Public water system · CA2700534
ActiveColonial Oak Wc Inc.
At a glance
Colonial Oak Wc Inc. (PWSID CA2700534) is an active community water system in Monterey County, California. It reports serving 198 people through 66 service connections. Its primary water source is groundwater, and EPA lists it as privately owned. Of the 12 most recent violations in EPA's records, 11 are health-based, and the most recent began in July 2025.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
198
Service connections
66
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Colonial Oak Wc Inc. compare with other water systems in Monterey County?
By EPA's size categories, Colonial Oak Wc Inc. is a very small system (500 people or fewer). Monterey County has 307 active public water systems. Its population served is well below the county average of 1,552 people per system, and accounts for less than 0.1% of the 476,419 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 Colonial Oak Wc Inc. 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. 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 Colonial Oak Wc Inc.?
EPA lists Colonial Oak Wc Inc. 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. 266 of the 307 active systems in Monterey County (87%) are also privately owned.
Does Colonial Oak Wc Inc. have drinking water violations?
Of the 12 most recent violations in EPA's records, 11 are health-based, and the most recent began in July 2025. The violations listed here began between December 2011 and July 2025. By type: 11 contaminant level above the legal limit and 1 reporting. The contaminant or rule involved most often is Total coliform bacteria (TCR) (8 of them). EPA lists 8 as resolved, 3 as archived and 1 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. 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. 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 |
|---|---|---|---|---|
| 2025-07-02 | ReportingNotification, Known or Potential LSL · code 4H | Lead and Copper Rule Revisionscode 5200 | No | Unaddressed |
| 2024-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01 | Nitratecode 1040 | Yes | Archived |
| 2023-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01 | Nitratecode 1040 | Yes | Archived |
| 2023-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01 | Nitratecode 1040 | Yes | Archived |
| 2015-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2015-06-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2015-05-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2015-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2014-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2012-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2012-06-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2011-12-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | 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.
Colonial Oak Wc Inc.: frequently asked questions
Who runs Colonial Oak Wc Inc.?
Colonial Oak Wc Inc. (PWSID CA2700534) is a community water system privately owned. It is regulated by the CA state drinking water program.
How many people does Colonial Oak Wc Inc. serve?
Colonial Oak Wc Inc. reports serving 198 people through 66 service connections in Monterey County, California.
Where does Colonial Oak Wc Inc. 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 Colonial Oak Wc Inc. have any drinking water violations?
Of the 12 most recent violations in EPA's records, 11 are health-based, and the most recent began in July 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 Colonial Oak Wc Inc.'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, 11 are health-based, and the most recent began in July 2025. For current results, consult the system's annual water quality report, EPA ECHO, or the CA state drinking water program.
Where can I find Colonial Oak Wc Inc.'s water quality report?
As a community water system, Colonial Oak Wc Inc. 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 Monterey County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Cwsc Salinas | Monterey | 123,679 | Community | Groundwater |
| Cal Am Water Company - Monterey | Monterey | 92,450 | Community | Groundwater under influence of surface water |
| Alco Water Service | Monterey | 56,253 | Community | Groundwater |
| Marina Coast Water District | Monterey | 38,377 | Community | Groundwater |
| Soledad, City of | Monterey | 19,455 | Community | Groundwater |
| Greenfield, City of | Monterey | 18,967 | 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, “Colonial Oak Wc Inc., PWSID CA2700534, California”, https://aquacensus.com/water-systems/california/colonial-oak-wc-inc-ca2700534 (data as of October 1, 2026).