Lagoon systems: wastewater treatment plants in Indiana
163 plants · 38% of the state · 141 MGD reported by 150 plants
Klarifi identifies 163 publicly owned wastewater treatment plants with lagoon systems in Indiana, 38% of the 434 plants in the state (141 MGD reported by 150 plants). The largest is Saniatry District Of Hammond in Hammond at 34.49 MGD.
Lagoon systems treat wastewater in large earthen ponds over weeks of retention time, with or without mechanical aeration. They serve thousands of small towns because they are cheap to run, but they struggle with ammonia and nutrient limits, fill with sludge over decades and are the plants most often converted or upgraded when a permit is renewed.
The largest lagoons in Indiana
| # | Facility | City | Avg flow (MGD) | NPDES permit | Expires | Violations (3y) |
|---|---|---|---|---|---|---|
| 1 | Saniatry District Of Hammond | Hammond | 34.49 | IN0023060 | Apr 2027 | 21 |
| 2 | Lafayette WWTP | Lafayette | 18 | IN0032468 | Jul 2028 | 0 |
| 3 | Dillman Waste Water Treatment Plant | Bloomington | 11.49 | IN0035718 | Aug 2029 | 7 |
| 4 | East Chicago Sanitary District | East Chicago | 9.42 | IN0022829 | Jun 2026 | 41 |
| 5 | Franklin Wwtp, City Of | Franklin | 4.65 | IN0021181 | Aug 2027 | 14 |
| 6 | New Castle WWTP | New Castle | 4.53 | IN0023914 | Jul 2031 | 37 |
| 7 | City Of La Porte - Wastewater Treatment Plant | La Porte | 3.91 | IN0025577 | Feb 2030 | 39 |
| 8 | Peru Utilities WWTP | Peru | 3.54 | IN0032328 | Nov 2030 | 23 |
| 9 | Frankfort Wwtp, City Of | Frankfort | 3.53 | IN0022934 | Apr 2030 | 7 |
| 10 | Newburgh WWTP | Newburgh | 3.17 | IN0023892 | Mar 2031 | 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
Lagoon systems in other states
Lagoon systems 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: WWTP · POTW · Biosolids · FOG · Equalization tank · all terms