Public water system · WA5397750
ActiveWinthrop Town of
At a glance
Town of Winthrop (PWSID WA5397750) is an active community water system in Okanogan County, Washington. It reports serving 1,350 people through 484 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, one is health-based, and the most recent began in December 2024.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
1,350
Service connections
484
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Town of Winthrop compare with other water systems in Okanogan County?
By EPA's size categories, Town of Winthrop is a small system (501 to 3,300 people). Okanogan County has 119 active public water systems. Its population served is about 3.5 times the county average of 383 people per system, and accounts for 3% of the 45,608 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 Town of Winthrop 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 Town of Winthrop?
EPA lists Town of Winthrop 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. 16 of the 119 active systems in Okanogan County (13%) are also owned by a local government.
Does Town of Winthrop have drinking water violations?
Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in December 2024. The violations listed here began between November 2003 and December 2024. By type: 4 monitoring, 4 monitoring and reporting, 3 public notice, recordkeeping or other and 1 contaminant level above the legal limit. The contaminant or rule involved most often is Revised Total Coliform Rule (4 of them). EPA lists 11 as resolved and 1 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 |
|---|---|---|---|---|
| 2024-12-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2024-08-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2024-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2024-06-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2024-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 2022-01-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2018-01-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2016-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2011-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2009-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 2009-01-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2003-11-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Archived |
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.
Town of Winthrop: frequently asked questions
Who runs Town of Winthrop?
Town of Winthrop (PWSID WA5397750) is a community water system owned by a local government. It is regulated by the WA state drinking water program.
How many people does Town of Winthrop serve?
Town of Winthrop reports serving 1,350 people through 484 service connections in Okanogan County, Washington.
Where does Town of Winthrop 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 Town of Winthrop have any drinking water violations?
Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in December 2024. 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 Town of Winthrop'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, one is health-based, and the most recent began in December 2024. For current results, consult the system's annual water quality report, EPA ECHO, or the WA state drinking water program.
Where can I find Town of Winthrop's water quality report?
As a community water system, Town of Winthrop 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 Okanogan County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Omak City of | Okanogan | 4,940 | Community | Groundwater |
| Brewster City of | Okanogan | 3,843 | Community | Groundwater |
| Okanogan Water Department City of | Okanogan | 3,817 | Community | Groundwater |
| Oroville City of | Okanogan | 3,256 | Community | Groundwater |
| Tonasket Water System | Okanogan | 2,398 | Community | Groundwater |
| Pearrygin Lake State Park - Both Cg | Okanogan | 2,103 | Transient non-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, “Winthrop Town of, PWSID WA5397750, Washington”, https://aquacensus.com/water-systems/washington/winthrop-town-of-wa5397750 (data as of October 1, 2026).