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Public water system · WA5310811

Active

Maxwelton Water System

At a glance

Maxwelton Water System (PWSID WA5310811) is an active non-transient non-community water system in Island County, Washington. It reports serving 1,700 people through 5 service connections. Its primary water source is groundwater, and EPA lists it as privately owned. Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in February 2026.

Dataset updated . Source: EPA SDWIS/ECHO public records.

Population served

1,700

Service connections

5

Primary source

GW

Groundwater

System type

NTNCWS

Non-transient non-community water system

System record

PWSIDWA5310811
System typeNon-transient non-community water system
Activity statusActive
Population served1,700
Service connections5
Primary water sourceGroundwater
Owner typePrivate
Primacy agencyWA state drinking water program
City served—
StateWashington
ZIP—
CountyIsland County

How does Maxwelton Water System compare with other water systems in Island County?

By EPA's size categories, Maxwelton Water System is a small system (501 to 3,300 people). Island County has 307 active public water systems. Its population served is about 5.1 times the county average of 335 people per system, and accounts for 1.7% of the 102,977 people reported by systems filed under the county. Across Washington, the 4,705 active systems average 2,172 people each. Nationally, the average active non-transient non-community water system reports serving 430 people, so Maxwelton Water System is about 4 times 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. Washington has 400 active non-transient non-community water systems, 8.5% of the state's 4,705 active systems. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 4,370 Washington systems (93%) list groundwater as their primary source.

Who owns and regulates Maxwelton Water System?

EPA lists Maxwelton Water System as privately owned. The WA state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 274 of the 307 active systems in Island County (89%) are also privately owned.

Does Maxwelton Water System have drinking water violations?

Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in February 2026. The violations listed here began between January 2020 and February 2026. By type: 11 monitoring and reporting and 1 monitoring. The contaminant or rule involved most often is Total trihalomethanes (TTHM) (3 of them). EPA lists 6 as resolved, 5 as archived and 1 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.

BeganViolationContaminant or ruleHealth-basedStatus
2026-02-01MonitoringMonitoring, Routine (RTCR) · code 3ARevised Total Coliform Rulecode 8000NoResolved
2025-01-01Monitoring and reportingMonitoring and Reporting (DBP) · code 27Total trihalomethanes (TTHM)code 2950NoArchived
2025-01-01Monitoring and reportingMonitoring and Reporting (DBP) · code 27Haloacetic acids (HAA5)code 2456NoArchived
2024-01-01Monitoring and reportingMonitoring, Regular · code 03Nitratecode 1040NoResolved
2024-01-01Monitoring and reportingMonitoring and Reporting (DBP) · code 27Total trihalomethanes (TTHM)code 2950NoResolved
2024-01-01Monitoring and reportingMonitoring and Reporting (DBP) · code 27Haloacetic acids (HAA5)code 2456NoResolved
2023-01-01Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52Lead and Copper Rulecode 5000NoUnaddressed
2022-01-01Monitoring and reportingMonitoring and Reporting (DBP) · code 27Haloacetic acids (HAA5)code 2456NoResolved
2022-01-01Monitoring and reportingMonitoring and Reporting (DBP) · code 27Total trihalomethanes (TTHM)code 2950NoResolved
2020-01-01Monitoring and reportingMonitoring, Regular · code 03Tetrachloroethylenecode 2987NoArchived
2020-01-01Monitoring and reportingMonitoring, Regular · code 03Styrenecode 2996NoArchived
2020-01-01Monitoring and reportingMonitoring, Regular · code 03Benzenecode 2990NoArchived

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.

Maxwelton Water System: frequently asked questions

Who runs Maxwelton Water System?

Maxwelton Water System (PWSID WA5310811) is a non-transient non-community water system privately owned. It is regulated by the WA state drinking water program.

How many people does Maxwelton Water System serve?

Maxwelton Water System reports serving 1,700 people through 5 service connections in Island County, Washington.

Where does Maxwelton Water System 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 Maxwelton Water System have any drinking water violations?

Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in February 2026. 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 Maxwelton Water System'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, none is health-based, and the most recent began in February 2026. For current results, consult EPA ECHO, or the WA state drinking water program.

Where can I find Maxwelton Water System's water quality report?

The annual Consumer Confidence Report requirement applies to community water systems. Maxwelton Water System 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 Island County

Water systemCountyPopulation servedTypeSource
Oak Harbor City ofIsland23,675CommunityPurchased surface water
Naval Air Station/Whidbey IslandIsland16,595CommunityPurchased surface water
Coupeville Town ofIsland4,142CommunityGroundwater
Camano Water AssociationIsland2,592CommunityGroundwater
Clinton Water DistrictIsland1,980CommunityGroundwater
Camano Island State ParkIsland1,718Transient non-communityGroundwater

Related pages

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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, “Maxwelton Water System, PWSID WA5310811, Washington”, https://aquacensus.com/water-systems/washington/maxwelton-water-system-wa5310811 (data as of October 1, 2026).