Public water system · WA5355820
ActiveMonroe Water System
At a glance
Monroe Water System (PWSID WA5355820) is an active community water system in Snohomish County, Washington. It reports serving 23,467 people through 8,699 service connections. Its primary water source is purchased surface water, and EPA lists it as owned by a local government. Of the 12 most recent violations in EPA's records, 3 are health-based, and the most recent began in July 2024.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
23,467
Service connections
8,699
Primary source
SWP
Purchased surface water
System type
CWS
Community water system
System record
How does Monroe Water System compare with other water systems in Snohomish County?
By EPA's size categories, Monroe Water System is a large system (10,001 to 100,000 people). Snohomish County has 167 active public water systems. Its population served is about 3.8 times the county average of 6,200 people per system, and accounts for 2.3% of the 1,035,433 people reported by systems filed under the county. Across Washington, the 4,705 active systems average 2,172 people each. Nationally, the average active community water system reports serving 6,703 people, so Monroe Water System is about 3.5 times 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. Washington has 2,392 active community water systems, 51% of the state's 4,705 active systems. Purchased surface water means the system buys surface water from another public water system rather than drawing its own. 130 Washington systems (2.8%) list purchased surface water as their primary source.
Who owns and regulates Monroe Water System?
EPA lists Monroe Water System as owned by a local government. 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. 36 of the 167 active systems in Snohomish County (22%) are also owned by a local government.
Does Monroe Water System have drinking water violations?
Of the 12 most recent violations in EPA's records, 3 are health-based, and the most recent began in July 2024. The violations listed here began between December 1991 and July 2024. By type: 5 monitoring and reporting, 4 public notice, recordkeeping or other and 3 contaminant level above the legal limit. The contaminant or rule involved most often is Total coliform bacteria (TCR) (8 of them). EPA lists 8 as archived and 4 as resolved. 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. 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 |
|---|---|---|---|---|
| 2024-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2022-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2018-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2011-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2003-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Archived |
| 1998-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Archived |
| 1997-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Archived |
| 1992-10-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Archived |
| 1992-09-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Archived |
| 1992-02-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Archived |
| 1992-01-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Archived |
| 1991-12-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | 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.
Monroe Water System: frequently asked questions
Who runs Monroe Water System?
Monroe Water System (PWSID WA5355820) is a community water system owned by a local government. It is regulated by the WA state drinking water program.
How many people does Monroe Water System serve?
Monroe Water System reports serving 23,467 people through 8,699 service connections in Snohomish County, Washington.
Where does Monroe Water System get its water?
EPA SDWIS lists this system's primary water source as purchased surface water. Purchased surface water means the system buys surface water from another public water system rather than drawing its own.
Does Monroe Water System have any drinking water violations?
Of the 12 most recent violations in EPA's records, 3 are health-based, and the most recent began in July 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 Monroe 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, 3 are health-based, and the most recent began in July 2024. For current results, consult the system's annual water quality report, EPA ECHO, or the WA state drinking water program.
Where can I find Monroe Water System's water quality report?
As a community water system, Monroe Water System 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 Snohomish County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Alderwood Water District | Snohomish | 245,715 | Community | Purchased surface water |
| Everett Public Works Dept. City of | Snohomish | 215,774 | Community | Surface water |
| Marysville Utilities | Snohomish | 88,582 | Community | Purchased surface water |
| Lynnwood City of | Snohomish | 68,204 | Community | Purchased surface water |
| Sno PUD 1 - Lake Stevens | Snohomish | 67,710 | Community | Purchased surface water |
| Silver Lake Water & Sewer District | Snohomish | 65,033 | Community | Purchased surface water |
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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, “Monroe Water System, PWSID WA5355820, Washington”, https://aquacensus.com/water-systems/washington/monroe-water-system-wa5355820 (data as of October 1, 2026).