Ontario, WI: 1 Health Violation — 69/100 (2026)
1 ZIP code · 1 water system · Updated 2026-06-03
Compliance figures for Ontario indicate average water quality in WI overall — some service areas have recorded health-based violations in recent monitoring cycles, while others operate cleanly, making system-level data the most actionable reference point for residents.
How Ontario Compares
Data: EPA SDWIS Last verified: 2026-06-03
Ontario Water: The Quick Version
- Your city's water systems recorded 3 violations in the past 5 years.
- Average lead level: 0.0013 mg/L.
- Homes built before 1986: 58% — older plumbing may contain lead solder.
- Estimated remediation: $3,300 per household.
- CDC health risk index: 14.36 — above typical levels.
Water Systems Serving Ontario
Ontario, WI draws its water from one primary utility across 1 tracked system.
Overview
We track water quality and home safety data for 1 ZIP code in Ontario, Wisconsin, covering 1 community water system serving approximately 1,225 people.
1 of 1 ZIP code (100%) have recorded EPA violations. 1 health-based violation documented.
Home Safety Score
Average Home Safety Score for Ontario: C (69/100)
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
Ontario water systems draw from: Groundwater.
Lead & Copper
- Average lead level (90th percentile): 0.0013 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 |
|---|---|---|---|
| Stage 2 DBP Rule | Treatment Technique | 2 | 1 |
| Lead and Copper Rule | Treatment Technique | 2 | 1 |
| Consumer Confidence Report Rule | Reporting | 2 | 1 |
Areas with Most Violations
| ZIP Code | Safety Score | Violations | Health-Based | System |
|---|---|---|---|---|
| 54651 | C | 3 | 1 | Ontario Waterworks |
All ZIP Codes in Ontario
- 54651 [C] — 3 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 Ontario
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 Ontario
Based on EPA violation records. Check your ZIP code report for system-specific contaminant data.
How Old Is Ontario's Housing Stock?
With 58% 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
What does a median build year of 1971 mean for water safety in Ontario? It means the majority of the city's residential plumbing was installed before 1986, when lead solder was federally banned, and a large share may predate 1970, when lead pipes were commonly used — making plumbing age a central variable in household-level lead risk across much of the city.
Over half of homes in Ontario 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.
Ontario: Remediation Cost in Perspective
Given current Ontario property values, the remediation share falls in the moderate tier — an indicator that the household financial perspective here calls for advance planning rather than dismissal, with most homeowners positioned to address documented issues through deliberate budgeting rather than needing to treat remediation as a significant equity event or financial emergency.
Remediation costs are moderate relative to home values in Ontario. The estimated $2,150–$4,600 range is manageable for most homeowners but still worth budgeting for. Home values are 14% below the Wisconsin average.
Protecting Children from Lead in Ontario
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.
Practically, the structural drivers in Ontario — 58% pre-rule stock and citywide monitoring at or beyond the regulatory benchmark — make an in-home draw the practical way to translate aggregate averages into the specific conditions at one address.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Climate-Related Water Risk for Ontario
Flood exposure in Ontario is meaningful by NFIP measures — 5 claims on record and 100% of ZIP codes carrying FEMA flood zone designations. That level of activity makes flood history a relevant factor when evaluating local water quality over time.
Ontario has a moderate flood history with 5 FEMA claims averaging $31,519 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>$3,300</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 Ontario
- 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 Stage 2 DBP Rule can reduce the most common contaminant found in Ontario's water.
- Check your home's plumbing. With 58% of homes built before 1986, lead solder is a real possibility.
Deep Dive Reports
Detailed analysis for Ontario, WI