Public water system · CA3700936
ActiveRancho Estates Mutual Water Co.
At a glance
Rancho Estates Mutual Water Co. (PWSID CA3700936) is an active community water system in San Diego County, California. It reports serving 200 people through 92 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, 8 are health-based, and the most recent began in April 2018.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
200
Service connections
92
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Rancho Estates Mutual Water Co. compare with other water systems in San Diego County?
By EPA's size categories, Rancho Estates Mutual Water Co. is a very small system (500 people or fewer). San Diego County has 191 active public water systems. Its population served is well below the county average of 19,427 people per system, and accounts for less than 0.1% of the 3,710,459 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 Rancho Estates Mutual Water Co. 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 Rancho Estates Mutual Water Co.?
EPA lists Rancho Estates Mutual Water Co. 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. 101 of the 191 active systems in San Diego County (53%) are also privately owned.
Does Rancho Estates Mutual Water Co. have drinking water violations?
Of the 12 most recent violations in EPA's records, 8 are health-based, and the most recent began in April 2018. The violations listed here began between January 2016 and April 2018. By type: 8 contaminant level above the legal limit, 3 monitoring and reporting and 1 reporting. The contaminant or rule involved most often is Nitrate (5 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 |
|---|---|---|---|---|
| 2018-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01 | Nitrate-Nitritecode 1038 | Yes | Resolved |
| 2018-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01 | Nitrate-Nitritecode 1038 | Yes | Resolved |
| 2017-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01 | Nitrate-Nitritecode 1038 | Yes | Resolved |
| 2017-09-01 | ReportingNotification, E Coli Positive (RTCR) · code 4D | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2017-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01 | Nitrate-Nitritecode 1038 | Yes | Resolved |
| 2017-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01 | Nitratecode 1040 | Yes | Resolved |
| 2017-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01 | Nitratecode 1040 | Yes | Resolved |
| 2016-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01 | Nitratecode 1040 | Yes | Resolved |
| 2016-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Benzenecode 2990 | No | Resolved |
| 2016-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 2016-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01 | Nitratecode 1040 | Yes | Resolved |
| 2016-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Combined Uraniumcode 4006 | 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.
Rancho Estates Mutual Water Co.: frequently asked questions
Who runs Rancho Estates Mutual Water Co.?
Rancho Estates Mutual Water Co. (PWSID CA3700936) is a community water system privately owned. It is regulated by the CA state drinking water program.
How many people does Rancho Estates Mutual Water Co. serve?
Rancho Estates Mutual Water Co. reports serving 200 people through 92 service connections in San Diego County, California.
Where does Rancho Estates Mutual Water Co. 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 Rancho Estates Mutual Water Co. have any drinking water violations?
Of the 12 most recent violations in EPA's records, 8 are health-based, and the most recent began in April 2018. 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 Rancho Estates Mutual Water Co.'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, 8 are health-based, and the most recent began in April 2018. For current results, consult the system's annual water quality report, EPA ECHO, or the CA state drinking water program.
Where can I find Rancho Estates Mutual Water Co.'s water quality report?
As a community water system, Rancho Estates Mutual Water Co. 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 San Diego County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| San Diego, City of | San Diego | 1,385,379 | Community | Surface water |
| Helix Water District | San Diego | 277,668 | Community | Surface water |
| Otay Water District | San Diego | 238,008 | Community | Purchased surface water |
| Sweetwater Authority | San Diego | 191,282 | Community | Surface water |
| Oceanside, City of | San Diego | 171,483 | Community | Purchased surface water |
| Escondido, City of | San Diego | 137,044 | 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, “Rancho Estates Mutual Water Co., PWSID CA3700936, California”, https://aquacensus.com/water-systems/california/rancho-estates-mutual-water-co-ca3700936 (data as of October 1, 2026).