Public water system · WA5352550
ActiveSunnyslope Mutual Water System
At a glance
Sunnyslope Mutual Water System (PWSID WA5352550) is an active community water system in King County, Washington. It reports serving 85 people through 38 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 January 2023.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
85
Service connections
38
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Sunnyslope Mutual Water System compare with other water systems in King County?
By EPA's size categories, Sunnyslope Mutual 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 Sunnyslope Mutual 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. 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 Sunnyslope Mutual Water System?
EPA lists Sunnyslope Mutual 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 Sunnyslope Mutual 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 January 2023. The violations listed here began between January 2005 and January 2023. By type: 12 monitoring and reporting. The contaminants or rules involved are Lead and Copper Rule, Total coliform bacteria (TCR), 1,2,4-Trichlorobenzene and Atrazine. EPA lists 11 as resolved 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. 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 |
|---|---|---|---|---|
| 2023-01-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Unaddressed |
| 2014-09-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2005-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,2,4-Trichlorobenzenecode 2378 | No | Resolved |
| 2005-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Atrazinecode 2050 | No | Resolved |
| 2005-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,1-Dichloroethylenecode 2977 | No | Resolved |
| 2005-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Bariumcode 1010 | No | Resolved |
| 2005-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Chlorobenzenecode 2989 | No | Resolved |
| 2005-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,2-Dichloropropanecode 2983 | No | Resolved |
| 2005-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | cis-1,2-Dichloroethylenecode 2380 | No | Resolved |
| 2005-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Styrenecode 2996 | No | Resolved |
| 2005-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nickelcode 1036 | No | Resolved |
| 2005-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Toluenecode 2991 | 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.
Sunnyslope Mutual Water System: frequently asked questions
Who runs Sunnyslope Mutual Water System?
Sunnyslope Mutual Water System (PWSID WA5352550) is a community water system privately owned. It is regulated by the WA state drinking water program.
How many people does Sunnyslope Mutual Water System serve?
Sunnyslope Mutual Water System reports serving 85 people through 38 service connections in King County, Washington.
Where does Sunnyslope Mutual 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 Sunnyslope Mutual 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 January 2023. 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 Sunnyslope Mutual 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 January 2023. For current results, consult the system's annual water quality report, EPA ECHO, or the WA state drinking water program.
Where can I find Sunnyslope Mutual Water System's water quality report?
As a community water system, Sunnyslope Mutual 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, “Sunnyslope Mutual Water System, PWSID WA5352550, Washington”, https://aquacensus.com/water-systems/washington/sunnyslope-mutual-water-system-wa5352550 (data as of October 1, 2026).