Oshkosh, WI: 10 Health Violations — 55/100 (2026)
5 ZIP codes · 8 water systems · Updated 2026-06-03
Public water data for Oshkosh, WI reveals a split picture — tap water quality varies meaningfully by service area and the city's grade reflects that variability.
How Oshkosh Compares
Data: EPA SDWIS Last verified: 2026-06-03
Water Quality Map: Oshkosh, WI
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Score Distribution
Distribution of water safety grades across Oshkosh.
Oshkosh Water: The Quick Version
- Your city's water systems recorded 60 violations in the past 5 years.
- Average lead level: 0.011 mg/L.
- Homes built before 1986: 62% — older plumbing may contain lead solder.
- Estimated remediation: $1,900 per household.
- CDC health risk index: 12.89 — above typical levels.
Water Systems Serving Oshkosh
Throughout Oshkosh, WI, water comes from one of 3 primary utilities out of 8 total systems — independent providers with different rate structures, infrastructure, and compliance records that vary across the service territory.
Overview
We track water quality and home safety data for 5 ZIP codes in Oshkosh, Wisconsin, covering 8 community water systems serving approximately 81,409 people.
5 of 5 ZIP codes (100%) have recorded EPA violations. 10 health-based violations documented.
Home Safety Score
Average Home Safety Score for Oshkosh: C (55/100)
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
Oshkosh water systems draw from: Groundwater, Surface water.
Lead & Copper
- Average lead level (90th percentile): 0.0110 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)
- Zone 1 (High): 0 ZIP codes
- Zone 2 (Moderate): 5 ZIP codes
- Zone 3 (Low): 0 ZIP codes
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 | 18 | 5 |
| Lead and Copper Rule | Treatment Technique | 18 | 5 |
| Contaminant 1011 | Other | 6 | 5 |
| Total Coliform | Microbiological | 6 | 5 |
| Radium-226 | Radionuclides | 6 | 5 |
Areas with Most Violations
| ZIP Code | Safety Score | Violations | Health-Based | System |
|---|---|---|---|---|
| 54901 | C | 12 | 2 | Oshkosh Waterworks |
| 54902 | D | 12 | 2 | Oshkosh Waterworks |
| 54903 | C | 12 | 2 | Oshkosh Waterworks |
| 54904 | C | 12 | 2 | Oshkosh Waterworks |
| 54906 | D | 12 | 2 | Oshkosh Waterworks |
All ZIP Codes in Oshkosh
- 54901 [C] — 12 violations ⚠
- 54902 [D] — 12 violations ⚠
- 54903 [C] — 12 violations ⚠
- 54904 [C] — 12 violations ⚠
- 54906 [D] — 12 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 Oshkosh
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 Oshkosh
Based on EPA violation records. Check your ZIP code report for system-specific contaminant data.
How Old Is Oshkosh's Housing Stock?
With 62% 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
The median home in Oshkosh was built in 1971 — a figure that places most of the city's residential stock in the era when lead solder was still standard in copper plumbing. Homes built before 1986 may have lead-soldered joints; those built before 1970 face the additional possibility of lead pipes in the service line itself.
Over half of homes in Oshkosh 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.
Oshkosh: Remediation Cost in Perspective
How does remediation fit within the broader financial picture for Oshkosh homeowners? The equity share is moderate — large enough that treating it as a real planning consideration makes sense, and manageable enough that most homeowners have a clear path to addressing documented water and safety issues when they approach the commitment with deliberate advance budgeting rather than as an unplanned expense.
Remediation costs are moderate relative to home values in Oshkosh. The estimated $950–$3,120 range is manageable for most homeowners but still worth budgeting for. Home values are 29% below the Wisconsin average.
Protecting Children from Lead in Oshkosh
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.
Despite citywide averages serving as the standard public reference point, those aggregates cannot resolve what is happening at one specific faucet — and where 62% of Oshkosh homes come from before the solder rule or where utility samples sit at or above the action mark, the gap between system data and faucet reality matters more than it does in lower-exposure communities. An in-home draw closes that gap, with certified filtration through retailer networks available where confirmed faucet results warrant additional measures.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Climate-Related Water Risk for Oshkosh
Across the NFIP's long tracking period, Oshkosh shows 99 claims and 80% of ZIP codes within FEMA-designated flood zones — figures that place it in moderate flood exposure territory. At this level, the water-quality implications of flooding — contaminated wells, stressed treatment intake, distribution backflow — move from theoretical edge cases to genuine periodic risks, particularly during higher-severity events.
Oshkosh has a moderate flood history with 99 FEMA claims averaging $26,762 per payout. 80% 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>$1,900</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 Oshkosh
- Test your water at home. City-level data shows averages — your tap may differ. Lead testing is especially recommended given the area's lead levels.
- Install a certified water filter. Filters rated for Stage 2 DBP Rule can reduce the most common contaminant found in Oshkosh's water.
- Check your home's plumbing. With 62% of homes built before 1986, lead solder is a real possibility.
Deep Dive Reports
Detailed analysis for Oshkosh, WI