Public water system · CA4010007
ActiveCity of Paso Robles Water Division
At a glance
City of Paso Robles Water Division (PWSID CA4010007) is an active community water system in San Luis Obispo County, California. It reports serving 31,176 people through 10,867 service connections. Its primary water source is surface water, and EPA lists it as owned by a local government. EPA's records list 4 violations for this system; 1 is health-based, and the most recent began in June 2015.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
31,176
Service connections
10,867
Primary source
SW
Surface water
System type
CWS
Community water system
System record
How does City of Paso Robles Water Division compare with other water systems in San Luis Obispo County?
By EPA's size categories, City of Paso Robles Water Division is a large system (10,001 to 100,000 people). San Luis Obispo County has 171 active public water systems, and City of Paso Robles Water Division is the 3rd-largest of them by population served. Its population served is about 15 times the county average of 2,038 people per system, and accounts for 8.9% 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 City of Paso Robles Water Division is about 4.7 times 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. 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 City of Paso Robles Water Division?
EPA lists City of Paso Robles Water Division 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 City of Paso Robles Water Division have drinking water violations?
EPA's records list 4 violations for this system; 1 is health-based, and the most recent began in June 2015. The violations listed here began between June 1993 and June 2015. By type: 3 monitoring and reporting and 1 required treatment not met. The contaminants or rules involved are E. coli, Total coliform bacteria (TCR), Lead and Copper Rule and Surface Water Treatment Rule. 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 |
|---|---|---|---|---|
| 2015-06-01 | Monitoring and reportingMonitoring, Source Water (GWR) · code 34 | E. colicode 3014 | No | Resolved |
| 2008-04-01 | Monitoring and reportingMonitoring, Repeat Minor (TCR) · code 26 | Total coliform bacteria (TCR)code 3100 | No | Resolved |
| 1993-06-30 | Monitoring and reportingInitial Tap Sampling for Pb and Cu · code 51 | Lead and Copper Rulecode 5000 | No | Resolved |
| 1993-06-01 | Required treatment not metTreatment Technique (SWTR and GWR) · code 41 | Surface Water Treatment Rulecode 0200 | 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.
City of Paso Robles Water Division: frequently asked questions
Who runs City of Paso Robles Water Division?
City of Paso Robles Water Division (PWSID CA4010007) is a community water system owned by a local government. It is regulated by the CA state drinking water program.
How many people does City of Paso Robles Water Division serve?
City of Paso Robles Water Division reports serving 31,176 people through 10,867 service connections in San Luis Obispo County, California.
Where does City of Paso Robles Water Division 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 City of Paso Robles Water Division have any drinking water violations?
EPA's records list 4 violations for this system; 1 is health-based, and the most recent began in June 2015. 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 City of Paso Robles Water Division'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 June 2015. For current results, consult the system's annual water quality report, EPA ECHO, or the CA state drinking water program.
Where can I find City of Paso Robles Water Division's water quality report?
As a community water system, City of Paso Robles Water Division 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 |
| 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 |
| Nipomo Comm Services Dist | San Luis Obispo | 13,771 | 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, “City of Paso Robles Water Division, PWSID CA4010007, California”, https://aquacensus.com/water-systems/california/city-of-paso-robles-water-division-ca4010007 (data as of October 1, 2026).