Pennington County, South Dakota
17 ZIP codes · Avg score 69/100 · Grade C · Updated 2026-06-03
Covering 17 ZIP codes, Pennington County falls in the average tier for tap water safety — violations appear in a meaningful share of areas, and the data suggests quality depends heavily on which specific part of the county a household sits in.
How Pennington County Compares
How Pennington County Compares
Pennington County scores 9 points above the South Dakota state average (60/100) and 1 points above the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: Pennington 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: 13.1 (asthma 10.4%, diabetes 12.1%)
Estimated additional annual cost per homeowner: $1,072, driven primarily by flood
Infrastructure: 0.361% avg pipe failure probability, 25% of ZIPs at high risk
62.9% of homes built before 1978 (lead paint era)
Violation History (2021–2025)
↓ Improving trendEPA violation counts by year across Pennington County water systems. Health-based shown in red, total in blue.
Peak year: 2022 with 8 violations. Past 5 years: 20 total (20 health-based). Health-based violations are declining versus the prior 2-year window.
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: $1,072
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
51,800 housing units in Pennington 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 Pennington County
Remediation costs are relatively manageable for most homeowners in Pennington 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 Pennington 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 Pennington County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Southern Black Hills Water | 492 | 12 |
| 2 | WR/LJ - CREIGHTON PROJECT | 1,170 | 11 |
| 3 | Rapid City | 72,009 | 6 |
| 4 | Rapid Valley Sanitary District | 11,408 | 6 |
| 5 | Bear Butte Valley Water | 450 | 6 |
25 total water systems serve Pennington County.
All ZIP Codes in Pennington County
17 ZIP codes tracked in Pennington County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 57745 | Hill City | 83 | B | 1 | $324K |
| 2 | 57751 | Keystone | 83 | B | 0 | $388K |
| 3 | 57767 | Owanka | 83 | B | 0 | — |
| 4 | 57790 | Wall | 83 | B | 0 | $188K |
| 5 | 57761 | New Underwood | 82 | B | 5 (1 health) | $264K |
| 6 | 57709 | Rapid City | 80 | B | 0 | — |
| 7 | 57701 | Rapid City | 76 | B | 0 | $230K |
| 8 | 57702 | Rapid City | 76 | B | 0 | $341K |
| 9 | 57703 | Rapid City | 76 | B | 0 | $250K |
| 10 | 57719 | Box Elder | 66 | C | 6 (6 health) | $275K |
| 11 | 57759 | Nemo | 63 | C | 0 | $474K |
| 12 | 57725 | Caputa | 53 | D | 0 | $275K |
| 13 | 57737 | Enning | 53 | D | 0 | — |
| 14 | 57750 | Interior | 53 | D | 0 | — |
| 15 | 57775 | Quinn | 53 | D | 0 | $179K |
| 16 | 57780 | Scenic | 53 | D | 0 | — |
| 17 | 57792 | White Owl | 53 | D | 0 | — |
Recommended Buyer Guides for Pennington County
Four sources — EPA, NSF, FEMA, CDC — drive the match.
- Best Lead Paint Test Kits — 62.9% 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 Pennington County, South Dakota
Overview
Pennington County in South Dakota covers 17 ZIP codes with an average Home Safety Score of C (69/100).
3 of 17 ZIP codes have recorded EPA violations. 7 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.