Public water system · WA5388200
ActiveThunder Ridge Water System
At a glance
Thunder Ridge Water System (PWSID WA5388200) is an active community water system in Island County, Washington. It reports serving 145 people through 143 service connections. Its primary water source is groundwater, and EPA lists it as privately owned. Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in January 2022.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
145
Service connections
143
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Thunder Ridge Water System compare with other water systems in Island County?
By EPA's size categories, Thunder Ridge Water System is a very small system (500 people or fewer). Island County has 307 active public water systems. Its population served is about 57% below the county average of 335 people per system, and accounts for 0.1% of the 102,977 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 Thunder Ridge Water System 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 Thunder Ridge Water System?
EPA lists Thunder Ridge Water System 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. 274 of the 307 active systems in Island County (89%) are also privately owned.
Does Thunder Ridge Water System have drinking water violations?
Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in January 2022. The violations listed here began between October 1979 and January 2022. By type: 11 monitoring and reporting and 1 contaminant level above the legal limit. The contaminant or rule involved most often is Nitrate (2 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 |
|---|---|---|---|---|
| 2022-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 2020-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Arseniccode 1005 | No | Resolved |
| 2019-01-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2011-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Acute (TCR) · code 21 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 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 | Cadmiumcode 1015 | No | Archived |
| 1979-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Fluoridecode 1025 | No | Archived |
| 1979-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Seleniumcode 1045 | No | Archived |
| 1979-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Bariumcode 1010 | No | Archived |
| 1979-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Archived |
| 1979-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Arseniccode 1005 | No | Archived |
| 1979-10-01 | Monitoring and reportingMonitoring, Regular · code 03 | Mercurycode 1035 | 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.
Thunder Ridge Water System: frequently asked questions
Who runs Thunder Ridge Water System?
Thunder Ridge Water System (PWSID WA5388200) is a community water system privately owned. It is regulated by the WA state drinking water program.
How many people does Thunder Ridge Water System serve?
Thunder Ridge Water System reports serving 145 people through 143 service connections in Island County, Washington.
Where does Thunder Ridge Water System 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 Thunder Ridge Water System 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 January 2022. 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 Thunder Ridge Water System'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 January 2022. For current results, consult the system's annual water quality report, EPA ECHO, or the WA state drinking water program.
Where can I find Thunder Ridge Water System's water quality report?
As a community water system, Thunder Ridge Water System 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 Island County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Oak Harbor City of | Island | 23,675 | Community | Purchased surface water |
| Naval Air Station/Whidbey Island | Island | 16,595 | Community | Purchased surface water |
| Coupeville Town of | Island | 4,142 | Community | Groundwater |
| Camano Water Association | Island | 2,592 | Community | Groundwater |
| Clinton Water District | Island | 1,980 | Community | Groundwater |
| Camano Island State Park | Island | 1,718 | 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, “Thunder Ridge Water System, PWSID WA5388200, Washington”, https://aquacensus.com/water-systems/washington/thunder-ridge-water-system-wa5388200 (data as of October 1, 2026).