Public water system · CA5510024
ActiveSonora Water Resources, Inc.
At a glance
Sonora Water Resources, Inc. (PWSID CA5510024) is an active community water system in Tuolumne County, California. It reports serving 1,154 people through 130 service connections. Its primary water source is purchased surface water, and EPA lists it as privately owned. EPA's records list 3 violations for this system; none is health-based, and the most recent began in January 2006.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
1,154
Service connections
130
Primary source
SWP
Purchased surface water
System type
CWS
Community water system
System record
How does Sonora Water Resources, Inc. compare with other water systems in Tuolumne County?
By EPA's size categories, Sonora Water Resources, Inc. is a small system (501 to 3,300 people). Tuolumne County has 117 active public water systems. Its population served is about 63% above the county average of 706 people per system, and accounts for 1.4% of the 82,611 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 Sonora Water Resources, Inc. 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. Purchased surface water means the system buys surface water from another public water system rather than drawing its own. 506 California systems (6.8%) list purchased surface water as their primary source.
Who owns and regulates Sonora Water Resources, Inc.?
EPA lists Sonora Water Resources, Inc. 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. 75 of the 117 active systems in Tuolumne County (64%) are also privately owned.
Does Sonora Water Resources, Inc. have drinking water violations?
EPA's records list 3 violations for this system; none is health-based, and the most recent began in January 2006. The violations listed here began between July 1993 and January 2006. By type: 3 monitoring and reporting. The contaminant or rule involved most often is Lead and Copper Rule (3 of them). EPA lists 3 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 |
|---|---|---|---|---|
| 2006-01-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
| 1996-01-02 | Monitoring and reportingInitial Tap Sampling for Pb and Cu · code 51 | Lead and Copper Rulecode 5000 | No | Resolved |
| 1993-07-01 | Monitoring and reportingInitial Tap Sampling for Pb and Cu · code 51 | Lead and Copper Rulecode 5000 | No | Resolved |
All 3 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.
Sonora Water Resources, Inc.: frequently asked questions
Who runs Sonora Water Resources, Inc.?
Sonora Water Resources, Inc. (PWSID CA5510024) is a community water system privately owned. It is regulated by the CA state drinking water program.
How many people does Sonora Water Resources, Inc. serve?
Sonora Water Resources, Inc. reports serving 1,154 people through 130 service connections in Tuolumne County, California.
Where does Sonora Water Resources, Inc. get its water?
EPA SDWIS lists this system's primary water source as purchased surface water. Purchased surface water means the system buys surface water from another public water system rather than drawing its own.
Does Sonora Water Resources, Inc. have any drinking water violations?
EPA's records list 3 violations for this system; none is health-based, and the most recent began in January 2006. 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 Sonora Water Resources, Inc.'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 3 violations for this system; none is health-based, and the most recent began in January 2006. For current results, consult the system's annual water quality report, EPA ECHO, or the CA state drinking water program.
Where can I find Sonora Water Resources, Inc.'s water quality report?
As a community water system, Sonora Water Resources, Inc. 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 Tuolumne County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Tud - Upper Basin Water System | Tuolumne | 13,280 | Community | Surface water |
| Tud - Sonora/Jamestown Water System | Tuolumne | 11,054 | Community | Surface water |
| Tud - Columbia Water System | Tuolumne | 5,463 | Community | Surface water |
| Peppery Bar and Grill, the | Tuolumne | 4,500 | Transient non-community | Groundwater |
| Cdcr - Sierra Conservation Center | Tuolumne | 3,571 | Community | Surface water |
| Groveland Community Serv Dist | Tuolumne | 3,400 | 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, “Sonora Water Resources, Inc., PWSID CA5510024, California”, https://aquacensus.com/water-systems/california/sonora-water-resources-inc-ca5510024 (data as of October 1, 2026).