Public water system · WA53AD423
ActiveSundquist Twh-Terrace Heights
At a glance
Sundquist Twh-Terrace Heights (PWSID WA53AD423) is an active community water system in Yakima County, Washington. It reports serving 192 people through 1 service connection. Its primary water source is groundwater, and EPA lists it as privately owned. EPA's records list 3 violations for this system; none is health-based, and the most recent began in September 2019.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
192
Service connections
1
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Sundquist Twh-Terrace Heights compare with other water systems in Yakima County?
By EPA's size categories, Sundquist Twh-Terrace Heights is a very small system (500 people or fewer). Yakima County has 217 active public water systems. Its population served is well below the county average of 1,230 people per system, and accounts for less than 0.1% 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 Sundquist Twh-Terrace Heights 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 Sundquist Twh-Terrace Heights?
EPA lists Sundquist Twh-Terrace Heights 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. 182 of the 217 active systems in Yakima County (84%) are also privately owned.
Does Sundquist Twh-Terrace Heights have drinking water violations?
EPA's records list 3 violations for this system; none is health-based, and the most recent began in September 2019. The violations listed here began between July 2018 and September 2019. By type: 2 monitoring and 1 monitoring and reporting. The contaminant or rule involved most often is Revised Total Coliform Rule (2 of them). EPA lists 3 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 |
|---|---|---|---|---|
| 2019-09-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2019-08-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2018-07-01 | Monitoring and reportingInitial Tap Sampling for Pb and Cu · code 51 | Lead and Copper Rulecode 5000 | No | Resolved |
All 3 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.
Sundquist Twh-Terrace Heights: frequently asked questions
Who runs Sundquist Twh-Terrace Heights?
Sundquist Twh-Terrace Heights (PWSID WA53AD423) is a community water system privately owned. It is regulated by the WA state drinking water program.
How many people does Sundquist Twh-Terrace Heights serve?
Sundquist Twh-Terrace Heights reports serving 192 people through 1 service connection in Yakima County, Washington.
Where does Sundquist Twh-Terrace Heights 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 Sundquist Twh-Terrace Heights have any drinking water violations?
EPA's records list 3 violations for this system; none is health-based, and the most recent began in September 2019. 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 Sundquist Twh-Terrace Heights' 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 3 violations for this system; none is health-based, and the most recent began in September 2019. For current results, consult the system's annual water quality report, EPA ECHO, or the WA state drinking water program.
Where can I find Sundquist Twh-Terrace Heights' water quality report?
As a community water system, Sundquist Twh-Terrace Heights 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, “Sundquist Twh-Terrace Heights, PWSID WA53AD423, Washington”, https://aquacensus.com/water-systems/washington/sundquist-twh-terrace-heights-wa53ad423 (data as of October 1, 2026).