Public water system · WA5374375
ActiveRosemount
At a glance
Rosemount (PWSID WA5374375) is an active community water system in Pierce County, Washington. It reports serving 320 people through 121 service connections. Its primary water source is groundwater, and EPA lists it as privately owned. EPA's records list 4 violations for this system; 3 are health-based, and the most recent began in February 1994.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
320
Service connections
121
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Rosemount compare with other water systems in Pierce County?
By EPA's size categories, Rosemount is a very small system (500 people or fewer). Pierce County has 358 active public water systems. Its population served is well below the county average of 3,335 people per system, and accounts for less than 0.1% of the 1,193,797 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 Rosemount 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 Rosemount?
EPA lists Rosemount 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. 257 of the 358 active systems in Pierce County (72%) are also privately owned.
Does Rosemount have drinking water violations?
EPA's records list 4 violations for this system; 3 are health-based, and the most recent began in February 1994. The violations listed here began between October 1979 and February 1994. By type: 3 contaminant level above the legal limit and 1 monitoring and reporting. The contaminant or rule involved most often is Total coliform bacteria (TCR) (3 of them). EPA lists 4 as archived. 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 |
|---|---|---|---|---|
| 1994-02-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Archived |
| 1994-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Archived |
| 1993-08-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Archived |
| 1979-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Gross alpha (excluding radon and uranium)code 4000 | No | Archived |
All 4 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.
Rosemount: frequently asked questions
Who runs Rosemount?
Rosemount (PWSID WA5374375) is a community water system privately owned. It is regulated by the WA state drinking water program.
How many people does Rosemount serve?
Rosemount reports serving 320 people through 121 service connections in Pierce County, Washington.
Where does Rosemount 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 Rosemount have any drinking water violations?
EPA's records list 4 violations for this system; 3 are health-based, and the most recent began in February 1994. 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 Rosemount'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. EPA's records list 4 violations for this system; 3 are health-based, and the most recent began in February 1994. For current results, consult the system's annual water quality report, EPA ECHO, or the WA state drinking water program.
Where can I find Rosemount's water quality report?
As a community water system, Rosemount 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 Pierce County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Tacoma Water Division City of | Pierce | 446,170 | Community | Surface water |
| Puyallup City of | Pierce | 94,520 | Community | Purchased surface water |
| Lakewood Water District | Pierce | 82,425 | Community | Groundwater |
| Southwood | Pierce | 64,155 | Community | Purchased surface water |
| Bonney Lake Water Department City | Pierce | 43,371 | Community | Purchased surface water |
| Firgrove Mutual Inc. | Pierce | 36,168 | Community | Purchased surface water |
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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, “Rosemount, PWSID WA5374375, Washington”, https://aquacensus.com/water-systems/washington/rosemount-wa5374375 (data as of October 1, 2026).