Johns Island, SC: 3 Violations - Home Safety 82/100
2 ZIP codes · 4 water systems · Updated
ZipCheckup grade for Johns Island: B.
This ZIP has a few items worth a quick check.
Johns Island, SC scores in the upper band of the ZipCheckup grade.
How Johns Island Compares
Data: EPA SDWIS
Johns Island Water: The Quick Version
- Your city's water systems recorded 3 violations since 2021.
- Average of reported 90th-percentile lead results: 0.004 mg/L.
- Estimated remediation: $500 per household.
- Health risk index (ZipCheckup composite of CDC data): 11.36.
Water Systems Serving Johns Island
Sorted by reported population served, the top 3 of 4 public water systems mapped to Johns Island, SC appear below, each with its own federal compliance record.
- B
- B
- B
Overview
We track home safety data for 2 ZIP codes in Johns Island, South Carolina (population ~26,308), covering 4 community water systems serving approximately 365,503 people region-wide. The EPA snapshots used for this build directly map water systems to 1 of 2 ZIP codes.
1 of 1 ZIP code with a reported violation count in the available EPA record (100%) have recorded EPA violations. The available record reports no health-based violations for this measured scope.
Home Safety Score
Average Home Safety Score for Johns Island: B (82/100)
Model 4.0.0 uses four measured components across three equally weighted domains. If a required domain is unavailable, no score is published:
| Factor | What It Measures |
|---|---|
| Water Quality | EPA violations and compliance history |
| PFAS MCL Screen | UCMR 5 testing against the covered federal MCLs |
| Radon Risk | EPA radon zone classification |
| Annual AQI | EPA AirData county-year median with at least 90 observed days |
Water Sources
Johns Island water systems draw from: Surface water.
Lead & Copper
- Average of reported 90th-percentile lead results: 0.0040 mg/L (EPA action level: 0.015 mg/L)
- 0 of 1 ZIP code with known status exceed the EPA lead action level
Radon Risk
2 of 2 ZIP records with known zones are in EPA Radon Zone 3.
The EPA recommends testing all homes regardless of radon zone. County radon zones cannot replace an in-home radon test.
Top Contaminants
| Contaminant | Category | Violations | ZIPs Affected |
|---|---|---|---|
| Revised Total Coliform Rule | Microbiological | 2 | 1 |
| Surface Water Treatment Rule | Treatment Technique | 2 | 1 |
| Chlorine | Disinfectant | 2 | 1 |
Areas with Most Violations
| ZIP Code | Safety Score | Violations | Health-Based | System |
|---|---|---|---|---|
| 29455 | B | 3 | 0 | St John's Water (sc1020002) |
All ZIP Codes in Johns Island
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Lead/copper: EPA Lead and Copper Rule sampling data
- Radon: EPA Map of Radon Zones
Reporting periods vary by source. Missing data is shown as unavailable, not as zero.
CDC Health Data for Johns Island
Source: CDC PLACES (County-level estimates). County health indicators are shown for context only and are not linked to this area's water records.
Compared to National Average
Vertical line = national average. ■ Above national · ■ Below national
Key Contaminants Detected in Johns Island
Based on EPA violation records. Check your ZIP code report for system-specific contaminant data.
Johns Island: Remediation Cost in Perspective
Estimated remediation for Johns Island is a small fraction of median property value - one percent or less - though the ratio does not describe any single household.
Estimated remediation costs in Johns Island can be compared with local home values. The $300–$800 estimated range can be set against the median property value; actual costs vary by home. Home values are 142% above the South Carolina average.
Protecting Children from Lead in Johns Island
Why children are most at risk: The CDC states that no safe blood lead level in children has been identified. Children under 6 absorb lead more readily than adults, and even low levels can cause developmental delays, learning difficulties, and behavioral problems.
Available area-level lead records for Johns Island do not determine the lead level at an individual tap. Testing is the only way to confirm your water's lead content.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Historical Flood-Claim Evidence for Johns Island
Historical NFIP data for Johns Island contains 1,029 flood insurance claims. Among claims with payment data, the average reported building, contents, and ICC component sum is $10,152. Among ZIP codes with claim records, 100% have an A- or V-family dominant rated zone recorded in those historical claims. This is not a complete current FEMA property-map inventory.
How flooding affects water quality: Flood events can introduce sewage, agricultural runoff, and industrial chemicals into water supplies. Even after floodwaters recede, contamination can persist in wells and aging infrastructure. The $500 remediation estimate shown here excludes flood insurance and is not derived from NFIP claim count.
Claim count does not establish current property risk. Check the exact address in FEMA's current map and obtain a property-specific insurance quote when relevant.
Source: historical FEMA National Flood Insurance Program (NFIP) claim records. No current FEMA property-map designation is asserted.
Deep Dive Reports
Detailed analysis for Johns Island, SC