Is Janesville, WI tap water safe?
Supplied by Janesville Water Utility · serves 64,415 people (23,857 connections) · Groundwater · EPA ID WI1540127
Data: U.S. EPA · How we read the data · How we check it
Most of Janesville gets its water from Janesville Water Utility. Parts of the city are served by 2 smaller systems: Rockvale MHP (1,200 people), Caravilla Education and Rehab Center Water System (298 people). Your water bill names your system.
Summary
No federal limits exceeded in EPA data.
- PFAS
- Not detectedNone of 29 PFAS found above EPA's reporting limits in 6 samples (2023–2025).
- Lead
- Below action level2.4 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 Jun 2026. Your home's pipes can make yours higher.
- Violations
- None health-basedNo health-based violations since 2016.
- 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.
- Tested your own tap? Compare your result with these numbers. Moving? Compare this system with another.
- Read Janesville Water Utility's annual water quality report (Consumer Confidence Report). It lists every regulated contaminant tested and is usually on the utility's website or mailed with your bill. EPA: how to find it.
PFAS (“forever chemicals”)
EPA UCMR 5: 3 entry points tested Aug 2024 to Feb 2025. "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 Not detected Limit 10 ppt | – |
| 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) Not detected Limit 1 | – |
| PFBS Not detected Guideline 2,000 ppt | – |
| PFBA Not detected Guideline 6,000 ppt | – |
| PFHxA Not detected Guideline 3,000 ppt | – |
29 PFAS tested, 0 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 6 samples (reporting limit 9 ppb). About lithium.
Lead and copper
Latest 90th percentile: 2.4 ppb lead (Jan 2026 – Jun 2026). Below action level
Highest since 2016: 10 ppb (Oct 2020).
| Monitoring period | Lead (90th pct.) |
|---|---|
| Jan 2026 – Jun 2026 | 2.4 ppb |
| Jul 2020 – Oct 2020 | 10 ppb |
| Jun 2017 – Sep 2017 | 7.3 ppb |
Earlier results (9)
| Jun 2016 – Sep 2016 | 6.8 ppb |
| Jun 2013 – Sep 2013 | 4.7 ppb |
| Jan 2010 – Dec 2010 | 9.49 ppb |
| Jan 2007 – Dec 2007 | 7.1 ppb |
| Jan 2004 – Dec 2004 | 4.6 ppb |
| Mar 2001 – Aug 2001 | 4.8 ppb |
| Jul 2000 – Dec 2000 | 4.48 ppb |
| Jul 1997 – Dec 1997 | 5.22 ppb |
| Jan 1997 – Jun 1997 | 4.9 ppb |
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
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 | 4.26 ppb | 300 ppb |
| Vanadium | 0.53 ppb | 21 ppb |
| Strontium | 0.12 ppm | 1.5 ppm |
| Chromium-6 | 0.68 ppb | – |
Where it serves
Janesville
ZIP codes the system reported serving: 53545, 53546, 53547, 53548
Nearby utilities
- Palmyra Waterworks Palmyra · 25 mi · PFAS above limit
- Lake Geneva Utility Commission Lake Geneva · 30 mi · PFAS above limit
- Madison Water Utility Madison · 35 mi
- Waukesha Water Utility Waukesha · 45 mi
- Pewaukee City Water and Sewer Utility Pewaukee · 47 mi · PFAS above limit
- West Allis Waterworks West Allis · 55 mi
Questions
Is Janesville tap water safe to drink?
Most of Janesville gets its water from Janesville Water Utility. Janesville Water Utility has no health-based violations since 2016. 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 Janesville water have PFAS?
EPA tested Janesville Water Utility for 29 PFAS between Aug 2024 and Feb 2025 and none were detected above the reporting limits (about 2 to 20 ppt depending on the chemical).
What is the lead level in Janesville water?
The most recent 90th-percentile lead result for Janesville Water Utility is 2.4 ppb, for the period ending Jun 2026. 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 WI1540127: violations, enforcement and inspections, straight from EPA.
- EPA UCMR 5 data: the PFAS and lithium results (search the file for PWSID WI1540127).
- EPA SDWIS download: the lead results, population and violation records we use.
- The utility's annual water quality report (Consumer Confidence Report): ask Janesville Water Utility, or see EPA's guide to finding it.
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.