McCook County, South Dakota
7 ZIP codes · Avg score 60/100 · Grade C · Updated 2026-06-03
Water monitoring across McCook County's 7 ZIP codes paints a mid-range picture — solid compliance in some zones, documented concerns in others; most violations on record are concentrated in specific prior years rather than spread evenly across the full compliance history, and the overall county grade has held steady in the middle tier without major shifts in either direction.
How McCook County Compares
How McCook County Compares
McCook 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: 2026-06-03
ZIP Code Risk Map
Water Quality Map: McCook 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: 12.7 (asthma 9.7%, diabetes 11%)
Estimated additional annual cost per homeowner: $861, driven primarily by water_lead
Infrastructure: 0.413% avg pipe failure probability, 71% of ZIPs at high risk
72.7% 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: $861
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
3,356 housing units in McCook 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 McCook County
Remediation costs are relatively manageable for most homeowners in McCook 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 McCook 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 McCook County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Tm Rural Water District | 4,250 | 2 |
| 2 | Hanson Rural Water System | 2,685 | 1 |
| 3 | Canistota | 642 | 1 |
| 4 | Minnehaha Community Water Corporation | 13,435 | 1 |
| 5 | Kingbrook I Rural Water System | 6,455 | 1 |
13 total water systems serve McCook County.
All ZIP Codes in McCook County
7 ZIP codes tracked in McCook County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 57043 | Marion | 70 | B | 0 | $198K |
| 2 | 57374 | Spencer | 70 | B | 0 | $199K |
| 3 | 57012 | Canistota | 66 | C | 1 | $164K |
| 4 | 57319 | Bridgewater | 66 | C | 0 | $151K |
| 5 | 57048 | Montrose | 63 | C | 1 | $328K |
| 6 | 57058 | Salem | 45 | D | 0 | $200K |
| 7 | 57047 | Monroe | 40 | D | 0 | $49K |
Recommended Buyer Guides for McCook County
Designed to find the guide that fits the county, not the other way around — the system reads EPA detections, FEMA hazard layers, and CDC lead-exposure markers, then outputs the categories that resolve those specific risks for households here, with NSF-certified products surfaced when the matching contaminant appears in the local monitoring data.
- Best Water Filters for Lead — Lead above EPA action level in 1 ZIP code
- Best Lead Paint Test Kits — 72.7% of homes built before 1978
- Best Under-Sink Reverse Osmosis Systems — Multi-contaminant removal at the kitchen tap
- Best Radon Test Kits — EPA Radon Zone 1 (highest risk) dominant in county
Deep Dive Reports
Detailed analysis for McCook County, South Dakota
Overview
McCook County in South Dakota covers 7 ZIP codes with an average Home Safety Score of C (60/100).
2 of 7 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.