Public water system · 105300089
ActiveCuyamaca
At a glance
Cuyamaca (PWSID 105300089) is an active community water system in Washington. It reports serving 375 people through 71 service connections. Its primary water source is groundwater, and EPA lists it as Native American-owned. Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in April 2025.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
375
Service connections
71
Primary source
GW
Groundwater
System type
CWS
Community water system
System record
How does Cuyamaca compare with other water systems in Washington?
By EPA's size categories, Cuyamaca is a very small system (500 people or fewer). Across Washington, the 4,705 active systems average 2,172 people each. Nationally, the average active community water system reports serving 6,703 people, so Cuyamaca 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. Washington has 2,392 active community water systems, 51% of the state's 4,705 active systems. Groundwater means the system draws its water from wells or springs fed by underground aquifers. 4,370 Washington systems (93%) list groundwater as their primary source.
Who owns and regulates Cuyamaca?
EPA lists Cuyamaca as Native American-owned. The EPA Region 10 is its primacy agency, the regulator with primary enforcement responsibility for the system under the Safe Drinking Water Act.
Does Cuyamaca have drinking water violations?
Of the 12 most recent violations in EPA's records, one is health-based, and the most recent began in April 2025. The violations listed here began between March 2022 and April 2025. By type: 8 monitoring and reporting, 2 monitoring, 1 public notice, recordkeeping or other and 1 required treatment not met. The contaminant or rule involved most often is Revised Total Coliform Rule (2 of them). EPA lists 8 as resolved and 4 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. 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 |
|---|---|---|---|---|
| 2025-04-03 | Public notice, recordkeeping or otherPublic Notification Violation for NPDWR Violation · code 75 | Public Noticecode 7500 | No | Resolved |
| 2024-10-17 | Required treatment not metLSL Inventory · code 2E | Lead and Copper Rule Revisionscode 5200 | Yes | Resolved |
| 2024-07-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Chlorinecode 0999 | No | Resolved |
| 2024-07-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | Resolved |
| 2024-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Archived |
| 2024-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Archived |
| 2023-10-31 | Monitoring and reportingLead Consumer Notice · code 66 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2023-10-01 | Monitoring and reportingFollow-up Or Routine LCR Tap M/R · code 52 | Lead and Copper Rulecode 5000 | No | Resolved |
| 2023-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Haloacetic acids (HAA5)code 2456 | No | Archived |
| 2023-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 2023-01-01 | Monitoring and reportingMonitoring and Reporting (DBP) · code 27 | Total trihalomethanes (TTHM)code 2950 | No | Archived |
| 2022-03-01 | MonitoringMonitoring, Routine (RTCR) · code 3A | Revised Total Coliform Rulecode 8000 | No | 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.
Cuyamaca: frequently asked questions
Who runs Cuyamaca?
Cuyamaca (PWSID 105300089) is a community water system Native American-owned. It is regulated by the EPA Region 10.
How many people does Cuyamaca serve?
Cuyamaca reports serving 375 people through 71 service connections in Washington.
Where does Cuyamaca 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 Cuyamaca have any drinking water violations?
Of the 12 most recent violations in EPA's records, one is 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 Cuyamaca'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, one is 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 EPA Region 10.
Where can I find Cuyamaca's water quality report?
As a community water system, Cuyamaca 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 Washington
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Seattle Public Utilities | King | 1,161,961 | Community | Surface water |
| Tacoma Water Division City of | Pierce | 446,170 | Community | Surface water |
| Vancouver City of | Clark | 373,047 | Community | Groundwater |
| Spokane City of | Spokane | 346,138 | Community | Groundwater |
| Bellevue City of | King | 321,349 | Community | Purchased surface water |
| Alderwood Water District | Snohomish | 245,715 | 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, “Cuyamaca, PWSID 105300089, Washington”, https://aquacensus.com/water-systems/washington/cuyamaca-105300089 (data as of October 1, 2026).