Columbia County, Wisconsin
13 ZIP codes · Avg score 72/100 · Grade B · Updated 2026-06-04
Within Columbia County, all 13 tracked ZIP codes show above-average drinking water safety — violations are infrequent and typically minor.
How Columbia County Compares
How Columbia County Compares
Columbia County scores 6 points above the Wisconsin state average (66/100) and 4 points above the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-04
ZIP Code Risk Map
Water Quality Map: Columbia County, Wisconsin
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 12.9 (asthma 10.8%, diabetes 11.5%)
Estimated additional annual cost per homeowner: $1,148, driven primarily by flood
Infrastructure: 0.422% avg pipe failure probability, 62% of ZIPs at high risk
65.1% of homes built before 1978 (lead paint era)
Violation History (2021–2025)
↑ Worsening trendEPA violation counts by year across Columbia County water systems. Health-based shown in red, total in blue.
Peak year: 2024 with 16 violations. Past 5 years: 30 total (30 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: $1,148
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
25,264 housing units in Columbia 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 Columbia County
Remediation costs are relatively manageable for most homeowners in Columbia 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 Columbia 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 Columbia County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Harmony Grove San District | 1,950 | 27 |
| 2 | Capital Hill Mobile Home Park | 36 | 24 |
| 3 | Poynette Waterworks | 2,520 | 16 |
| 4 | Poynette Mobile Estates | 150 | 16 |
| 5 | Inch Heights Llc | 47 | 16 |
30 total water systems serve Columbia County.
All ZIP Codes in Columbia County
13 ZIP codes tracked in Columbia County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 53923 | Cambria | 83 | B | 1 | $211K |
| 2 | 53969 | Wyocena | 83 | B | 0 | $200K |
| 3 | 53911 | Arlington | 82 | B | 3 (1 health) | $286K |
| 4 | 53928 | Doylestown | 82 | B | 3 | $138K |
| 5 | 53935 | Friesland | 82 | B | 3 | $147K |
| 6 | 53954 | Pardeeville | 80 | B | 7 | $249K |
| 7 | 53960 | Rio | 79 | B | 3 (1 health) | $247K |
| 8 | 53932 | Fall River | 77 | B | 5 (2 health) | $277K |
| 9 | 53901 | Portage | 69 | C | 4 (1 health) | $214K |
| 10 | 53925 | Columbus | 61 | C | 4 (1 health) | $258K |
| 11 | 53955 | Poynette | 61 | C | 16 (5 health) | $285K |
| 12 | 53926 | Dalton | 53 | D | 0 | $216K |
| 13 | 53555 | Lodi | 43 | D | 8 (7 health) | $360K |
Recommended Buyer Guides for Columbia 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 Lead — Lead above EPA action level in 1 ZIP code
- Best Lead Paint Test Kits — 65.1% of homes built before 1978
- Best Under-Sink Reverse Osmosis Systems — Multi-contaminant removal at the kitchen tap
- Best Sump Pumps — Flood is the top compound risk factor
- Best Mold Test Kits — Flood-driven moisture and mold risk
Deep Dive Reports
Detailed analysis for Columbia County, Wisconsin
Overview
Columbia County in Wisconsin covers 13 ZIP codes with an average Home Safety Score of B (72/100).
11 of 13 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.