Public water system · CA4010006
ActiveCayucos Beach Mutual Water Company
At a glance
Cayucos Beach Mutual Water Company (PWSID CA4010006) is an active community water system in San Luis Obispo County, California. It reports serving 2,567 people through 778 service connections. Its primary water source is purchased surface water, and EPA lists it as owned by a local government. EPA's records list one violation for this system; it is health-based, and the most recent began in July 1993.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
2,567
Service connections
778
Primary source
SWP
Purchased surface water
System type
CWS
Community water system
System record
How does Cayucos Beach Mutual Water Company compare with other water systems in San Luis Obispo County?
By EPA's size categories, Cayucos Beach Mutual Water Company is a small system (501 to 3,300 people). San Luis Obispo County has 171 active public water systems. Its population served is about 26% above the county average of 2,038 people per system, and accounts for 0.7% of the 348,510 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 Cayucos Beach Mutual Water Company is about 62% 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. Purchased surface water means the system buys surface water from another public water system rather than drawing its own. 506 California systems (6.8%) list purchased surface water as their primary source.
Who owns and regulates Cayucos Beach Mutual Water Company?
EPA lists Cayucos Beach Mutual Water Company 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. 33 of the 171 active systems in San Luis Obispo County (19%) are also owned by a local government.
Does Cayucos Beach Mutual Water Company have drinking water violations?
EPA's records list one violation for this system; it is health-based, and the most recent began in July 1993. By type: 1 required treatment not met. The contaminant or rule involved is Surface Water Treatment Rule. EPA lists 1 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 |
|---|---|---|---|---|
| 1993-07-01 | Required treatment not metTreatment Technique (SWTR and GWR) · code 41 | Surface Water Treatment Rulecode 0200 | Yes | Resolved |
The one violation in EPA's records.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.
Cayucos Beach Mutual Water Company: frequently asked questions
Who runs Cayucos Beach Mutual Water Company?
Cayucos Beach Mutual Water Company (PWSID CA4010006) is a community water system owned by a local government. It is regulated by the CA state drinking water program.
How many people does Cayucos Beach Mutual Water Company serve?
Cayucos Beach Mutual Water Company reports serving 2,567 people through 778 service connections in San Luis Obispo County, California.
Where does Cayucos Beach Mutual Water Company get its water?
EPA SDWIS lists this system's primary water source as purchased surface water. Purchased surface water means the system buys surface water from another public water system rather than drawing its own.
Does Cayucos Beach Mutual Water Company have any drinking water violations?
EPA's records list one violation for this system; it is health-based, and the most recent began in July 1993. 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 Cayucos Beach 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. EPA's records list one violation for this system; it is health-based, and the most recent began in July 1993. For current results, consult the system's annual water quality report, EPA ECHO, or the CA state drinking water program.
Where can I find Cayucos Beach Mutual Water Company's water quality report?
As a community water system, Cayucos Beach 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 San Luis Obispo County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Santa Margarita Recreation Area | San Luis Obispo | 50,001 | Transient non-community | Groundwater |
| San Luis Obispo Water Department | San Luis Obispo | 47,788 | Community | Surface water |
| City of Paso Robles Water Division | San Luis Obispo | 31,176 | Community | Surface water |
| Atascadero Mutual Water Co | San Luis Obispo | 30,618 | Community | Groundwater |
| City of Arroyo Grande Utilities Division | San Luis Obispo | 17,963 | Community | Purchased surface water |
| California Mens Colony | San Luis Obispo | 15,000 | 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, “Cayucos Beach Mutual Water Company, PWSID CA4010006, California”, https://aquacensus.com/water-systems/california/cayucos-beach-mutual-water-company-ca4010006 (data as of October 1, 2026).