Public water system · OR4105229
ActiveOak Knoll Winery
At a glance
Oak Knoll Winery (PWSID OR4105229) is an active transient non-community water system in Washington County, Oregon. It reports serving 50 people through 2 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 August 2011.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
50
Service connections
2
Primary source
GW
Groundwater
System type
TNCWS
Transient non-community water system
System record
How does Oak Knoll Winery compare with other water systems in Washington County?
By EPA's size categories, Oak Knoll Winery is a very small system (500 people or fewer). Washington County has 97 active public water systems. Its population served is well below the county average of 6,158 people per system, and accounts for less than 0.1% of the 597,296 people reported by systems filed under the county. Across Oregon, the 2,536 active systems average 1,587 people each. Nationally, the average active transient non-community water system reports serving 144 people, so Oak Knoll Winery is about 65% below that figure.
What does “transient non-community water system” mean?
A transient non-community water system serves places where people do not stay long, such as gas stations and campgrounds, and regularly serves at least 25 people a day for at least 60 days a year. Oregon has 1,250 active transient non-community water systems, 49% 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 Oak Knoll Winery?
EPA lists Oak Knoll Winery 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. 65 of the 97 active systems in Washington County (67%) are also privately owned.
Does Oak Knoll Winery have drinking water violations?
Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in August 2011. The violations listed here began between October 1993 and August 2011. By type: 10 monitoring and reporting, 1 public notice, recordkeeping or other and 1 contaminant level above the legal limit. The contaminant or rule involved most often is Total coliform bacteria (TCR) (9 of them). EPA lists 11 as resolved and 1 as unaddressed. 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. Unaddressed means the violation is not resolved or archived and is not yet covered by formal enforcement.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2011-08-27 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Unaddressed |
| 2011-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2003-10-01 | Monitoring and reportingMonitoring, Repeat Major (TCR) · code 25 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2003-03-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2002-10-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2001-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 2000-10-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1999-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 1999-01-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1994-04-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1994-01-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1993-10-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | 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.
Oak Knoll Winery: frequently asked questions
Who runs Oak Knoll Winery?
Oak Knoll Winery (PWSID OR4105229) is a transient non-community water system privately owned. It is regulated by the OR state drinking water program.
How many people does Oak Knoll Winery serve?
Oak Knoll Winery reports serving 50 people through 2 service connections in Washington County, Oregon.
Where does Oak Knoll Winery 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 Oak Knoll Winery 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 August 2011. 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 Oak Knoll Winery'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 August 2011. For current results, consult EPA ECHO, or the OR state drinking water program.
Where can I find Oak Knoll Winery's water quality report?
The annual Consumer Confidence Report requirement applies to community water systems. Oak Knoll Winery is a transient non-community water system, so it is not required to publish one; like every public water system, it must notify the people it serves about violations under EPA's public notification rules.
Other water systems in Washington County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Tualatin Valley Water District | Washington | 224,600 | Community | Purchased surface water |
| Hillsboro, City of | Washington | 92,632 | Community | Purchased surface water |
| Beaverton, City of | Washington | 88,045 | Community | Purchased surface water |
| Tigard, City of | Washington | 62,500 | Community | Purchased surface water |
| Tualatin, City of | Washington | 28,106 | Community | Purchased surface water |
| Forest Grove, City of | Washington | 26,838 | Community | Surface water |
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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, “Oak Knoll Winery, PWSID OR4105229, Oregon”, https://aquacensus.com/water-systems/oregon/oak-knoll-winery-or4105229 (data as of October 1, 2026).