Ann Arbor WWTP
49 South Dixboro Road, Ann Arbor, MI 48105 · Washtenaw County · Publicly Owned Treatment Works
- Average flow
- 14.38 MGD
- Design flow
- —
- NPDES permit
- MI0022217
- Administratively continued
- Permit expires
- October 2025
- Population served
- 152,564
- CWNS 2022
Ann Arbor WWTP is a publicly owned wastewater treatment works in Ann Arbor, Washtenaw County, Michigan treating an average of 14.38 million gallons per day, serving about 152,564 residents. It discharges under NPDES permit MI0022217 (administratively continued), which expires in October 2025, with 9 recorded violations in the last three years. EPA has recorded 1 formal enforcement action naming the plant, the latest in December 1986.
Treatment technology
2 treatment structures and unit processes identified at Ann Arbor WWTP.
Available with a free Klarifi account
See the full treatment train at Ann Arbor WWTP: structures, unit processes and planned upgrades, with exact unit counts.
Compliance snapshot (last 3 years)
- Total violations
- 9
- Effluent violations
- 9
Based on NPDES Discharge Monitoring Reports. Full violation history, parameters and discharge data available in the Klarifi platform.
EPA enforcement history
Federal civil enforcement cases, compliance inspections and informal actions recorded for Ann Arbor WWTP in EPA's ICIS system.
- Formal actions
- 1
- 0 since FY2020
- Penalties assessed
- $4,960
- all cases
- EPA inspections
- 0
- none on record
Latest case · Dec 1986
ANN ARBOR WASTEWATER TREATMENT PLANT
Administrative order · TSCA, PCBS · Source Agrees · Penalty $4,960
Source: EPA ECHO, civil enforcement case 05-1986-0256.
Full case history with a free Klarifi account
Every action against Ann Arbor WWTP with dates, milestones, violation types and EPA's complete case summaries, plus inspections and informal actions.
Industrial users and pretreatment
Industries that discharge process wastewater to Ann Arbor WWTP, from the plant's pretreatment programme records.
- Industrial users
- 4
- 1 categorical
- Sampled for PFAS
- 2
- 2023–2024
- Above 12 ng/L PFOS
- 0
- highest 1.7 ng/L
Among them: Ann Arbor Municipal Landfill (Ann Arbor), 1.7 ng/L; Endress + Hauser, Inc (Ann Arbor); Macom (Ann Arbor). Most users are in automotive, metal and equipment manufacturing and landfills and waste management.
Industrial users of Ann Arbor WWTP →PFAS sources at all Michigan plants →
Unlock all 4 industrial users of this plant
Discharge flow, federal category, full PFAS sampling history, source documents and contacts for every industrial user of Ann Arbor WWTP. Free with a Klarifi account.
Capital improvement projects in Ann Arbor
Ann Arbor's capital improvement plan lists 151 water, sewer and wastewater line items worth $503M starting 2025–2032. The largest budgeted items are shown here.
All water and sewer capital projects in Ann Arbor →
| Project | Budget | Years |
|---|---|---|
| WTP: Plant 1 Replacement Project | $142,000,000 | 2025–2031 |
| High Level Trunkline Sewer Capacity Improvements | $20,500,000 | 2025–2027 |
| Dams: Barton Dam Embankment Rehabilitation | $12,920,000 | 2025–2027 |
| WTP: Plant 2 Readiness | $9,050,000 | 2028–2030 |
| Galvanized Water Services Replacements | $9,000,000 | 2025–2029 |
Full project details — scope, funding source, engineering consultant and the decision-makers behind each project — are available in Klarifi, along with similar wastewater capital projects in other cities.
Key contacts
36 verified contacts for Ann Arbor WWTP, with validated emails and direct phone numbers.
Unlock 36 verified contacts (33 more than shown)
Names, validated emails and direct phone numbers for decision-makers at Ann Arbor WWTP, plus the full compliance history and discharge data.
Nearby wastewater treatment plants in Michigan
Ypsilanti · 6 mi away
23.69 MGD
Saline · 10 mi away
1.33 MGD
Salem · 10 mi away
0.02 MGD
Dexter · 13 mi away
0.32 MGD
South Lyon · 13 mi away
1.12 MGD
Whitmore Lake · 13 mi away
0.79 MGD
Milan · 13 mi away
1.06 MGD
Saline · 14 mi away
0.01 MGD
Ann Arbor WWTP: frequently asked 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; facility record last updated May 20, 2025.
Wastewater terms: POTW · MGD · NPDES permit · Inflow and infiltration · Anaerobic digester · Lift station · all terms