Public water system · CA5510016
ActiveSierra Park Water Company Inc..
At a glance
Sierra Park Water Company Inc.. (PWSID CA5510016) is an active community water system in Tuolumne County, California. It reports serving 400 people through 346 service connections. Its primary water source is groundwater, and EPA lists it as privately owned. EPA's records list 8 violations for this system; 2 are health-based, and the most recent began in April 2025.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
400
Service connections
346
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Sierra Park Water Company Inc.. compare with other water systems in Tuolumne County?
By EPA's size categories, Sierra Park Water Company Inc.. is a very small system (500 people or fewer). Tuolumne County has 117 active public water systems. Its population served is about 43% below the county average of 706 people per system, and accounts for 0.5% 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 Sierra Park Water Company 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. 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 Sierra Park Water Company Inc..?
EPA lists Sierra Park Water Company 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 Sierra Park Water Company Inc.. have drinking water violations?
EPA's records list 8 violations for this system; 2 are health-based, and the most recent began in April 2025. The violations listed here began between January 1993 and April 2025. By type: 5 monitoring and reporting, 2 contaminant level above the legal limit and 1 monitoring. The contaminant or rule involved most often is Total coliform bacteria (TCR) (5 of them). EPA lists 8 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 |
|---|---|---|---|---|
| 2025-04-01 | MonitoringMonitoring, Lab Certification/Method Error (RTCR) · code 3D | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2007-12-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2006-01-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2005-08-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2001-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1994-10-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1993-07-01 | Monitoring and reportingInitial Tap Sampling for Pb and Cu · code 51 | Lead and Copper Rulecode 5000 | No | Resolved |
| 1993-01-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
All 8 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.
Sierra Park Water Company Inc..: frequently asked questions
Who runs Sierra Park Water Company Inc..?
Sierra Park Water Company Inc.. (PWSID CA5510016) is a community water system privately owned. It is regulated by the CA state drinking water program.
How many people does Sierra Park Water Company Inc.. serve?
Sierra Park Water Company Inc.. reports serving 400 people through 346 service connections in Tuolumne County, California.
Where does Sierra Park Water Company Inc.. 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 Sierra Park Water Company Inc.. have any drinking water violations?
EPA's records list 8 violations for this system; 2 are health-based, and the most recent began in April 2025. 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 Sierra Park Water Company 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 8 violations for this system; 2 are health-based, and the most recent began in April 2025. For current results, consult the system's annual water quality report, EPA ECHO, or the CA state drinking water program.
Where can I find Sierra Park Water Company Inc..'s water quality report?
As a community water system, Sierra Park Water Company 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, “Sierra Park Water Company Inc.., PWSID CA5510016, California”, https://aquacensus.com/water-systems/california/sierra-park-water-company-inc-ca5510016 (data as of October 1, 2026).