Public water system · CA2900548
ActiveSierra Estates Mutual Water Company
At a glance
Sierra Estates Mutual Water Company (PWSID CA2900548) is an active community water system in Nevada County, California. It reports serving 100 people through 32 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, 10 are health-based, and the most recent began in October 2024.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
100
Service connections
32
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Sierra Estates Mutual Water Company compare with other water systems in Nevada County?
By EPA's size categories, Sierra Estates Mutual Water Company is a very small system (500 people or fewer). Nevada County has 82 active public water systems. Its population served is well below the county average of 1,263 people per system, and accounts for less than 0.1% of the 103,540 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 Estates Mutual Water Company 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 Estates Mutual Water Company?
EPA lists Sierra Estates Mutual Water Company 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. 49 of the 82 active systems in Nevada County (60%) are also privately owned.
Does Sierra Estates Mutual Water Company have drinking water violations?
Of the 12 most recent violations in EPA's records, 10 are health-based, and the most recent began in October 2024. The violations listed here began between January 2000 and October 2024. By type: 9 contaminant level above the legal limit, 1 reporting, 1 required treatment not met and 1 monitoring and reporting. The contaminant or rule involved most often is Total coliform bacteria (TCR) (9 of them). EPA lists 9 as resolved, 2 as unaddressed and 1 as archived. 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. Unaddressed means the violation is not resolved or archived and is not yet covered by formal enforcement. 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 |
|---|---|---|---|---|
| 2024-10-17 | ReportingLSL Reporting · code 4G | Lead and Copper Rule Revisionscode 5200 | No | Unaddressed |
| 2024-10-17 | Required treatment not metLSL Inventory · code 2E | Lead and Copper Rule Revisionscode 5200 | Yes | Unaddressed |
| 2023-10-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2015-03-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2009-05-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Acute (TCR) · code 21 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2009-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Acute (TCR) · code 21 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2008-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2003-08-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Archived |
| 2003-03-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Acute (TCR) · code 21 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2003-01-01 | 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 |
| 2000-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | 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.
Sierra Estates Mutual Water Company: frequently asked questions
Who runs Sierra Estates Mutual Water Company?
Sierra Estates Mutual Water Company (PWSID CA2900548) is a community water system privately owned. It is regulated by the CA state drinking water program.
How many people does Sierra Estates Mutual Water Company serve?
Sierra Estates Mutual Water Company reports serving 100 people through 32 service connections in Nevada County, California.
Where does Sierra Estates Mutual Water Company 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 Estates Mutual Water Company have any drinking water violations?
Of the 12 most recent violations in EPA's records, 10 are health-based, and the most recent began in October 2024. 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 Estates Mutual Water Company'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, 10 are health-based, and the most recent began in October 2024. 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 Estates Mutual Water Company's water quality report?
As a community water system, Sierra Estates Mutual Water Company 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 Nevada County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Truckee-Donner PUD, Main | Nevada | 36,730 | Community | Groundwater |
| Nevada Id - E. George, Banner Mountain | Nevada | 17,154 | Community | Surface water |
| Nevada Id - Loma Rica | Nevada | 14,072 | Community | Surface water |
| Nevada Id - Lake Wildwood | Nevada | 9,108 | Community | Surface water |
| Nevada Id - Lake of Pines | Nevada | 6,870 | Community | Surface water |
| City of Grass Valley | Nevada | 4,947 | 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 Estates Mutual Water Company, PWSID CA2900548, California”, https://aquacensus.com/water-systems/california/sierra-estates-mutual-water-company-ca2900548 (data as of October 1, 2026).