Based on current EPA data, Madison, WI reflects fair but uneven tap water safety.

Data: EPA SDWIS, FEMA NFIP, Census ACS Last verified: 2026-07-19

Water Quality in Madison

We track water quality and home safety data for 35 ZIP codes in Madison, Wisconsin, covering 11 community water systems serving approximately 308,771 people.

35 of 35 ZIP codes (100%) have recorded EPA violations - 385 total, including 105 health-based violations.

Average Home Safety Score: C (60/100)

Water sources: Groundwater.

Top Contaminants

Lead Risk

• Average lead level (90th percentile): 0.0018 mg/L
• 61% of housing built before 1986 (when lead solder was banned)
• 23% of housing built before 1950 (when lead pipes were standard)
• Median year built: 1972
• Most common estimated pipe material: Copper
• Lead exposure risk score: 44/100
• Estimated lead service line probability: 20%
• 7 ZIP codes classified as high or very high lead risk

With 61% of homes built before the 1986 lead solder ban, Madison residents - especially those in older neighborhoods - should consider testing their tap water for lead. Homes built before 1950 are at the highest risk of having lead service lines.

Housing Age Distribution

145,325 total housing units across 35 ZIP codes:

Flood Risk

FEMA National Flood Insurance Program data for Madison:

• 112 flood insurance claims on record
• $1,235,902 total paid out
• $11,035 average claim payout
• Dominant FEMA flood zone: X (Low risk)
• 2 of 35 ZIP codes in high-risk flood zones (A/V)

Radon Risk

Dominant EPA radon zone: Zone 1 (High Risk)

• Zone 1 (High): 35 ZIP codes
• Zone 2 (Moderate): 0 ZIP codes
• Zone 3 (Low): 0 ZIP codes

The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.

Neighborhoods by Safety Score

Safest Areas

Areas Needing Attention

What Madison Residents Can Do

Test Your Water

• Order a certified lab test - home test kits cost $20–50 and cover lead, bacteria, and common contaminants
• Request your utility's CCR (Consumer Confidence Report) - your water provider must publish this annually
• Check your ZIP code - each area in Madison has different water systems and risk levels

Filter Your Water

• NSF-certified pitcher filter removes chlorine taste and some contaminants ($20–40)
• NSF 53-certified filter for lead - recommended for homes built before 1986
• Reverse osmosis system removes 95%+ of contaminants including lead, PFAS, and nitrates ($150–400)

Test for Radon

• Madison is in a high-risk radon area
• Short-term radon test kits cost $10–25
• If levels exceed 4 pCi/L, EPA recommends professional mitigation

Stay Informed

• Visit your ZIP code report for detailed, address-level data
• Sign up for EPA water quality alerts
• Review the annual water quality report from your local utility

All ZIP Codes in Madison

• 53701 [C] - 11 violations ⚠
• 53702 [C] - 11 violations ⚠
• 53703 [C] - 11 violations ⚠
• 53704 [C] - 11 violations ⚠
• 53705 [C] - 11 violations ⚠
• 53706 [C] - 11 violations ⚠
• 53707 [C] - 11 violations ⚠
• 53708 [C] - 11 violations ⚠
• 53711 [C] - 11 violations ⚠
• 53713 [C] - 11 violations ⚠
• 53714 [C] - 11 violations ⚠
• 53715 [C] - 11 violations ⚠
• 53716 [C] - 11 violations ⚠
• 53717 [C] - 11 violations ⚠
• 53718 [C] - 11 violations ⚠
• 53719 [C] - 11 violations ⚠
• 53725 [C] - 11 violations ⚠
• 53726 [C] - 11 violations ⚠
• 53744 [C] - 11 violations ⚠
• 53774 [C] - 11 violations ⚠
• 53777 [C] - 11 violations ⚠
• 53778 [C] - 11 violations ⚠
• 53779 [C] - 11 violations ⚠
• 53782 [C] - 11 violations ⚠
• 53783 [C] - 11 violations ⚠
• 53784 [C] - 11 violations ⚠
• 53785 [C] - 11 violations ⚠
• 53786 [C] - 11 violations ⚠
• 53788 [C] - 11 violations ⚠
• 53789 [C] - 11 violations ⚠
• 53790 [C] - 11 violations ⚠
• 53791 [C] - 11 violations ⚠
• 53792 [C] - 11 violations ⚠
• 53793 [C] - 11 violations ⚠
• 53794 [C] - 11 violations ⚠

Frequently Asked Questions

Is the tap water safe to drink in Madison, WI?

Madison has an average Home Safety Score of 60/100 (grade C) across 35 ZIP codes. There are 385 recorded EPA violations, 105 of which are health-based. Safety varies by neighborhood - check your specific ZIP code report for details.

Does Madison have lead in the water?

The average 90th-percentile lead level across Madison is 0.0018 mg/L, below the EPA action level of 0.015 mg/L. No ZIP codes currently exceed the EPA lead action level. About 61% of housing was built before 1986, when lead solder was banned.

Is Madison at risk for flooding?

FEMA data shows 112 flood insurance claims in Madison ZIP codes, with an average payout of $11,035. 2 of 35 ZIP codes are in high-risk FEMA flood zones (A or V).

Are there lead pipes in Madison homes?

61% of Madison housing was built before 1986, when lead solder was common in plumbing. 23% was built before 1950, when lead pipes were standard. The most common estimated pipe material is Copper. The estimated probability of lead service lines is 20%. We recommend testing your water if your home was built before 1986.

What contaminants have been found in Madison water?

The most common contaminants by violation count are Surface Water Treatment Rule, Stage 2 DBP Rule, Lead and Copper Rule. Across 35 ZIP codes, 35 have recorded EPA violations. Check your ZIP code report for the specific contaminants in your area.

Data Sources

• Water quality: EPA Safe Drinking Water Information System (SDWIS)
• Lead/copper: EPA Lead and Copper Rule sampling data
• Housing age: U.S. Census Bureau American Community Survey
• Flood data: FEMA National Flood Insurance Program
• Lead exposure: Composite risk score based on housing age, water lead levels, and service line estimates
• Radon: EPA Map of Radon Zones

Updated daily.

Housing Age Profile

Congress banned lead solder in residential plumbing in 1986, drawing a clear line in housing risk by era. Madison's median build year of 1972 puts most of its residential stock on the newer side of that boundary - a profile that generally correlates with lower plumbing-sourced lead exposure across the city.

1972

Median Year Built

0%

Pre-1986 (Lead Paint Risk)

0%

Pre-1970 (Lead Pipes Risk)

Most homes in Madison were built after 1986, reducing the risk of lead contamination from plumbing. Older homes should still be tested.

Source: U.S. Census Bureau ACS B25034.

Lead Exposure Risk for Children in Madison

0.0018

mg/L Avg Lead (Limit: 0.015)

Why children are most at risk: The CDC states there is no safe level of lead exposure for children. Children under 6 absorb lead more readily than adults, and even low levels can cause developmental delays, learning difficulties, and behavioral problems.

Lead risk in Madison appears low overall, but individual homes may differ. Testing is the only way to confirm your water's lead content.

Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.

Flood & Climate Risk in Madison

The NFIP claim record for Madison - 112 filed incidents - reflects genuine, recurring flood exposure rather than an isolated event or two. When a community accumulates flood claims at this volume and carries 0% of its ZIP codes inside FEMA-designated zones, flood history starts to factor into water quality planning in ways it doesn't for lower-exposure areas. Flooding introduces specific contamination pathways - runoff overwhelming treatment facility intake, surface water infiltrating private wells, and pressure disruptions in distribution systems allowing backflow - all of which become more relevant as flood frequency increases.

112

Total FEMA Flood Claims

~6

Est. Claims/Year

Madison has a moderate flood history with 112 FEMA claims. Flood events can contaminate drinking water and overwhelm treatment systems.

How flooding affects water quality: Flood events can introduce sewage, agricultural runoff, and industrial chemicals into water supplies. Even after floodwaters recede, contamination can persist in wells and aging infrastructure.

Residents in flood-prone areas should consider flood insurance even outside FEMA zones - over 25% of flood claims come from low-to-moderate risk areas. After any flood event, test your water before drinking.

Source: FEMA National Flood Insurance Program (NFIP) claims data, FEMA flood zone designations.