B70/100
Johns Island Tap Water Quality: Is It Safe to Drink? (2026 Report)
Serving 28,531 residents · South Carolina
What's In Johns Island's Tap Water?
69
Contaminants Tested
2
Exceed EPA Limits
1
Above EPA Goals
3 contaminants above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
PFOS | 0.007 µg/L | 0.004 µg/L | Over Limit |
PFOA | 0.005 µg/L | 0.004 µg/L | Over Limit |
Lead (90th percentile) | 0.002 mg/L | 0.015 mg/L | Above Goal |
EPA Violation History
No violations in the past 5 years
Full EPA compliance since 2015.
Understanding violation severity
Tier 1Urgent health risk. Utility must notify all customers within 24 hours.Tier 2Important health or treatment issue. Customers notified within 30 days.Tier 3Administrative or monitoring issue. Reported in the annual water quality report.
Source: EPA Safe Drinking Water Information System (SDWIS) · Updated quarterly
Water Utility Details
SEABROOK ISLAND TOWN OF (1010009)
Population Served
5,939
Water Source
Purchased Surface Water
System ID
SC1010009
ST JOHN'S WATER (SC1020002)
Population Served
22,592
Water Source
Purchased Surface Water
System ID
SC1020002
Frequently Asked Questions About Johns Island Water
Is Johns Island tap water safe to drink?
Johns Island, South Carolina tap water receives a grade of B (70/100), which is considered good. Out of 69 contaminants tested, 2 exceed EPA maximum contaminant levels (MCLs) and 3 exceed health guidelines (MCLGs). While the water meets federal standards, some residents may still choose to use a filter for additional peace of mind.
What contaminants are in Johns Island's water?
Of the 69 contaminants tested in Johns Island's water supply, the most notable include PFOS, PFOA, Lead (90th percentile). 2 contaminant(s) exceed EPA legal limits (MCLs). 3 contaminant(s) exceed EPA health goals (MCLGs), which are non-enforceable targets set at levels with no known health risk.
Does Johns Island have any water quality violations?
Yes, Johns Island has 14 EPA violation(s) on record, with the most recent in 2024. Violation types include MR, MON, Other. 2 of these are health-based violations, which are the most serious category.
Do I need a water filter in Johns Island?
Based on EPA data, using a water filter in Johns Island is recommended. 2 contaminant(s) exceed legal limits. An NSF-certified filter — such as a reverse osmosis or activated carbon system — can effectively reduce many common contaminants. Choose a filter certified to remove the specific contaminants found in your area.
Where does Johns Island's tap water come from?
Johns Island's drinking water is sourced from purchased surface water and supplied by SEABROOK ISLAND TOWN OF (1010009) and 1 other water system(s). The system serves approximately 28,531 people. Surface water sources include rivers, lakes, and reservoirs.
How often is Johns Island's water tested?
Under the Safe Drinking Water Act (SDWA), water utilities are required to regularly test for over 90 contaminants. Testing frequency varies by contaminant — some are tested monthly, others quarterly or annually. Johns Island's water systems must report results to the EPA and publish an annual Consumer Confidence Report (CCR). The data on this page reflects the latest available EPA testing data.
How does Johns Island's water compare to other cities in South Carolina?
Johns Island's water quality score of 70/100 earns a grade of B, which is considered good. This is an above-average score compared to many cities nationwide. Visit our South Carolina state page to see how all cities in the state compare.
What should I do if I'm concerned about Johns Island's water quality?
If you have concerns about Johns Island's tap water, consider these steps: (1) Request your utility's annual Consumer Confidence Report for detailed local data. (2) Get your water independently tested through a state-certified laboratory. (3) Consider an NSF-certified water filter rated for the contaminants found in your area. (4) Contact your water utility (SEABROOK ISLAND TOWN OF (1010009)) with specific questions. (5) Report water quality issues to your state drinking water program or the EPA Safe Drinking Water Hotline at 800-426-4791.