Grant County, Wisconsin
20 ZIP codes · Avg score 64/100 · Grade C · Updated 2026-06-03
Safe water is the norm for most of Grant County's 20 ZIP codes — but a notable subset have documented violations that push the grade to the middle tier.
How Grant County Compares
How Grant County Compares
Grant County scores 2 points below the Wisconsin state average (66/100) and 4 points below the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: Grant County, Wisconsin
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 13.3 (asthma 11%, diabetes 11.5%)
Estimated additional annual cost per homeowner: $936, driven primarily by energy_code_gap
Infrastructure: 0.405% avg pipe failure probability, 42% of ZIPs at high risk
68.9% of homes built before 1978 (lead paint era)
Violation History (2022–2025)
↑ Worsening trendEPA violation counts by year across Grant County water systems. Health-based shown in red, total in blue.
Peak year: 2024 with 14 violations. Past 5 years: 24 total (24 health-based). Health-based violations are rising versus the prior 2-year window — worth closer monitoring.
Source: EPA SDWIS historical violations. Data may lag 6–12 months for the most recent year.
County Health Indicators vs National Average
Black markers indicate national averages. Source: CDC PLACES, Census ACS.
Infrastructure Overview
Sources: Census ACS (housing age), EPA SDWIS (infrastructure risk model), state bridge inspection data.
Compound Risk Breakdown
Estimated additional annual cost per homeowner: $936
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
21,601 housing units in Grant County
Source: U.S. Census Bureau ACS B25034 (Year Structure Built).
Water Safety Affordability
How much it costs to fix water issues relative to home values in Grant County
Remediation costs are relatively manageable for most homeowners in Grant County, representing a small fraction of property value.
Remediation includes water filtration, lead abatement, radon mitigation, and flood protection where applicable. Source: Census ACS, EPA SDWIS.
Health Outcomes vs National Average
CDC PLACES data for Grant County residents
Black markers = national averages. Red = above national avg. Green = below. Source: CDC PLACES, Census ACS.
Water Systems with Most Violations
Top 5 systems in Grant County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Cuba City Waterworks | 2,141 | 45 |
| 2 | Oak Park Community | 90 | 34 |
| 3 | Dickeyville Waterworks | 1,069 | 27 |
| 4 | Hazel Green Waterworks | 1,193 | 25 |
| 5 | Stateline Mobile Home Park | 37 | 23 |
27 total water systems serve Grant County.
All ZIP Codes in Grant County
20 ZIP codes tracked in Grant County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 53813 | Lancaster | 70 | B | 1 | $205K |
| 2 | 53807 | Cuba City | 69 | C | 2 (1 health) | $210K |
| 3 | 53808 | Dickeyville | 68 | C | 16 (2 health) | $183K |
| 4 | 53820 | Potosi | 68 | C | 9 (2 health) | $204K |
| 5 | 53554 | Livingston | 66 | C | 0 | $166K |
| 6 | 53809 | Fennimore | 66 | C | 1 | $183K |
| 7 | 53811 | Hazel Green | 66 | C | 23 (4 health) | $219K |
| 8 | 53817 | Patch Grove | 66 | C | 0 | $140K |
| 9 | 53824 | Sinsinawa | 66 | C | 0 | — |
| 10 | 53804 | Bloomington | 65 | C | 2 | $164K |
| 11 | 53805 | Boscobel | 65 | C | 1 | $147K |
| 12 | 53812 | Kieler | 65 | C | 2 (1 health) | $195K |
| 13 | 53816 | Mount Hope | 65 | C | 2 (1 health) | $208K |
| 14 | 53569 | Montfort | 64 | C | 5 (2 health) | $198K |
| 15 | 53801 | Bagley | 64 | C | 2 | $128K |
| 16 | 53806 | Cassville | 64 | C | 5 (1 health) | $145K |
| 17 | 53825 | Stitzer | 60 | C | 4 (2 health) | $144K |
| 18 | 53818 | Platteville | 54 | D | 18 (2 health) | $214K |
| 19 | 53802 | Beetown | 53 | D | 0 | $206K |
| 20 | 53810 | Glen Haven | 53 | D | 0 | $152K |
Recommended Buyer Guides for Grant County
Retailer arrangements don't shape what appears here — the selection logic is independent, filtered against EPA detections and the federal hazard data on file for this county.
- Best Water Filters for PFAS — PFAS detected in 1 ZIP code
- Best Lead Paint Test Kits — 68.9% of homes built before 1978
- Best Under-Sink Reverse Osmosis Systems — Multi-contaminant removal at the kitchen tap
- Best Radon Test Kits — EPA Radon Zone 1 (highest risk) dominant in county
Deep Dive Reports
Detailed analysis for Grant County, Wisconsin
Overview
Grant County in Wisconsin covers 20 ZIP codes with an average Home Safety Score of C (64/100).
15 of 20 ZIP codes have recorded EPA violations. 18 health-based violations have been documented.
← Back to Wisconsin water quality report
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Home values: U.S. Census Bureau ACS (median estimates by ZCTA)
Updated daily.