Public water system · CA5010014
ActiveOakdale, City of
At a glance
City of Oakdale (PWSID CA5010014) is an active community water system in Stanislaus County, California. It reports serving 23,235 people through 8,335 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. EPA's records list 11 violations for this system; 5 are health-based, and the most recent began in October 2024.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
23,235
Service connections
8,335
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does City of Oakdale compare with other water systems in Stanislaus County?
By EPA's size categories, City of Oakdale is a large system (10,001 to 100,000 people). Stanislaus County has 191 active public water systems, and City of Oakdale is the 6th-largest of them by population served. Its population served is about 8.7 times the county average of 2,684 people per system, and accounts for 4.5% of the 512,656 people reported by systems filed under the county. Across California, the 7,479 active systems average 5,706 people each. Nationally, the average active community water system reports serving 6,703 people, so City of Oakdale is about 3.5 times 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. California has 2,997 active community water systems, 40% of the state's 7,479 active systems. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 6,179 California systems (83%) list groundwater as their primary source.
Who owns and regulates City of Oakdale?
EPA lists City of Oakdale as owned by a local government. The CA state drinking water program is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act. 57 of the 191 active systems in Stanislaus County (30%) are also owned by a local government.
Does City of Oakdale have drinking water violations?
EPA's records list 11 violations for this system; 5 are health-based, and the most recent began in October 2024. The violations listed here began between March 1988 and October 2024. By type: 5 monitoring and reporting, 4 contaminant level above the legal limit, 1 required treatment not met and 1 reporting. The contaminant or rule involved most often is Total coliform bacteria (TCR) (5 of them). EPA lists 5 as resolved, 4 as archived and 2 as addressed. 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. 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. Addressed means the violation is not resolved or archived and is covered by formal enforcement.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2024-10-17 | Required treatment not metLSL Inventory · code 2E | Lead and Copper Rule Revisionscode 5200 | Yes | Addressed |
| 2024-10-17 | ReportingLSL Reporting · code 4G | Lead and Copper Rule Revisionscode 5200 | No | Addressed |
| 2009-08-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2005-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1995-11-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1995-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1993-09-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1988-03-01 | Monitoring and reportingMonitoring, Regular · code 03 | Seleniumcode 1045 | No | Archived |
| 1988-03-01 | Monitoring and reportingMonitoring, Regular · code 03 | Arseniccode 1005 | No | Archived |
| 1988-03-01 | Monitoring and reportingMonitoring, Regular · code 03 | Fluoridecode 1025 | No | Archived |
| 1988-03-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Archived |
All 11 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 Oakdale: frequently asked questions
Who runs City of Oakdale?
City of Oakdale (PWSID CA5010014) is a community water system owned by a local government. It is regulated by the CA state drinking water program.
How many people does City of Oakdale serve?
City of Oakdale reports serving 23,235 people through 8,335 service connections in Stanislaus County, California.
Where does City of Oakdale 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 Oakdale have any drinking water violations?
EPA's records list 11 violations for this system; 5 are health-based, and the most recent began in October 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 Oakdale'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 11 violations for this system; 5 are health-based, and the most recent began in October 2024. For current results, consult the system's annual water quality report, EPA ECHO, or the CA state drinking water program.
Where can I find City of Oakdale's water quality report?
As a community water system, City of Oakdale 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 Stanislaus County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Modesto, City of | Stanislaus | 218,771 | Community | Purchased surface water |
| Turlock, City of | Stanislaus | 72,682 | Community | Purchased surface water |
| Ceres, City of | Stanislaus | 54,513 | Community | Purchased surface water |
| Patterson, City of | Stanislaus | 24,977 | Community | Groundwater |
| Riverbank, City of | Stanislaus | 24,834 | Community | Groundwater |
| City of Modesto - Salida | Stanislaus | 14,537 | Community | Purchased 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, “Oakdale, City of, PWSID CA5010014, California”, https://aquacensus.com/water-systems/california/oakdale-city-of-ca5010014 (data as of October 1, 2026).