Activated sludge and clarifiers: wastewater treatment plants in Michigan
116 plants · 38% of the state · 715 MGD reported by 113 plants
Klarifi identifies 116 publicly owned wastewater treatment plants with activated sludge and clarifiers in Michigan, 38% of the 305 plants in the state (715 MGD reported by 113 plants). The largest is GLWA Water Resource Recovery Facility in Detroit at 349 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 Michigan
| # | Facility | City | Avg flow (MGD) | NPDES permit | Expires | Violations (3y) |
|---|---|---|---|---|---|---|
| 1 | GLWA Water Resource Recovery Facility | Detroit | 349 | MIL022802 | Dec 2030 | 38 |
| 2 | City Of Grand Rapids Wastewater Treatment Plant | Grand Rapids | 33.4 | MI0026069 | Oct 2029 | 9 |
| 3 | Wyandotte Wastewater Plant | Wyandotte | 26.9 | MI0021156 | Oct 2021 | 5 |
| 4 | Kalamazoo Water Reclamation Plant | Kalamazoo | 24.94 | MI0023299 | Oct 2025 | 37 |
| 5 | Ycua Regional Wastewater Treatment Plant | Ypsilanti | 23.05 | MIL042676 | Dec 2030 | 5 |
| 6 | Anthony Ragnone Wastewater Treatment Plant | Montrose | 23.04 | MI0022977 | Oct 2023 | 3 |
| 7 | Southgate-Wyandotte Cso Rtf | Wyandotte | 16.88 | MI0036072 | Oct 2026 | 2 |
| 8 | City Of Wyoming Clean Water Plant | Grandville | 14.38 | MI0024392 | Oct 2030 | 74 |
| 9 | Ann Arbor WWTP | Ann Arbor | 13.6 | MI0022217 | Oct 2025 | 9 |
| 10 | City Of Saginaw Wastewater Treatment Plant | Saginaw | 13.41 | MI0025577 | Oct 2029 | 21 |
| 11 | Warren Waste Water Treatment Plant | Warren | 12.1 | MI0024295 | Oct 2025 | 8 |
| 12 | Clinton River WRRF | Pontiac | 10.99 | MI0023825 | Oct 2025 | 3 |
| 13 | Jackson WWTP | Jackson | 10.52 | MI0023256 | Oct 2027 | 41 |
| 14 | Lansing WWTP | Lansing | 10.06 | MI0023400 | Oct 2027 | 5 |
| 15 | East Lansing Wastewater Treatment Plant | East Lansing | 9.13 | MI0022853 | Oct 2027 | 1 |
| 16 | Holland WWTP | Holland | 8.7 | MI0023108 | Oct 2028 | 0 |
| 17 | Monroe Metro Wastewater Facility | Monroe | 8.5 | MI0028401 | Oct 2024 | 4 |
| 18 | Battle Creek WWTP | Battle Creek | 7.55 | MI0022276 | Oct 2030 | 9 |
| 19 | Bay City Wastewater Treatment Plant | Bay City | 6.6 | MI0022284 | Oct 2015 | 25 |
| 20 | West Bay County Department Of Water/sewer | Bay City | 4 | MI0042439 | Oct 2023 | 2 |
| 21 | Delta Twp WWTP | Lansing | 3.87 | MI0022799 | Oct 2027 | 4 |
| 22 | Saginaw Twp WWTP | Saginaw | 3.24 | MI0023973 | Oct 2028 | 10 |
| 23 | Cbpu Waste Water Treatment Plant | Coldwater | 3.2 | MI0020117 | Oct 2026 | 9 |
| 24 | Niles WWTP | Niles | 3.2 | MI0023701 | Oct 2017 | 0 |
| 25 | Adrian WWTP | Adrian | 2.88 | MI0022152 | Oct 2028 | 0 |
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 Michigan
Activated sludge and clarifiers in other states
Activated sludge and clarifiers in Michigan: 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.