Public water system · CA4410306

Active

Csp - Rancho Del Oso

At a glance

Csp - Rancho Del Oso (PWSID CA4410306) is an active transient non-community water system in Santa Cruz County, California. It reports serving 669 people through 2 service connections. Its primary water source is groundwater, and EPA lists it as owned by a state government. EPA's records list 9 violations for this system; 5 are health-based, and the most recent began in December 2005.

Dataset updated October 2026 . Source: EPA SDWIS/ECHO public records.

Population served

669

Service connections

Primary source

Groundwater

System type

TNCWS

Transient non-community water system

System record

PWSIDCA4410306

System typeTransient non-community water system

Activity statusActive

Population served669

Service connections2

Primary water sourceGroundwater

Owner typeState government

Primacy agencyCA state drinking water program

City served—

StateCalifornia

ZIP—

CountySanta Cruz County

How does Csp - Rancho Del Oso compare with other water systems in Santa Cruz County?

By EPA's size categories, Csp - Rancho Del Oso is a small system (501 to 3,300 people). Santa Cruz County has 96 active public water systems. Its population served is well below the county average of 2,856 people per system, and accounts for 0.2% of the 274,204 people reported by systems filed under the county. Across California, the 7,479 active systems average 5,706 people each. Nationally, the average active transient non-community water system reports serving 144 people, so Csp - Rancho Del Oso is about 4.6 times that figure.

What does “transient non-community water system” mean?

A transient non-community water system serves places where people do not stay long, such as gas stations and campgrounds, and regularly serves at least 25 people a day for at least 60 days a year. California has 3,016 active transient non-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 Csp - Rancho Del Oso?

EPA lists Csp - Rancho Del Oso as owned by a state 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. 3 of the 96 active systems in Santa Cruz County (3.1%) are also owned by a state government.

Does Csp - Rancho Del Oso have drinking water violations?

EPA's records list 9 violations for this system; 5 are health-based, and the most recent began in December 2005. The violations listed here began between January 1999 and December 2005. By type: 4 monitoring and reporting, 3 contaminant level above the legal limit and 2 required treatment not met. The contaminant or rule involved most often is Total coliform bacteria (TCR) (4 of them). EPA lists 9 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
2005-12-01	Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22	Total coliform bacteria (TCR)code 3100	Yes	Resolved
2005-06-01	Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22	Total coliform bacteria (TCR)code 3100	Yes	Resolved
2004-01-01	Required treatment not metTreatment Technique (SWTR and GWR) · code 41	Surface Water Treatment Rulecode 0200	Yes	Resolved
2004-01-01	Monitoring and reportingMonitoring, Routine Minor (TCR) · code 24	Total coliform bacteria (TCR)code 3100	No	Resolved
2002-10-01	Required treatment not metTreatment Technique (SWTR and GWR) · code 41	Surface Water Treatment Rulecode 0200	Yes	Resolved
2001-01-01	Monitoring and reportingMonitoring, Regular · code 03	Nitratecode 1040	No	Resolved
2000-07-01	Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22	Total coliform bacteria (TCR)code 3100	Yes	Resolved
2000-01-01	Monitoring and reportingMonitoring, Regular · code 03	Nitratecode 1040	No	Resolved
1999-01-01	Monitoring and reportingMonitoring, Regular · code 03	Nitratecode 1040	No	Resolved

All 9 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.

Csp - Rancho Del Oso: frequently asked questions

Who runs Csp - Rancho Del Oso?

Csp - Rancho Del Oso (PWSID CA4410306) is a transient non-community water system owned by a state government. It is regulated by the CA state drinking water program.

How many people does Csp - Rancho Del Oso serve?

Csp - Rancho Del Oso reports serving 669 people through 2 service connections in Santa Cruz County, California.

Where does Csp - Rancho Del Oso 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 Csp - Rancho Del Oso have any drinking water violations?

EPA's records list 9 violations for this system; 5 are health-based, and the most recent began in December 2005. 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 Csp - Rancho Del Oso'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 9 violations for this system; 5 are health-based, and the most recent began in December 2005. For current results, consult EPA ECHO, or the CA state drinking water program.

Where can I find Csp - Rancho Del Oso's water quality report?

The annual Consumer Confidence Report requirement applies to community water systems. Csp - Rancho Del Oso is a 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 Santa Cruz County

Water system	County	Population served	Type	Source
Santa Cruz Water Department	Santa Cruz	94,626	Community	Surface water
Watsonville, City of	Santa Cruz	65,231	Community	Surface water
Soquel Creek Water District	Santa Cruz	40,809	Community	Purchased surface water
San Lorenzo Valley Water Dist	Santa Cruz	21,145	Community	Surface water
Cabrillo College	Santa Cruz	12,000	Non-transient non-community	Groundwater
Scotts Valley Water District	Santa Cruz	11,197	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, “Csp - Rancho Del Oso, PWSID CA4410306, California”, https://aquacensus.com/water-systems/california/csp-rancho-del-oso-ca4410306 (data as of October 1, 2026).