COUNTY REPORT SD

Gregory County, South Dakota

7 ZIP codes · Avg score 70/100 · Grade B · Updated 2026-06-03

Recent water monitoring in Gregory County shows 7 ZIP codes with consistently safe results.

How Gregory County Compares

Gregory County70/100
South Dakota avg60/100
National avg68/100

How Gregory County Compares

B
County Grade
70/100
Avg Safety Score
7
ZIP Codes
5
Water Systems

Gregory County scores 10 points above the South Dakota state average (60/100) and 2 points above the national average (68/100).

Data: EPA SDWIS Last verified: 2026-06-03

B
County Grade
70
Avg Safety Score
7
ZIP Codes
Best ZIP: 57317 (83/100)
Lowest ZIP: 57571 (53/100)
$121K
Median Home Value
$757
Avg Remediation (63% of home value)

ZIP Code Risk Map

Water Quality Map: Gregory County, South Dakota

Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.

A B C D F

Key Risk Factors

Health risk index: 14.8 (asthma 10.2%, diabetes 14.1%)

Estimated additional annual cost per homeowner: $611, driven primarily by water_lead

Infrastructure: 0.439% avg pipe failure probability, 86% of ZIPs at high risk

79% of homes built before 1978 (lead paint era)

County Health Indicators vs National Average

Asthma 10.2% (national: 8.9%)
Diabetes 14.1% (national: 10.5%)
Obesity 35.9% (national: 32.4%)

Black markers indicate national averages. Source: CDC PLACES, Census ACS.

Infrastructure Overview

1954
Median Build Year
79%
Pre-1978 Housing
44%
Pipe Failure Probability
86%
ZIPs at High Infra Risk
High
Lead Pipe Risk

Sources: Census ACS (housing age), EPA SDWIS (infrastructure risk model), state bridge inspection data.

Compound Risk Breakdown

Estimated additional annual cost per homeowner: $611

Water / Lead $364/yr
Energy Code Gap $219/yr
Flood $29/yr

Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).

Housing Age Distribution

2,274 housing units in Gregory County

Pre-1940 38%
1940–1959 17%
1960–1979 19%
1980–1999 12%
2000+ 14%

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 Gregory County

$121K
Median Home Value
$757
Est. Remediation Cost
0.6%
of Home Value
Remediation as % of home value low burden

Remediation costs are relatively manageable for most homeowners in Gregory 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 Gregory County residents

Asthma 10.2% (US avg: 8.9%)
Diabetes 14.1% (US avg: 11%)
Obesity 35.9% (US avg: 32.4%)

Black markers = national averages. Red = above national avg. Green = below. Source: CDC PLACES, Census ACS.

Water Systems with Most Violations

Top 5 systems in Gregory County ranked by EPA violation count.

# Water System Population Violations
1 TRIPP COUNTY WATER USER DISTRICT 4,860 0
2 Bonesteel 275 0
3 Burke 575 0
4 Dallas 89 0
5 Gregory 1,221 0

All ZIP Codes in Gregory County

7 ZIP codes tracked in Gregory County.

# ZIP Code City Safety Score Grade Violations Home Value
1 57317 Bonesteel 83 B 0 $120K
2 57523 Burke 83 B 0 $207K
3 57529 Dallas 83 B 0 $278K
4 57533 Gregory 83 B 0 $113K
5 57335 Fairfax 53 D 0 $121K
6 57538 Herrick 53 D 0
7 57571 Saint Charles 53 D 0 $73K

Recommended Buyer Guides for Gregory County

Below: editorial picks, no sponsored placements.

Overview

Gregory County in South Dakota covers 7 ZIP codes with an average Home Safety Score of B (70/100).

No EPA violations recorded across any tracked ZIP codes in Gregory County.

← Back to South Dakota water quality report

Data Sources

Updated daily.

Frequently Asked Questions

Is water safe in Gregory County?
Gregory County receives a grade of B, indicating generally safe tap water across its 7 ZIP codes.
How many water systems serve Gregory County?
Gregory County is served by 5 public water systems that supply drinking water to residents across 7 ZIP codes.
What is the biggest environmental risk in Gregory County?
The primary environmental risk factor in Gregory County is water_lead. This contributes to an estimated additional annual cost of $611 per homeowner.
How old are homes in Gregory County?
The median home build year in Gregory County is 1954. 79% of homes were built before 1978, which means they may contain lead-based paint and older plumbing materials.
How does Gregory County compare to South Dakota?
Gregory County has an average water safety score of 70/100, which is above the South Dakota state average of 60/100.

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