Public water system · OR4191083
ActiveOprd Maud Williamson State Pk
At a glance
Oprd Maud Williamson State Pk (PWSID OR4191083) is an active transient non-community water system in Yamhill County, Oregon. It reports serving 55 people through 3 service connections. Its primary water source is groundwater, and EPA lists it as owned by a state government. Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in January 2025.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
55
Service connections
3
Primary source
GW
Groundwater
System type
TNCWS
Transient non-community water system
System record
How does Oprd Maud Williamson State Pk compare with other water systems in Yamhill County?
By EPA's size categories, Oprd Maud Williamson State Pk is a very small system (500 people or fewer). Yamhill County has 91 active public water systems. Its population served is well below the county average of 998 people per system, and accounts for less than 0.1% of the 90,787 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 Oprd Maud Williamson State Pk is about 62% 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 Oprd Maud Williamson State Pk?
EPA lists Oprd Maud Williamson State Pk as owned by a state government. 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. 1 of the 91 active systems in Yamhill County (1.1%) are also owned by a state government.
Does Oprd Maud Williamson State Pk have drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in January 2025. The violations listed here began between May 2003 and January 2025. By type: 10 monitoring and reporting and 2 monitoring. The contaminant or rule involved most often is Total coliform bacteria (TCR) (7 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 |
|---|---|---|---|---|
| 2025-01-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2025-01-01 | Monitoring and reportingFailure to Conduct Assessment Monitoring · code 19 | Coliphagecode 3028 | No | Resolved |
| 2024-07-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2014-10-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2012-01-01 | Monitoring and reportingFailure to Conduct Assessment Monitoring · code 19 | Coliphagecode 3028 | No | Resolved |
| 2009-04-01 | Monitoring and reportingMonitoring, Repeat Major (TCR) · code 25 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2007-04-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2007-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 2006-10-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2005-07-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2004-01-01 | Monitoring and reportingMonitoring, Repeat Minor (TCR) · code 26 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2003-05-01 | 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.
Oprd Maud Williamson State Pk: frequently asked questions
Who runs Oprd Maud Williamson State Pk?
Oprd Maud Williamson State Pk (PWSID OR4191083) is a transient non-community water system owned by a state government. It is regulated by the OR state drinking water program.
How many people does Oprd Maud Williamson State Pk serve?
Oprd Maud Williamson State Pk reports serving 55 people through 3 service connections in Yamhill County, Oregon.
Where does Oprd Maud Williamson State Pk 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 Oprd Maud Williamson State Pk 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 January 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 Oprd Maud Williamson State Pk'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 January 2025. For current results, consult EPA ECHO, or the OR state drinking water program.
Where can I find Oprd Maud Williamson State Pk's water quality report?
The annual Consumer Confidence Report requirement applies to community water systems. Oprd Maud Williamson State Pk 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 Yamhill County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Mcminnville Water & Light | Yamhill | 34,515 | Community | Surface water |
| Newberg, City of | Yamhill | 25,138 | Community | Groundwater |
| Sheridan, City of | Yamhill | 6,494 | Community | Surface water |
| Lafayette, City of | Yamhill | 4,423 | Community | Purchased surface water |
| Dundee, City of | Yamhill | 2,960 | Community | Groundwater |
| Dayton, City of | Yamhill | 2,535 | 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, “Oprd Maud Williamson State Pk, PWSID OR4191083, Oregon”, https://aquacensus.com/water-systems/oregon/oprd-maud-williamson-state-pk-or4191083 (data as of October 1, 2026).