (91 MGD reported by 91 plants). The largest is East Chicago Sanitary District in East Chicago at 9.42 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 Indiana
| # | Facility | City | Avg flow (MGD) | NPDES permit | Expires | Violations (3y) |
|---|---|---|---|---|---|---|
| 1 | East Chicago Sanitary District | East Chicago | 9.42 | IN0022829 | Jun 2026 | 41 |
| 2 | New Albany WWTP | New Albany | 7.82 | IN0023884 | May 2027 | 14 |
| 3 | Jeffersonville Municipal WWTP | Jeffersonville | 5.13 | IN0023302 | Feb 2031 | 9 |
| 4 | Franklin Wwtp, City Of | Franklin | 4.65 | IN0021181 | Aug 2027 | 14 |
| 5 | Seymour Wastewater Treatment Facility | Seymour | 4.59 | IN0024473 | Apr 2031 | 22 |
| 6 | Portage Utility Service Facility WWTP | Portage | 4.21 | IN0024368 | Aug 2030 | 4 |
| 7 | Warsaw WWTP | Warsaw | 3.23 | IN0060917 | May 2027 | 6 |
| 8 | Washington WWTP | Washington | 3.2 | IN0025658 | Jun 2028 | 130 |
| 9 | Brownsburg WWTP | Brownsburg | 2.86 | IN0021245 | Sep 2030 | 8 |
| 10 | Lebanon WWTP | Lebanon | 2.86 | IN0020818 | Mar 2030 | 2 |
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 Indiana
Oxidation ditches in other states
Oxidation ditches in Indiana: 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: Oxidation ditch · Activated sludge · Biological nutrient removal · Tertiary treatment · Significant industrial user · all terms