Custer County, South Dakota
5 ZIP codes · Avg score 72/100 · Grade B · Updated 2026-06-03
Unlike many counties its size, Custer County keeps violation rates low — all 5 ZIP codes score at or above the state average for tap water safety, with no systemic concerns flagged in the current data set.
How Custer County Compares
How Custer County Compares
Custer County scores 12 points above the South Dakota state average (60/100) and 4 points above the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: Custer County, South Dakota
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 14.4 (asthma 9.8%, diabetes 13.9%)
Estimated additional annual cost per homeowner: $1,126, driven primarily by flood
Infrastructure: 0.364% avg pipe failure probability, 20% of ZIPs at high risk
51.2% of homes built before 1978 (lead paint era)
Violation History (2024–2025)
→ Stable trendEPA violation counts by year across Custer County water systems. Health-based shown in red, total in blue.
Peak year: 2024 with 2 violations. Past 5 years: 4 total (4 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: $1,126
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
4,756 housing units in Custer 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 Custer County
Remediation costs are relatively manageable for most homeowners in Custer 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 Custer 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 Custer County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Southern Black Hills Water | 492 | 20 |
| 2 | Buffalo Gap | 126 | 9 |
| 3 | Fairburn Water Association | 65 | 6 |
| 4 | Hermosa-old System | 420 | 5 |
| 5 | Hermosa Water Users Association | 108 | 5 |
7 total water systems serve Custer County.
All ZIP Codes in Custer County
5 ZIP codes tracked in Custer County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 57738 | Fairburn | 82 | B | 6 (1 health) | $486K |
| 2 | 57730 | Custer | 78 | B | 0 | $324K |
| 3 | 57722 | Buffalo Gap | 77 | B | 9 (2 health) | $68K |
| 4 | 57744 | Hermosa | 69 | C | 5 (1 health) | $351K |
| 5 | 57773 | Pringle | 53 | D | 0 | $10K |
Recommended Buyer Guides for Custer 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 — 51.2% of homes built before 1978
- Best Under-Sink Reverse Osmosis Systems — Multi-contaminant removal at the kitchen tap
- Best Sump Pumps — Flood is the top compound risk factor
- Best Mold Test Kits — Flood-driven moisture and mold risk
Deep Dive Reports
Detailed analysis for Custer County, South Dakota
Overview
Custer County in South Dakota covers 5 ZIP codes with an average Home Safety Score of B (72/100).
3 of 5 ZIP codes have recorded EPA violations. 4 health-based violations 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.