Sister Bay, WI: High Radon Risk — 67/100 (2026)
1 ZIP code · 1 water system · Updated 2026-06-03
Sister Bay water quality is uneven — some service areas show clean compliance; others carry documented violations in WI EPA records.
How Sister Bay Compares
Data: EPA SDWIS Last verified: 2026-06-03
Key Facts for Sister Bay Residents
- Average lead level: 0.0061 mg/L.
- Homes built before 1986: 48% — older plumbing may contain lead solder.
- Estimated remediation: $3,000 per household.
- CDC health risk index: 14.01 — above typical levels.
Sister Bay's Water Providers
Consolidated water delivery characterizes Sister Bay, WI: among 1 system in federal records, one utility holds the dominant service position — carrying the rate-setting authority, the infrastructure obligations, and the EPA reporting burden for most residential addresses.
Overview
We track water quality and home safety data for 1 ZIP code in Sister Bay, Wisconsin, covering 1 community water system serving approximately 2,130 people.
No EPA violations recorded across any ZIP codes in Sister Bay — an excellent indicator of water quality.
Home Safety Score
Average Home Safety Score for Sister Bay: C (67/100)
The score combines three factors:
| Factor | What It Measures |
|---|---|
| Water Quality | EPA violations and compliance history |
| Lead Levels | 90th percentile lead concentration vs EPA action level |
| Radon Risk | EPA radon zone classification |
Water Sources
Sister Bay water systems draw from: Groundwater.
Lead & Copper
- Average lead level (90th percentile): 0.0061 mg/L (EPA action level: 0.015 mg/L)
- 0 ZIP codes exceed the EPA lead action level
Radon Risk
Dominant radon zone: Zone 1 (High Risk)
The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.
Areas with No Violations
| ZIP Code | Safety Score | System | Population |
|---|---|---|---|
| 54234 | C | Sister Bay Waterworks | 1,000 |
All ZIP Codes in Sister Bay
- 54234 [C]
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Lead/copper: EPA Lead and Copper Rule sampling data
- Radon: EPA Map of Radon Zones
Updated daily.
Sister Bay Community Health Snapshot
Source: CDC PLACES (County-level estimates). Water contamination can correlate with respiratory and chronic health conditions.
Compared to National Average
Vertical line = national average. ■ Above national · ■ Below national
Sister Bay Infrastructure Age
With 48% of homes built before 1986, lead solder in plumbing is a potential concern. The EPA banned lead solder in 1986, but many older homes retain original plumbing.
Source: U.S. Census Bureau American Community Survey (ACS).
Housing Age Profile
For a city with a median build year of 1982, Sister Bay carries a housing profile that straddles the 1986 federal ban on lead solder in plumbing. Neither predominantly new nor predominantly old, the stock presents a moderate aggregate risk environment — with individual risk varying sharply depending on when and where a specific home was built.
Most homes in Sister Bay were built after 1986, reducing the risk of lead contamination from plumbing. Older homes should still be tested.
Source: U.S. Census Bureau ACS B25034.
How Remediation Costs Compare in Sister Bay
When estimated remediation is placed alongside median property values in Sister Bay, the resulting ratio is low — a finding consistent with a household financial perspective where documented issues can be addressed without a meaningful impact on overall equity position, making this market one of the more favorable contexts for remediation planning.
Remediation costs in Sister Bay are relatively low compared to home values. The $2,000–$4,000 estimated range is a small fraction of median property value. Home values are 82% above the Wisconsin average.
Sister Bay: Lead Risk & Vulnerable Populations
Why children are most at risk: The CDC states there is no safe level of lead exposure for children. Children under 6 absorb lead more readily than adults, and even low levels can cause developmental delays, learning difficulties, and behavioral problems.
Reading the local data together points toward a structural gap that matters more here than in low-exposure communities. 48% of Sister Bay stock comes from the pre-rule era, and citywide monitoring either approaches or sits beyond the federal benchmark under Lead and Copper Rule sampling. A baseline kit fits the routine-diligence category, with certified filtration available via retailer networks where confirmed faucet results warrant additional measures.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Sister Bay: Flood History & Water Damage Risk
Although Sister Bay's flood history doesn't reach high-severity thresholds, NFIP data documents 1 claim and FEMA maps place 100% of ZIP codes in designated flood zones — a combined profile that makes flood-related water quality considerations a reasonable planning baseline.
Sister Bay has a moderate flood history with 1 FEMA claims. 100% of ZIP codes fall within FEMA flood zones. Flood events can contaminate drinking water and overwhelm treatment systems.
How flooding affects water quality: Flood events can introduce sewage, agricultural runoff, and industrial chemicals into water supplies. Even after floodwaters recede, contamination can persist in wells and aging infrastructure. Flood damage can add significantly to the estimated <strong>$3,000</strong> remediation cost per household.
Residents in flood-prone areas should consider flood insurance even outside FEMA zones — over 25% of flood claims come from low-to-moderate risk areas. After any flood event, test your water before drinking.
Source: FEMA National Flood Insurance Program (NFIP) claims data, FEMA flood zone designations.
What You Can Do in Sister Bay
- Test your water at home. City-level data shows averages — your tap may differ. NSF-certified test kits cost $20-40 and give results in days.
- Install a certified water filter. An NSF-certified pitcher or under-sink filter removes most common contaminants.
- Check your home's plumbing. With 48% of homes built before 1986, lead solder is a real possibility.
Deep Dive Reports
Detailed analysis for Sister Bay, WI