Updated 2026-09-16
County water report

Grant County Water Quality

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

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.

Lead (90th percentile)PLATTEVILLE WATERWORKS15 µg/L federal action level · US EPA10.3 µg/L
30 substances tested, none detected in this systemShow

Tested in this system: PLATTEVILLE WATERWORKS

  • 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)
  • Lithium
  • 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)
  • Perfluorobutanesulfonic acid (PFBS)
  • Perfluorobutanoic acid (PFBA)
  • Perfluorodecanoic acid (PFDA)
  • Perfluorododecanoic acid (PFDoA)
  • Perfluoroheptanesulfonic acid (PFHpS)
  • Perfluoroheptanoic acid (PFHpA)
  • Perfluorohexanesulfonic acid (PFHxS)
  • Perfluorohexanoic acid (PFHxA)
  • Perfluorononanoic acid (PFNA)
  • Perfluorooctanesulfonic acid (PFOS)
  • Perfluorooctanoic acid (PFOA)
  • Perfluoropentanesulfonic acid (PFPeS)
  • Perfluoropentanoic acid (PFPeA)
  • Perfluorotetradecanoic acid (PFTA)
  • Perfluorotridecanoic acid (PFTrDA)
  • Perfluoroundecanoic acid (PFUnA)
1 city

Cities ranked by the records

Showing 1 of 1 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 Grant CountyPFAS detected in 0 of 1 city; none above a federal limit
4.0 ng/L federal MCL · PFOS, ng/LPFAS in Wisconsin
Lead

0of 1 city 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. PlattevillePLATTEVILLE WATERWORKS · WI1220115
    12,268 served
Questions

Frequently asked

How does Grant County tap water compare across cities?

PurityMap ranks 1 city in Grant 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 Platteville's main water system: PLATTEVILLE WATERWORKS · PWSID WI1220115 · Purity Score 88 (Good) · 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 Grant County cities have PFAS above the federal limit?

None of the 1 Grant County cities on record had a regulated PFAS above the 2024 federal limit in EPA's UCMR 5 testing. PFAS were detected below the limit in 0.

Is there lead in Grant County tap water?

Utilities report lead as a 90th-percentile result from home taps. 1 of 1 Grant 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.