Public water system · WA5397500
ActiveWinlock City of
At a glance
City of Winlock (PWSID WA5397500) is an active community water system in Lewis County, Washington. It reports serving 3,502 people through 1,040 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, none is health-based, and the most recent began in July 2014.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
3,502
Service connections
1,040
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does City of Winlock compare with other water systems in Lewis County?
By EPA's size categories, City of Winlock is a medium system (3,301 to 10,000 people). Lewis County has 166 active public water systems, and City of Winlock is the 3rd-largest of them by population served. Its population served is about 6.5 times the county average of 537 people per system, and accounts for 3.9% of the 89,186 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 City of Winlock is about half of 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 City of Winlock?
EPA lists City of Winlock 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. 37 of the 166 active systems in Lewis County (22%) are also owned by a local government.
Does City of Winlock 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 2014. The violations listed here began between April 2008 and July 2014. By type: 9 monitoring and reporting and 3 public notice, recordkeeping or other. The contaminant or rule involved most often is Consumer Confidence Rule (3 of them). EPA lists 8 as archived and 4 as resolved. 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. 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 |
|---|---|---|---|---|
| 2014-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2012-07-01 | 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 |
| 2010-06-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2008-04-01 | Monitoring and reportingMonitoring, Regular · code 03 | Aldicarb sulfoxidecode 2043 | No | Archived |
| 2008-04-01 | Monitoring and reportingMonitoring, Regular · code 03 | Oxamylcode 2036 | No | Archived |
| 2008-04-01 | Monitoring and reportingMonitoring, Regular · code 03 | Benzo(a)pyrenecode 2306 | No | Archived |
| 2008-04-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,2,4-Trichlorobenzenecode 2378 | No | Archived |
| 2008-04-01 | Monitoring and reportingMonitoring, Regular · code 03 | Heptachlorcode 2065 | No | Archived |
| 2008-04-01 | Monitoring and reportingMonitoring, Regular · code 03 | Atrazinecode 2050 | No | Archived |
| 2008-04-01 | Monitoring and reportingMonitoring, Regular · code 03 | Ethylbenzenecode 2992 | No | Archived |
| 2008-04-01 | Monitoring and reportingMonitoring, Regular · code 03 | Toluenecode 2991 | No | 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.
City of Winlock: frequently asked questions
Who runs City of Winlock?
City of Winlock (PWSID WA5397500) is a community water system owned by a local government. It is regulated by the WA state drinking water program.
How many people does City of Winlock serve?
City of Winlock reports serving 3,502 people through 1,040 service connections in Lewis County, Washington.
Where does City of Winlock 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 City of Winlock 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 2014. 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 City of Winlock'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 2014. For current results, consult the system's annual water quality report, EPA ECHO, or the WA state drinking water program.
Where can I find City of Winlock's water quality report?
As a community water system, City of Winlock 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 Lewis County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Centralia Public Works - Water | Lewis | 28,164 | Community | Groundwater |
| Chehalis Water Department | Lewis | 11,718 | Community | Surface water |
| Napavine City of | Lewis | 3,095 | Community | Groundwater |
| Boistfort Valley | Lewis | 2,389 | Community | Surface water |
| Morton City of | Lewis | 2,147 | Community | Surface water |
| White Pass Company Inc. | Lewis | 2,094 | Non-transient non-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, “Winlock City of, PWSID WA5397500, Washington”, https://aquacensus.com/water-systems/washington/winlock-city-of-wa5397500 (data as of October 1, 2026).