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Updated 2026-09-16
State water report

Wisconsin Water Quality: 89 Cities Ranked by the Records

Water quality across 89 cities in Wisconsin, drawn from EPA drinking-water records. Each city page shows the measured contaminants and a reproducible Purity Score.

Finding by finding

What Wisconsin's records show

Counts of cities whose serving system reported each result. There is no statewide score: PurityMap does not average local records into a statewide safety verdict. 6 cities have a past health-based violation on record.

PFAS above a 2024 limit

MCL

6of 89 cities

Cities whose system reported a PFAS above its federal limit.

PFOS in Wisconsin →
City rankings

Wisconsin cities ranked by the records

Highest first. A summary of each serving system’s record, not a safety verdict.

  1. 1
    New BerlinNEW BERLIN WATER UTILITY · WI2680217
    Report →
  2. 2
    OnalaskaONALASKA WATERWORKS · WI6320327
    Report →
  3. 3
    GreendaleGREENDALE WATERWORKS · WI2410571
    Report →
  4. 4
    Darboy Sanitary DistDARBOY SANITARY DIST 1 · WI4450117
    Report →
  5. 5
    MequonMEQUON WATER UTILITY · WI2460112
    Report →
  6. 6
    AppletonAPPLETON WATERWORKS · WI4450333
    Report →
  7. 7
    De Pere SaDE PERE WATERWORKS SA 1 · WI4050453
    Report →
  8. 8
    MenomonieMENOMONIE WATERWORKS · WI6170268
    Report →
  9. 9
    Menasha Elec UtilMENASHA ELEC & WATER UTIL · WI4710334
    Report →
  10. 10
    Brown DeerBROWN DEER WATERWORKS · WI2410556
    Report →

Showing the top 10 of 89 scored cities.

See all 89 in the table

89 cities, highest Purity Score first

  1. 1New Berlin
    NEW BERLIN WATER UTILITY · PWSID WI2680217 · Purity Score 100/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
    No PFAS detected; lead 0.33 µg/LDetected
  2. 2Onalaska
    ONALASKA WATERWORKS · PWSID WI6320327 · Purity Score 100/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
    PFAS detected below their limitsDetected
  3. 3Greendale
    GREENDALE WATERWORKS · PWSID WI2410571 · Purity Score 100/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
    No PFAS detected; lead 0.32 µg/LDetected
  4. 4Darboy Sanitary Dist
    DARBOY SANITARY DIST 1 · PWSID WI4450117 · Purity Score 100/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
    No PFAS detected; lead 0.47 µg/LDetected
  5. 5Mequon
    MEQUON WATER UTILITY · PWSID WI2460112 · Purity Score 100/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
    No PFAS detected; lead 0.52 µg/LDetected
  6. 6Appleton
    APPLETON WATERWORKS · PWSID WI4450333 · Purity Score 99/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
    PFBA 5.9 ng/L detected, no federal or state limit; lead 1.3 µg/LDetected
  7. 7De Pere Sa
    DE PERE WATERWORKS SA 1 · PWSID WI4050453 · Purity Score 99/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
    No PFAS detected; lead 0.66 µg/LDetected
  8. 8Menomonie
    MENOMONIE WATERWORKS · PWSID WI6170268 · Purity Score 99/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
    No PFAS detected; lead 1.3 µg/LDetected
  9. 9Menasha Elec Util
    MENASHA ELEC & WATER UTIL · PWSID WI4710334 · Purity Score 99/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
    No PFAS detected; lead 1.1 µg/LDetected
  10. 10Brown Deer
    BROWN DEER WATERWORKS · PWSID WI2410556 · Purity Score 99/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
    No PFAS detected; lead 0.9 µg/LDetected
  11. 11Marinette
    MARINETTE WATERWORKS · PWSID WI4380395 · Purity Score 99/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
    No PFAS detected; lead 0.93 µg/LDetected
  12. 12Waunakee
    WAUNAKEE WATERWORKS · PWSID WI1130265 · Purity Score 98/100 (Excellent) · Confidence: moderate · Assessed at the water-system level
    No PFAS detected; lead 1.7 µg/LDetected
Showing 12 of 89.

Ranked by the Purity Score of each city's main water system, highest first. Scores belong to water systems; there is no state score. The score is computed only from contaminants measured in the published EPA record, so this ranks the record, not which city's water is safest. How the score works. See how Wisconsin compares with other states.

By contaminant

PFAS and lead in Wisconsin

Counties

Wisconsin counties

32 counties with city reports
Show all 32 counties
Suppliers

Largest water systems

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Full indexAll 89 Wisconsin city reports, A–Z
Next step

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Questions

Wisconsin water, frequently asked

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How does Wisconsin tap water compare across cities?

PurityMap ranks 89 cities in Wisconsin by the Purity Score of each city's main water system, computed only from contaminants measured in the published EPA record. Scores belong to water systems, not to cities. The highest published score is New Berlin's main water system: NEW BERLIN WATER UTILITY · PWSID WI2680217 · Purity Score 100 (Excellent) · Confidence: moderate · Assessed at the water-system level. The ranking compares the records, not which city's water is safest, and your own tap can differ with household plumbing.

How many Wisconsin cities have PFAS above the federal limit?

6 cities of 89 had at least one regulated PFAS (PFOA, PFOS or PFHxS) measured above the 2024 federal limit in EPA's UCMR 5 testing, including Marshfield (PFOS 14 ng/L), Weston (PFOS 13 ng/L), Hartford (PFOA 6.8 ng/L). PFAS were detected at any level in 21.

Is there lead in Wisconsin tap water?

Utilities report lead as a 90th-percentile result from home taps. 88 of 89 Wisconsin cities reported a value above zero, and none was above the 15 µg/L federal action level. Lead usually comes from a building's own pipes and fixtures, so only a test at your tap tells you what you drink.

Have Wisconsin water systems had drinking-water violations?

6 cities in Wisconsin have a health-based violation in the federal SDWIS record within about the last ten years. Each city report lists the contaminant, year and whether it was resolved.

Limits, sources and corrections

A statewide page cannot tell you what reaches a specific address. Water quality varies by supplier, sampling period and household plumbing; open a city report for the evidence behind a local result.

Sources: EPA UCMR 5 (PFAS, 2024), SDWIS Lead and Copper Rule 90th-percentile results and health-based violations, and utility Consumer Confidence Reports where on file. Every city report links its dated source records.

Updated 2026-09-16. How PurityMap analyzes water data · Report an error