Public water system · CA4901265
ActiveSonoma State U.-Fairfield Osborn Pres
At a glance
Sonoma State U.-Fairfield Osborn Pres (PWSID CA4901265) is an active transient non-community water system in Sonoma County, California. It reports serving 151 people through 1 service connection. Its primary water source is groundwater, and EPA lists it as owned by a state government. EPA's records list 8 violations for this system; 2 are health-based, and the most recent began in June 2014.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
151
Service connections
1
Primary source
GW
Groundwater
System type
TNCWS
Transient non-community water system
System record
How does Sonoma State U.-Fairfield Osborn Pres compare with other water systems in Sonoma County?
By EPA's size categories, Sonoma State U.-Fairfield Osborn Pres is a very small system (500 people or fewer). Sonoma County has 441 active public water systems. Its population served is well below the county average of 1,092 people per system, and accounts for less than 0.1% of the 481,435 people reported by systems filed under the county. Across California, the 7,479 active systems average 5,706 people each. Nationally, the average active transient non-community water system reports serving 144 people, so Sonoma State U.-Fairfield Osborn Pres is roughly in line with that figure.
What does “transient non-community water system” mean?
A transient non-community water system serves places where people do not stay long, such as gas stations and campgrounds, and regularly serves at least 25 people a day for at least 60 days a year. California has 3,016 active transient non-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 Sonoma State U.-Fairfield Osborn Pres?
EPA lists Sonoma State U.-Fairfield Osborn Pres as owned by a state 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. 10 of the 441 active systems in Sonoma County (2.3%) are also owned by a state government.
Does Sonoma State U.-Fairfield Osborn Pres have drinking water violations?
EPA's records list 8 violations for this system; 2 are health-based, and the most recent began in June 2014. The violations listed here began between July 2003 and June 2014. By type: 6 monitoring and reporting and 2 contaminant level above the legal limit. The contaminant or rule involved most often is Total coliform bacteria (TCR) (8 of them). EPA lists 8 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 |
|---|---|---|---|---|
| 2014-06-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2012-04-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2011-01-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2009-07-01 | Monitoring and reportingMonitoring, Repeat Major (TCR) · code 25 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2008-04-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2006-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Acute (TCR) · code 21 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2006-04-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2003-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Acute (TCR) · code 21 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
All 8 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.
Sonoma State U.-Fairfield Osborn Pres: frequently asked questions
Who runs Sonoma State U.-Fairfield Osborn Pres?
Sonoma State U.-Fairfield Osborn Pres (PWSID CA4901265) is a transient non-community water system owned by a state government. It is regulated by the CA state drinking water program.
How many people does Sonoma State U.-Fairfield Osborn Pres serve?
Sonoma State U.-Fairfield Osborn Pres reports serving 151 people through 1 service connection in Sonoma County, California.
Where does Sonoma State U.-Fairfield Osborn Pres 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 Sonoma State U.-Fairfield Osborn Pres have any drinking water violations?
EPA's records list 8 violations for this system; 2 are health-based, and the most recent began in June 2014. 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 Sonoma State U.-Fairfield Osborn Pres' 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 8 violations for this system; 2 are health-based, and the most recent began in June 2014. For current results, consult EPA ECHO, or the CA state drinking water program.
Where can I find Sonoma State U.-Fairfield Osborn Pres' water quality report?
The annual Consumer Confidence Report requirement applies to community water systems. Sonoma State U.-Fairfield Osborn Pres is a transient non-community water system, so it is not required to publish one; like every public water system, it must notify the people it serves about violations under EPA's public notification rules.
Other water systems in Sonoma County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Santa Rosa, City of | Sonoma | 175,396 | Community | Groundwater |
| Petaluma, City of | Sonoma | 60,781 | Community | Groundwater |
| Rohnert Park, City of | Sonoma | 43,821 | Community | Groundwater |
| Windsor, Town of | Sonoma | 25,561 | Community | Groundwater |
| Valley of the Moon Water District | Sonoma | 23,107 | Community | Groundwater |
| Sonoma, City of | Sonoma | 11,725 | 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, “Sonoma State U.-Fairfield Osborn Pres, PWSID CA4901265, California”, https://aquacensus.com/water-systems/california/sonoma-state-u-fairfield-osborn-pres-ca4901265 (data as of October 1, 2026).