Public water system · CA2600622
ActiveSierra East Hoa
At a glance
Sierra East Hoa (PWSID CA2600622) is an active community water system in Mono County, California. It reports serving 84 people through 30 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 July 2025.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
84
Service connections
30
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Sierra East Hoa compare with other water systems in Mono County?
By EPA's size categories, Sierra East Hoa is a very small system (500 people or fewer). Mono County has 84 active public water systems. Its population served is well below the county average of 424 people per system, and accounts for 0.2% of the 35,602 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 East Hoa 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 East Hoa?
EPA lists Sierra East Hoa 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. 46 of the 84 active systems in Mono County (55%) are also privately owned.
Does Sierra East Hoa have drinking water violations?
Of the 12 most recent violations in EPA's records, 10 are health-based, and the most recent began in July 2025. The violations listed here began between April 2020 and July 2025. By type: 9 contaminant level above the legal limit, 2 reporting and 1 required treatment not met. The contaminant or rule involved most often is Arsenic (9 of them). EPA lists 9 as archived and 3 as unaddressed. 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. Unaddressed means the violation is not resolved or archived and is not yet covered by formal enforcement.
| Began | Violation | Contaminant or rule | Health-based | Status |
|---|---|---|---|---|
| 2025-07-02 | ReportingNotification, Known or Potential LSL · code 4H | Lead and Copper Rule Revisionscode 5200 | No | Unaddressed |
| 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 |
| 2021-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Archived |
| 2021-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Archived |
| 2021-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Archived |
| 2021-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Archived |
| 2020-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Archived |
| 2020-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Archived |
| 2020-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Archived |
| 2020-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | Yes | Archived |
| 2020-04-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Average · code 02 | Arseniccode 1005 | 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.
Sierra East Hoa: frequently asked questions
Who runs Sierra East Hoa?
Sierra East Hoa (PWSID CA2600622) is a community water system privately owned. It is regulated by the CA state drinking water program.
How many people does Sierra East Hoa serve?
Sierra East Hoa reports serving 84 people through 30 service connections in Mono County, California.
Where does Sierra East Hoa 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 East Hoa 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 July 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 East Hoa'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 July 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 East Hoa's water quality report?
As a community water system, Sierra East Hoa 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 Mono County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Mammoth Cwd | Mono | 8,234 | Community | Surface water |
| Mammoth Mountain Ski Area - Outpost 14 | Mono | 7,736 | Non-transient non-community | Groundwater |
| June Lake PUD - Down Canyon | Mono | 2,810 | Community | Surface water |
| June Lake PUD Village | Mono | 2,763 | Community | Surface water |
| Usmc/Mtn Warfare Trng Ctr - Bridgeport | Mono | 1,200 | Community | Groundwater |
| Mammoth Lakes Basin | Mono | 1,000 | Transient non-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, “Sierra East Hoa, PWSID CA2600622, California”, https://aquacensus.com/water-systems/california/sierra-east-hoa-ca2600622 (data as of October 1, 2026).