A83/100
Mosinee Tap Water Quality: Is It Safe to Drink? (2026 Report)
Serving 4,452 residents · Wisconsin
What's In Mosinee's Tap Water?
2
Contaminants Tested
1
Exceed EPA Limits
1
Above EPA Goals
2 contaminants above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
Copper (90th percentile) | 1.40 mg/L | 1.30 mg/L | Over Limit |
Lead (90th percentile) | 0.002 mg/L | 0.015 mg/L | Above Goal |
EPA Violation History
2
Violations (last 5yr)
2
Unresolved
1
Health-Related
TIER 2Unresolved
Treatment technique violation
TIER 3Unresolved
Disinfection byproduct treatment technique failure
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
MOSINEE WATERWORKS
Population Served
3,406
Water Source
Groundwater
System ID
WI7370159
MOSINEE EAST SYSTEM
Population Served
1,046
Water Source
Groundwater
System ID
WI7372480
Frequently Asked Questions About Mosinee Water
Is Mosinee tap water safe to drink?
Mosinee, Wisconsin tap water receives a grade of A (83/100), which is considered excellent. Out of 2 contaminants tested, 1 exceed EPA maximum contaminant levels (MCLs) and 2 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 Mosinee's water?
Of the 2 contaminants tested in Mosinee's water supply, the most notable include Copper (90th percentile), Lead (90th percentile). 1 contaminant(s) exceed EPA legal limits (MCLs). 2 contaminant(s) exceed EPA health goals (MCLGs), which are non-enforceable targets set at levels with no known health risk.
Does Mosinee have any water quality violations?
Yes, Mosinee has 10 EPA violation(s) on record, with the most recent in 2024. Violation types include TT, Other, MR. 3 of these are health-based violations, which are the most serious category.
Do I need a water filter in Mosinee?
Based on EPA data, using a water filter in Mosinee is recommended. 1 contaminant(s) exceed legal limits. An NSF-certified filter — such as a reverse osmosis or activated carbon system — can effectively reduce many common contaminants. Choose a filter certified to remove the specific contaminants found in your area.
Where does Mosinee's tap water come from?
Mosinee's drinking water is sourced from groundwater and supplied by MOSINEE WATERWORKS and 1 other water system(s). The system serves approximately 4,452 people. Groundwater is pumped from underground aquifers, which often provides natural filtration.
How often is Mosinee'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. Mosinee'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 Mosinee's water compare to other cities in Wisconsin?
Mosinee's water quality score of 83/100 earns a grade of A, which is considered excellent. This places Mosinee among the better-performing water systems in Wisconsin. Visit our Wisconsin state page to see how all cities in the state compare.
What should I do if I'm concerned about Mosinee's water quality?
If you have concerns about Mosinee'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 (MOSINEE WATERWORKS) 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.