Oconomowoc, WI: 6 Violations — 54/100 (2026)
1 ZIP code · 10 water systems · Updated 2026-06-03
Public water data for Oconomowoc, WI shows a low safety grade — health-based violations appear across a meaningful share of service areas in current EPA records.
How Oconomowoc Compares
Data: EPA SDWIS Last verified: 2026-06-03
Oconomowoc Water: The Quick Version
- Your city's water systems recorded 6 violations in the past 5 years.
- Average lead level: 0.0068 mg/L.
- Homes built before 1986: 53% — older plumbing may contain lead solder.
- Estimated remediation: $2,900 per household.
- CDC health risk index: 11.81.
Water Systems Serving Oconomowoc
Federal records list 10 water systems tied to Oconomowoc, WI. Of those, 3 are the primary providers, meaning service conditions, rate structures, and compliance histories can differ depending on where a property sits.
Overview
We track water quality and home safety data for 1 ZIP code in Oconomowoc, Wisconsin, covering 10 community water systems serving approximately 37,056 people.
1 of 1 ZIP code (100%) have recorded EPA violations. All violations are monitoring/reporting type.
Home Safety Score
Average Home Safety Score for Oconomowoc: D (54/100)
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
Oconomowoc water systems draw from: Groundwater.
Lead & Copper
- Average lead level (90th percentile): 0.0068 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.
Top Contaminants
| Contaminant | Category | Violations | ZIPs Affected |
|---|---|---|---|
| Consumer Confidence Report Rule | Reporting | 4 | 1 |
| Lead | Inorganic | 2 | 1 |
| Stage 1 DBP Rule | Treatment Technique | 2 | 1 |
| Surface Water Treatment Rule | Treatment Technique | 2 | 1 |
| Revised Total Coliform Rule | Microbiological | 2 | 1 |
Areas with Most Violations
| ZIP Code | Safety Score | Violations | Health-Based | System |
|---|---|---|---|---|
| 53066 | D | 6 | 0 | Oconomowoc Waterworks |
All ZIP Codes in Oconomowoc
- 53066 [D] — 6 violations
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.
CDC Health Data for Oconomowoc
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
Key Contaminants Detected in Oconomowoc
Based on EPA violation records. Check your ZIP code report for system-specific contaminant data.
How Old Is Oconomowoc's Housing Stock?
With 53% 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
Pre-1986 plumbing is not a rare legacy case in Oconomowoc — it's the dominant profile. The median build year of 1988 indicates a housing stock where lead-soldered copper joints are a common structural feature of residences across the city.
Over half of homes in Oconomowoc were built before 1986, when lead solder was banned. Older plumbing may leach lead into drinking water, especially with corrosive water chemistry.
Source: U.S. Census Bureau ACS B25034.
Oconomowoc: Remediation Cost in Perspective
In Oconomowoc, the equity impact of remediation is proportionally small — not the kind of financial commitment that rises to the level of a genuine planning constraint, but a minor share of what most properties here are worth.
Remediation costs in Oconomowoc are relatively low compared to home values. The $1,900–$4,100 estimated range is a small fraction of median property value. Home values are 74% above the Wisconsin average.
Protecting Children from Lead in Oconomowoc
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.
Older interior plumbing shapes the local picture: 53% of Oconomowoc homes predate the federal solder ban, and aggregate sampling either approaches or crosses the action benchmark. That mix makes a single-home draw a standard pre-purchase or pre-occupancy step.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Climate-Related Water Risk for Oconomowoc
How does Oconomowoc's flood record connect to local water quality? The NFIP documents 37 claims — enough to signal recurring events — and 100% of ZIP codes carry FEMA flood zone status. That combination places flooding in the category of factors that can periodically affect water infrastructure, even if the area isn't among the highest-exposure communities in the NFIP dataset.
Oconomowoc has a moderate flood history with 37 FEMA claims averaging $15,265 per payout. 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>$2,900</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 Oconomowoc
- 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. Filters rated for Consumer Confidence Report Rule can reduce the most common contaminant found in Oconomowoc's water.
- Check your home's plumbing. With 53% of homes built before 1986, lead solder is a real possibility.
- Review your water system's CCR. Your utility publishes an annual Consumer Confidence Report with detailed test results. Request it or find it online.
Deep Dive Reports
Detailed analysis for Oconomowoc, WI