Public water system · OR4100673
ActivePrairie City
At a glance
Prairie City (PWSID OR4100673) is an active community water system in Grant County, Oregon. It reports serving 841 people through 443 service connections. Its primary water source is groundwater under influence of surface water, and EPA lists it as owned by a local government. Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in February 2026.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
841
Service connections
443
Primary source
GU
Groundwater under influence of surface water
System type
CWS
Community water system
System record
How does Prairie City compare with other water systems in Grant County?
By EPA's size categories, Prairie City is a small system (501 to 3,300 people). Grant County has 15 active public water systems, and Prairie City is the 2nd-largest of them by population served. Its population served is about 148% above the county average of 339 people per system, and accounts for 17% of the 5,090 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 Prairie City 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 under the influence of surface water is well or spring water that the regulator has found to be affected by nearby surface water, so it is regulated under the surface-water treatment rules. 21 Oregon systems (0.8%) list groundwater under influence of surface water as their primary source.
Who owns and regulates Prairie City?
EPA lists Prairie City 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. 8 of the 15 active systems in Grant County (53%) are also owned by a local government.
Does Prairie City have drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in February 2026. The violations listed here began between January 2022 and February 2026. By type: 10 monitoring and reporting, 1 monitoring and 1 public notice, recordkeeping or other. The contaminant or rule involved most often is Surface Water Treatment Rule (3 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 |
|---|---|---|---|---|
| 2026-02-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2025-10-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2025-10-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2025-06-01 | Monitoring and reportingMonitoring of Treatment (SWTR-Filter) · code 36 | Surface Water Treatment Rulecode 0200 | No | Resolved |
| 2025-06-01 | Monitoring and reportingMonitoring of Treatment (SWTR-Filter) · code 36 | Surface Water Treatment Rulecode 0200 | No | Resolved |
| 2025-06-01 | Monitoring and reportingMonitoring of Treatment (SWTR-Filter) · code 36 | Surface Water Treatment Rulecode 0200 | No | Resolved |
| 2024-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2022-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Ethylbenzenecode 2992 | No | Resolved |
| 2022-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | trans-1,2-Dichloroethylenecode 2979 | No | Resolved |
| 2022-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,2-Dichloroethanecode 2980 | No | Resolved |
| 2022-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,2-Dichloropropanecode 2983 | No | Resolved |
| 2022-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | 1,1,2-Trichloroethanecode 2985 | 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.
Prairie City: frequently asked questions
Who runs Prairie City?
Prairie City (PWSID OR4100673) is a community water system owned by a local government. It is regulated by the OR state drinking water program.
How many people does Prairie City serve?
Prairie City reports serving 841 people through 443 service connections in Grant County, Oregon.
Where does Prairie City get its water?
EPA SDWIS lists this system's primary water source as groundwater under influence of surface water. Groundwater under the influence of surface water is well or spring water that the regulator has found to be affected by nearby surface water, so it is regulated under the surface-water treatment rules.
Does Prairie City 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 February 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 Prairie City'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 February 2026. For current results, consult the system's annual water quality report, EPA ECHO, or the OR state drinking water program.
Where can I find Prairie City's water quality report?
As a community water system, Prairie City 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 Grant County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| John Day, City of | Grant | 1,617 | Community | Groundwater |
| Canyon City Water Department | Grant | 666 | Community | Groundwater under influence of surface water |
| Mount Vernon, City of | Grant | 510 | Community | Groundwater |
| Oprd Clyde Holliday Wayside | Grant | 450 | Transient non-community | Groundwater |
| Seneca, City of | Grant | 200 | Community | Groundwater |
| Long Creek, City of | Grant | 173 | 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, “Prairie City, PWSID OR4100673, Oregon”, https://aquacensus.com/water-systems/oregon/prairie-city-or4100673 (data as of October 1, 2026).