PlainWater
Counties → California

Los Angeles County, California

Water Systems
276
Population Served
10,109,089
Total Violations
3,972
1,260 health-based
PFAS Detected
95
of 117 tested

Violation Analysis

93.1%
Systems with Violations
14.4
Avg Violations per System
31.7%
Health-Based Violations

Water Source Types

SW
39 systems (14%)
GW
11 systems (4%)

PFAS Contamination

117
Systems Tested
95
PFAS Detected
81.2%
Detection Rate

PFAS (per- and polyfluoroalkyl substances) are persistent chemicals found in drinking water. The EPA has set enforceable limits for several PFAS compounds under UCMR5 monitoring.

Compliance Snapshot

Los Angeles California water systems by violation status, EPA SDWIS records.

No violations on record (3) One or more violations (47)

Violation history is cumulative, many flagged systems have already returned to compliance. Detail pages show per-system context.

Water Systems

System Name Population Violations PFAS
Los Angeles-City, Dept. of Water & Power 3,875,566 33 Clean
Long Beach Utilities Department 466,772 6 Clean
Santa Clarita Valley Water Agency 294,090 4 Detected
Gswc - Southwest 277,740 11 Clean
San Gabriel Valley Water Co.-El Monte 248,000 13 Detected
Los Angeles Cwwd 40 Reg 4 & 34 Lancaster 208,129 11 Clean
Glendale-City, Water Dept. 188,784 2 Detected
Suburban Water Systems-San Jose 168,843 10 Detected
Pasadena Water and Power 164,344 8 Clean
California Water Service Co. - Ela 152,474 13 Detected
Pomona - City, Water Dept. 151,713 14 Detected
California Water Service Co. - Dominguez 143,996 19 Detected
Palmdale Water Dist. 126,804 12 Detected
Azusa Light and Water 110,044 2 Detected
Downey - City, Water Dept. 108,816 16 Detected
Torrance-City, Water Dept. 106,183 57 Clean
Burbank-City, Water Dept. 105,603 16 Detected
Walnut Valley Water District 100,941 5 Clean
California Water Service Co. - Herm/Redo 96,853 10 Clean
Santa Monica-City, Water Division 89,947 3 Detected
Inglewood- City, Water Dept. 80,824 16 Detected
City of Alhambra 79,776 8 Clean
South Gate-City, Water Dept. 76,443 127 Detected
Compton-City, Water Dept. 74,877 20 Detected
Liberty Utilities - Bellflower-Norwalk 72,624 4 Detected
Las Virgenes MWD 72,602 9 Clean
California Water Service Co. - Palos Ver 71,452 6 Clean
Valley County Water Dist. 68,871 8 Clean
Lynwood-City, Water Dept. 66,967 20 Detected
Lakewood - City, Water Dept. 66,135 6 Detected
Suburban Water Systems-Whittier 66,045 4 Detected
Gswc - Florence/Graham 63,500 2 Clean
Monterey Park-City, Water Dept. 62,183 9 Detected
Suburban Water Systems-la Mirada 56,793 0 Detected
Gswc-San Dimas 56,538 5 Detected
Paramount - City, Water Dept. 55,200 7 Clean
Gswc - Bell, Bell Gardens 54,877 8 Detected
Rowland Water District 54,660 4 Detected
City of Arcadia 51,361 17 Detected
Gswc - Artesia 50,375 5 Detected
Whittier-City, Water Dept. 49,954 0 Clean
Glendora-City, Water Dept. 49,934 4 Clean
Cal/Am Water Company - San Marino 47,995 2 Detected
Cerritos - City, Water Dept. 47,475 0 Detected
Bellflower - Somerset MWC 46,300 2 Detected
Hawthorne-City Water Dept. 44,718 8 Clean
Gswc - Norwalk 43,176 3 Detected
Pico Rivera - City, Water Dept. 40,600 17 Detected
Beverly Hills-City, Water Dept. 40,121 91 Clean
Gswc - Claremont 39,730 6 Detected

Other Counties in California

San Diego County
197 systems · 3,744,323 served · 4,832 violations
Orange County
46 systems · 3,201,893 served · 507 violations
Riverside County
201 systems · 2,839,125 served · 6,103 violations
San Bernardino County
318 systems · 2,830,626 served · 4,611 violations
Alameda County
27 systems · 2,249,634 served · 275 violations
Santa Clara County
119 systems · 2,097,044 served · 2,640 violations

Drinking Water Guides

Frequently Asked Questions

How many water violations are in Los Angeles County? ▼
Los Angeles County has 3,972 total drinking water violations across 276 water systems, of which 1,260 are health-based violations. 93.1% of systems have at least one violation.
How many people get water from Los Angeles County systems? ▼
Water systems in Los Angeles County serve approximately 10,109,089 people through 276 public water systems.
Has PFAS been detected in Los Angeles County water? ▼
Of 117 water systems tested for PFAS in Los Angeles County, 95 had PFAS detected (81.2% detection rate).
What types of water sources supply Los Angeles County? ▼
Water systems in Los Angeles County use SW (39 systems), GW (11 systems) as their primary water sources.
Are health-based violations serious? ▼
Health-based violations indicate that drinking water exceeded Maximum Contaminant Levels (MCLs) set by the EPA or failed treatment technique requirements. 31.7% of Los Angeles County's violations are health-based. Not all violations indicate immediate health risk, but they require corrective action.
Data Sources & Methodology

Drinking water violation data from the EPA Safe Drinking Water Information System (SDWIS). PFAS testing data from the UCMR5 monitoring program. SDWIS tracks all public water systems regulated under the Safe Drinking Water Act.

Violations are categorized as health-based (Maximum Contaminant Level exceedances, treatment technique failures) or monitoring/reporting violations. Not all violations indicate an immediate health risk.

Read our methodology - how this data is sourced, computed, and verified.

Data sourced from EPA SDWIS and UCMR5 PFAS monitoring data. See our methodology for details. Retrieved and formatted by PlainWater Editorial

Every figure on PlainWater is rendered directly from EPA SDWIS drinking-water data, no number is typed in by an editor. This page draws directly on EPA SDWIS data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.