Public water system · CA3610030
ActiveMariana Ranchos Cwd
At a glance
Mariana Ranchos Cwd (PWSID CA3610030) is an active community water system in San Bernardino County, California. It reports serving 1,502 people through 455 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. EPA's records list 11 violations for this system; 6 are health-based, and the most recent began in July 2015.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
1,502
Service connections
455
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Mariana Ranchos Cwd compare with other water systems in San Bernardino County?
By EPA's size categories, Mariana Ranchos Cwd is a small system (501 to 3,300 people). San Bernardino County has 306 active public water systems. Its population served is well below the county average of 9,227 people per system, and accounts for less than 0.1% of the 2,823,318 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 Mariana Ranchos Cwd 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 Mariana Ranchos Cwd?
EPA lists Mariana Ranchos Cwd as owned by a local government. 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. 74 of the 306 active systems in San Bernardino County (24%) are also owned by a local government.
Does Mariana Ranchos Cwd have drinking water violations?
EPA's records list 11 violations for this system; 6 are health-based, and the most recent began in July 2015. The violations listed here began between August 1994 and July 2015. By type: 6 contaminant level above the legal limit, 4 monitoring and reporting and 1 public notice, recordkeeping or other. The contaminant or rule involved most often is Total coliform bacteria (TCR) (10 of them). EPA lists 11 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 |
|---|---|---|---|---|
| 2015-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2012-06-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2010-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2008-10-01 | Public notice, recordkeeping or otherNotification, State · code 05 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2008-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2008-10-01 | Monitoring and reportingMonitoring, Repeat Major (TCR) · code 25 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2008-07-01 | Monitoring and reportingMonitoring, Repeat Minor (TCR) · code 26 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2005-03-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2003-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1996-05-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1994-08-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
All 11 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.
Mariana Ranchos Cwd: frequently asked questions
Who runs Mariana Ranchos Cwd?
Mariana Ranchos Cwd (PWSID CA3610030) is a community water system owned by a local government. It is regulated by the CA state drinking water program.
How many people does Mariana Ranchos Cwd serve?
Mariana Ranchos Cwd reports serving 1,502 people through 455 service connections in San Bernardino County, California.
Where does Mariana Ranchos Cwd 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 Mariana Ranchos Cwd have any drinking water violations?
EPA's records list 11 violations for this system; 6 are health-based, and the most recent began in July 2015. 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 Mariana Ranchos Cwd'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 11 violations for this system; 6 are health-based, and the most recent began in July 2015. For current results, consult the system's annual water quality report, EPA ECHO, or the CA state drinking water program.
Where can I find Mariana Ranchos Cwd's water quality report?
As a community water system, Mariana Ranchos Cwd 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 Bernardino County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| San Gabriel Valley Wc - Fontana | San Bernardino | 237,700 | Community | Surface water |
| San Bernardino City | San Bernardino | 214,665 | Community | Groundwater |
| Cucamonga Valley Water District | San Bernardino | 211,069 | Community | Surface water |
| Ontario Municipal Utilities Company | San Bernardino | 185,010 | Community | Purchased surface water |
| Victorville Water District | San Bernardino | 135,983 | Community | Purchased surface water |
| San Bernardino Valley Wd | San Bernardino | 109,608 | 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, “Mariana Ranchos Cwd, PWSID CA3610030, California”, https://aquacensus.com/water-systems/california/mariana-ranchos-cwd-ca3610030 (data as of October 1, 2026).