C51/100
Deerfield Tap Water Quality: Is It Safe to Drink? (2026 Report)
Serving 2,510 residents · Wisconsin
What's In Deerfield'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) | 1.84 mg/L | 1.30 mg/L | Over Limit |
Lead (90th percentile) | 0.002 mg/L | 0.015 mg/L | Above Goal |
EPA Violation History
No violations in the past 5 years
Full EPA compliance since 2012.
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
DEERFIELD WATERWORKS
Population Served
2,510
Water Source
Groundwater
System ID
WI1130223
Frequently Asked Questions About Deerfield Water
Is Deerfield tap water safe to drink?
Deerfield, Wisconsin tap water receives a grade of C (51/100), which is considered fair. 1 contaminant(s) exceed EPA maximum contaminant levels and 10 violation(s) are on record. Residents should consider using an NSF-certified water filter to reduce contaminant exposure.
What contaminants are in Deerfield's water?
Of the 2 contaminants tested in Deerfield'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 Deerfield have any water quality violations?
Yes, Deerfield has 10 EPA violation(s) on record, with the most recent in 2012. Violation types include MR, MCL. 7 of these are health-based violations, which are the most serious category.
Do I need a water filter in Deerfield?
Based on EPA data, using a water filter in Deerfield 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 Deerfield's tap water come from?
Deerfield's drinking water is sourced from groundwater and supplied by DEERFIELD WATERWORKS. The system serves approximately 2,510 people. Groundwater is pumped from underground aquifers, which often provides natural filtration.
How often is Deerfield'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. Deerfield'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 Deerfield's water compare to other cities in Wisconsin?
Deerfield's water quality score of 51/100 earns a grade of C, which is considered fair. This is a below-average score that indicates room for improvement. Visit our Wisconsin state page to see how all cities in the state compare.
What should I do if I'm concerned about Deerfield's water quality?
If you have concerns about Deerfield'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 (DEERFIELD 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.