Sister Bay Waterworks
EPA ID: WI4150510 · 1,000 people served · 4 ZIP codes
ZipCheckup's reading of EPA SDWIS for Sister Bay Waterworks (WI4150510): no EPA violations recorded in the last five years. Five clean years on EPA record - Sister Bay Waterworks, 1,000 residents served.
Data: EPA SDWIS
Service Area Map
Coverage area for Sister Bay Waterworks Source: EPA SDWIS service area boundaries.
Service area boundary
Service Area Demographics
The Sister Bay Waterworks serves a community with a median household income of $76,329 and an estimated 5,081 residents across its service area. Approximately 55% of housing stock was built before 1986, which increases the likelihood of lead service lines and older plumbing.
💧 Where Does Your Water Come From?
Sister Bay Waterworks's water is pumped from underground aquifers. Groundwater is naturally filtered through rock and soil, but it can be vulnerable to PFAS contamination, nitrates from agriculture, and industrial chemicals that seep into the water table.
Infrastructure Risk
Comparable Water Systems
Similar-sized systems in Wisconsin
Estimated Remediation Costs
Average estimated costs across ZIP codes served by this system
Based on national averages for common remediation projects. Actual costs vary by property. Only issues flagged by EPA, FEMA, or state data for each ZIP code are included.
System Overview
Sister Bay Waterworks (EPA ID: WI4150510) is a community water system in Wisconsin that serves approximately 1,000 people from groundwater sources.
This system provides water to 4 ZIP codes across 4 communities.
Violation History
Lead & Copper
EPA Lead and Copper Rule evidence attributed directly to this water system:
| Lead Level | Exceeds Action Level | Sample Date |
|---|---|---|
| 0.0061 mg/L | No | N/A |
No copper action-level exceedance record appears for this PWSID in the accepted LCR snapshot. This does not establish a clean copper measurement.
Radon Risk in Service Area
Dominant radon zone for ZIP codes served by this system: Zone 1 (High Risk)
The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.
Need help with your water quality?
Typical cost: Water test: typically $20–$50 (DIY kit) · Professional inspection: $150–$400
Find the Right Water FilterFree tip: Let cold water run for 2 minutes before drinking — this helps flush lead from your pipes.
ZIP Codes Served
Coverage: Service area ZIP codes sourced from EPA Community Water System Service Area Boundaries v3 (March 2026 release). These ZIPs reflect the actual deployment footprint recorded by WI or modeled from parcel and building-footprint data.
Data Sources
This report uses public data from the EPA Safe Drinking Water Information System (SDWIS). View the full compliance record for Sister Bay Waterworks (WI4150510) on EPA.gov.
Frequently Asked Questions
Is Sister Bay Waterworks water safe to drink?
The accepted 2026Q2 ECHO snapshot contains zero violation records for Sister Bay Waterworks in the inclusive 2021-2026 record-year window. This is a compliance-record finding, not a guarantee about water at a specific tap.
How many people does Sister Bay Waterworks serve?
Sister Bay Waterworks serves approximately 1,000 people across 4 ZIP codes in Wisconsin.
Where does Sister Bay Waterworks get its water?
The primary water source is groundwater.
Frequently Asked Questions
How to cite this page
ZipCheckup. (n.d.). Sister Bay Waterworks Water Quality Report, WI. https://zipcheckup.com/water-system/wi4150510/
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