Public water system · CA3500581
ActiveRancho San Joaquin Mwc
At a glance
Rancho San Joaquin Mwc (PWSID CA3500581) is an active community water system in San Benito County, California. It reports serving 914 people through 30 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, 3 are health-based, and the most recent began in October 2024.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
914
Service connections
30
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Rancho San Joaquin Mwc compare with other water systems in San Benito County?
By EPA's size categories, Rancho San Joaquin Mwc is a small system (501 to 3,300 people). San Benito County has 63 active public water systems. Its population served is about 30% below the county average of 1,312 people per system, and accounts for 1.1% of the 82,670 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 San Joaquin Mwc 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 San Joaquin Mwc?
EPA lists Rancho San Joaquin Mwc 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. 46 of the 63 active systems in San Benito County (73%) are also privately owned.
Does Rancho San Joaquin Mwc have drinking water violations?
Of the 12 most recent violations in EPA's records, 3 are health-based, and the most recent began in October 2024. The violations listed here began between July 2012 and October 2024. By type: 6 monitoring and reporting, 2 contaminant level above the legal limit, 1 reporting, 1 required treatment not met, 1 public notice, recordkeeping or other and 1 monitoring. The contaminant or rule involved most often is Lead and Copper Rule Revisions (2 of them). EPA lists 8 as resolved, 2 as unaddressed and 2 as archived. 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. 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.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2024-10-17 | ReportingLSL Reporting · code 4G | Lead and Copper Rule Revisionscode 5200 | No | Unaddressed |
| 2024-10-17 | Required treatment not metLSL Inventory · code 2E | Lead and Copper Rule Revisionscode 5200 | Yes | Unaddressed |
| 2024-04-01 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Resolved |
| 2023-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Archived |
| 2022-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Archived |
| 2021-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2021-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2018-02-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2017-10-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2017-10-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2012-10-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2012-07-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | 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 San Joaquin Mwc: frequently asked questions
Who runs Rancho San Joaquin Mwc?
Rancho San Joaquin Mwc (PWSID CA3500581) is a community water system privately owned. It is regulated by the CA state drinking water program.
How many people does Rancho San Joaquin Mwc serve?
Rancho San Joaquin Mwc reports serving 914 people through 30 service connections in San Benito County, California.
Where does Rancho San Joaquin Mwc 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 San Joaquin Mwc have any drinking water violations?
Of the 12 most recent violations in EPA's records, 3 are health-based, and the most recent began in October 2024. 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 San Joaquin Mwc'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, 3 are health-based, and the most recent began in October 2024. 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 San Joaquin Mwc's water quality report?
As a community water system, Rancho San Joaquin Mwc 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 Benito County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Hollister, City of | San Benito | 26,017 | Community | Purchased surface water |
| Sunnyslope County Water Dist | San Benito | 24,954 | Community | Purchased surface water |
| 33rd District Agricultural Association | San Benito | 9,000 | Transient non-community | Groundwater |
| San Benito High School | San Benito | 3,310 | Non-transient non-community | Groundwater |
| Aromas Water District | San Benito | 2,988 | Community | Groundwater |
| San Juan Bautista, City of | San Benito | 2,335 | 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, “Rancho San Joaquin Mwc, PWSID CA3500581, California”, https://aquacensus.com/water-systems/california/rancho-san-joaquin-mwc-ca3500581 (data as of October 1, 2026).