Public water system · CA2702456
ActiveMonterey One Water
At a glance
Monterey One Water (PWSID CA2702456) is an active non-transient non-community water system in Monterey County, California. It reports serving 73 people through 1 service connection. Its primary water source is groundwater, and EPA lists it as owned by a local government. Of the 12 most recent violations in EPA's records, 5 are health-based, and the most recent began in October 2013.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
73
Service connections
1
Primary source
GW
Groundwater
System type
NTNCWS
Non-transient non-community water system
System record
How does Monterey One Water compare with other water systems in Monterey County?
By EPA's size categories, Monterey One Water is a very small system (500 people or fewer). Monterey County has 307 active public water systems. Its population served is well below the county average of 1,552 people per system, and accounts for less than 0.1% of the 476,419 people reported by systems filed under the county. Across California, the 7,479 active systems average 5,706 people each. Nationally, the average active non-transient non-community water system reports serving 430 people, so Monterey One Water is well below that figure.
What does “non-transient non-community water system” mean?
A non-transient non-community water system regularly serves at least 25 of the same people for more than six months a year, but not where they live. Schools, factories, office buildings and hospitals with their own supply are typical examples. California has 1,466 active non-transient non-community water systems, 20% 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 Monterey One Water?
EPA lists Monterey One Water as owned by a local government. 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. 28 of the 307 active systems in Monterey County (9.1%) are also owned by a local government.
Does Monterey One Water have drinking water violations?
Of the 12 most recent violations in EPA's records, 5 are health-based, and the most recent began in October 2013. The violations listed here began between October 2002 and October 2013. By type: 7 monitoring and reporting and 5 contaminant level above the legal limit. The contaminant or rule involved most often is Total coliform bacteria (TCR) (12 of them). EPA lists 12 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 |
|---|---|---|---|---|
| 2013-10-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Acute (TCR) · code 21 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2009-07-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2008-03-01 | Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2006-08-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2005-12-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2005-11-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 2004-05-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2003-07-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2003-02-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2002-12-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2002-11-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 2002-10-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | 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.
Monterey One Water: frequently asked questions
Who runs Monterey One Water?
Monterey One Water (PWSID CA2702456) is a non-transient non-community water system owned by a local government. It is regulated by the CA state drinking water program.
How many people does Monterey One Water serve?
Monterey One Water reports serving 73 people through 1 service connection in Monterey County, California.
Where does Monterey One Water 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 Monterey One Water have any drinking water violations?
Of the 12 most recent violations in EPA's records, 5 are health-based, and the most recent began in October 2013. 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 Monterey One Water'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, 5 are health-based, and the most recent began in October 2013. For current results, consult EPA ECHO, or the CA state drinking water program.
Where can I find Monterey One Water's water quality report?
The annual Consumer Confidence Report requirement applies to community water systems. Monterey One Water is a non-transient non-community water system, so it is not required to publish one; like every public water system, it must notify the people it serves about violations under EPA's public notification rules.
Other water systems in Monterey County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Cwsc Salinas | Monterey | 123,679 | Community | Groundwater |
| Cal Am Water Company - Monterey | Monterey | 92,450 | Community | Groundwater under influence of surface water |
| Alco Water Service | Monterey | 56,253 | Community | Groundwater |
| Marina Coast Water District | Monterey | 38,377 | Community | Groundwater |
| Soledad, City of | Monterey | 19,455 | Community | Groundwater |
| Greenfield, City of | Monterey | 18,967 | 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, “Monterey One Water, PWSID CA2702456, California”, https://aquacensus.com/water-systems/california/monterey-one-water-ca2702456 (data as of October 1, 2026).