Activated sludge and clarifiers: wastewater treatment plants in Michigan
117 plants · 35% of the state · 904 MGD reported by 116 plants
Klarifi identifies 117 publicly owned wastewater treatment plants with activated sludge and clarifiers in Michigan, 35% of the 334 plants in the state (904 MGD reported by 116 plants). The largest is GLWA Water Resource Recovery Facility in Detroit at 416.18 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 | 416.18 | MI0022802 | Oct 2027 | 37 |
| 2 | City Of Grand Rapids Wastewater Treatment Plant | Grand Rapids | 42.18 | MI0026069 | Oct 2029 | 9 |
| 3 | City Of Saginaw Wastewater Treatment Plant | Saginaw | 34.99 | MI0025577 | Oct 2029 | 21 |
| 4 | Southgate-Wyandotte Cso Rtf | Wyandotte | 34.9 | MI0036072 | Oct 2026 | 2 |
| 5 | Wyandotte Wastewater Plant | Wyandotte | 33.91 | MI0021156 | Oct 2021 | 5 |
| 6 | Anthony Ragnone Wastewater Treatment Plant | Montrose | 32.01 | MI0022977 | Oct 2023 | 3 |
| 7 | Kalamazoo Water Reclamation Plant | Kalamazoo | 27.05 | MI0023299 | Oct 2030 | 37 |
| 8 | Ycua Regional Wastewater Treatment Plant | Ypsilanti | 23.69 | MIL042676 | Dec 2030 | 5 |
| 9 | City Of Wyoming Clean Water Plant | Grandville | 16.16 | MI0024392 | Oct 2030 | 74 |
| 10 | Warren Waste Water Treatment Plant | Warren | 16.05 | MI0024295 | Oct 2025 | 9 |
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 October 26, 2026.
Wastewater terms: Activated sludge · Biological nutrient removal · Equalization tank · WWTP · Biosolids · all terms