Public water system · MA4096001
ActiveOtis Air National Guard Base
At a glance
Otis Air National Guard Base (PWSID MA4096001) is an active community water system in Barnstable County, Massachusetts. It reports serving 6,000 people through 337 service connections. Its primary water source is groundwater, and EPA lists it as owned by the federal government. Of the 12 most recent violations in EPA's records, 8 are health-based, and the most recent began in October 2024.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
6,000
Service connections
337
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Otis Air National Guard Base compare with other water systems in Barnstable County?
By EPA's size categories, Otis Air National Guard Base is a medium system (3,301 to 10,000 people). Barnstable County has 125 active public water systems. Its population served is about 20% above the county average of 5,016 people per system, and accounts for 1% of the 627,054 people reported by systems filed under the county. Across Massachusetts, the 1,636 active systems average 6,275 people each. Nationally, the average active community water system reports serving 6,703 people, so Otis Air National Guard Base is about 10% below that figure.
What does “community water system” mean?
A community water system serves at least 15 connections used by year-round residents, or regularly serves at least 25 year-round residents. Homes, apartments and mobile-home parks are served by these. Massachusetts has 531 active community water systems, 32% of the state's 1,636 active systems. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 1,354 Massachusetts systems (83%) list groundwater as their primary source.
Who owns and regulates Otis Air National Guard Base?
EPA lists Otis Air National Guard Base as owned by the federal government. The MA state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 10 of the 125 active systems in Barnstable County (8%) are also owned by the federal government.
Does Otis Air National Guard Base have drinking water violations?
Of the 12 most recent violations in EPA's records, 8 are health-based, and the most recent began in October 2024. The violations listed here began between July 1999 and October 2024. By type: 7 contaminant level above the legal limit, 3 monitoring and reporting, 1 reporting and 1 required treatment not met. The contaminant or rule involved most often is Total coliform bacteria (TCR) (6 of them). EPA lists 6 as resolved, 4 as archived and 2 as unaddressed. 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. Archived means the violation was not marked resolved but is more than five years past the end of the noncompliance period, so it no longer counts toward current compliance status. Unaddressed means the violation is not resolved or archived and is not yet covered by formal enforcement.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2024-10-17 | ReportingLSL Reporting · code 4G | Lead and Copper Rule Revisionscode 5200 | No | Unaddressed |
| 2024-10-17 | Required treatment not metLSL Inventory · code 2E | Lead and Copper Rule Revisionscode 5200 | Yes | Unaddressed |
| 2021-09-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, E. coli (RTCR) · code 1A | Revised Total Coliform Rulecode 8000 | Yes | Resolved |
| 2017-08-22 | Monitoring and reportingMonitoring, Source Water (GWR) · code 34 | E. colicode 3014 | No | Resolved |
| 2014-08-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2013-09-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2007-08-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2005-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2004-08-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Archived |
| 2000-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Archived |
| 1999-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | Gross Beta Particle Activitycode 4100 | No | Archived |
| 1999-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | Strontium-90code 4174 | No | Archived |
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.
Otis Air National Guard Base: frequently asked questions
Who runs Otis Air National Guard Base?
Otis Air National Guard Base (PWSID MA4096001) is a community water system owned by the federal government. It is regulated by the MA state drinking water program.
How many people does Otis Air National Guard Base serve?
Otis Air National Guard Base reports serving 6,000 people through 337 service connections in Barnstable County, Massachusetts.
Where does Otis Air National Guard Base 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 Otis Air National Guard Base have any drinking water violations?
Of the 12 most recent violations in EPA's records, 8 are health-based, and the most recent began in October 2024. 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 Otis Air National Guard Base'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, 8 are health-based, and the most recent began in October 2024. For current results, consult the system's annual water quality report, EPA ECHO, or the MA state drinking water program.
Where can I find Otis Air National Guard Base's water quality report?
As a community water system, Otis Air National Guard Base must deliver an annual water quality report, called a Consumer Confidence Report, to its customers by July 1 each year, covering the previous calendar year. The system can provide a copy on request.
Other water systems in Barnstable County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Falmouth Water Dept | Barnstable | 97,551 | Community | Surface water |
| Dennis Water District | Barnstable | 65,000 | Community | Groundwater |
| Upper Cape Regional Water Cooperative | Barnstable | 56,250 | Community | Groundwater |
| Centerville Osterville Marstons Mills Wd | Barnstable | 50,000 | Community | Groundwater |
| Harwich Water Department | Barnstable | 39,144 | Community | Groundwater |
| Yarmouth Water Department | Barnstable | 38,900 | Community | Groundwater |
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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, “Otis Air National Guard Base, PWSID MA4096001, Massachusetts”, https://aquacensus.com/water-systems/massachusetts/otis-air-national-guard-base-ma4096001 (data as of October 1, 2026).