Public water system · CA1110003
ActiveCal-Water Service Co.-Willows
At a glance
Cal-Water Service Co.-Willows (PWSID CA1110003) is an active community water system in Glenn County, California. It reports serving 7,240 people through 2,371 service connections. Its primary water source is groundwater, and EPA lists it as privately owned. EPA's records list 2 violations for this system; all are health-based, and the most recent began in October 1996.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
7,240
Service connections
2,371
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Cal-Water Service Co.-Willows compare with other water systems in Glenn County?
By EPA's size categories, Cal-Water Service Co.-Willows is a medium system (3,301 to 10,000 people). Glenn County has 34 active public water systems, and Cal-Water Service Co.-Willows is the 4th-largest of them by population served. Its population served is about 6.7 times the county average of 1,085 people per system, and accounts for 20% of the 36,902 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 Cal-Water Service Co.-Willows is roughly in line with 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 Cal-Water Service Co.-Willows?
EPA lists Cal-Water Service Co.-Willows 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. 19 of the 34 active systems in Glenn County (56%) are also privately owned.
Does Cal-Water Service Co.-Willows have drinking water violations?
EPA's records list 2 violations for this system; all are health-based, and the most recent began in October 1996. The violations listed here began between October 1992 and October 1996. By type: 2 contaminant level above the legal limit. The contaminant or rule involved most often is Total coliform bacteria (TCR) (2 of them). EPA lists 2 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 |
|---|---|---|---|---|
| 1996-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1992-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
All 2 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.
Cal-Water Service Co.-Willows: frequently asked questions
Who runs Cal-Water Service Co.-Willows?
Cal-Water Service Co.-Willows (PWSID CA1110003) is a community water system privately owned. It is regulated by the CA state drinking water program.
How many people does Cal-Water Service Co.-Willows serve?
Cal-Water Service Co.-Willows reports serving 7,240 people through 2,371 service connections in Glenn County, California.
Where does Cal-Water Service Co.-Willows 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 Cal-Water Service Co.-Willows have any drinking water violations?
EPA's records list 2 violations for this system; all are health-based, and the most recent began in October 1996. 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 Cal-Water Service Co.-Willows' 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 2 violations for this system; all are health-based, and the most recent began in October 1996. For current results, consult the system's annual water quality report, EPA ECHO, or the CA state drinking water program.
Where can I find Cal-Water Service Co.-Willows' water quality report?
As a community water system, Cal-Water Service Co.-Willows 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 Glenn County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| City of Orland | Glenn | 8,298 | Community | Groundwater |
| Caltrans-Willows Reststop-Sb | Glenn | 7,500 | Transient non-community | Groundwater |
| Caltrans-Willows Reststop-Nb | Glenn | 7,500 | Transient non-community | Groundwater |
| Cal-Water Service Co.-Hamilton City | Glenn | 1,799 | Community | Groundwater |
| Sacramento Nat. Wildlife Refuge | Glenn | 824 | Transient non-community | Groundwater |
| Johns Manville | Glenn | 340 | Non-transient non-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, “Cal-Water Service Co.-Willows, PWSID CA1110003, California”, https://aquacensus.com/water-systems/california/cal-water-service-co-willows-ca1110003 (data as of October 1, 2026).