Douglas County, South Dakota
4 ZIP codes · Avg score 60/100 · Grade C · Updated 2026-06-04
Tracking 4 ZIP codes in Douglas County reveals a mixed picture — tap water quality varies meaningfully by location.
How Douglas County Compares
How Douglas County Compares
Douglas County scores 0 points above the South Dakota state average (60/100) and 8 points below the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-04
Key Risk Factors
Health risk index: 14.5 (asthma 10.1%, diabetes 13.6%)
Estimated additional annual cost per homeowner: $550, driven primarily by water_lead
Infrastructure: 0.422% avg pipe failure probability, 75% of ZIPs at high risk
72% 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: $550
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
1,353 housing units in Douglas 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 Douglas County
Remediation costs are relatively manageable for most homeowners in Douglas 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 Douglas 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 Douglas County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | By Water District | 13,320 | 5 |
| 2 | RANDALL COMMUNITY WATER DISTRICT | 6,248 | 5 |
| 3 | Corsica | 561 | 2 |
| 4 | Delmont | 153 | 2 |
| 5 | Clearfield Colony | 120 | 2 |
7 total water systems serve Douglas County.
All ZIP Codes in Douglas County
4 ZIP codes tracked in Douglas County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 57313 | Armour | 70 | B | 1 | $107K |
| 2 | 57328 | Corsica | 65 | C | 2 | $178K |
| 3 | 57330 | Delmont | 65 | C | 2 | $151K |
| 4 | 57344 | Harrison | 40 | D | 0 | — |
Recommended Buyer Guides for Douglas County
Below: editorial picks, no sponsored placements.
- Best Lead Paint Test Kits — 72% of homes built before 1978
- Best Radon Test Kits — EPA Radon Zone 1 (highest risk) dominant in county
Overview
Douglas County in South Dakota covers 4 ZIP codes with an average Home Safety Score of C (60/100).
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.