Clay County, South Dakota
3 ZIP codes · Avg score 63/100 · Grade C · Updated 2026-06-04
Clay County shows moderate water quality across its 3 ZIP codes — some areas carry violations worth monitoring.
How Clay County Compares
How Clay County Compares
Clay County scores 3 points above the South Dakota state average (60/100) and 5 points below the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-04
Key Risk Factors
Health risk index: 10.7 (asthma 10.5%, diabetes 8.1%)
Estimated additional annual cost per homeowner: $793, driven primarily by water_lead
Infrastructure: 0.4% avg pipe failure probability, 67% 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: $793
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
5,856 housing units in Clay 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 Clay County
Remediation costs are relatively manageable for most homeowners in Clay 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 Clay 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 Clay County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Clay Rural Water System | 4,780 | 1 |
| 2 | Tm Rural Water District | 4,250 | 1 |
| 3 | Clay Rws/south Union | 1,447 | 1 |
| 4 | Wakonda | 276 | 1 |
| 5 | VERMILLION | 11,695 | 0 |
6 total water systems serve Clay County.
All ZIP Codes in Clay County
3 ZIP codes tracked in Clay County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 57069 | Vermillion | 70 | B | 0 | $226K |
| 2 | 57073 | Wakonda | 65 | C | 1 (1 health) | $114K |
| 3 | 57010 | Burbank | 53 | D | 0 | $222K |
Recommended Buyer Guides for Clay County
Editorial methodology pairs each documented risk in this county with the buyer category that addresses it, drawing on water-quality detections, housing-stock lead exposure, EPA Radon Zone designation, and FEMA flood and wildfire ratings. NSF-certified options surface where applicable, and products that match the specific contaminant take priority.
- 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
Overview
Clay County in South Dakota covers 3 ZIP codes with an average Home Safety Score of C (63/100).
1 of 3 ZIP codes have recorded EPA violations. 1 health-based violation have been documented.
← Back to South 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.