Is Madison tap water safe to drink?

Use caution filtration recommended

Madison's water has significant quality concerns. We strongly recommend a certified water filter.

58/100
Purity Score
4
Issues Found
15.5 GPG
Hardness
Detected
PFAS

4 Issues Detected in Madison

PFAS (Forever Chemicals) Detected

PFAS are man-made chemicals that do not break down and accumulate in the body.

PFAS details for Madison

Very Hard Water (15.5 GPG)

Hard water causes scale in pipes and shortens appliance lifespan.

Hardness data for Madison

Moderate Chlorine Level

Chlorine within EPA limits but may affect taste.

Chlorine info for Madison

Arsenic Approaching Limit (0.4 mg/L)

EPA limit is 0.010 mg/L.

Arsenic info for Madison
Wisconsin

537,015,370,253,703 · Groundwater deep sandstone aquifer

Madison, WI Water Quality Report

Elevated Risk Updated March 2026 275,000 residents
58
Purity Score

Health Insights

  • 1
    At 15.5 GPG, Madison's water qualifies as very hard. This can cause limescale in pipes and shorten appliance lifespan.
  • 2
    PFAS have been identified in Madison's water at 3.4 parts per trillion. A reverse osmosis system is the most reliable home treatment.
  • 3
    Chlorine levels may affect the taste of Madison's tap water. A carbon filter improves flavor.

Score

58 /100
Poor
"Good" threshold (70)

Madison tap water is sourced from Groundwater deep sandstone aquifer and treated by Madison Water Utility. PFAS forever chemicals have been detected. Water hardness is very hard at 15.5 GPG which may cause scale buildup. TDS is 545 ppm which is above the EPA secondary guideline of 500 ppm. Overall purity score: 58/100 (Poor). Updated for 2026.

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Madison Water FAQ

Is Madison WI tap water safe to drink in 2026?
Madison tap water meets EPA federal drinking water standards and scores 58/100 (Poor) on PurityMap for 2026. PFAS forever chemicals have been detected at 3.4 ppt. An NSF-certified filter is strongly recommended. For most healthy adults the water is considered safe but point-of-use filtration adds an important layer of protection.
Does Madison WI use chlorine or chloramine for disinfection?
Madison uses chlorine as the primary disinfectant with a residual level of 1.2 ppm. Standard activated carbon filters including pitcher filters are effective at removing free chlorine taste and odor.
How hard is Madison WI water and what is the TDS level?
Madison water hardness is 15.5 grains per gallon (very hard) with a TDS of 545 ppm (unacceptable). This level causes noticeable scale buildup in water heaters kettles and dishwashers. A water softener is recommended to protect plumbing and reduce soap usage.
Has PFAS been found in Madison WI drinking water?
Yes. PFAS forever chemicals have been detected in Madison water at approximately 3.4 ppt according to EPA UCMR5 monitoring data. A reverse osmosis or NSF P473-certified filter is the most effective residential solution.
What is the best water filter for Madison?
Based on Madison's water profile, we recommend the Clearly Filtered Water Pitcher. Madison: PFAS detected or elevated lead risk. Reverse osmosis is the only residential technology proven to reduce both below detection limits. TDS will also drop significantly.

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Data Sources

  • EPA SDWIS
  • EWG Tap Water Database
  • Madison Water Utility CCR
  • USGS monitoring data

PurityMap compiles public data. Updated March 2026.

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