Activated sludge and clarifiers: wastewater treatment plants in Indiana
209 plants · 48% of the state · 366 MGD reported by 205 plants
Klarifi identifies 209 publicly owned wastewater treatment plants with activated sludge and clarifiers in Indiana, 48% of the 432 plants in the state (366 MGD reported by 205 plants). The largest is Gary Sanitary District in Gary at 32.6 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 | Gary Sanitary District | Gary | 32.6 | IN0022977 | Jun 2027 | 24 |
| 2 | Water Pollution Control Plant | Fort Wayne | 29.9 | IN0032191 | Feb 2026 | 2 |
| 3 | Saniatry District Of Hammond | Hammond | 25.83 | IN0023060 | Apr 2027 | 21 |
| 4 | City Of South Bend Wastewater Treatment Plant | South Bend | 23.29 | IN0024520 | Nov 2026 | 4 |
| 5 | Lafayette WWTP | Lafayette | 15.2 | IN0032468 | Jul 2028 | 0 |
| 6 | East Chicago Sanitary District | East Chicago | 13.24 | IN0022829 | Jun 2026 | 44 |
| 7 | Muncie Water Pollution Control Facility | Muncie | 12.2 | IN0025631 | Jun 2029 | 0 |
| 8 | Evansville Westside WWTP | Evansville | 10.6 | IN0032956 | Jan 2027 | 10 |
| 9 | Eastside Wastewater Treatment Plant | Evansville | 9.8 | IN0033073 | Jan 2027 | 13 |
| 10 | Mishawaka Wastewater Treatment Plant | Mishawaka | 9.43 | IN0025640 | Apr 2027 | 2 |
| 11 | Elkhart Public Works And Utilities | Elkhart | 9.19 | IN0025674 | Apr 2027 | 179 |
| 12 | West Lafayette WWTP | West Lafayette | 7.9 | IN0024821 | Jan 2031 | 10 |
| 13 | Anderson WWTP | Anderson | 7 | IN0032476 | Sep 2030 | 11 |
| 14 | Fishers Cheeney Creek WWTP | Fishers | 6.9 | IN0055484 | Oct 2027 | 2 |
| 15 | Noblesville Wwtp, City Of | Noblesville | 6.05 | IN0020168 | May 2031 | 2 |
| 16 | City Of Kokomo Waste Water Treatment Facility | Kokomo | 5.96 | IN0032875 | Nov 2026 | 19 |
| 17 | New Albany WWTP | New Albany | 5.41 | IN0023884 | May 2027 | 14 |
| 18 | Schererville WWTP | Schererville | 4.75 | IN0024457 | Jul 2028 | 8 |
| 19 | Jeffersonville Municipal WWTP | Jeffersonville | 4.48 | IN0023302 | Feb 2031 | 9 |
| 20 | Elden Kuehl Pollution Control Facility | Valparaiso | 4.41 | IN0024660 | Sep 2027 | 3 |
| 21 | Richmond Wwtp, City Of | Richmond | 3.96 | IN0025615 | Feb 2031 | 14 |
| 22 | Shelbyville Wwtp, City Of | Shelbyville | 3.81 | IN0032867 | Mar 2031 | 24 |
| 23 | City Of La Porte - Wastewater Treatment Plant | La Porte | 3.47 | IN0025577 | Feb 2030 | 39 |
| 24 | Portage Utility Service Facility WWTP | Portage | 3.33 | IN0024368 | Aug 2030 | 4 |
| 25 | Goshen City Waste Water Treatment Plant Improvements | Goshen | 3.1 | IN0025755 | Jun 2031 | 13 |
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 September 11, 2026.