Williams County, North Dakota
13 ZIP codes · Avg score 56/100 · Grade C · Updated 2026-06-03
While Williams County avoids the worst tiers, a portion of its 13 ZIP codes have logged violations.
How Williams County Compares
How Williams County Compares
Williams County scores 0 points above the North Dakota state average (56/100) and 12 points below the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: Williams County, North Dakota
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 12.1 (asthma 10.3%, diabetes 9.2%)
Estimated additional annual cost per homeowner: $453, driven primarily by water_lead
Infrastructure: 0.353% avg pipe failure probability, 23% of ZIPs at high risk
61.6% of homes built before 1978 (lead paint era)
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: $453
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
20,589 housing units in Williams 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 Williams County
Remediation costs are relatively manageable for most homeowners in Williams 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 Williams 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 Williams County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Northwest Rural Water District | 5,102 | 9 |
| 2 | City of Williston | 26,426 | 6 |
| 3 | Inspire Communities-springbrook | 300 | 6 |
| 4 | Prairie View Hoa | 226 | 6 |
| 5 | Western Area Water Supply Authority | — | 6 |
11 total water systems serve Williams County.
All ZIP Codes in Williams County
13 ZIP codes tracked in Williams County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 58795 | Wildrose | 66 | C | 0 | $132K |
| 2 | 58802 | Williston | 66 | C | 2 | — |
| 3 | 58845 | Grenora | 66 | C | 0 | $182K |
| 4 | 58849 | Ray | 66 | C | 1 | $239K |
| 5 | 58853 | Trenton | 64 | C | 2 | — |
| 6 | 58803 | Williston | 62 | C | 2 | — |
| 7 | 58852 | Tioga | 62 | C | 0 | $207K |
| 8 | 58801 | Williston | 61 | C | 2 | $280K |
| 9 | 58755 | Mcgregor | 53 | D | 0 | — |
| 10 | 58794 | White Earth | 40 | D | 0 | — |
| 11 | 58830 | Alamo | 40 | D | 0 | $181K |
| 12 | 58843 | Epping | 40 | D | 0 | $296K |
| 13 | 58856 | Zahl | 40 | D | 0 | $248K |
Recommended Buyer Guides for Williams County
Eight risk categories drive the selection — PFAS exceedance, lead above EPA action level, pre-1978 housing share, EPA Radon Zone 1, flood-top-risk, wildfire-top-risk, multi-contaminant load, and a baseline fallback — and each category maps to a specific buyer-guide track that surfaces when the county data hits its threshold for that hazard signal.
- Best Lead Paint Test Kits — 61.6% of homes built before 1978
- Best Radon Test Kits — EPA Radon Zone 1 (highest risk) dominant in county
Deep Dive Reports
Detailed analysis for Williams County, North Dakota
Overview
Williams County in North Dakota covers 13 ZIP codes with an average Home Safety Score of C (56/100).
5 of 13 ZIP codes have recorded EPA violations. All violations are monitoring/reporting type.
← Back to North Dakota 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.