Public water system · WA5338000
ActiveKelso City of
At a glance
City of Kelso (PWSID WA5338000) is an active community water system in Cowlitz County, Washington. It reports serving 15,775 people through 5,082 service connections. Its primary water source is groundwater under influence of surface water, 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 2018.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
15,775
Service connections
5,082
Primary source
GU
Groundwater under influence of surface water
System type
CWS
Community water system
System record
How does City of Kelso compare with other water systems in Cowlitz County?
By EPA's size categories, City of Kelso is a large system (10,001 to 100,000 people). Cowlitz County has 77 active public water systems, and City of Kelso is the 2nd-largest of them by population served. Its population served is about 9.7 times the county average of 1,628 people per system, and accounts for 13% of the 125,351 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 Kelso is about 135% above 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 under the influence of surface water is well or spring water that the regulator has found to be affected by nearby surface water, so it is regulated under the surface-water treatment rules. 9 Washington systems (0.2%) list groundwater under influence of surface water as their primary source.
Who owns and regulates City of Kelso?
EPA lists City of Kelso 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. 14 of the 77 active systems in Cowlitz County (18%) are also owned by a local government.
Does City of Kelso 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 2018. The violations listed here began between October 1979 and December 2018. By type: 10 monitoring and reporting, 1 public notice, recordkeeping or other and 1 required treatment not met. The contaminants or rules involved are Long Term 2 Enhanced Surface Water Treatment Rule, Consumer Confidence Rule, Surface Water Treatment Rule and Total coliform bacteria (TCR). EPA lists 10 as archived and 2 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 |
|---|---|---|---|---|
| 2018-12-01 | Monitoring and reportingMonitoring of Treatment (SWTR-Filter) · code 36 | Long Term 2 Enhanced Surface Water Treatment Rulecode 0800 | No | Resolved |
| 2011-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2000-01-01 | Required treatment not metFailure to Filter (SWTR) · code 42 | Surface Water Treatment Rulecode 0200 | Yes | Archived |
| 1992-01-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Archived |
| 1979-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Fluoridecode 1025 | No | Archived |
| 1979-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Arseniccode 1005 | No | Archived |
| 1979-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Bariumcode 1010 | No | Archived |
| 1979-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Chromiumcode 1020 | No | Archived |
| 1979-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Cadmiumcode 1015 | No | Archived |
| 1979-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Mercurycode 1035 | No | Archived |
| 1979-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Gross alpha (excluding radon and uranium)code 4000 | No | Archived |
| 1979-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | 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 Kelso: frequently asked questions
Who runs City of Kelso?
City of Kelso (PWSID WA5338000) 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 Kelso serve?
City of Kelso reports serving 15,775 people through 5,082 service connections in Cowlitz County, Washington.
Where does City of Kelso get its water?
EPA SDWIS lists this system's primary water source as groundwater under influence of surface water. Groundwater under the influence of surface water is well or spring water that the regulator has found to be affected by nearby surface water, so it is regulated under the surface-water treatment rules.
Does City of Kelso 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 2018. 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 Kelso'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 2018. 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 Kelso's water quality report?
As a community water system, City of Kelso 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 Cowlitz County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Longview Water Department | Cowlitz | 57,617 | Community | Groundwater |
| Beacon Hill Water & Sewer District | Cowlitz | 11,969 | Community | Purchased groundwater |
| Woodland City of | Cowlitz | 10,640 | Community | Groundwater under influence of surface water |
| Kalama City of | Cowlitz | 8,020 | Community | Groundwater under influence of surface water |
| Castle Rock Municipal Water | Cowlitz | 4,367 | Community | Surface water |
| Toutle River Rest Area Nb/Sb | Cowlitz | 3,590 | 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, “Kelso City of, PWSID WA5338000, Washington”, https://aquacensus.com/water-systems/washington/kelso-city-of-wa5338000 (data as of October 1, 2026).