Walworth County, South Dakota
4 ZIP codes · Avg score 59/100 · Grade C · Updated 2026-06-04
While Walworth County avoids the worst tiers, a portion of its 4 ZIP codes have logged violations.
How Walworth County Compares
How Walworth County Compares
Walworth County scores 1 points below the South Dakota state average (60/100) and 9 points below the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-04
Key Risk Factors
Health risk index: 14 (asthma 10.3%, diabetes 13.4%)
Estimated additional annual cost per homeowner: $563, driven primarily by wildfire
Infrastructure: 0.39% avg pipe failure probability, 50% of ZIPs at high risk
74.8% 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: $563
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
2,675 housing units in Walworth 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 Walworth County
Remediation costs are relatively manageable for most homeowners in Walworth 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 Walworth 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 Walworth County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Web Water Development Association | 20,750 | 5 |
| 2 | SELBY | 645 | 3 |
| 3 | Java | 121 | 1 |
| 4 | Mobridge | 3,261 | 1 |
| 5 | Tri-county Rural Water System | 2,190 | 1 |
6 total water systems serve Walworth County.
All ZIP Codes in Walworth County
4 ZIP codes tracked in Walworth County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 57601 | Mobridge | 66 | C | 1 | $153K |
| 2 | 57472 | Selby | 65 | C | 3 | $119K |
| 3 | 57452 | Java | 64 | C | 1 | $70K |
| 4 | 57420 | Akaska | 40 | D | 0 | $80K |
Recommended Buyer Guides for Walworth County
While many sites publish identical guide lists across every county they cover, the selection here changes by location — driven by the EPA, NSF, FEMA, and CDC datasets that describe the actual conditions documented for this jurisdiction in the federal record.
- Best Lead Paint Test Kits — 74.8% of homes built before 1978
- 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
Walworth County in South Dakota covers 4 ZIP codes with an average Home Safety Score of C (59/100).
3 of 4 ZIP codes have recorded EPA violations. All violations are monitoring/reporting type.
← 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.