Thomas County, Kansas
6 ZIP codes · Avg score 53/100 · Grade D · Updated 2026-06-03
The latest EPA cycle for Thomas County covers 6 ZIP codes and shows a low safety grade — systemic compliance gaps have persisted over multiple reporting periods, and the county has not moved out of the bottom tier in recent years.
How Thomas County Compares
How Thomas County Compares
Thomas County scores 11 points below the Kansas state average (64/100) and 15 points below the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: Thomas County, Kansas
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 12.6 (asthma 9.9%, diabetes 10.6%)
Estimated additional annual cost per homeowner: $518, driven primarily by water_lead
Infrastructure: 0.41% avg pipe failure probability, 50% of ZIPs at high risk
74.3% 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: $518
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
3,522 housing units in Thomas 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 Thomas County
Remediation costs are relatively manageable for most homeowners in Thomas 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 Thomas County residents
Black markers = national averages. Red = above national avg. Green = below. Source: CDC PLACES, Census ACS.
Water Systems with Most Violations
Top 3 systems in Thomas County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | REXFORD, CITY OF | 198 | 3 |
| 2 | City of Brewster, | 290 | 1 |
| 3 | City of Colby, | 5,516 | 0 |
All ZIP Codes in Thomas County
6 ZIP codes tracked in Thomas County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 67701 | Colby | 70 | B | 0 | $167K |
| 2 | 67732 | Brewster | 66 | C | 1 | $153K |
| 3 | 67753 | Rexford | 62 | C | 3 | $124K |
| 4 | 67733 | Edson | 40 | D | 0 | $152K |
| 5 | 67734 | Gem | 40 | D | 0 | $70K |
| 6 | 67743 | Levant | 40 | D | 0 | $160K |
Recommended Buyer Guides for Thomas County
Strictly editorial — no paid placements influence which guides appear; the selection draws on NSF certifications and EPA detection records for water systems serving this county.
- Best Lead Paint Test Kits — 74.3% of homes built before 1978
- Best Radon Test Kits — EPA Radon Zone 1 (highest risk) dominant in county
Deep Dive Reports
Detailed analysis for Thomas County, Kansas
Overview
Thomas County in Kansas covers 6 ZIP codes with an average Home Safety Score of D (53/100).
2 of 6 ZIP codes have recorded EPA violations. All violations are monitoring/reporting type.
← Back to Kansas 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.
What You Can Do
Thomas County has a grade of D. Here are steps to protect your household.
Test your tap water
Order a certified lab test kit ($20-$50) to check for lead, bacteria, and other contaminants specific to your ZIP code.
Consider a certified water filter
NSF-certified filters can remove most common contaminants. Match the filter to your test results for best protection. Try our filter matcher
Contact your water utility
Request the latest Consumer Confidence Report (CCR) from your water provider. It details exactly what was found in your water supply.
Check for lead in your home
74.3% of homes in this county were built before 1978. Older plumbing and solder can leach lead into drinking water, especially in the morning.