Public water system · CA1910154
ActiveCity of South Pasadena
At a glance
City of South Pasadena (PWSID CA1910154) is an active community water system in Los Angeles County, California. It reports serving 25,329 people through 6,147 service connections. Its primary water source is purchased surface water, and EPA lists it as owned by a local government. EPA's records list 3 violations for this system; all are health-based, and the most recent began in December 1999.
Dataset updated . Source: EPA SDWIS/ECHO public records.
Population served
25,329
Service connections
6,147
Primary source
SWP
Purchased surface water
System type
CWS
Community water system
System record
How does City of South Pasadena compare with other water systems in Los Angeles County?
By EPA's size categories, City of South Pasadena is a large system (10,001 to 100,000 people). Los Angeles County has 275 active public water systems. Its population served is about 31% below the county average of 36,762 people per system, and accounts for 0.3% of the 10,109,668 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 South Pasadena is about 3.8 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. 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 City of South Pasadena?
EPA lists City of South Pasadena 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. 100 of the 275 active systems in Los Angeles County (36%) are also owned by a local government.
Does City of South Pasadena have drinking water violations?
EPA's records list 3 violations for this system; all are health-based, and the most recent began in December 1999. The violations listed here began between January 1993 and December 1999. By type: 3 contaminant level above the legal limit. The contaminant or rule involved most often is Total coliform bacteria (TCR) (2 of them). EPA lists 3 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 |
|---|---|---|---|---|
| 1999-12-01 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Monthly (TCR) · code 22 | Total coliform bacteria (TCR)code 3100 | Yes | Resolved |
| 1995-05-23 | Contaminant level above the legal limitMaximum Contaminant Level Violation, Single Sample · code 01 | Nitratecode 1040 | Yes | 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 3 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 South Pasadena: frequently asked questions
Who runs City of South Pasadena?
City of South Pasadena (PWSID CA1910154) 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 South Pasadena serve?
City of South Pasadena reports serving 25,329 people through 6,147 service connections in Los Angeles County, California.
Where does City of South Pasadena 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 City of South Pasadena have any drinking water violations?
EPA's records list 3 violations for this system; all are health-based, and the most recent began in December 1999. 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 South Pasadena'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 3 violations for this system; all are health-based, and the most recent began in December 1999. 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 South Pasadena's water quality report?
As a community water system, City of South Pasadena 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 Los Angeles County
| Water system | County | Population served | Type | Source |
|---|---|---|---|---|
| Los Angeles-City, Dept. of Water & Power | Los Angeles | 3,875,566 | Community | Surface water |
| Long Beach Utilities Department | Los Angeles | 466,772 | Community | Purchased surface water |
| Santa Clarita Valley Water Agency | Los Angeles | 294,090 | Community | Surface water |
| Gswc - Southwest | Los Angeles | 277,740 | Community | Purchased surface water |
| San Gabriel Valley Water Co.-El Monte | Los Angeles | 248,000 | Community | Groundwater |
| Los Angeles Cwwd 40 Reg 4 & 34 Lancaster | Los Angeles | 208,129 | Community | Purchased surface water |
Related pages
Working with water-system records? Pro adds alerts, change history and CSV export ($49/mo); Enterprise adds full national files, the API and an MCP server for AI tools.
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 South Pasadena, PWSID CA1910154, California”, https://aquacensus.com/water-systems/california/city-of-south-pasadena-ca1910154 (data as of October 1, 2026).