Onalaska, WI Water Safety: 78/100 (2026)
1 ZIP code · 3 water systems · Updated 2026-06-03
Water systems serving Onalaska hold a strong EPA compliance record — the city places among the better-performing areas in WI with few health-based violations on file.
How Onalaska Compares
Data: EPA SDWIS Last verified: 2026-06-03
Onalaska Water: The Quick Version
- Average lead level: 0.0014 mg/L.
- Homes built before 1986: 48% — older plumbing may contain lead solder.
- Estimated remediation: $2,100 per household.
- CDC health risk index: 12.13 — above typical levels.
Water Systems Serving Onalaska
3 water utilities share the residential service territory in Onalaska, WI — out of 3 total systems in federal records.
Overview
We track water quality and home safety data for 1 ZIP code in Onalaska, Wisconsin (population ~24,619), covering 3 community water systems serving approximately 81,147 people region-wide.
No EPA violations recorded across any ZIP codes in Onalaska — an excellent indicator of water quality.
Home Safety Score
Average Home Safety Score for Onalaska: B (78/100)
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
Onalaska water systems draw from: Groundwater.
Lead & Copper
- Average lead level (90th percentile): 0.0014 mg/L (EPA action level: 0.015 mg/L)
- 0 ZIP codes exceed the EPA lead action level
Radon Risk
Dominant radon zone: Zone 2 (Moderate 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 |
|---|---|---|---|
| 54650 | B | Onalaska Waterworks | 18,000 |
All ZIP Codes in Onalaska
- 54650 [B]
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 Onalaska
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
How Old Is Onalaska's Housing Stock?
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
Reading the housing data for Onalaska, with a median build year of 1982, reveals a community where neither old nor new construction dominates. That balanced profile means lead-solder-era plumbing is present throughout a meaningful portion of the residential inventory — with risk concentrated in properties built before 1986 and most acute in those that predate 1970.
Most homes in Onalaska 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.
Onalaska: Remediation Cost in Perspective
Setting Onalaska remediation figures against its property market, the resulting ratio sits comfortably in the low tier — a classification that reflects the kind of household financial position where most homeowners can identify documented issues, schedule the work, and absorb the cost without it registering as a significant budget disruption.
Remediation costs in Onalaska are relatively low compared to home values. The $1,100–$3,400 estimated range is a small fraction of median property value. Home values are 21% above the Wisconsin average.
Protecting Children from Lead in Onalaska
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.
Locally, 48% of Onalaska homes carry interior plumbing from the era when lead solder was still permitted in new builds, and citywide monitoring approaches or crosses the EPA action benchmark. Households can find a draw-test kit and certified filtration through verified retailers.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Climate-Related Water Risk for Onalaska
Although Onalaska's flood history doesn't reach high-severity thresholds, NFIP data documents 19 claims 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.
Onalaska has a moderate flood history with 19 FEMA claims averaging $4,387 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>$2,100</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.
Deep Dive Reports
Detailed analysis for Onalaska, WI