Barnwell County, South Carolina
5 ZIP codes · Avg score 89/100 · Grade A · Updated 2026-06-04
Throughout Barnwell County, the 5 monitored ZIP codes show low violation rates and healthy safety scores — a pattern that puts the county well above the state baseline for drinking water quality.
How Barnwell County Compares
How Barnwell County Compares
Barnwell County scores 11 points above the South Carolina state average (78/100) and 21 points above the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-04
ZIP Code Risk Map
Water Quality Map: Barnwell County, South Carolina
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 17.1 (asthma 11%, diabetes 19.8%)
Estimated additional annual cost per homeowner: $2,200, driven primarily by sea_level
Infrastructure: 0.308% avg pipe failure probability
59.8% 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: $2,200
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
5,817 housing units in Barnwell 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 Barnwell County
Remediation costs are relatively manageable for most homeowners in Barnwell 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 Barnwell 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 Barnwell County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Barnwell Town of (sc0610001) | 4,693 | 3 |
| 2 | Williston Town of (sc0610002) | 3,251 | 3 |
| 3 | Hilda Town of (sc0610004) | 318 | 2 |
| 4 | Blackville Town of (sc0610003) | 1,934 | 2 |
| 5 | Elko Town of (0610005) | 340 | 1 |
All ZIP Codes in Barnwell County
5 ZIP codes tracked in Barnwell County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 29826 | Elko | 99 | A | 1 | — |
| 2 | 29853 | Williston | 99 | A | 1 | $101K |
| 3 | 29813 | Hilda | 95 | A | 2 | — |
| 4 | 29817 | Blackville | 88 | A | 2 | $80K |
| 5 | 29836 | Martin | 66 | C | 0 | $56K |
Recommended Buyer Guides for Barnwell 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 Lead Paint Test Kits — 59.8% of homes built before 1978
Deep Dive Reports
Detailed analysis for Barnwell County, South Carolina
Overview
Barnwell County in South Carolina covers 5 ZIP codes with an average Home Safety Score of A (89/100).
4 of 5 ZIP codes have recorded EPA violations. All violations are monitoring/reporting type.
← Back to South Carolina 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.