Public water system · WA5344200
ActiveLake Margaret Water System
At a glance
Lake Margaret Water System (PWSID WA5344200) is an active community water system in King County, Washington. It reports serving 406 people through 152 service connections. Its primary water source is surface water, 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 July 2025.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
406
Service connections
152
Primary source
SW
Surface water
System type
CWS
Community water system
System record
How does Lake Margaret Water System compare with other water systems in King County?
By EPA's size categories, Lake Margaret Water System is a very small system (500 people or fewer). King County has 214 active public water systems. Its population served is well below the county average of 15,523 people per system, and accounts for less than 0.1% of the 3,321,960 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 Lake Margaret Water System is well 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. Washington has 2,392 active community water systems, 51% of the state's 4,705 active systems. Surface water means the system draws its water from rivers, lakes, streams or reservoirs. 140 Washington systems (3%) list surface water as their primary source.
Who owns and regulates Lake Margaret Water System?
EPA lists Lake Margaret 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. 142 of the 214 active systems in King County (66%) are also privately owned.
Does Lake Margaret 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 July 2025. The violations listed here began between January 2024 and July 2025. By type: 11 monitoring and reporting and 1 public notice, recordkeeping or other. The contaminants or rules involved are Consumer Confidence Rule, 1,2,4-Trichlorobenzene, o-Dichlorobenzene and 1,1-Dichloroethylene. 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 |
|---|---|---|---|---|
| 2025-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,2,4-Trichlorobenzenecode 2378 | No | Resolved |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | o-Dichlorobenzenecode 2968 | No | Resolved |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,1-Dichloroethylenecode 2977 | No | Resolved |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,2-Dichloroethanecode 2980 | No | Resolved |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Chlorobenzenecode 2989 | No | Resolved |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Vinyl chloridecode 2976 | No | Resolved |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | p-Dichlorobenzenecode 2969 | No | Resolved |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Styrenecode 2996 | No | Resolved |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Ethylbenzenecode 2992 | No | Resolved |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Toluenecode 2991 | No | Resolved |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | trans-1,2-Dichloroethylenecode 2979 | 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.
Lake Margaret Water System: frequently asked questions
Who runs Lake Margaret Water System?
Lake Margaret Water System (PWSID WA5344200) is a community water system privately owned. It is regulated by the WA state drinking water program.
How many people does Lake Margaret Water System serve?
Lake Margaret Water System reports serving 406 people through 152 service connections in King County, Washington.
Where does Lake Margaret Water System get its water?
EPA SDWIS lists this system's primary water source as surface water. Surface water means the system draws its water from rivers, lakes, streams or reservoirs.
Does Lake Margaret 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 July 2025. 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 Lake Margaret 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 July 2025. For current results, consult the system's annual water quality report, EPA ECHO, or the WA state drinking water program.
Where can I find Lake Margaret Water System's water quality report?
As a community water system, Lake Margaret 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 King County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Seattle Public Utilities | King | 1,161,961 | Community | Surface water |
| Bellevue City of | King | 321,349 | Community | Purchased surface water |
| Kent Water Department | King | 166,421 | Community | Purchased surface water |
| Redmond Water System City of | King | 163,335 | Community | Purchased surface water |
| Lakehaven Water and Sewer District | King | 148,809 | Community | Purchased surface water |
| Renton City of | King | 108,091 | 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, “Lake Margaret Water System, PWSID WA5344200, Washington”, https://aquacensus.com/water-systems/washington/lake-margaret-water-system-wa5344200 (data as of October 1, 2026).