Water Quality in Grand Isle, ME: 3 Violations — Grade C
Grade C · Score 69/100 · 1 water system · Updated 2026-05-03
Grand Isle's water has moderate compliance issues. Residents in affected areas should consider filtration.
Data: EPA Safe Drinking Water Information System (SDWIS) Last verified: 2026-05-03
The compliance history for Grand Isle, ME includes 3 water violations on file with the EPA — a federal tally that spans health-based exceedances, monitoring failures, and enforcement actions logged under the Safe Drinking Water Act.
Water Quality by ZIP Code in Grand Isle
Water quality varies across Grand Isle's 1 ZIP codes. Check your specific ZIP for detailed contaminant data.
| ZIP Code | Grade | Score | Violations | Health | |
|---|---|---|---|---|---|
| 04746 | C | 69 | 3 | 0 | View report → |
Water Quality Overview
Grand Isle, Maine receives a water quality grade of C with an overall score of 69 out of 100, based on EPA compliance data from the Safe Drinking Water Information System (SDWIS).
The 1 water system serving Grand Isle have accumulated 3 EPA violations (all monitoring/reporting type). These violations are tracked across 1 ZIP codes serving approximately 278 people.
What Grade C Means
A grade of C indicates moderate compliance issues. Grand Isle's water systems have some violations that warrant attention. While the water may still be safe for most people, residents in affected ZIP codes should consider additional testing or filtration.
Lead Levels
The average 90th percentile lead level across Grand Isle water systems is 0.0021 mg/L — within EPA limits. No ZIP codes exceed the EPA lead action level.
With 78% of homes built before 1986, Grand Isle has a higher-than-average risk of lead from older plumbing. Lead solder was banned in 1986, and homes built before this date may have lead in pipes, solder joints, or fixtures.
Radon Risk
Grand Isle is in EPA Radon Zone 1 (High risk). The EPA recommends all homes in Zone 1 areas be tested for radon. Radon is the second leading cause of lung cancer after smoking.
Water Systems Serving Grand Isle
Grand Isle is served by 1 community water system regulated under the Safe Drinking Water Act. These systems collectively serve approximately 278 people across 1 ZIP codes.
Each water system is identified by a Public Water System ID (PWSID) and is required to:
- Test for over 90 regulated contaminants on a regular schedule
- Report results to the EPA and state regulators
- Issue an annual Consumer Confidence Report (CCR) to all customers
- Take corrective action when violations occur
The EPA has taken 9 enforcement actions against water systems serving Grand Isle. Enforcement actions range from informal compliance assistance to formal orders and penalties.
How to Check Your Water in Grand Isle
Enter your ZIP code on ZipCheckup to see your specific water system data, including contaminant levels, violation history, and safety scores
Request your CCR — your water utility must provide an annual Consumer Confidence Report with detailed test results for all monitored contaminants
Get a home test — certified kits cost $20–$50 and test for lead, bacteria, and common contaminants. Professional lab tests ($150–$400) cover a broader panel
Consider filtration — NSF-certified filters can remove specific contaminants. Reverse osmosis removes the broadest range; activated carbon is effective for chlorine and many organics
Check for advisories — monitor your local utility website and local news for boil water advisories or system alerts
Contaminants Detected in Grand Isle Water Systems
The following contaminants have been detected or caused violations across Grand Isle's water systems:
| Contaminant | Category | MCL | Violations | ZIPs Affected | Health-Based |
|---|---|---|---|---|---|
| Stage 1 DBP Rule | Treatment Technique | N/A | 1 | 1 | No |
| Surface Water Treatment Rule | Treatment Technique | N/A | 1 | 1 | No |
MCL = Maximum Contaminant Level (EPA enforceable standard). Health-based violations indicate levels that may pose direct health risks.
EPA Enforcement History
The EPA and state regulators have taken 9 enforcement actions against water systems serving Grand Isle. Recent actions:
| Date | Action Type |
|---|---|
| 2025-09-29 | State Informal Action |
| 2025-03-06 | State Order Extension |
| 2025-02-25 | State Filed Judgment |
| 2025-02-25 | State Informal Enforcement |
| 2025-02-24 | State Filed Judgment |
| 2025-02-24 | State Informal Enforcement |
| 2025-01-22 | State Order Extension |
| 2022-03-25 | State Order Extension |
| 2022-03-14 | State Filed Judgment |
Enforcement actions range from informal compliance assistance to formal orders and penalties. The most recent action was on 2025-09-29.
Grand Isle vs. Nearby Maine Cities
How Grand Isle's water quality compares to similar cities in Maine:
| City | Grade | Violations | Systems | Population |
|---|---|---|---|---|
| Grand Isle | C | 3 | 1 | 278 |
| Saint David | D | 0 | 1 | 278 |
| Union | B | 3 | 2 | 288 |
| Andover | D | 0 | 1 | 265 |
Common Questions About Grand Isle Water
These are the most common questions residents search for about water quality in Grand Isle, Maine:
Is Grand Isle water hard or soft? Water hardness varies by source. Grand Isle's 1 water system uses a single source. Check your ZIP code report for specific hardness data.
Can I drink Grand Isle tap water? Grand Isle's water receives a grade of C (69/100). No health-based violations have been recorded, but home testing is always recommended.
What is the best water filter for Grand Isle? A NSF/ANSI 53-certified filter for lead removal is a good general choice. See our Water Filter Matcher for personalized recommendations.
Grand Isle vs. Maine Average
Understanding how Grand Isle compares to the broader Maine average helps contextualize your local water quality. Factors like water source, treatment methods, and infrastructure age all contribute to differences between cities in the same state.
To see how individual neighborhoods compare, check the ZIP code reports below — water quality can vary significantly even within Grand Isle.
ZIP Codes in Grand Isle
Grand Isle spans 1 ZIP code. The ZIP with the lowest water quality score is 04746. Each ZIP code has its own water quality profile based on the specific water system serving that area. Check each ZIP code for detailed contaminant data, violation history, and system information.
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
- Enforcement: EPA ECHO database
- Filter recommendations: NSF/ANSI certified products
Updated daily.