Public water system · CA1710013
ActiveCallayomi County Water District
At a glance
Callayomi County Water District (PWSID CA1710013) is an active community water system in Lake County, California. It reports serving 1,598 people through 534 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. EPA's records list 5 violations for this system; 3 are health-based, and the most recent began in October 2024.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
1,598
Service connections
534
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Callayomi County Water District compare with other water systems in Lake County?
By EPA's size categories, Callayomi County Water District is a small system (501 to 3,300 people). Lake County has 81 active public water systems. Its population served is about 79% above the county average of 895 people per system, and accounts for 2.2% of the 72,454 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 Callayomi County Water District 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 Callayomi County Water District?
EPA lists Callayomi County Water District 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. 17 of the 81 active systems in Lake County (21%) are also owned by a local government.
Does Callayomi County Water District have drinking water violations?
EPA's records list 5 violations for this system; 3 are health-based, and the most recent began in October 2024. The violations listed here began between August 1995 and October 2024. By type: 2 contaminant level above the legal limit, 1 reporting, 1 required treatment not met and 1 monitoring and reporting. The contaminant or rule involved most often is Total coliform bacteria (TCR) (3 of them). EPA lists 3 as resolved and 2 as unaddressed. 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.
| 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 |
| 2000-07-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1995-11-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1995-08-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
All 5 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.
Callayomi County Water District: frequently asked questions
Who runs Callayomi County Water District?
Callayomi County Water District (PWSID CA1710013) is a community water system owned by a local government. It is regulated by the CA state drinking water program.
How many people does Callayomi County Water District serve?
Callayomi County Water District reports serving 1,598 people through 534 service connections in Lake County, California.
Where does Callayomi County Water District 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 Callayomi County Water District have any drinking water violations?
EPA's records list 5 violations for this system; 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 Callayomi County Water District'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 5 violations for this system; 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 Callayomi County Water District's water quality report?
As a community water system, Callayomi County Water District 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 Lake County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Highlands Mutual Water Company | Lake | 7,772 | Community | Surface water |
| Hidden Valley Lake Csd | Lake | 6,235 | Community | Groundwater |
| Konocti County Water District | Lake | 5,928 | Community | Surface water |
| Lakeport, City of | Lake | 4,762 | Community | Surface water |
| Golden State Water Co.-Clearlake System | Lake | 4,644 | Community | Surface water |
| Mt. Konocti Mutual Water Company | Lake | 4,360 | Community | Surface water |
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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, “Callayomi County Water District, PWSID CA1710013, California”, https://aquacensus.com/water-systems/california/callayomi-county-water-district-ca1710013 (data as of October 1, 2026).