Johnson County, Wyoming
3 ZIP codes · Avg score 57/100 · Grade C · Updated 2026-06-03
Water monitoring across Johnson County's 3 ZIP codes paints a mid-range picture — solid compliance in some zones, documented concerns in others; most violations on record are concentrated in specific prior years rather than spread evenly across the full compliance history, and the overall county grade has held steady in the middle tier without major shifts in either direction.
How Johnson County Compares
How Johnson County Compares
Johnson County scores 2 points above the Wyoming state average (55/100) and 11 points below the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
Key Risk Factors
Health risk index: 14.3 (asthma 10.2%, diabetes 13.1%)
Estimated additional annual cost per homeowner: $593, driven primarily by wildfire
Infrastructure: 0.36% avg pipe failure probability
50.5% of homes built before 1978 (lead paint era)
Violation History (2023–2024)
→ Stable trendEPA violation counts by year across Johnson County water systems. Health-based shown in red, total in blue.
Peak year: 2024 with 6 violations. Past 5 years: 8 total (8 health-based).
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: $593
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
4,483 housing units in Johnson 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 Johnson County
Remediation costs are relatively manageable for most homeowners in Johnson 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 Johnson County residents
Black markers = national averages. Red = above national avg. Green = below. Source: CDC PLACES, Census ACS.
Water Systems with Most Violations
Top 4 systems in Johnson County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | City of Buffalo, | 4,419 | 6 |
| 2 | Bald Mountain Trailer Court | 150 | 6 |
| 3 | Bighorn Mountain Campground | 29 | 6 |
| 4 | Kaycee, Town of | 263 | 2 |
All ZIP Codes in Johnson County
3 ZIP codes tracked in Johnson County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 82639 | Kaycee | 69 | C | 2 | $252K |
| 2 | 82834 | Buffalo | 63 | C | 6 (4 health) | $297K |
| 3 | 82840 | Saddlestring | 40 | D | 0 | — |
Recommended Buyer Guides for Johnson 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 Lead Paint Test Kits — 50.5% 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
- Best HEPA Air Purifiers for Wildfire Smoke — Wildfire is the top compound risk factor
Overview
Johnson County in Wyoming covers 3 ZIP codes with an average Home Safety Score of C (57/100).
2 of 3 ZIP codes have recorded EPA violations. 4 health-based violations have been documented.
← Back to Wyoming 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.