Public water system · OR4100252
ActiveDayton, City of
At a glance
City of Dayton (PWSID OR4100252) is an active community water system in Yamhill County, Oregon. It reports serving 2,535 people through 904 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. Of the 12 most recent violations in EPA's records, 2 are health-based, and the most recent began in July 2024.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
2,535
Service connections
904
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does City of Dayton compare with other water systems in Yamhill County?
By EPA's size categories, City of Dayton is a small system (501 to 3,300 people). Yamhill County has 91 active public water systems, and City of Dayton is the 6th-largest of them by population served. Its population served is about 154% above the county average of 998 people per system, and accounts for 2.8% 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 community water system reports serving 6,703 people, so City of Dayton is about 62% 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 City of Dayton?
EPA lists City of Dayton as owned by a local 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. 17 of the 91 active systems in Yamhill County (19%) are also owned by a local government.
Does City of Dayton have drinking water violations?
Of the 12 most recent violations in EPA's records, 2 are health-based, and the most recent began in July 2024. The violations listed here began between January 2005 and July 2024. By type: 9 monitoring and reporting, 1 public notice, recordkeeping or other, 1 required treatment not met and 1 contaminant level above the legal limit. The contaminant or rule involved most often is Groundwater Rule (3 of them). EPA lists 10 as resolved and 2 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 |
|---|---|---|---|---|
| 2024-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2020-12-01 | Monitoring and reportingMonitoring of Treatment (SWTR-Unfilt/GWR) · code 31 | Groundwater Rulecode 0700 | No | Resolved |
| 2018-11-01 | Required treatment not metTreatment Technique (SWTR and GWR) · code 41 | Groundwater Rulecode 0700 | Yes | Resolved |
| 2015-07-01 | Monitoring and reportingMonitoring of Treatment (SWTR-Unfilt/GWR) · code 31 | Groundwater Rulecode 0700 | No | Resolved |
| 2010-09-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2010-08-01 | Monitoring and reportingMonitoring, Source Water (GWR) · code 34 | E. colicode 3014 | No | Unaddressed |
| 2010-08-01 | Monitoring and reportingMonitoring, Source Water (GWR) · code 34 | E. colicode 3014 | No | Unaddressed |
| 2010-01-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2009-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 2007-09-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Acute (TCR) · code 21 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2005-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 2005-01-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | 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.
City of Dayton: frequently asked questions
Who runs City of Dayton?
City of Dayton (PWSID OR4100252) is a community water system owned by a local government. It is regulated by the OR state drinking water program.
How many people does City of Dayton serve?
City of Dayton reports serving 2,535 people through 904 service connections in Yamhill County, Oregon.
Where does City of Dayton 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 City of Dayton have any drinking water violations?
Of the 12 most recent violations in EPA's records, 2 are health-based, and the most recent began in July 2024. 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 City of Dayton'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, 2 are health-based, and the most recent began in July 2024. For current results, consult the system's annual water quality report, EPA ECHO, or the OR state drinking water program.
Where can I find City of Dayton's water quality report?
As a community water system, City of Dayton 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 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 |
| Carlton, City of | Yamhill | 2,270 | 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, “Dayton, City of, PWSID OR4100252, Oregon”, https://aquacensus.com/water-systems/oregon/dayton-city-of-or4100252 (data as of October 1, 2026).