Public water system · CA3901474
ActiveFremont One
At a glance
Fremont One (PWSID CA3901474) is an active community water system in San Joaquin County, California. It reports serving 39 people through 15 service connections. Its primary water source is groundwater, and EPA lists it as privately owned. Of the 12 most recent violations in EPA's records, 12 are health-based, and the most recent began in January 2026.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
39
Service connections
15
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Fremont One compare with other water systems in San Joaquin County?
By EPA's size categories, Fremont One is a very small system (500 people or fewer). San Joaquin County has 302 active public water systems. Its population served is well below the county average of 2,571 people per system, and accounts for less than 0.1% of the 776,334 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 Fremont One 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 Fremont One?
EPA lists Fremont One 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. 225 of the 302 active systems in San Joaquin County (75%) are also privately owned.
Does Fremont One have drinking water violations?
Of the 12 most recent violations in EPA's records, 12 are health-based, and the most recent began in January 2026. The violations listed here began between July 2022 and January 2026. By type: 12 contaminant level above the legal limit. The contaminant or rule involved most often is Nitrate (12 of them). EPA lists 12 as archived. Archived means the violation was not marked resolved but is more than five years past the end of the noncompliance period, so it no longer counts toward current compliance status.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2026-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Nitratecode 1040 | Yes | Archived |
| 2025-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Nitratecode 1040 | Yes | Archived |
| 2025-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Nitratecode 1040 | Yes | Archived |
| 2025-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Nitratecode 1040 | Yes | Archived |
| 2025-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Nitratecode 1040 | Yes | Archived |
| 2024-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Nitratecode 1040 | Yes | Archived |
| 2024-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Nitratecode 1040 | Yes | Archived |
| 2024-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Nitratecode 1040 | Yes | Archived |
| 2024-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Nitratecode 1040 | Yes | Archived |
| 2023-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Nitratecode 1040 | Yes | Archived |
| 2022-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Nitratecode 1040 | Yes | Archived |
| 2022-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Nitratecode 1040 | Yes | Archived |
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.
Fremont One: frequently asked questions
Who runs Fremont One?
Fremont One (PWSID CA3901474) is a community water system privately owned. It is regulated by the CA state drinking water program.
How many people does Fremont One serve?
Fremont One reports serving 39 people through 15 service connections in San Joaquin County, California.
Where does Fremont One 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 Fremont One have any drinking water violations?
Of the 12 most recent violations in EPA's records, 12 are health-based, and the most recent began in January 2026. 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 Fremont One'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, 12 are health-based, and the most recent began in January 2026. For current results, consult the system's annual water quality report, EPA ECHO, or the CA state drinking water program.
Where can I find Fremont One's water quality report?
As a community water system, Fremont One 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 San Joaquin County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| City of Stockton | San Joaquin | 191,302 | Community | Surface water |
| California Water Service - Stockton | San Joaquin | 176,266 | Community | Purchased surface water |
| Tracy, City of | San Joaquin | 96,609 | Community | Surface water |
| Manteca, City of | San Joaquin | 84,928 | Community | Purchased surface water |
| Lodi, City of | San Joaquin | 68,272 | Community | Surface water |
| City of Lathrop | San Joaquin | 35,080 | Community | Purchased 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, “Fremont One, PWSID CA3901474, California”, https://aquacensus.com/water-systems/california/fremont-one-ca3901474 (data as of October 1, 2026).