PlainWater
Counties → California

Orange County, California

Water Systems
46
Population Served
3,201,893
Total Violations
507
108 health-based
PFAS Detected
30
of 30 tested

Violation Analysis

89.1%
Systems with Violations
11.0
Avg Violations per System
21.3%
Health-Based Violations

Water Source Types

SW
36 systems (78%)
GW
10 systems (22%)

PFAS Contamination

30
Systems Tested
30
PFAS Detected
100.0%
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

Orange California water systems by violation status, EPA SDWIS records.

No violations on record (5) One or more violations (41)

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
Irvine Ranch Water District 444,800 12 Detected
City of Anaheim 348,593 5 Detected
City of Santa Ana 310,539 20 Detected
City of Huntington Beach 201,000 9 Detected
City of Garden Grove 174,226 0 Detected
Moulton Niguel Water District 170,236 0 Clean
Santa Margarita Water District 168,289 2 Clean
City of Fullerton 139,461 14 Detected
City of Orange 120,770 6 Detected
Golden State WC - West Orange County 114,379 0 Detected
Mesa Water District 110,000 4 Clean
City of Westminster 90,911 13 Detected
Yorba Linda Water District 84,292 4 Detected
City of Buena Park 81,998 12 Detected
City of Newport Beach 68,572 7 Clean
City of Tustin 66,600 17 Detected
City of la Habra 63,118 101 Clean
City of Fountain Valley 56,747 8 Detected
El Toro Water District 51,800 1 Detected
City of San Clemente 51,545 4 Clean
Golden State WC - Placentia/Yorba Linda 50,381 0 Detected
City of Brea 48,479 3 Clean
South Coast Water District 41,118 4 Detected
Santa Margarita Water District-Id9 39,684 22 Clean
City of Seal Beach 24,937 4 Clean
Laguna Beach County WD 18,404 2 Clean
City of la Palma 15,948 8 Clean
Trabuco Canyon Water District 13,659 16 Clean
Golden State WC - Cowan Heights 6,997 1 Detected
Serrano Water District 5,659 8 Detected
Joint Regional Water Supply System 3,947 0 -
East Orange County WD - Rz 3,464 3 -
Knott S Berry Farm 3,000 10 -
Eastside Water Association 2,000 11 -
Los Alamitos Race Course 1,600 18 -
Smwd-Nichols Institute 1,600 2 -
Midway City Mutual WC 1,305 32 -
South Midway City Mutual Water Co. 891 12 -
Canyon RV Park 294 10 -
Caspers Regional Wilderness Park 215 6 -
Hynes Estates Mutual Water Co. 168 21 -
Page Avenue Mutual Water Company 119 24 -
Liberty Park Water Association 85 19 -
Lazy W Ranch Water System 63 5 -
East Orange County WD - Wz 0 6 -
San Juan Basin Authority 0 21 -

Other Counties in California

Los Angeles County
276 systems · 10,109,089 served · 3,972 violations
San Diego County
197 systems · 3,744,323 served · 4,832 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 Orange County? ▼
Orange County has 507 total drinking water violations across 46 water systems, of which 108 are health-based violations. 89.1% of systems have at least one violation.
How many people get water from Orange County systems? ▼
Water systems in Orange County serve approximately 3,201,893 people through 46 public water systems.
Has PFAS been detected in Orange County water? ▼
Of 30 water systems tested for PFAS in Orange County, 30 had PFAS detected (100.0% detection rate).
What types of water sources supply Orange County? ▼
Water systems in Orange County use SW (36 systems), GW (10 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. 21.3% of Orange 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.