Public water system · CA4910702
ActiveU.S. Army Corps-Lake Sonoma Headquarters
At a glance
U.S. Army Corps-Lake Sonoma Headquarters (PWSID CA4910702) is an active transient non-community water system in Sonoma County, California. It reports serving 52 people through 12 service connections. Its primary water source is groundwater, and EPA lists it as owned by the federal government. EPA's records list 3 violations for this system; 2 are health-based, and the most recent began in June 2017.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
52
Service connections
12
Primary source
GW
Groundwater
System type
TNCWS
Transient non-community water system
System record
How does U.S. Army Corps-Lake Sonoma Headquarters compare with other water systems in Sonoma County?
By EPA's size categories, U.S. Army Corps-Lake Sonoma Headquarters 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 U.S. Army Corps-Lake Sonoma Headquarters is about 64% below 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 U.S. Army Corps-Lake Sonoma Headquarters?
EPA lists U.S. Army Corps-Lake Sonoma Headquarters as owned by the federal 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. 2 of the 441 active systems in Sonoma County (0.5%) are also owned by the federal government.
Does U.S. Army Corps-Lake Sonoma Headquarters have drinking water violations?
EPA's records list 3 violations for this system; 2 are health-based, and the most recent began in June 2017. The violations listed here began between June 1993 and June 2017. By type: 1 monitoring, 1 contaminant level above the legal limit and 1 required treatment not met. The contaminants or rules involved are Revised Total Coliform Rule, Total coliform bacteria (TCR) and Surface Water Treatment Rule. EPA lists 3 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 |
|---|---|---|---|---|
| 2017-06-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 1999-06-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Acute (TCR) · code 21 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1993-06-01 | Required treatment not metTreatment Technique (SWTR and GWR) · code 41 | Surface Water Treatment Rulecode 0200 | Yes | Resolved |
All 3 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.
U.S. Army Corps-Lake Sonoma Headquarters: frequently asked questions
Who runs U.S. Army Corps-Lake Sonoma Headquarters?
U.S. Army Corps-Lake Sonoma Headquarters (PWSID CA4910702) is a transient non-community water system owned by the federal government. It is regulated by the CA state drinking water program.
How many people does U.S. Army Corps-Lake Sonoma Headquarters serve?
U.S. Army Corps-Lake Sonoma Headquarters reports serving 52 people through 12 service connections in Sonoma County, California.
Where does U.S. Army Corps-Lake Sonoma Headquarters 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 U.S. Army Corps-Lake Sonoma Headquarters have any drinking water violations?
EPA's records list 3 violations for this system; 2 are health-based, and the most recent began in June 2017. 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 U.S. Army Corps-Lake Sonoma Headquarters' 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 3 violations for this system; 2 are health-based, and the most recent began in June 2017. For current results, consult EPA ECHO, or the CA state drinking water program.
Where can I find U.S. Army Corps-Lake Sonoma Headquarters' water quality report?
The annual Consumer Confidence Report requirement applies to community water systems. U.S. Army Corps-Lake Sonoma Headquarters 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, “U.S. Army Corps-Lake Sonoma Headquarters, PWSID CA4910702, California”, https://aquacensus.com/water-systems/california/u-s-army-corps-lake-sonoma-headquarters-ca4910702 (data as of October 1, 2026).