Marathon, WI: 4 Violations — 67/100 (2026)
1 ZIP code · 3 water systems · Updated 2026-06-03
If you're checking Marathon, WI tap water safety, the short answer is: average — violations are present in parts of the city and specifics depend on which water system serves your address.
How Marathon Compares
Data: EPA SDWIS Last verified: 2026-06-03
What You Should Know About Marathon Water
- Your city's water systems recorded 4 violations in the past 5 years.
- Average lead level: 0.0006 mg/L.
- Homes built before 1986: 57% — older plumbing may contain lead solder.
- Estimated remediation: $2,400 per household.
- CDC health risk index: 12.89 — above typical levels.
Who Supplies Your Water in Marathon
Residential water in Marathon, WI is supplied by 3 separate utilities — not one centralized authority. Each of those providers operates under its own service territory boundary, maintains its own distribution infrastructure, and files compliance documentation with the EPA on its own timeline. Federal data counts 3 water systems in the area, with these providers collectively accounting for the dominant share of household connections.
Overview
We track water quality and home safety data for 1 ZIP code in Marathon, Wisconsin (population ~4,243), covering 3 community water systems serving approximately 41,528 people region-wide.
1 of 1 ZIP code (100%) have recorded EPA violations. All violations are monitoring/reporting type.
Home Safety Score
Average Home Safety Score for Marathon: 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
Marathon water systems draw from: Groundwater.
Lead & Copper
- Average lead level (90th percentile): 0.0006 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 |
|---|---|---|---|
| Surface Water Treatment Rule | Treatment Technique | 4 | 1 |
| Stage 1 DBP Rule | Treatment Technique | 2 | 1 |
| Stage 2 DBP Rule | Treatment Technique | 2 | 1 |
Areas with Most Violations
| ZIP Code | Safety Score | Violations | Health-Based | System |
|---|---|---|---|---|
| 54448 | C | 4 | 0 | Wausau Waterworks |
All ZIP Codes in Marathon
- 54448 [C] — 4 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.
Health Outcomes in Marathon
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
Top Contaminants in Marathon Water
Based on EPA violation records. Check your ZIP code report for system-specific contaminant data.
Housing & Infrastructure in Marathon
With 57% 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
Decades of residential development in Marathon took place before the two main regulatory milestones that reduced plumbing-era lead risk: the phase-out of lead pipes before 1970, and the federal ban on lead solder in 1986. With a median build year of 1970, the housing stock here is anchored in that earlier period. The distinction between pre-1970 and 1970-to-1986 construction matters: the oldest homes may have lead pipes in the service line and lead solder in the copper joints, while the 1970-to-1986 tier still carries the solder risk even after lead pipes became less common. Together, these two risk layers affect a majority of the residential properties in the city — a fact the aggregate water quality data doesn't directly reveal.
Over half of homes in Marathon 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.
Cost Context: What Remediation Means for Marathon Homeowners
When remediation costs are measured against Marathon home values, the resulting ratio is in the low tier — addressing documented water and safety issues here claims only a minor fraction of typical equity, and most homeowners are in a position where the financial commitment is straightforward rather than a material burden on their household budget.
Remediation costs in Marathon are relatively low compared to home values. The $1,600–$3,300 estimated range is a small fraction of median property value. Home values are 4% above the Wisconsin average.
Lead Exposure Risk for Children in Marathon
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.
Although utility-side compliance with federal Lead and Copper requirements remains the system reference, that compliance does not extend down into interior plumbing. With 57% of Marathon stock built before the solder ban and aggregate readings at or beyond the action mark, a household-level sample becomes the practical way to close that information gap.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Flood & Climate Risk in Marathon
Flood history in Marathon spans 5 NFIP claims and 100% flood zone coverage — enough to place it in moderate-exposure territory where flood events are genuinely recurring rather than statistical outliers. That distinction matters for water quality assessment because the connection between flooding and water safety is not uniform across communities. In low-exposure areas, flooding rarely generates the conditions needed to compromise treatment or distribution infrastructure. In high-exposure areas, it can do so repeatedly. Moderate-exposure communities sit in between: flood events occur with enough frequency to make periodic infrastructure stress a reasonable concern, particularly for private well owners and residents in lower-elevation FEMA-designated zones.
Marathon has a moderate flood history with 5 FEMA claims averaging $3,204 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>$2,400</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 Marathon
- 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 Surface Water Treatment Rule can reduce the most common contaminant found in Marathon's water.
- Check your home's plumbing. With 57% of homes built before 1986, lead solder is a real possibility.
Deep Dive Reports
Detailed analysis for Marathon, WI