ZIP Code 54935 Water Quality & Testing Report
Fond Du Lac, WI · Fond Du Lac County County · Updated for 2026
Is Tap Water Safe to Drink in ZIP 54935 (Fond Du Lac, WI)?
Caution / Filtration Recommended: Tap water in ZIP code 54935 (Fond Du Lac, WI) has compliance concerns, earning an EPA Safety Grade of D (42/100) due to 2 health violation(s) and 9.5 ppb lead. While treated by Fond Du Lac Waterworks, residents are advised to use an NSF/ANSI 53 certified water filter for drinking and cooking.
Water Safety Grade
Poor — Multiple violations recorded
Health Violations
2
Total Violations
13
Lead Risk
High
Contaminants
1
About Tap Water in ZIP Code 54935
Tap water in ZIP code 54935 (Fond Du Lac, WI) is distributed by Fond Du Lac Waterworks (EPA ID: WI4200469), serving approximately 44,303 residents. Based on EPA Safe Drinking Water Act compliance records, this system receives a water safety grade of D with a composite quality score of 42/100.
Water System
Fond Du Lac Waterworks
EPA ID: WI4200469
Water Source
Ground Water
Population Served
44,303 residents
County
Fond Du Lac County County, Wisconsin
Lead Levels in ZIP 54935
EPA action level: 15 ppb | Public health goal: 0 ppb
Lead Level: 9.5 ppb — Moderate
Lead exposure risk in 54935 is rated High. EPA models estimate a 68% exposure probability based on housing and infrastructure age.
EPA model estimate based on housing age and infrastructure
Water Hardness & Mineral Content
Grains per gallon (GPG) & Parts per million (PPM / mg/L)
Water in ZIP 54935 is Hard (163 mg/L / 9.5 GPG). Residents may notice white mineral spots on glassware, reduced soap efficiency, and mineral scale on faucets and showerheads.
Grains per gallon
Parts per million CaCO3
Official EPA SDWIS Database Entry
Utility: Fond Du Lac Waterworks · PWSID: WI4200469
Violation History
Past 5 years — EPA SDWIS data
Fond Du Lac Waterworks has recorded 2 health-based violations out of 13 total violations over the past 5 years. 1 violation remains unresolved in EPA tracking records.
Regulatory compliance risk for this utility is rated High based on past reporting and enforcement records.
Contaminants Detected
Contaminants with health-based violations on record
EPA records identify 1 contaminant with health-based violations in the past 5 years: Stage 2 DBP Rule.
⚖ Enforcement Actions
Water Source & Environmental Factors
Ground Water
This system draws water from underground aquifers. Groundwater is naturally filtered through soil and rock, but can still contain naturally occurring minerals like arsenic, radium, or nitrates.
Highest potential
Estimated annual flood-related costs per property
% of household income spent on energy — indicator of older infrastructure
EPA Radon Zone 1 — highest potential for radon in indoor air. Homeowners should test their home for radon and consider mitigation if levels exceed 4 pCi/L.
Water Quality Testing in ZIP 54935
Tap Water & Well Testing Recommendations
Residents in ZIP code 54935 served by Fond Du Lac Waterworks can test tap water or private well systems to verify water purity. Testing detects hidden contaminants before they impact family health.
Tap Water Testing Steps
- 1.Conduct a certified lead check if your home was constructed before 1986.
- 2.Use certified lab testing kits rather than uncalibrated test strips for regulated compliance.
- 3.Sample water from both your kitchen faucet and water heater to compare line purity.
Private Well Testing Steps
- •Test for Coliform bacteria and Nitrates annually.
- •Test for heavy metals, radon, and PFAS every 3 years.
- •Send samples to a state-certified drinking water laboratory recognized by Wisconsin Department of Natural Resources.
🛡 What Should You Do? — ZIP 54935 Recommendations
Serious water quality concerns — action recommended
- 🚨 Install a certified NSF/ANSI 53 or 58 (reverse osmosis) filter immediately for drinking and cooking
- 🚨 Do not give unfiltered water to children, pregnant women, or immunocompromised individuals
- 🚨 Contact Fond Du Lac Waterworks to request the current violation status and corrective action plan
- 🚨 Report concerns to your state environmental agency or call the EPA hotline: 1-800-426-4791
- 🚨 Consider having your home's tap water independently tested by a certified lab
Recommended Water Treatment Systems:
NSF 53 Lead Pitcher Filter
Certified to remove lead. Recommended for immediate protection.
NSF 58 Under-Sink RO System
Reverse Osmosis system certified to remove PFAS, heavy metals, and viruses.
Frequently Asked Questions — ZIP 54935 Water Quality
Is tap water safe to drink in ZIP code 54935?+
How do I get my water tested in ZIP 54935 (Fond Du Lac, WI)?+
How hard is the tap water in 54935?+
Should I test private well water in 54935?+
What is the lead level in 54935 tap water?+
Is there an active boil water notice in 54935?+
Who provides tap water to 54935?+
What water filter should I use in 54935?+
Data Sources & Methodology
Water quality data for ZIP code 54935 is compiled from the EPA Safe Drinking Water Information System (SDWIS), EPA ECHO enforcement database, UCMR5 unregulated contaminant monitoring, and Consumer Confidence Reports filed by Fond Du Lac Waterworks. Safety scores are composite metrics derived from violation history, lead levels, enforcement actions, and infrastructure risk indicators. Data reflects a 5-year monitoring window. Last dataset update: 2024. View EPA source data →