Public water system · CA5500020
ActiveOld Oak Ranch
At a glance
Old Oak Ranch (PWSID CA5500020) is an active transient non-community water system in Tuolumne County, California. It reports serving 217 people through 26 service connections. Its primary water source is surface water, and EPA lists it as privately owned. Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in April 2025.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
217
Service connections
26
Primary source
SW
Surface water
System type
TNCWS
Transient non-community water system
System record
How does Old Oak Ranch compare with other water systems in Tuolumne County?
By EPA's size categories, Old Oak Ranch is a very small system (500 people or fewer). Tuolumne County has 117 active public water systems. Its population served is well below the county average of 706 people per system, and accounts for 0.3% of the 82,611 people reported by systems filed under the county. Across California, the 7,479 active systems average 5,706 people each. Nationally, the average active transient non-community water system reports serving 144 people, so Old Oak Ranch is about 51% above 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. California has 3,016 active transient non-community water systems, 40% of the state's 7,479 active systems. Surface water means the system draws its water from rivers, lakes, streams or reservoirs. 609 California systems (8.1%) list surface water as their primary source.
Who owns and regulates Old Oak Ranch?
EPA lists Old Oak Ranch as privately owned. 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. 75 of the 117 active systems in Tuolumne County (64%) are also privately owned.
Does Old Oak Ranch have drinking water violations?
Of the 12 most recent violations in EPA's records, none is health-based, and the most recent began in April 2025. The violations listed here began between December 1983 and April 2025. By type: 10 public notice, recordkeeping or other, 1 monitoring and 1 monitoring and reporting. The contaminants or rules involved are Revised Total Coliform Rule and Total coliform bacteria (TCR). EPA lists 10 as archived and 2 as resolved. 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.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2025-04-01 | MonitoringMonitoring, Lab Certification/Method Error (RTCR) · code 3D | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 1997-04-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1984-09-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
| 1984-08-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
| 1984-07-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
| 1984-06-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
| 1984-05-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
| 1984-04-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
| 1984-03-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
| 1984-02-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
| 1984-01-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
| 1983-12-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
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.
Old Oak Ranch: frequently asked questions
Who runs Old Oak Ranch?
Old Oak Ranch (PWSID CA5500020) is a transient non-community water system privately owned. It is regulated by the CA state drinking water program.
How many people does Old Oak Ranch serve?
Old Oak Ranch reports serving 217 people through 26 service connections in Tuolumne County, California.
Where does Old Oak Ranch get its water?
EPA SDWIS lists this system's primary water source as surface water. Surface water means the system draws its water from rivers, lakes, streams or reservoirs.
Does Old Oak Ranch 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 April 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 Old Oak Ranch'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 April 2025. For current results, consult EPA ECHO, or the CA state drinking water program.
Where can I find Old Oak Ranch's water quality report?
The annual Consumer Confidence Report requirement applies to community water systems. Old Oak Ranch 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 Tuolumne County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Tud - Upper Basin Water System | Tuolumne | 13,280 | Community | Surface water |
| Tud - Sonora/Jamestown Water System | Tuolumne | 11,054 | Community | Surface water |
| Tud - Columbia Water System | Tuolumne | 5,463 | Community | Surface water |
| Peppery Bar and Grill, the | Tuolumne | 4,500 | Transient non-community | Groundwater |
| Cdcr - Sierra Conservation Center | Tuolumne | 3,571 | Community | Surface water |
| Groveland Community Serv Dist | Tuolumne | 3,400 | 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, “Old Oak Ranch, PWSID CA5500020, California”, https://aquacensus.com/water-systems/california/old-oak-ranch-ca5500020 (data as of October 1, 2026).