Public water system · ME0000424
ActiveAos 91 Mt Desert Island High School
At a glance
Aos 91 Mt Desert Island High School (PWSID ME0000424) is an active non-transient non-community water system in Hancock County, Maine. It reports serving 615 people through 1 service connection. Its primary water source is groundwater, and EPA lists it as owned by a local government. Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in May 1999.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
615
Service connections
1
Primary source
GW
Groundwater
System type
NTNCWS
Non-transient non-community water system
System record
How does Aos 91 Mt Desert Island High School compare with other water systems in Hancock County?
By EPA's size categories, Aos 91 Mt Desert Island High School is a small system (501 to 3,300 people). Hancock County has 203 active public water systems. Its population served is about 166% above the county average of 232 people per system, and accounts for 1.3% of the 47,019 people reported by systems filed under the county. Across Maine, the 1,862 active systems average 503 people each. Nationally, the average active non-transient non-community water system reports serving 430 people, so Aos 91 Mt Desert Island High School is about 43% above that figure.
What does “non-transient non-community water system” mean?
A non-transient non-community water system regularly serves at least 25 of the same people for more than six months a year, but not where they live. Schools, factories, office buildings and hospitals with their own supply are typical examples. Maine has 385 active non-transient non-community water systems, 21% of the state's 1,862 active systems. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 1,780 Maine systems (96%) list groundwater as their primary source.
Who owns and regulates Aos 91 Mt Desert Island High School?
EPA lists Aos 91 Mt Desert Island High School as owned by a local government. The ME state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 30 of the 203 active systems in Hancock County (15%) are also owned by a local government.
Does Aos 91 Mt Desert Island High School have drinking water violations?
Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in May 1999. The violations listed here began between January 1996 and May 1999. By type: 11 monitoring and reporting and 1 contaminant level above the legal limit. The contaminants or rules involved are Total coliform bacteria (TCR), 1,1,2-Trichloroethane, p-Dichlorobenzene and Vinyl chloride. EPA lists 12 as resolved. Resolved means at least one resolving action is on record: the system returned to compliance, the rule no longer applies, or no further action was needed.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 1999-05-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1996-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,1,2-Trichloroethanecode 2985 | No | Resolved |
| 1996-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | p-Dichlorobenzenecode 2969 | No | Resolved |
| 1996-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Vinyl chloridecode 2976 | No | Resolved |
| 1996-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | trans-1,2-Dichloroethylenecode 2979 | No | Resolved |
| 1996-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,1,1-Trichloroethanecode 2981 | No | Resolved |
| 1996-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Carbon tetrachloridecode 2982 | No | Resolved |
| 1996-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,2-Dichloropropanecode 2983 | No | Resolved |
| 1996-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,1-Dichloroethylenecode 2977 | No | Resolved |
| 1996-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Chlorobenzenecode 2989 | No | Resolved |
| 1996-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,2,4-Trichlorobenzenecode 2378 | No | Resolved |
| 1996-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Dichloromethanecode 2964 | No | Resolved |
The 12 most recent violations in EPA's records, newest first.Labels and codes come from EPA's SDWIS reference tables. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found. "Health-based" marks violations of a legal limit or required treatment.
Aos 91 Mt Desert Island High School: frequently asked questions
Who runs Aos 91 Mt Desert Island High School?
Aos 91 Mt Desert Island High School (PWSID ME0000424) is a non-transient non-community water system owned by a local government. It is regulated by the ME state drinking water program.
How many people does Aos 91 Mt Desert Island High School serve?
Aos 91 Mt Desert Island High School reports serving 615 people through 1 service connection in Hancock County, Maine.
Where does Aos 91 Mt Desert Island High School get its water?
EPA SDWIS lists this system's primary water source as groundwater. Groundwater means the system draws its water from wells or springs fed by underground aquifers.
Does Aos 91 Mt Desert Island High School have any drinking water violations?
Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in May 1999. A monitoring or reporting violation means a required test or report was missed or late; it does not by itself mean a contaminant was found.
Is Aos 91 Mt Desert Island High School's water safe to drink?
AquaCensus shows EPA compliance records, not current water test results, so it cannot say whether the water is safe at a given moment. Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in May 1999. For current results, consult EPA ECHO, or the ME state drinking water program.
Where can I find Aos 91 Mt Desert Island High School's water quality report?
The annual Consumer Confidence Report requirement applies to community water systems. Aos 91 Mt Desert Island High School is a non-transient non-community water system, so it is not required to publish one; like every public water system, it must notify the people it serves about violations under EPA's public notification rules.
Other water systems in Hancock County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Town of Bar Harbor- Water Division | Hancock | 4,443 | Community | Surface water |
| Ellsworth Water Department | Hancock | 3,910 | Community | Surface water |
| Southwest Harbor Water & Sewer District | Hancock | 2,480 | Community | Surface water |
| Maine Water Company Bucksport Division | Hancock | 1,700 | Community | Surface water |
| Mount Desert Water Dist North | Hancock | 1,623 | Community | Surface water |
| Castine Water Department | Hancock | 983 | Community | Groundwater under influence of surface water |
Related pages
Working with water-system records? Pro adds alerts, change history and CSV export ($49/mo); Enterprise adds full national files, the API and an MCP server for AI tools.
About this data
Source: U.S. EPA Safe Drinking Water Information System (SDWIS) and SDWA violation records, via EPA ECHO, as published October 1, 2026 — AquaCensus refreshes it quarterly. See the methodology for how records are matched, cleaned and scored.
Cite as: AquaCensus, “Aos 91 Mt Desert Island High School, PWSID ME0000424, Maine”, https://aquacensus.com/water-systems/maine/aos-91-mt-desert-island-high-school-me0000424 (data as of October 1, 2026).