Public water system · WA5390200
ActiveUnderwood
At a glance
Underwood (PWSID WA5390200) is an active community water system in Skamania County, Washington. It reports serving 1,000 people through 379 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 April 2025.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
1,000
Service connections
379
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Underwood compare with other water systems in Skamania County?
By EPA's size categories, Underwood is a small system (501 to 3,300 people). Skamania County has 56 active public water systems, and Underwood is the 6th-largest of them by population served. Its population served is about 199% above the county average of 335 people per system, and accounts for 5.3% of the 18,736 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 Underwood 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 Underwood?
EPA lists Underwood 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. 10 of the 56 active systems in Skamania County (18%) are also owned by a local government.
Does Underwood have drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in April 2025. The violations listed here began between January 2023 and April 2025. By type: 10 monitoring and reporting and 2 monitoring. The contaminant or rule involved most often is Revised Total Coliform Rule (2 of them). EPA lists 12 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 |
|---|---|---|---|---|
| 2025-04-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2023-09-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2023-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Alachlor (Lasso)code 2051 | No | Resolved |
| 2023-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Heptachlor epoxidecode 2067 | No | Resolved |
| 2023-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Chlordanecode 2959 | No | Resolved |
| 2023-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Atrazinecode 2050 | No | Resolved |
| 2023-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Hexachlorobenzenecode 2274 | No | Resolved |
| 2023-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Toxaphenecode 2020 | No | Resolved |
| 2023-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Lindane (gamma-BHC)code 2010 | No | Resolved |
| 2023-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Endrincode 2005 | No | Resolved |
| 2023-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Hexachlorocyclopentadienecode 2042 | No | Resolved |
| 2023-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Benzo(a)pyrenecode 2306 | No | Resolved |
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.
Underwood: frequently asked questions
Who runs Underwood?
Underwood (PWSID WA5390200) is a community water system owned by a local government. It is regulated by the WA state drinking water program.
How many people does Underwood serve?
Underwood reports serving 1,000 people through 379 service connections in Skamania County, Washington.
Where does Underwood 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 Underwood 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 April 2025. 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 Underwood'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 April 2025. For current results, consult the system's annual water quality report, EPA ECHO, or the WA state drinking water program.
Where can I find Underwood's water quality report?
As a community water system, Underwood 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 Skamania County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Stevenson Water Dept | Skamania | 4,702 | Community | Surface water |
| Carson | Skamania | 3,015 | Community | Surface water |
| Johnston Ridge Observatory | Skamania | 2,506 | Transient non-community | Groundwater |
| Beacon Rock State Park 1 | Skamania | 1,375 | Transient non-community | Groundwater |
| North Bonneville City of | Skamania | 1,048 | Community | Groundwater |
| Cape Horn Skye Grade School | Skamania | 610 | 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, “Underwood, PWSID WA5390200, Washington”, https://aquacensus.com/water-systems/washington/underwood-wa5390200 (data as of October 1, 2026).