Public water system · WA5301300
ActiveAlderwood Water District
At a glance
Alderwood Water District (PWSID WA5301300) is an active community water system in Snohomish County, Washington. It reports serving 245,715 people through 85,285 service connections. Its primary water source is purchased surface water, and EPA lists it as owned by a local government. EPA's records list 5 violations for this system; none is health-based, and the most recent began in December 1992.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
245,715
Service connections
85,285
Primary source
SWP
Purchased surface water
System type
CWS
Community water system
System record
How does Alderwood Water District compare with other water systems in Snohomish County?
By EPA's size categories, Alderwood Water District is a very large system (more than 100,000 people). Snohomish County has 167 active public water systems, and Alderwood Water District is the largest of them by population served. Its population served is about 40 times the county average of 6,200 people per system, and accounts for 24% 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 Alderwood Water District is about 37 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 Alderwood Water District?
EPA lists Alderwood Water District 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 Alderwood Water District have drinking water violations?
EPA's records list 5 violations for this system; none is health-based, and the most recent began in December 1992. The violations listed here began between December 1991 and December 1992. By type: 5 monitoring and reporting. The contaminant or rule involved most often is Total coliform bacteria (TCR) (5 of them). EPA lists 5 as archived. 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.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 1992-12-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Archived |
| 1992-11-01 | Monitoring and reportingMonitoring, Repeat Minor (TCR) · code 26 | Total coliform bacteria (TCR)code 3100 | No | Archived |
| 1992-10-01 | Monitoring and reportingMonitoring, Repeat Minor (TCR) · code 26 | Total coliform bacteria (TCR)code 3100 | No | Archived |
| 1992-08-01 | Monitoring and reportingMonitoring, Repeat Minor (TCR) · code 26 | Total coliform bacteria (TCR)code 3100 | No | Archived |
| 1991-12-01 | Monitoring and reportingMonitoring, Repeat Minor (TCR) · code 26 | Total coliform bacteria (TCR)code 3100 | No | Archived |
All 5 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.
Alderwood Water District: frequently asked questions
Who runs Alderwood Water District?
Alderwood Water District (PWSID WA5301300) is a community water system owned by a local government. It is regulated by the WA state drinking water program.
How many people does Alderwood Water District serve?
Alderwood Water District reports serving 245,715 people through 85,285 service connections in Snohomish County, Washington.
Where does Alderwood Water District 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 Alderwood Water District have any drinking water violations?
EPA's records list 5 violations for this system; none is health-based, and the most recent began in December 1992. 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 Alderwood Water District'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. EPA's records list 5 violations for this system; none is health-based, and the most recent began in December 1992. For current results, consult the system's annual water quality report, EPA ECHO, or the WA state drinking water program.
Where can I find Alderwood Water District's water quality report?
As a community water system, Alderwood Water District 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 |
|---|---|---|---|---|
| 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 |
| Edmonds City of | Snohomish | 34,065 | 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, “Alderwood Water District, PWSID WA5301300, Washington”, https://aquacensus.com/water-systems/washington/alderwood-water-district-wa5301300 (data as of October 1, 2026).