Water Quality in Madison, WI: 385 Violations — Grade C
Grade C · Score 60/100 · 5 water systems · Updated 2026-05-03
Madison's water has moderate compliance issues. Residents in affected areas should consider filtration.
Data: EPA Safe Drinking Water Information System (SDWIS) Last verified: 2026-05-03
EPA monitoring has flagged 385 reportable events for water systems in Madison, WI.
Water Quality Map: Madison, WI
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Water Quality by ZIP Code in Madison
Water quality varies across Madison's 35 ZIP codes. Check your specific ZIP for detailed contaminant data.
| ZIP Code | Grade | Score | Violations | Health | |
|---|---|---|---|---|---|
| 53701 | C | 59 | 11 | 3 | View report → |
| 53702 | C | 59 | 11 | 3 | View report → |
| 53703 | C | 59 | 11 | 3 | View report → |
| 53704 | C | 59 | 11 | 3 | View report → |
| 53706 | C | 59 | 11 | 3 | View report → |
| 53707 | C | 59 | 11 | 3 | View report → |
| 53708 | C | 59 | 11 | 3 | View report → |
| 53711 | C | 59 | 11 | 3 | View report → |
| 53713 | C | 59 | 11 | 3 | View report → |
| 53716 | C | 59 | 11 | 3 | View report → |
| 53718 | C | 59 | 11 | 3 | View report → |
| 53725 | C | 59 | 11 | 3 | View report → |
| 53726 | C | 59 | 11 | 3 | View report → |
| 53744 | C | 59 | 11 | 3 | View report → |
| 53774 | C | 59 | 11 | 3 | View report → |
Violation Trend
EPA violations recorded for water systems serving Madison.
Water Quality Overview
Madison, Wisconsin receives a water quality grade of C with an overall score of 60 out of 100, based on EPA compliance data from the Safe Drinking Water Information System (SDWIS).
The 5 water systems serving Madison have accumulated 385 EPA violations, including 105 health-based violations. These violations are tracked across 35 ZIP codes serving approximately 282,013 people.
What Grade C Means
A grade of C indicates moderate compliance issues. Madison's water systems have some violations that warrant attention. While the water may still be safe for most people, residents in affected ZIP codes should consider additional testing or filtration.
Lead Levels
The average 90th percentile lead level across Madison water systems is 0.0018 mg/L — within EPA limits. No ZIP codes exceed the EPA lead action level.
With 61% of homes built before 1986, Madison has a higher-than-average risk of lead from older plumbing. Lead solder was banned in 1986, and homes built before this date may have lead in pipes, solder joints, or fixtures.
Radon Risk
Madison is in EPA Radon Zone 1 (High risk). The EPA recommends all homes in Zone 1 areas be tested for radon. Radon is the second leading cause of lung cancer after smoking.
Water Systems Serving Madison
Madison is served by 5 community water systems regulated under the Safe Drinking Water Act. These systems collectively serve approximately 282,013 people across 35 ZIP codes.
Each water system is identified by a Public Water System ID (PWSID) and is required to:
- Test for over 90 regulated contaminants on a regular schedule
- Report results to the EPA and state regulators
- Issue an annual Consumer Confidence Report (CCR) to all customers
- Take corrective action when violations occur
The EPA has taken 350 enforcement actions against water systems serving Madison. Enforcement actions range from informal compliance assistance to formal orders and penalties.
How to Check Your Water in Madison
Enter your ZIP code on ZipCheckup to see your specific water system data, including contaminant levels, violation history, and safety scores
Request your CCR — your water utility must provide an annual Consumer Confidence Report with detailed test results for all monitored contaminants
Get a home test — certified kits cost $20–$50 and test for lead, bacteria, and common contaminants. Professional lab tests ($150–$400) cover a broader panel
Consider filtration — NSF-certified filters can remove specific contaminants. Reverse osmosis removes the broadest range; activated carbon is effective for chlorine and many organics
Check for advisories — monitor your local utility website and local news for boil water advisories or system alerts
Contaminants Detected in Madison Water Systems
The following contaminants have been detected or caused violations across Madison's water systems:
| Contaminant | Category | MCL | Violations | ZIPs Affected | Health-Based |
|---|---|---|---|---|---|
| Surface Water Treatment Rule | Treatment Technique | N/A | 140 | 35 | No |
| Stage 2 DBP Rule | Treatment Technique | N/A | 105 | 35 | Yes |
| Lead and Copper Rule | Treatment Technique | N/A | 70 | 35 | No |
| Gross Beta | Radionuclides | 50 pCi/L | 35 | 35 | Yes |
| Stage 1 DBP Rule | Treatment Technique | N/A | 35 | 35 | No |
MCL = Maximum Contaminant Level (EPA enforceable standard). Health-based violations indicate levels that may pose direct health risks.
Violation Trend Over Time
Year-by-year EPA violations recorded for water systems serving Madison:
| Year | Total Violations | Health-Based |
|---|---|---|
| 2023 | 35 | 35 |
| 2024 | 70 | 70 |
Violations have increased from 35 in 2023 to 70 in 2024. This trend warrants monitoring.
EPA Enforcement History
The EPA and state regulators have taken 9 enforcement actions against water systems serving Madison. Recent actions:
| Date | Action Type |
|---|---|
| 2025-08-11 | State Order Extension |
| 2024-12-13 | State Order Extension |
| 2024-11-14 | State Order Extension |
| 2024-11-04 | State Order Extension |
| 2024-08-12 | State Order Extension |
| 2024-08-12 | State Informal Action |
| 2024-07-23 | State Informal Action |
| 2024-07-17 | State Order Extension |
| 2024-01-26 | State Informal Action |
Enforcement actions range from informal compliance assistance to formal orders and penalties. The most recent action was on 2025-08-11.
Madison vs. Nearby Wisconsin Cities
How Madison's water quality compares to similar cities in Wisconsin:
| City | Grade | Violations | Systems | Population |
|---|---|---|---|---|
| Madison | C | 385 | 5 | 282,013 |
| Green Bay | B | 72 | 5 | 177,103 |
| Racine | B | 112 | 4 | 128,750 |
| Oneida | C | 0 | 1 | 107,369 |
Recommended Water Filters for Madison
Based on contaminants detected in Madison's water supply, these filter types are recommended:
Reverse Osmosis (under-sink)
- Removes: Copper
- Effectiveness: 95-99%
- Cost range: $150–$500
- Certification: NSF/ANSI 58
- Recommended products:
Water Quality by ZIP Code in Madison
Water quality varies across Madison's ZIP codes. The table below shows the worst-scoring and best-scoring areas:
| ZIP Code | Score | Grade | Violations | Health-Based |
|---|---|---|---|---|
| 53701 | 59 | C | 11 | 3 |
| 53702 | 59 | C | 11 | 3 |
| 53703 | 59 | C | 11 | 3 |
| 53704 | 59 | C | 11 | 3 |
| 53706 | 59 | C | 11 | 3 |
| 53707 | 59 | C | 11 | 3 |
| 53708 | 59 | C | 11 | 3 |
| 53711 | 59 | C | 11 | 3 |
| 53713 | 59 | C | 11 | 3 |
| 53716 | 59 | C | 11 | 3 |
| 53719 | 64 | C | 11 | 3 |
| 53717 | 64 | C | 11 | 3 |
| 53715 | 64 | C | 11 | 3 |
| 53714 | 64 | C | 11 | 3 |
| 53705 | 64 | C | 11 | 3 |
Common Questions About Madison Water
These are the most common questions residents search for about water quality in Madison, Wisconsin:
Is Madison water hard or soft? Water hardness varies by source. Madison's 5 water systems use multiple sources. Check your ZIP code report for specific hardness data.
Can I drink Madison tap water? Madison's water receives a grade of C (60/100). There are 105 health-based violations — consider filtration.
What is the best water filter for Madison? Based on detected contaminants, a reverse osmosis (under-sink) filter is most recommended. See our Water Filter Matcher for personalized recommendations.
Madison vs. Wisconsin Average
Understanding how Madison compares to the broader Wisconsin average helps contextualize your local water quality. Factors like water source, treatment methods, and infrastructure age all contribute to differences between cities in the same state.
To see how individual neighborhoods compare, check the ZIP code reports below — water quality can vary significantly even within Madison.
ZIP Codes in Madison
Madison spans 35 ZIP codes. The ZIP with the lowest water quality score is 53701. Each ZIP code has its own water quality profile based on the specific water system serving that area. Check each ZIP code for detailed contaminant data, violation history, and system information.
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Lead/copper: EPA Lead and Copper Rule sampling data
- Radon: EPA Map of Radon Zones
- Enforcement: EPA ECHO database
- Filter recommendations: NSF/ANSI certified products
Updated daily.