Sister Bay Wastewater Treatment Facility
Sister Bay, WI · Door County · Publicly Owned Treatment Works
- Average flow
- 0.2 MGD
- Design flow
- 0.3 MGD
- NPDES permit
- WI0022071
- Expired
- Permit expires
- December 2021
- Population served
- 3,150
- CWNS 2022
Sister Bay Wastewater Treatment Facility is a publicly owned wastewater treatment works in Sister Bay, Door County, Wisconsin treating an average of 0.2 million gallons per day against a permitted design capacity of 0.3 MGD, serving about 3,150 residents. Treatment on site includes clarifiers, aerated lagoons, carrousels / oxidation ditches, biogas balloons. It discharges under NPDES permit WI0022071 (expired), which expires in December 2021, with 0 recorded violations in the last three years.
Treatment technology
Treatment structures identified at this facility. Exact unit counts are available in Klarifi.
Clarifiers
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Aerated lagoons
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Carrousels / oxidation ditches
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Biogas balloons
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Compliance snapshot (last 3 years)
- Total violations
- 0
- Effluent violations
- 0
Based on NPDES Discharge Monitoring Reports. Full violation history, parameters and discharge data available in the Klarifi platform.
Capital improvement projects in Sister Bay
Sister Bay's capital improvement plan lists 14 water, sewer and wastewater line items worth $1M starting 2025–2029. The largest budgeted items are shown here.
All water and sewer capital projects in Sister Bay →
| Project | Budget | Years |
|---|---|---|
| Screw Press for Sludge Dryer System | $608,000 | 2026–2026 |
| Meters | $225,000 | 2025–2029 |
| PRV Refurbishment | $75,000 | 2025–2029 |
| 2018 Truck Replacement | $45,000 | 2028–2028 |
| Well No. 3 Rebuild/ Inspection | $40,000 | 2026–2026 |
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
3 verified contacts for Sister Bay Wastewater Treatment Facility, with validated emails and direct phone numbers.
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Names, validated emails and direct phone numbers for decision-makers at Sister Bay Wastewater Treatment Facility, plus the full compliance history and discharge data.
Nearby wastewater treatment plants in Wisconsin
Ephraim · 3 mi away
0.08 MGD
Fish Creek · 7 mi away
0.11 MGD
Baileys Harbor · 10 mi away
0.06 MGD
Marinette · 26 mi away
1.55 MGD
Sturgeon Bay · 29 mi away
1.06 MGD
Peshtigo · 33 mi away
—
Forestville · 39 mi away
0.02 MGD
Oconto · 43 mi away
0.38 MGD
Sister Bay Wastewater Treatment Facility: 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 September 11, 2026; facility record last updated November 6, 2025.