Public water system · CA0409181
ActiveBlue Oak Terrace Mutual
At a glance
Blue Oak Terrace Mutual (PWSID CA0409181) is an active community water system in Butte County, California. It reports serving 81 people through 30 service connections. Its primary water source is groundwater, and EPA lists it as privately owned. EPA's records list 7 violations for this system; none is health-based, and the most recent began in October 2025.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
81
Service connections
30
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Blue Oak Terrace Mutual compare with other water systems in Butte County?
By EPA's size categories, Blue Oak Terrace Mutual is a very small system (500 people or fewer). Butte County has 86 active public water systems. Its population served is well below the county average of 2,697 people per system, and accounts for less than 0.1% of the 231,911 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 Blue Oak Terrace Mutual 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 Blue Oak Terrace Mutual?
EPA lists Blue Oak Terrace Mutual 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. 58 of the 86 active systems in Butte County (67%) are also privately owned.
Does Blue Oak Terrace Mutual have drinking water violations?
EPA's records list 7 violations for this system; none is health-based, and the most recent began in October 2025. The violations listed here began between January 2007 and October 2025. By type: 6 monitoring and reporting and 1 public notice, recordkeeping or other. The contaminant or rule involved most often is Nitrite (2 of them). EPA lists 6 as resolved 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. 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 |
|---|---|---|---|---|
| 2025-10-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Unaddressed |
| 2025-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
| 2020-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitritecode 1041 | No | Resolved |
| 2020-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Arseniccode 1005 | No | Resolved |
| 2007-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Benzenecode 2990 | No | Resolved |
| 2007-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitritecode 1041 | No | Resolved |
| 2007-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
All 7 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.
Blue Oak Terrace Mutual: frequently asked questions
Who runs Blue Oak Terrace Mutual?
Blue Oak Terrace Mutual (PWSID CA0409181) is a community water system privately owned. It is regulated by the CA state drinking water program.
How many people does Blue Oak Terrace Mutual serve?
Blue Oak Terrace Mutual reports serving 81 people through 30 service connections in Butte County, California.
Where does Blue Oak Terrace Mutual 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 Blue Oak Terrace Mutual have any drinking water violations?
EPA's records list 7 violations for this system; none is health-based, and the most recent began in October 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 Blue Oak Terrace Mutual'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 7 violations for this system; none is health-based, and the most recent began in October 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 Blue Oak Terrace Mutual's water quality report?
As a community water system, Blue Oak Terrace Mutual 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 Butte County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Cal-Water Service Co.-Chico | Butte | 114,925 | Community | Groundwater |
| South Feather W&P - Miners Ranch | Butte | 22,664 | Community | Surface water |
| Butte-Glenn Community College Dist | Butte | 18,000 | Non-transient non-community | Groundwater |
| Thermalito Water & Sewer Dist | Butte | 12,136 | Community | Surface water |
| Cal-Water Service Co.-Oroville | Butte | 11,106 | Community | Surface water |
| Del Oro Water Co.-Paradise Pines | Butte | 10,940 | 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, “Blue Oak Terrace Mutual, PWSID CA0409181, California”, https://aquacensus.com/water-systems/california/blue-oak-terrace-mutual-ca0409181 (data as of October 1, 2026).