Public water system · WA5390250
ActiveUnion Gap Water
At a glance
Union Gap Water (PWSID WA5390250) is an active community water system in Yakima County, Washington. It reports serving 6,433 people through 1,981 service connections. Its primary water source is groundwater, 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 December 2017.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
6,433
Service connections
1,981
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Union Gap Water compare with other water systems in Yakima County?
By EPA's size categories, Union Gap Water is a medium system (3,301 to 10,000 people). Yakima County has 217 active public water systems. Its population served is about 5.2 times the county average of 1,230 people per system, and accounts for 2.4% of the 266,832 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 Gap Water is roughly in line with 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 Gap Water?
EPA lists Union Gap Water 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. 21 of the 217 active systems in Yakima County (9.7%) are also owned by a local government.
Does Union Gap Water have drinking water violations?
Of the 12 most recent violations in EPA's records, 3 are health-based, and the most recent began in December 2017. The violations listed here began between January 1999 and December 2017. By type: 8 monitoring and reporting, 3 contaminant level above the legal limit and 1 monitoring. The contaminant or rule involved most often is Total coliform bacteria (TCR) (3 of them). EPA lists 8 as resolved and 4 as archived. 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. 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 |
|---|---|---|---|---|
| 2017-12-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2008-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Aldicarbcode 2047 | No | Resolved |
| 2008-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Carbofurancode 2046 | No | Resolved |
| 2008-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Aldicarb sulfonecode 2044 | No | Resolved |
| 2008-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Oxamylcode 2036 | No | Resolved |
| 2008-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Aldicarb sulfoxidecode 2043 | No | Resolved |
| 2006-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Diquatcode 2032 | No | Resolved |
| 2006-07-01 | Monitoring and reportingMonitoring, Regular · code 03 | Diquatcode 2032 | No | Archived |
| 2005-02-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Archived |
| 2004-11-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Archived |
| 1999-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Archived |
| 1999-01-01 | Monitoring and reportingInitial Tap Sampling for Pb and Cu · code 51 | Lead and Copper Rulecode 5000 | 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 Gap Water: frequently asked questions
Who runs Union Gap Water?
Union Gap Water (PWSID WA5390250) is a community water system owned by a local government. It is regulated by the WA state drinking water program.
How many people does Union Gap Water serve?
Union Gap Water reports serving 6,433 people through 1,981 service connections in Yakima County, Washington.
Where does Union Gap Water 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 Gap Water 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 December 2017. 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 Gap Water'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 December 2017. 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 Gap Water's water quality report?
As a community water system, Union Gap Water 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 Yakima County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Yakima Water Division City of | Yakima | 112,858 | Community | Surface water |
| Nob Hill Water Association | Yakima | 38,050 | Community | Groundwater |
| Sunnyside City of | Yakima | 17,194 | Community | Groundwater |
| Grandview City of | Yakima | 11,010 | Community | Groundwater |
| Selah City of | Yakima | 9,331 | Community | Groundwater |
| Toppenish Water Department | Yakima | 8,950 | 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, “Union Gap Water, PWSID WA5390250, Washington”, https://aquacensus.com/water-systems/washington/union-gap-water-wa5390250 (data as of October 1, 2026).