Public water system · OR4195757

Active

Columbia Basin Onion

At a glance

Columbia Basin Onion (PWSID OR4195757) is an active non-transient non-community water system in Umatilla County, Oregon. It reports serving 97 people through 2 service connections. Its primary water source is groundwater, and EPA lists it as privately owned. EPA's records list 9 violations for this system; 5 are health-based, and the most recent began in March 2026.

Dataset updated October 2026 . Source: EPA SDWIS/ECHO public records.

Population served

Service connections

Primary source

Groundwater

System type

NTNCWS

Non-transient non-community water system

System record

PWSIDOR4195757

System typeNon-transient non-community water system

Activity statusActive

Population served97

Service connections2

Primary water sourceGroundwater

Owner typePrivate

Primacy agencyOR state drinking water program

City served—

StateOregon

ZIP—

CountyUmatilla County

How does Columbia Basin Onion compare with other water systems in Umatilla County?

By EPA's size categories, Columbia Basin Onion is a very small system (500 people or fewer). Umatilla County has 66 active public water systems. Its population served is well below the county average of 1,041 people per system, and accounts for 0.1% of the 68,687 people reported by systems filed under the county. Across Oregon, the 2,536 active systems average 1,587 people each. Nationally, the average active non-transient non-community water system reports serving 430 people, so Columbia Basin Onion is well below that figure.

What does “non-transient non-community water system” mean?

A non-transient non-community water system regularly serves at least 25 of the same people for more than six months a year, but not where they live. Schools, factories, office buildings and hospitals with their own supply are typical examples. Oregon has 346 active non-transient non-community water systems, 14% 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 Columbia Basin Onion?

EPA lists Columbia Basin Onion 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. 43 of the 66 active systems in Umatilla County (65%) are also privately owned.

Does Columbia Basin Onion have drinking water violations?

EPA's records list 9 violations for this system; 5 are health-based, and the most recent began in March 2026. The violations listed here began between January 2025 and March 2026. By type: 4 contaminant level above the legal limit, 3 public notice, recordkeeping or other, 1 required treatment not met and 1 monitoring and reporting. The contaminant or rule involved most often is Nitrate (4 of them). EPA lists 4 as archived, 4 as resolved and 1 as unaddressed. 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. 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
2026-03-08	Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75	Public Noticecode 7500	No	Unaddressed
2026-01-01	Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01	Nitratecode 1040	Yes	Archived
2025-12-13	Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75	Public Noticecode 7500	No	Resolved
2025-10-04	Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75	Public Noticecode 7500	No	Resolved
2025-10-01	Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01	Nitratecode 1040	Yes	Archived
2025-07-13	Required treatment not metTreatment Technique, Level 1 Assessment (RTCR) · code 2A	Revised Total Coliform Rulecode 8000	Yes	Resolved
2025-07-01	Monitoring and reportingInitial Tap Sampling for Pb and Cu · code 51	Lead and Copper Rulecode 5000	No	Resolved
2025-07-01	Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01	Nitratecode 1040	Yes	Archived
2025-01-01	Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02	Nitratecode 1040	Yes	Archived

All 9 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.

Columbia Basin Onion: frequently asked questions

Who runs Columbia Basin Onion?

Columbia Basin Onion (PWSID OR4195757) is a non-transient non-community water system privately owned. It is regulated by the OR state drinking water program.

How many people does Columbia Basin Onion serve?

Columbia Basin Onion reports serving 97 people through 2 service connections in Umatilla County, Oregon.

Where does Columbia Basin Onion 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 Columbia Basin Onion have any drinking water violations?

EPA's records list 9 violations for this system; 5 are health-based, and the most recent began in March 2026. 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 Columbia Basin Onion'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 9 violations for this system; 5 are health-based, and the most recent began in March 2026. For current results, consult EPA ECHO, or the OR state drinking water program.

Where can I find Columbia Basin Onion's water quality report?

The annual Consumer Confidence Report requirement applies to community water systems. Columbia Basin Onion is a non-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 Umatilla County

Water system	County	Population served	Type	Source
Hermiston, City of	Umatilla	20,000	Community	Surface water
Pendleton, City of	Umatilla	16,996	Community	Surface water
Umatilla, City of	Umatilla	8,256	Community	Groundwater
Milton-Freewater, City of	Umatilla	7,145	Community	Groundwater
Stanfield, City of	Umatilla	2,115	Community	Groundwater
Pilot Rock, City of	Umatilla	1,326	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, “Columbia Basin Onion, PWSID OR4195757, Oregon”, https://aquacensus.com/water-systems/oregon/columbia-basin-onion-or4195757 (data as of October 1, 2026).