B65/100
Sun Prairie Tap Water Quality: Is It Safe to Drink? (2026 Report)
Serving 33,966 residents · Wisconsin
What's In Sun Prairie's Tap Water?
66
Contaminants Tested
0
Exceed EPA Limits
1
Above EPA Goals
1 contaminant above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
Lead (90th percentile) | 0.003 mg/L | 0.015 mg/L | Above Goal |
EPA Violation History
2
Violations (last 5yr)
0
Unresolved
1
Health-Related
TIER 2Resolved
Exceeded the Maximum Contaminant Level (running average)
When: January 1, 2023 – March 31, 2023Enforcement: Resolving — corrective action underway
TIER 3Resolved
Exceeded the MCL for disinfection byproducts
This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.
When: July 1, 2021 – September 30, 2021Enforcement: Resolving — corrective action underway
Understanding violation severity
Tier 1Urgent health risk. Utility must notify all customers within 24 hours.Tier 2Important health or treatment issue. Customers notified within 30 days.Tier 3Administrative or monitoring issue. Reported in the annual water quality report.
Source: EPA Safe Drinking Water Information System (SDWIS) · Updated quarterly
Water Utility Details
SUN PRAIRIE UTILITIES
Population Served
33,966
Water Source
Groundwater
System ID
WI1130258
Frequently Asked Questions About Sun Prairie Water
Is Sun Prairie tap water safe to drink?
Sun Prairie, Wisconsin tap water receives a grade of B (65/100), which is considered good. Out of 66 contaminants tested, none exceed EPA maximum contaminant levels (MCLs) and 1 exceed health guidelines (MCLGs). While the water meets federal standards, some residents may still choose to use a filter for additional peace of mind.
What contaminants are in Sun Prairie's water?
Of the 66 contaminants tested in Sun Prairie's water supply, the most notable include Lead (90th percentile). No contaminants exceed EPA legal limits. 1 contaminant(s) exceed EPA health goals (MCLGs), which are non-enforceable targets set at levels with no known health risk.
Does Sun Prairie have any water quality violations?
Yes, Sun Prairie has 24 EPA violation(s) on record, with the most recent in 2023. Violation types include MCL, MR. 2 of these are health-based violations, which are the most serious category.
Do I need a water filter in Sun Prairie?
Sun Prairie water meets EPA standards, so a filter is not strictly necessary. However, some residents prefer the added security of a water filter. EPA health goals (MCLGs) are stricter than legal limits and are set at levels with zero expected health risk. 1 contaminant(s) exceed these stricter goals.
Where does Sun Prairie's tap water come from?
Sun Prairie's drinking water is sourced from groundwater and supplied by SUN PRAIRIE UTILITIES. The system serves approximately 33,966 people. Groundwater is pumped from underground aquifers, which often provides natural filtration.
How often is Sun Prairie's water tested?
Under the Safe Drinking Water Act (SDWA), water utilities are required to regularly test for over 90 contaminants. Testing frequency varies by contaminant — some are tested monthly, others quarterly or annually. Sun Prairie's water systems must report results to the EPA and publish an annual Consumer Confidence Report (CCR). The data on this page reflects the latest available EPA testing data.
How does Sun Prairie's water compare to other cities in Wisconsin?
Sun Prairie's water quality score of 65/100 earns a grade of B, which is considered good. This is an above-average score compared to many cities nationwide. Visit our Wisconsin state page to see how all cities in the state compare.
What should I do if I'm concerned about Sun Prairie's water quality?
If you have concerns about Sun Prairie's tap water, consider these steps: (1) Request your utility's annual Consumer Confidence Report for detailed local data. (2) Get your water independently tested through a state-certified laboratory. (3) Consider an NSF-certified water filter rated for the contaminants found in your area. (4) Contact your water utility (SUN PRAIRIE UTILITIES) with specific questions. (5) Report water quality issues to your state drinking water program or the EPA Safe Drinking Water Hotline at 800-426-4791.