Public water system · CA4010305
ActiveMontana De Oro State Park
At a glance
Montana De Oro State Park (PWSID CA4010305) is an active transient non-community water system in San Luis Obispo County, California. It reports serving 990 people through 3 service connections. Its primary water source is surface water, and EPA lists it as owned by a state government. EPA's records list 4 violations for this system; 1 is health-based, and the most recent began in January 2023.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
990
Service connections
3
Primary source
SW
Surface water
System type
TNCWS
Transient non-community water system
System record
How does Montana De Oro State Park compare with other water systems in San Luis Obispo County?
By EPA's size categories, Montana De Oro State Park is a small system (501 to 3,300 people). San Luis Obispo County has 171 active public water systems. Its population served is about half of the county average of 2,038 people per system, and accounts for 0.3% 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 transient non-community water system reports serving 144 people, so Montana De Oro State Park is about 6.9 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. Surface water means the system draws its water from rivers, lakes, streams or reservoirs. 609 California systems (8.1%) list surface water as their primary source.
Who owns and regulates Montana De Oro State Park?
EPA lists Montana De Oro State Park 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. 6 of the 171 active systems in San Luis Obispo County (3.5%) are also owned by a state government.
Does Montana De Oro State Park have drinking water violations?
EPA's records list 4 violations for this system; 1 is health-based, and the most recent began in January 2023. The violations listed here began between January 1993 and January 2023. By type: 3 monitoring and reporting and 1 contaminant level above the legal limit. The contaminant or rule involved most often is Total coliform bacteria (TCR) (2 of them). EPA lists 4 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 |
|---|---|---|---|---|
| 2023-01-01 | Monitoring and reportingMonitoring, Regular · code 03 | Nitratecode 1040 | No | Resolved |
| 2017-10-01 | Monitoring and reportingMonitoring, Source Water (GWR) · code 34 | E. colicode 3014 | No | Resolved |
| 2006-06-01 | Monitoring and reportingMonitoring, Routine Major (TCR) · code 23 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1993-01-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
All 4 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.
Montana De Oro State Park: frequently asked questions
Who runs Montana De Oro State Park?
Montana De Oro State Park (PWSID CA4010305) 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 Montana De Oro State Park serve?
Montana De Oro State Park reports serving 990 people through 3 service connections in San Luis Obispo County, California.
Where does Montana De Oro State Park get its water?
EPA SDWIS lists this system's primary water source as surface water. Surface water means the system draws its water from rivers, lakes, streams or reservoirs.
Does Montana De Oro State Park have any drinking water violations?
EPA's records list 4 violations for this system; 1 is health-based, and the most recent began in January 2023. 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 Montana De Oro State Park'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 4 violations for this system; 1 is health-based, and the most recent began in January 2023. For current results, consult EPA ECHO, or the CA state drinking water program.
Where can I find Montana De Oro State Park's water quality report?
The annual Consumer Confidence Report requirement applies to community water systems. Montana De Oro State Park 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 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, “Montana De Oro State Park, PWSID CA4010305, California”, https://aquacensus.com/water-systems/california/montana-de-oro-state-park-ca4010305 (data as of October 1, 2026).