Public water system · WA5390260
ActiveUnion Hill Water Association Inc.
At a glance
Union Hill Water Association Inc. (PWSID WA5390260) is an active community water system in King County, Washington. It reports serving 8,720 people through 2,104 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 July 2013.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
8,720
Service connections
2,104
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Union Hill Water Association Inc. compare with other water systems in King County?
By EPA's size categories, Union Hill Water Association Inc. is a medium system (3,301 to 10,000 people). King County has 214 active public water systems. Its population served is about 44% below the county average of 15,523 people per system, and accounts for 0.3% 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 Union Hill Water Association Inc. is about 30% above 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 Union Hill Water Association Inc.?
EPA lists Union Hill Water Association Inc. 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 Union Hill Water Association Inc. 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 2013. The violations listed here began between January 2005 and July 2013. By type: 10 monitoring and reporting and 2 public notice, recordkeeping or other. The contaminant or rule involved most often is Consumer Confidence Rule (2 of them). 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 |
|---|---|---|---|---|
| 2013-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2010-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2005-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Toxaphenecode 2020 | No | Resolved |
| 2005-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Styrenecode 2996 | No | Resolved |
| 2005-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Picloramcode 2040 | No | Resolved |
| 2005-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Dalaponcode 2031 | No | Resolved |
| 2005-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Benzenecode 2990 | No | Resolved |
| 2005-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 2,4,5-TP (Silvex)code 2110 | No | Resolved |
| 2005-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Ethylbenzenecode 2992 | No | Resolved |
| 2005-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Lindane (gamma-BHC)code 2010 | No | Resolved |
| 2005-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Di(2-ethylhexyl) adipatecode 2035 | No | Resolved |
| 2005-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Aldicarb sulfoxidecode 2043 | 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.
Union Hill Water Association Inc.: frequently asked questions
Who runs Union Hill Water Association Inc.?
Union Hill Water Association Inc. (PWSID WA5390260) is a community water system privately owned. It is regulated by the WA state drinking water program.
How many people does Union Hill Water Association Inc. serve?
Union Hill Water Association Inc. reports serving 8,720 people through 2,104 service connections in King County, Washington.
Where does Union Hill Water Association Inc. 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 Union Hill Water Association Inc. 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 2013. 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 Union Hill Water Association Inc.'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 2013. For current results, consult the system's annual water quality report, EPA ECHO, or the WA state drinking water program.
Where can I find Union Hill Water Association Inc.'s water quality report?
As a community water system, Union Hill Water Association Inc. 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 |
Related pages
Working with water-system records? Pro adds alerts, change history and CSV export ($49/mo); Enterprise adds full national files, the API and an MCP server for AI tools.
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, “Union Hill Water Association Inc., PWSID WA5390260, Washington”, https://aquacensus.com/water-systems/washington/union-hill-water-association-inc-wa5390260 (data as of October 1, 2026).