Water Quality Report · Updated October 07, 2026
JANESVILLE WATER UTILITY
JANESVILLE WATER UTILITY delivers tap water graded D (62/100) by TapWaterSafety.org. The utility serves approximately 64,415 residents in JANESVILLE, Wisconsin using groundwater. The most significant water quality concerns are: PFAS contamination; Perfluorohexane sulfonate (PFHXS) significantly above health guideline; Total trihalomethanes (TTHMs) significantly above health guideline; Bromodichloromethane significantly above health guideline.
Is JANESVILLE tap water safe to drink?
JANESVILLE WATER UTILITY delivers tap water that earns a grade of D (62/100) from TapWaterSafety.org — a below-average rating, with multiple concerns including pfas contamination.
The utility serves 64,415 residents in JANESVILLE, drawing from groundwater.
Public testing data identifies 17 contaminants in this water above EWG's health-based guidelines, including: Perfluorohexane sulfonate (PFHXS), Total trihalomethanes (TTHMs), Bromodichloromethane, Nitrate, Nitrate and nitrite, Radium, combined (-226 and -228), Haloacetic acids (HAA9), Dibromochloromethane, Total PFOS and PFOA, Chromium (hexavalent), Dibromoacetic acid, Haloacetic acids (HAA5), Chloroform, Bromoform, Trichloroacetic acid, Dichloroacetic acid, Uranium. For most residents, a properly certified home filter at the kitchen tap is the most cost-effective way to reduce exposure to whatever's in your water. See our filter recommendations below, matched specifically to this utility's contaminant profile.
EPA compliance record
Official U.S. EPA records for JANESVILLE WATER UTILITY (system ID WI1540127) for the last 3 years. Checked 2026-10-07.
Source: U.S. EPA Enforcement and Compliance History Online (ECHO), from the Safe Drinking Water Information System. See EPA's full report.
Quick actions for JANESVILLE residents
Top concerns in this water
Based on the most recent EPA and EWG data, these are the most significant water quality issues for JANESVILLE WATER UTILITY.
PFAS contamination
Severe concernTotal PFOS and PFOA, Perfluorooctane sulfonate (PFOS) detected. PFAS are persistent chemicals linked to cancer and immune effects with no known safe exposure threshold.
Perfluorohexane sulfonate (PFHXS) significantly above health guideline
Moderate concernPerfluorohexane sulfonate (PFHXS) detected at 0.348 ppt, 348x above the EWG health guideline of 0.001 ppt.
Total trihalomethanes (TTHMs) significantly above health guideline
Moderate concernTotal trihalomethanes (TTHMs) detected at 15.9 ppb, 106x above the EWG health guideline of 0.15 ppb.
Bromodichloromethane significantly above health guideline
Moderate concernBromodichloromethane detected at 2.45 ppb, 41x above the EWG health guideline of 0.06 ppb.
Contact JANESVILLE WATER UTILITY
Reach the utility directly for service issues, water quality concerns, or to request your Consumer Confidence Report.
General Contact
Treatment Plant
Recommended water filters for JANESVILLE
Filters matched to the specific contaminants in this water supply.
Filter certified for PFOA/PFOS (NSF/ANSI 53 or 58)
$180-$750Reverse osmosis and some carbon block filters reduce PFAS. Look for certification to NSF/ANSI 53 or 58 for PFOA/PFOS.
Carbon filter certified for VOCs (NSF/ANSI 53)
$180-$599Activated carbon is effective for disinfection byproducts like TTHM. Look for NSF/ANSI 53 VOC or chloroform reduction.
Disclosure: TapWaterSafety earns a commission from purchases made through these links. This does not influence our scoring methodology or filter selection.
Score breakdown
This utility's overall score of 62/100 breaks down across five weighted components. Read the full methodology →
Contaminants detected — international standards comparison
Every contaminant detected, compared side-by-side against US EPA legal limits, the EU Drinking Water Directive (2020/2184), WHO Guidelines, and California's Public Health Goal (the strictest US benchmark). Why we show multiple standards →
| Contaminant | Detected | EWG US health-based |
EPA US legal |
EU DWD Europe |
WHO global |
CA PHG strictest US |
Tested sample year |
Status |
|---|---|---|---|---|---|---|---|---|
| Perfluorohexane sulfonate (PFHXS) PFAS |
0.348 ppt | 0.001 | 10.0 | — | — | — | — | 348× over |
| Total trihalomethanes (TTHMs) Disinfection byproduct |
15.9 ppb | 0.15 | 80.0 | 100 | — | — | — | 106× over |
| Bromodichloromethane Disinfection byproduct |
2.45 ppb | 0.06 | — | — | — | — | — | 41× over |
| Nitrate Inorganic |
5.77 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 41× over |
| Nitrate and nitrite Inorganic |
5.31 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 38× over |
| Radium, combined (-226 and -228) Radiological |
1.86 pCi/L | 0.05 | 5.0 | — | — | — | — | 37× over |
| Haloacetic acids (HAA9) Disinfection byproduct |
1.87 ppb | 0.06 | — | — | — | — | — | 31× over |
| Dibromochloromethane Disinfection byproduct |
3.03 ppb | 0.1 | — | — | — | — | — | 30× over |
| Total PFOS and PFOA PFAS |
0.209 ppt | 0.007 | — | 100 | 100 | 0.007 | — | 30× over |
| Chromium (hexavalent) Heavy metal |
0.546 ppb | 0.02 | — | — | — | — | — | 27× over |
| Dibromoacetic acid Disinfection byproduct |
0.563 ppb | 0.03 | — | — | — | — | — | 19× over |
| Haloacetic acids (HAA5) Disinfection byproduct |
1.38 ppb | 0.1 | 60.0 | 60 | — | — | — | 14× over |
| Chloroform Disinfection byproduct |
1.65 ppb | 0.4 | — | — | — | — | — | 4.1× over |
| Bromoform Disinfection byproduct |
1.7 ppb | 0.5 | — | — | — | — | — | 3.4× over |
| Trichloroacetic acid Disinfection byproduct |
0.328 ppb | 0.1 | — | — | — | — | — | 3.3× over |
| Dichloroacetic acid Disinfection byproduct |
0.42 ppb | 0.2 | — | — | — | — | — | 2.1× over |
| Uranium Radiological |
0.53 pCi/L | 0.43 | 20.0 | 30 | 30 | 0.43 | — | 1.2× over |
| Perfluorooctane sulfonate (PFOS) PFAS |
0.128 ppt | 0.3 | 4.0 | 100 | 100 | 1 | — | Below guideline |
| Perfluorooctanoic acid (PFOA) PFAS |
0.032 ppt | 0.09 | 4.0 | 100 | 100 | 0.007 | — | Below guideline |
| Manganese Heavy metal |
29.3 ppb | 100.0 | — | 50 | 80 | — | — | Below guideline |
| Barium Heavy metal |
50.0 ppb | 700.0 | 2000.0 | — | 1300 | 2000 | — | Below guideline |
| Atrazine Pesticide/Herbicide |
0.00237 ppb | 0.1 | 3.0 | 0.1 | 100 | 0.15 | — | Below guideline |
| Vanadium Other |
0.455 ppb | 21.0 | — | — | — | — | — | Below guideline |
| Monobromoacetic acid Disinfection byproduct |
0.0633 ppb | 25.0 | — | — | — | — | — | Below guideline |
| Perfluorobutane sulfonate (PFBS) PFAS |
0.292 ppt | 2000.0 | — | — | — | — | — | Below guideline |
| Strontium Radiological |
0.0972 ppb | 1500.0 | — | — | — | — | — | Below guideline |
| Perfluorohexanoic Acid (PFHxA) PFAS |
0.062 ppt | 1000.0 | — | — | — | — | — | Below guideline |
| Dibromomethane Other |
0.035 ppb | — | — | — | — | — | — | Below guideline |
| Fluoride Inorganic |
0.529 ppm | — | 4.0 | 1.5 | 1.5 | — | — | Below guideline |
All values in the unit of the detected level. Red cells indicate the detected level exceeds that standard. Some contaminants have limits in some jurisdictions but not others (shown as —). The "Tested" column shows the year each contaminant sample was collected.
Sources: US EPA, EU Drinking Water Directive 2020/2184, WHO Guidelines (4th ed.), California OEHHA PHGs, EWG Tap Water Database.
JANESVILLE WATER UTILITY service area
This water system serves 1 community in Rock County, Wisconsin. Click any city for its dedicated tap water quality page.
Find the right filter for JANESVILLE water
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