Maine Water Quality Report: 1,440 Violations Across 485 ZIPs
667 water systems · 485 ZIP codes · 1,440 violations · Updated 2026-05-31
Data: EPA Safe Drinking Water Information System (SDWIS), EPA ECHO Last verified: 2026-05-31
City Water Quality Map: Maine
Each circle represents a city. Size indicates population, color indicates water quality grade. Tap a circle for details.
Violation Trend
EPA violations across all water systems in Maine.
Cities with Most Violations in Maine
| # | City | Grade | Violations | Systems | Population | |
|---|---|---|---|---|---|---|
| 1 | Portland | C | 189 | 5 | 135,751 | Details → |
| 2 | Bangor | C | 58 | 5 | 27,891 | Details → |
| 3 | Waterville | F | 46 | 5 | 22,253 | Details → |
| 4 | Hancock | D | 40 | 5 | 609 | Details → |
| 5 | Augusta | C | 30 | 5 | 13,971 | Details → |
| 6 | Poland | F | 25 | 5 | 78,201 | Details → |
| 7 | Ellsworth | C | 22 | 3 | 4,008 | Details → |
| 8 | Wiscasset | C | 22 | 5 | 2,855 | Details → |
| 9 | Limestone | C | 22 | 3 | 1,110 | Details → |
| 10 | Auburn | D | 21 | 3 | 17,380 | Details → |
Most Common Contaminants in Maine
| Contaminant | Category | Violations | ZIPs Affected | Health Risk |
|---|---|---|---|---|
| Surface Water Treatment Rule | Treatment Technique | 338 | 147 | No |
| Stage 1 DBP Rule | Treatment Technique | 325 | 126 | Yes |
| Haloacetic Acids (HAA5) | Disinfection Byproducts | 95 | 26 | Yes |
| Lead and Copper Rule | Treatment Technique | 94 | 58 | No |
| Barium | Inorganic | 89 | 29 | Yes |
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 61 | 44 | Yes |
| Lead | Inorganic | 38 | 27 | Yes |
| Total Coliform | Microbiological | 35 | 32 | No |
| Gross Alpha | Radionuclides | 22 | 10 | Yes |
| Chlorite | Disinfection Byproducts | 22 | 13 | No |
Water Quality Overview
Maine has 667 community water systems serving approximately 2,004,501 people across 485 ZIP codes. These systems have accumulated 1,440 EPA violations, including 287 health-based violations.
Health-based violations account for 20% of all violations in Maine. These violations indicate contaminant levels that may pose direct risks to human health, as opposed to monitoring or reporting failures.
Violation Breakdown
| Violation Type | Count | Percentage |
|---|---|---|
| Health-based | 287 | 19.9% |
| Monitoring/Reporting | 1,153 | 80.1% |
| Total | 1,440 | 100% |
Health-based violations indicate contaminant levels exceeding EPA Maximum Contaminant Levels (MCLs). Monitoring violations indicate failures to test or report — these do not necessarily mean unsafe water, but they mean the water was not properly verified.
Cities with Most Violations
The following cities in Maine have the highest number of EPA violations:
| Rank | City | Grade | Violations | Water Systems | Population |
|---|---|---|---|---|---|
| 1 | Portland | C | 189 | 5 | 135,751 |
| 2 | Bangor | C | 58 | 5 | 27,891 |
| 3 | Waterville | F | 46 | 5 | 22,253 |
| 4 | Hancock | D | 40 | 5 | 609 |
| 5 | Augusta | C | 30 | 5 | 13,971 |
| 6 | Poland | F | 25 | 5 | 78,201 |
| 7 | Ellsworth | C | 22 | 3 | 4,008 |
| 8 | Wiscasset | C | 22 | 5 | 2,855 |
| 9 | Limestone | C | 22 | 3 | 1,110 |
| 10 | Auburn | D | 21 | 3 | 17,380 |
Violation counts are cumulative across all water systems serving each city. Higher counts may reflect larger systems with more monitoring requirements, not necessarily worse water quality.
Violation Trend Over Time
Year-by-year EPA violations recorded across all water systems in Maine:
| Year | Total Violations | Health-Based |
|---|---|---|
| 2021 | 83 | 83 |
| 2022 | 67 | 67 |
| 2023 | 75 | 75 |
| 2024 | 116 | 116 |
| 2025 | 57 | 57 |
Violations have decreased from 83 in 2021 to 57 in 2025, suggesting improving compliance across Maine.
Most Common Contaminants
The following contaminants have caused the most violations across Maine water systems:
| Contaminant | Category | Violations | ZIPs Affected | Health-Based |
|---|---|---|---|---|
| Surface Water Treatment Rule | Treatment Technique | 338 | 147 | No |
| Stage 1 DBP Rule | Treatment Technique | 325 | 126 | Yes |
| Haloacetic Acids (HAA5) | Disinfection Byproducts | 95 | 26 | Yes |
| Lead and Copper Rule | Treatment Technique | 94 | 58 | No |
| Barium | Inorganic | 89 | 29 | Yes |
| Total Trihalomethanes (TTHM) | Disinfection Byproducts | 61 | 44 | Yes |
| Lead | Inorganic | 38 | 27 | Yes |
| Total Coliform | Microbiological | 35 | 32 | No |
| Gross Alpha | Radionuclides | 22 | 10 | Yes |
| Chlorite | Disinfection Byproducts | 22 | 13 | No |
How to Check Your Water in Maine
Enter your ZIP code on ZipCheckup for detailed water system data including contaminant levels, violation history, and safety scores
Request your CCR — every water utility must provide an annual Consumer Confidence Report
Get a home test — certified kits ($20-$50) or professional lab tests ($150-$400)
Consider filtration — NSF-certified filters can address specific contaminants found in your area
EPA Enforcement
The EPA and state regulators have taken 3,266 enforcement actions against water systems in Maine. Enforcement actions range from compliance assistance to formal orders and penalties.
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Enforcement: EPA ECHO
Updated daily.
What are EPA violations?
Health-based violations mean a contaminant was detected above the EPA's Maximum Contaminant Level (MCL) — the legal limit designed to protect human health. Maine has 287 such violations across its water systems. Not all violations cause illness, but repeated exceedances increase risk, especially for children and immunocompromised individuals.
Understanding water quality grades
ZipCheckup grades water systems from A to F based on EPA violation history, contaminant levels, and system compliance. Grade A means few or no violations; Grade F indicates persistent or serious issues. Grades are calculated per ZIP code and aggregated at the city, county, and state level.
Wondering about your tap water?
Water quality varies by ZIP code. Enter yours to see contaminant data, violations, and filtration recommendations specific to your area.
Check Your ZIP Code Water Quality →Frequently Asked Questions
Is the tap water safe to drink in Maine?
Maine has 667 community water systems with 1,440 recorded EPA violations, including 287 health-based. Water quality varies by city and ZIP code — check your specific location for detailed results.
How many water violations does Maine have?
Maine has 1,440 total EPA violations across 485 ZIP codes. 287 are health-based violations that indicate contaminant levels potentially harmful to human health. The remainder are monitoring or reporting violations.
Which city in Maine has the worst water quality?
Portland, ME has the most EPA violations among major cities in Maine with 189 recorded violations. Check individual ZIP codes for the most accurate picture of your local water quality.
Which city in Maine has the best water quality?
Several cities in Maine maintain excellent EPA compliance. Check individual city reports for details.
What contaminants are found in Maine drinking water?
Maine water systems are monitored for over 90 EPA-regulated contaminants including lead, copper, nitrates, disinfection byproducts, and bacteria. The most common violations vary by region — check your ZIP code for contaminant-specific data.