Activated sludge and clarifiers: wastewater treatment plants in Indiana
208 plants · 48% of the state · 433 MGD reported by 203 plants
Klarifi identifies 208 publicly owned wastewater treatment plants with activated sludge and clarifiers in Indiana, 48% of the 434 plants in the state (433 MGD reported by 203 plants). The largest is Water Pollution Control Plant in Fort Wayne at 44.71 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 Indiana
| # | Facility | City | Avg flow (MGD) | NPDES permit | Expires | Violations (3y) |
|---|---|---|---|---|---|---|
| 1 | Water Pollution Control Plant | Fort Wayne | 44.71 | IN0032191 | Sep 2031 | 2 |
| 2 | Gary Sanitary District | Gary | 42.04 | IN0022977 | Jun 2027 | 23 |
| 3 | Saniatry District Of Hammond | Hammond | 34.49 | IN0023060 | Apr 2027 | 21 |
| 4 | Lafayette WWTP | Lafayette | 18 | IN0032468 | Jul 2028 | 0 |
| 5 | Muncie Water Pollution Control Facility | Muncie | 17.5 | IN0025631 | Jun 2029 | 0 |
| 6 | Mishawaka Wastewater Treatment Plant | Mishawaka | 12.29 | IN0025640 | Apr 2027 | 2 |
| 7 | Evansville Westside WWTP | Evansville | 11.68 | IN0032956 | Jan 2027 | 6 |
| 8 | Anderson WWTP | Anderson | 10.46 | IN0032476 | Sep 2030 | 9 |
| 9 | City Of Kokomo Waste Water Treatment Facility | Kokomo | 9.93 | IN0032875 | Nov 2026 | 21 |
| 10 | East Chicago Sanitary District | East Chicago | 9.42 | IN0022829 | Jun 2026 | 41 |
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
Activated sludge and clarifiers in other states
Activated sludge and clarifiers 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: Activated sludge · Biological nutrient removal · Equalization tank · Centrate · Ozonation · all terms