Public water system · CA1010034
ActiveSan Joaquin, City of
At a glance
City of San Joaquin (PWSID CA1010034) is an active community water system in Fresno County, California. It reports serving 4,060 people through 754 service connections. Its primary water source is groundwater, and EPA lists it as owned by a local government. Of the 12 most recent violations in EPA's records, 7 are health-based, and the most recent began in September 2010.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
4,060
Service connections
754
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does City of San Joaquin compare with other water systems in Fresno County?
By EPA's size categories, City of San Joaquin is a medium system (3,301 to 10,000 people). Fresno County has 328 active public water systems. Its population served is about 27% above the county average of 3,205 people per system, and accounts for 0.4% of the 1,051,276 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 City of San Joaquin is about 39% 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 City of San Joaquin?
EPA lists City of San Joaquin 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. 89 of the 328 active systems in Fresno County (27%) are also owned by a local government.
Does City of San Joaquin have drinking water violations?
Of the 12 most recent violations in EPA's records, 7 are health-based, and the most recent began in September 2010. The violations listed here began between January 2000 and September 2010. By type: 7 contaminant level above the legal limit and 5 monitoring and reporting. The contaminant or rule involved most often is Total coliform bacteria (TCR) (7 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 |
|---|---|---|---|---|
| 2010-09-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Acute (TCR) · code 21 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2005-06-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2005-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 2004-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2004-03-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2004-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Resolved |
| 2004-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Resolved |
| 2003-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2003-01-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2001-06-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2000-05-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2000-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | 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.
City of San Joaquin: frequently asked questions
Who runs City of San Joaquin?
City of San Joaquin (PWSID CA1010034) is a community water system owned by a local government. It is regulated by the CA state drinking water program.
How many people does City of San Joaquin serve?
City of San Joaquin reports serving 4,060 people through 754 service connections in Fresno County, California.
Where does City of San Joaquin 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 City of San Joaquin have any drinking water violations?
Of the 12 most recent violations in EPA's records, 7 are health-based, and the most recent began in September 2010. 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 City of San Joaquin'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, 7 are health-based, and the most recent began in September 2010. For current results, consult the system's annual water quality report, EPA ECHO, or the CA state drinking water program.
Where can I find City of San Joaquin's water quality report?
As a community water system, City of San Joaquin 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 Fresno County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| City of Fresno | Fresno | 545,716 | Community | Surface water |
| City of Clovis | Fresno | 130,130 | Community | Surface water |
| California State University Fresno | Fresno | 41,000 | Community | Groundwater |
| Cws - Selma | Fresno | 26,517 | Community | Groundwater |
| City of Sanger | Fresno | 26,357 | Community | Groundwater |
| Reedley, City of | Fresno | 26,076 | 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, “San Joaquin, City of, PWSID CA1010034, California”, https://aquacensus.com/water-systems/california/san-joaquin-city-of-ca1010034 (data as of October 1, 2026).