Public water system · CA0510001
ActiveUnion Public Utility District
At a glance
Union Public Utility District (PWSID CA0510001) is an active community water system in Calaveras County, California. It reports serving 4,774 people through 1,735 service connections. Its primary water source is surface water, and EPA lists it as owned by a local government. Of the 12 most recent violations in EPA's records, 11 are health-based, and the most recent began in January 2021.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
4,774
Service connections
1,735
Primary source
SW
Surface water
System type
CWS
Community water system
System record
How does Union Public Utility District compare with other water systems in Calaveras County?
By EPA's size categories, Union Public Utility District is a medium system (3,301 to 10,000 people). Calaveras County has 51 active public water systems, and Union Public Utility District is the 6th-largest of them by population served. Its population served is about 4.3 times the county average of 1,102 people per system, and accounts for 8.5% of the 56,208 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 Union Public Utility District is about 29% 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. Surface water means the system draws its water from rivers, lakes, streams or reservoirs. 609 California systems (8.1%) list surface water as their primary source.
Who owns and regulates Union Public Utility District?
EPA lists Union Public Utility 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. 12 of the 51 active systems in Calaveras County (24%) are also owned by a local government.
Does Union Public Utility District have drinking water violations?
Of the 12 most recent violations in EPA's records, 11 are health-based, and the most recent began in January 2021. The violations listed here began between July 2001 and January 2021. By type: 11 contaminant level above the legal limit and 1 public notice, recordkeeping or other. The contaminant or rule involved most often is Haloacetic acids (HAA5) (6 of them). EPA lists 12 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 |
|---|---|---|---|---|
| 2021-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Total trihalomethanes (TTHM)code 2950 | Yes | Resolved |
| 2021-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Total trihalomethanes (TTHM)code 2950 | Yes | Resolved |
| 2020-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Total trihalomethanes (TTHM)code 2950 | Yes | Resolved |
| 2020-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Total trihalomethanes (TTHM)code 2950 | Yes | Resolved |
| 2020-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Total trihalomethanes (TTHM)code 2950 | Yes | Resolved |
| 2006-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Haloacetic acids (HAA5)code 2456 | Yes | Resolved |
| 2005-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Haloacetic acids (HAA5)code 2456 | Yes | Resolved |
| 2005-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Haloacetic acids (HAA5)code 2456 | Yes | Resolved |
| 2005-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Haloacetic acids (HAA5)code 2456 | Yes | Resolved |
| 2005-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Haloacetic acids (HAA5)code 2456 | Yes | Resolved |
| 2004-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Haloacetic acids (HAA5)code 2456 | Yes | Resolved |
| 2001-07-01 | Public notice, recordkeeping or otherConsumer Confidence Report Complete Failure to Report · code 71 | Consumer Confidence Rulecode 7000 | No | Resolved |
The 12 most recent 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.
Union Public Utility District: frequently asked questions
Who runs Union Public Utility District?
Union Public Utility District (PWSID CA0510001) is a community water system owned by a local government. It is regulated by the CA state drinking water program.
How many people does Union Public Utility District serve?
Union Public Utility District reports serving 4,774 people through 1,735 service connections in Calaveras County, California.
Where does Union Public Utility District get its water?
EPA SDWIS lists this system's primary water source as surface water. Surface water means the system draws its water from rivers, lakes, streams or reservoirs.
Does Union Public Utility District have any drinking water violations?
Of the 12 most recent violations in EPA's records, 11 are health-based, and the most recent began in January 2021. 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 Union Public Utility 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. Of the 12 most recent violations in EPA's records, 11 are health-based, and the most recent began in January 2021. For current results, consult the system's annual water quality report, EPA ECHO, or the CA state drinking water program.
Where can I find Union Public Utility District's water quality report?
As a community water system, Union Public Utility 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 Calaveras County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Ccwd - Ebbetts Pass | Calaveras | 11,545 | Community | Surface water |
| Ccwd - Jenny Lind | Calaveras | 9,861 | Community | Surface water |
| Calaveras PUD | Calaveras | 6,286 | Community | Surface water |
| Ccwd - Copper Cove | Calaveras | 5,187 | Community | Surface water |
| Blue Lake Springs Mut Wtr | Calaveras | 4,841 | Community | Purchased surface water |
| Angels, City of | Calaveras | 3,836 | 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, “Union Public Utility District, PWSID CA0510001, California”, https://aquacensus.com/water-systems/california/union-public-utility-district-ca0510001 (data as of October 1, 2026).