Public water system · CA4300577
ActiveRancho Robles Mutual Water Company
At a glance
Rancho Robles Mutual Water Company (PWSID CA4300577) is an active community water system in Santa Clara County, California. It reports serving 103 people through 37 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, 4 are health-based, and the most recent began in July 2000.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
103
Service connections
37
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Rancho Robles Mutual Water Company compare with other water systems in Santa Clara County?
By EPA's size categories, Rancho Robles Mutual Water Company is a very small system (500 people or fewer). Santa Clara County has 121 active public water systems. Its population served is well below the county average of 17,334 people per system, and accounts for less than 0.1% of the 2,097,447 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 Robles Mutual Water Company 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 Robles Mutual Water Company?
EPA lists Rancho Robles Mutual Water Company 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. 82 of the 121 active systems in Santa Clara County (68%) are also privately owned.
Does Rancho Robles Mutual Water Company have drinking water violations?
Of the 12 most recent violations in EPA's records, 4 are health-based, and the most recent began in July 2000. The violations listed here began between December 1982 and July 2000. By type: 6 public notice, recordkeeping or other, 4 contaminant level above the legal limit and 2 monitoring and reporting. The contaminant or rule involved most often is Total coliform bacteria (TCR) (4 of them). EPA lists 8 as archived and 4 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 |
|---|---|---|---|---|
| 2000-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1998-03-01 | Monitoring and reportingMonitoring, Repeat Minor (TCR) · code 26 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1997-04-01 | Monitoring and reportingMonitoring, Repeat Major (TCR) · code 25 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1997-03-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | 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 |
| 1984-05-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01 | Nitratecode 1040 | Yes | Archived |
| 1984-05-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
| 1984-02-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01 | Nitratecode 1040 | Yes | Archived |
| 1984-02-01 | Public notice, recordkeeping or otherNotification, Public · code 06 | Not reported | No | Archived |
| 1982-12-01 | 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.
Rancho Robles Mutual Water Company: frequently asked questions
Who runs Rancho Robles Mutual Water Company?
Rancho Robles Mutual Water Company (PWSID CA4300577) is a community water system privately owned. It is regulated by the CA state drinking water program.
How many people does Rancho Robles Mutual Water Company serve?
Rancho Robles Mutual Water Company reports serving 103 people through 37 service connections in Santa Clara County, California.
Where does Rancho Robles Mutual Water Company 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 Robles Mutual Water Company have any drinking water violations?
Of the 12 most recent violations in EPA's records, 4 are health-based, and the most recent began in July 2000. 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 Robles Mutual Water Company'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, 4 are health-based, and the most recent began in July 2000. 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 Robles Mutual Water Company's water quality report?
As a community water system, Rancho Robles Mutual Water Company 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 Santa Clara County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| San Jose Water | Santa Clara | 1,039,920 | Community | Surface water |
| City of Sunnyvale | Santa Clara | 157,566 | Community | Purchased surface water |
| City of Santa Clara | Santa Clara | 130,746 | Community | Purchased surface water |
| Great Oaks Wc Inc. | Santa Clara | 110,088 | Community | Groundwater |
| City of San Jose - Evg/Edv/Coy | Santa Clara | 101,265 | Community | Purchased surface water |
| City of Milpitas | Santa Clara | 81,773 | 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, “Rancho Robles Mutual Water Company, PWSID CA4300577, California”, https://aquacensus.com/water-systems/california/rancho-robles-mutual-water-company-ca4300577 (data as of October 1, 2026).