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Updated 2026-10-15
County water report

Waukesha County Water Quality: 8 Cities Ranked by the Records

Waukesha County, Wisconsin: 8 city reports built from EPA and utility records. A county has many suppliers; each city shows the system that serves it.

Find my systemOpen on the mapPrivate wells in Waukesha County
Across the county's systems

Highest result for each contaminant

One row per contaminant: the highest result any system in the county reported, against its limit. Open a row for the systems behind it.

LithiumDetected in 3 systems of 8 tested10 µg/L EPA health reference level (screening, not a legal limit) · US EPAHighest14 µg/L
Perfluorooctanesulfonic acid (PFOS)Detected in 1 system of 8 tested4.0 ng/L federal MCL (2024) · US EPAHighest4.6 ng/L
Perfluorooctanoic acid (PFOA)Detected in 1 system of 8 tested4.0 ng/L federal MCL (2024) · US EPAHighest4.4 ng/L
Lead (90th percentile)Detected in 8 systems15 µg/L federal action level · US EPAHighest6.8 µg/L
Perfluorohexanesulfonic acid (PFHxS)Detected in 2 systems of 8 tested10 ng/L federal MCL (2024) · US EPAHighest3.6 ng/L
Perfluorobutanesulfonic acid (PFBS)Detected in 3 systems of 8 tested2,000 ng/L EPA health advisory (screening, not a legal limit) · US EPAHighest11 ng/L
Perfluorohexanoic acid (PFHxA)Detected in 2 systems of 8 tested400,000 ng/L Michigan EGLE state MCL (strictest US state) · Michigan EGLEHighest4.2 ng/L
Perfluorobutanoic acid (PFBA)Detected in 2 systems of 8 testedNo federal or state limit; shown for transparencyHighest5.4 ng/L
1 more contaminant detectedShow
Perfluoropentanoic acid (PFPeA)Detected in 2 systems of 8 testedNo federal or state limit; shown for transparencyHighest4.6 ng/L
22 PFAS tested, none detected in any systemShow

Tested in these 8 systems: BROOKFIELD WATER UTILITY, HARTLAND WATERWORKS, MENOMONEE FALLS WW - SURFACE WATER, MUSKEGO WATER UTILITY, NEW BERLIN WATER UTILITY, OCONOMOWOC WATERWORKS, SUSSEX VILLAGE HALL & WATER UTILITY, WAUKESHA WATER UTILITY

  • 11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS)
  • 1H, 1H, 2H, 2H-perfluorodecane sulfonic acid (8:2 FTS)
  • 1H, 1H, 2H, 2H-perfluorohexane sulfonic acid (4:2 FTS)
  • 1H, 1H, 2H, 2H-perfluorooctane sulfonic acid (6:2 FTS)
  • 4,8-Dioxa-3H-perfluorononanoic acid (ADONA)
  • 9-Chlorohexadecafluoro-3-oxanone-1-sulfonic acid (9Cl-PF3ONS)
  • Hexafluoropropylene oxide dimer acid (HFPO-DA) (GenX chemicals)
  • N-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA)
  • N-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA)
  • Nonafluoro-3,6-dioxaheptanoic acid (NFDHA)
  • Perfluoro (2-ethoxyethane) sulfonic acid (PFEESA)
  • Perfluoro-3-methoxypropanoic acid (PFMPA)
  • Perfluoro-4-methoxybutanoic acid (PFMBA)
  • Perfluorodecanoic acid (PFDA)
  • Perfluorododecanoic acid (PFDoA)
  • Perfluoroheptanesulfonic acid (PFHpS)
  • Perfluoroheptanoic acid (PFHpA)
  • Perfluorononanoic acid (PFNA)
  • Perfluoropentanesulfonic acid (PFPeS)
  • Perfluorotetradecanoic acid (PFTA)
  • Perfluorotridecanoic acid (PFTrDA)
  • Perfluoroundecanoic acid (PFUnA)
8 cities

Cities ranked by the records

Showing 6 of 8 cities · scores are system-level, not tap tests

Ranked by the Purity Score of each city's main water system, highest first. Scores belong to water systems; there is no county 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.

PFAS in Waukesha County1 of 8 city reports had a PFAS sample above a 2024 EPA limit
  1. Hartland4.6 ng/L
4.0 ng/L federal MCL · PFOS, ng/LPFAS in Wisconsin
Lead

0of 8 cities above the 15 µg/L action level

Based on each system's 90th-percentile result. Lead from household plumbing isn't in this record.

Lead in Wisconsin
Who supplies the county

Largest water systems

  1. WaukeshaWAUKESHA WATER UTILITY · WI2680238
    70,718 served
  2. BrookfieldBROOKFIELD WATER UTILITY · WI2680253
    29,070 served
  3. New BerlinNEW BERLIN WATER UTILITY · WI2680217
    27,899 served
  4. Menomonee FallsMENOMONEE FALLS WW - SURFACE WATER · WI2680082
    23,867 served
  5. OconomowocOCONOMOWOC WATERWORKS · WI2680227
    15,805 served
  6. SussexSUSSEX VILLAGE HALL & WATER UTILITY · WI2680233
    11,750 served
  7. HartlandHARTLAND WATERWORKS · WI2680205
    9,212 served
  8. MuskegoMUSKEGO WATER UTILITY · WI2681741
    8,150 served
Questions

Frequently asked

How does Waukesha County tap water compare across cities?

PurityMap ranks 8 cities in Waukesha County 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 Waukesha County cities had a PFAS sample above a 2024 EPA limit?

1 of 8 Waukesha County city reports had a PFAS sample above a 2024 EPA limit in EPA's UCMR 5 testing, including Hartland (PFOS 4.6 ng/L). That limit is judged on a yearly average, and water systems have until 2029 to meet it, so a single sample is not a violation. PFAS were detected at any level in 3.

Is there lead in Waukesha County tap water?

Utilities report lead as a 90th-percentile result from home taps. 8 of 8 Waukesha County 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 Waukesha County water systems had drinking-water violations?

3 cities in Waukesha County 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.

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