Public water system · OR4100061
ActiveKnappa Water Association
At a glance
Knappa Water Association (PWSID OR4100061) is an active community water system in Clatsop County, Oregon. It reports serving 1,800 people through 605 service connections. Its primary water source is groundwater, and EPA lists it as privately owned. EPA's records list 11 violations for this system; none is health-based, and the most recent began in December 2025.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
1,800
Service connections
605
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Knappa Water Association compare with other water systems in Clatsop County?
By EPA's size categories, Knappa Water Association is a small system (501 to 3,300 people). Clatsop County has 31 active public water systems, and Knappa Water Association is the 5th-largest of them by population served. Its population served is about 34% above the county average of 1,345 people per system, and accounts for 4.3% of the 41,699 people reported by systems filed under the county. Across Oregon, the 2,536 active systems average 1,587 people each. Nationally, the average active community water system reports serving 6,703 people, so Knappa Water Association 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. Oregon has 940 active community water systems, 37% of the state's 2,536 active systems. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 2,175 Oregon systems (86%) list groundwater as their primary source.
Who owns and regulates Knappa Water Association?
EPA lists Knappa Water Association as privately owned. The OR 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 31 active systems in Clatsop County (52%) are also privately owned.
Does Knappa Water Association have drinking water violations?
EPA's records list 11 violations for this system; none is health-based, and the most recent began in December 2025. The violations listed here began between June 1976 and December 2025. By type: 6 monitoring and reporting and 5 monitoring. The contaminant or rule involved most often is Revised Total Coliform Rule (5 of them). EPA lists 8 as resolved and 3 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 |
|---|---|---|---|---|
| 2025-12-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2025-11-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2023-11-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2022-07-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2021-10-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2016-07-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Archived |
| 2000-03-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1998-10-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1997-12-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1976-06-01 | Monitoring and reportingMonitoring, Regular · code 03 | Gross alpha (excluding radon and uranium)code 4000 | No | Archived |
| 1976-06-01 | Monitoring and reportingMonitoring, Regular · code 03 | Combined Radium (-226 and -228)code 4010 | No | Archived |
All 11 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.
Knappa Water Association: frequently asked questions
Who runs Knappa Water Association?
Knappa Water Association (PWSID OR4100061) is a community water system privately owned. It is regulated by the OR state drinking water program.
How many people does Knappa Water Association serve?
Knappa Water Association reports serving 1,800 people through 605 service connections in Clatsop County, Oregon.
Where does Knappa Water Association 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 Knappa Water Association have any drinking water violations?
EPA's records list 11 violations for this system; none is health-based, and the most recent began in December 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 Knappa Water Association'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. EPA's records list 11 violations for this system; none is health-based, and the most recent began in December 2025. For current results, consult the system's annual water quality report, EPA ECHO, or the OR state drinking water program.
Where can I find Knappa Water Association's water quality report?
As a community water system, Knappa Water Association 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 Clatsop County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Astoria, City of | Clatsop | 10,181 | Community | Surface water |
| Warrenton, City of | Clatsop | 9,100 | Community | Surface water |
| Seaside Water Department | Clatsop | 7,482 | Community | Surface water |
| Youngs River Lewis & Clark Wd | Clatsop | 2,580 | Community | Surface water |
| Gearhart Water Department | Clatsop | 1,780 | Community | Purchased surface water |
| Cannon Beach, City of | Clatsop | 1,710 | 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, “Knappa Water Association, PWSID OR4100061, Oregon”, https://aquacensus.com/water-systems/oregon/knappa-water-association-or4100061 (data as of October 1, 2026).