Is Madison, WI tap water safe?
Supplied by Madison Water Utility · serves 272,000 people (100,740 connections) · Groundwater · EPA ID WI1130224
Data: U.S. EPA · How we read the data · How we check it
Most of Madison gets its water from Madison Water Utility. Parts of the city are served by 10 smaller systems: Mendota Mental Health Inst Water System (2,787 people), Shorewood Hills Waterworks (1,670 people), Maple Bluff Waterworks (1,342 people), Lake Forest Water Coop (400 people) and 6 more. Your water bill names your system.
Summary
No federal limits exceeded in EPA data.
- PFAS
- Detected, below limit2 of 29 PFAS found at least once. All averages below the federal limits.
- Lead
- Below action level1.8 ppb (parts per billion) at the 90th percentile: 9 in 10 homes sampled were at or below it. Action level 15 ppb, falling to 10 ppb in Nov 2027. Monitoring period ending Sep 2023. Your home's pipes can make yours higher.
- Violations
- Resolved1 health-based violation since 2016, most recently Oct 2024.
- Built before 1986, or not sure what your service line is made of? Check your service line and test your tap. Utility data can't show your pipes.
- Want to reduce what was found? Filters for these results.
- Tested your own tap? Compare your result with these numbers. Moving? Compare this system with another.
- Read Madison Water Utility's 2026 water quality report (Consumer Confidence Report, from the utility). It lists every regulated contaminant tested, including ones not on this page.
PFAS (“forever chemicals”)
EPA UCMR 5: 20 entry points tested Oct 2023 to Oct 2024. "Average" is the highest entry-point average (non-detects counted as zero), the way EPA compares UCMR 5 results to the limits. ppt = parts per trillion. These results do not determine compliance.
| Contaminant | Highest average |
|---|---|
| PFOA Not detected Limit 4 ppt | – |
| PFOS Not detected Limit 4 ppt | – |
| PFHxS Detected, below limit Limit 10 ppt | 6.95 ppt 70% of the limit |
| PFNA Not detected Limit 10 ppt | – |
| HFPO-DA (GenX) Not detected Limit 10 ppt | – |
| Hazard Index (a combined score for PFHxS, PFNA, GenX and PFBS, where above 1 is over the limit) Detected, below limit Limit 1 | 0.69 |
| PFBS Not detected Guideline 2,000 ppt | – |
| PFBA Detected, below limit Guideline 6,000 ppt | 46.3 ppt |
| PFHxA Not detected Guideline 3,000 ppt | – |
29 PFAS tested, 2 detected at least once. "Not detected" means below EPA's reporting limit (about 2 to 20 ppt depending on the chemical), not proven zero. PFAS not listed were not detected. The limits for PFHxS, PFNA, GenX and the Hazard Index were proposed for rescission in May 2026. That proposal is not final. Systems have until 2029 to meet the limits.
Lithium
Not detected in 40 samples (reporting limit 9 ppb). About lithium.
Lead and copper
Latest 90th percentile: 1.8 ppb lead (Jun 2023 – Sep 2023). Below action level
Highest since 2016: 3.24 ppb (Oct 2020).
| Monitoring period | Lead (90th pct.) |
|---|---|
| Jun 2023 – Sep 2023 | 1.8 ppb |
| Jul 2020 – Oct 2020 | 3.24 ppb |
| Jun 2017 – Sep 2017 | 3.16 ppb |
Earlier results (6)
| Jun 2014 – Sep 2014 | 3.37 ppb |
| Jul 2011 – Dec 2011 | 3.36 ppb |
| Jan 2011 – Jun 2011 | 2.57 ppb |
| Jul 1997 – Dec 1997 | 16 ppb |
| Jan 1997 – Jun 1997 | 17 ppb |
| Jan 1992 – Jun 1992 | 16 ppb |
Lead service lines: Madison Water Utility publishes a service line inventory where you can look up what your line is made of. It doesn't publish summary counts.
Look up your address · Source (the utility, collected by us on Nov 14, 2026, not EPA data) · Checking your own line
Lead comes from pipes and fixtures, not the source water, so it varies home to home. The 90th percentile means 9 in 10 sampled homes were at or below it. More on lead.
Violations
| When | What happened |
|---|---|
| Oct 2024 | The system did not publish the required inventory of lead service lines (due October 2024). It says nothing about lead levels in the water. EPA record: Lead and copper rule revisions · LSL Inventory Resolved |
Health-based violations mean a contaminant exceeded a limit or a required treatment step was missed. Monitoring and reporting violations mean required tests or reports were late or missing, so the water's quality during that time is unknown. The total includes every violation in EPA's records, most of them paperwork.
Earlier EPA testing (2013–2020)
| Contaminant | Highest | Guideline |
|---|---|---|
| Manganese | 50.2 ppb | 300 ppb |
| Strontium | 0.1 ppm | 1.5 ppm |
| Cobalt | 1.6 ppb | 70 ppb |
| Chromium-6 | 3.3 ppb | – |
| Chlorate | 29 ppb | 210 ppb |
| Vanadium | 0.4 ppb | 21 ppb |
| 1,4-Dioxane | 0.43 ppb | 0.35 ppb |
Where it serves
Madison
ZIP codes the system reported serving: 53558, 53562, 53593, 53703, 53704, 53705, 53706, 53711, 53713, 53714, 53715, 53716, 53717, 53718, 53719, 53726
Nearby utilities
- Janesville Water Utility Janesville · 35 mi
- Palmyra Waterworks Palmyra · 44 mi · PFAS above limit
- Hartford Waterworks Hartford · 57 mi · PFAS above limit
- Pewaukee City Water and Sewer Utility Pewaukee · 60 mi · PFAS above limit
- Waukesha Water Utility Waukesha · 60 mi
- Lake Geneva Utility Commission Lake Geneva · 61 mi · PFAS above limit
Questions
Is Madison tap water safe to drink?
Most of Madison gets its water from Madison Water Utility. Madison Water Utility had 1 health-based violation since 2016, all since resolved. EPA testing found no PFAS above the federal limits. Federal data can't tell you about your own pipes: lead comes from service lines and plumbing, so test your tap if your home was built before 1986. For the official word, read the utility's annual Consumer Confidence Report.
Does Madison water have PFAS?
Yes. EPA's 2023–2025 testing of Madison Water Utility found 2 PFAS at least once. None of the averages were above the federal limits.
What is the lead level in Madison water?
The most recent 90th-percentile lead result for Madison Water Utility is 1.8 ppb, for the period ending Sep 2023. The federal action level is 15 ppb, falling to 10 ppb in November 2027. The 90th percentile means 9 in 10 homes sampled were at or below this number. Individual homes can be higher.
Check these numbers yourself
Every figure on this page comes from public EPA records. You don't have to take our word for it:
- EPA's own report for WI1130224: violations, enforcement and inspections, straight from EPA.
- EPA UCMR 5 data: the PFAS and lithium results (search the file for PWSID WI1130224).
- EPA SDWIS download: the lead results, population and violation records we use.
- Madison Water Utility's 2026 water quality report: the utility's own annual report, including contaminants EPA's national database doesn't carry (link checked Nov 14, 2026).
- Madison Water Utility website
Found something that doesn't match? Tell us and we'll check it against EPA's records. How we check our data.
Source: U.S. EPA drinking water records and PFAS testing (UCMR 5). How we read the data.