PlainWater
Counties → California

Merced County, California

Water Systems
119
Population Served
267,234
Total Violations
1,403
887 health-based
PFAS Detected
7
of 11 tested

Violation Analysis

79.8%
Systems with Violations
11.8
Avg Violations per System
63.2%
Health-Based Violations

Water Source Types

GW
43 systems (36%)
SW
7 systems (6%)

PFAS Contamination

11
Systems Tested
7
PFAS Detected
63.6%
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

Merced 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
City of Merced 93,692 11 Detected
City of los Banos 47,419 10 Clean
City of Atwater 29,479 19 Detected
City of Livingston 14,894 35 Clean
Winton Water & Sanitary Dist 9,745 15 Clean
Delhi Cwd 7,784 34 Detected
City of Dos Palos 7,452 57 Clean
Cal Trans Erreca Rest Area 6,150 8 -
City of Gustine 6,110 21 Clean
Cal Am - Meadowbrook 5,656 14 Detected
Hilmar County Water District 5,504 16 Clean
Planada Csd 4,164 14 Detected
Santa Nella County Water District 2,211 41 -
Le Grand Comm Services Dist 1,739 28 -
Castle Airport 1,650 15 -
Hilmar Cheese Company 1,629 14 -
Dole Atwater Plant 1,500 18 -
Lake Yosemite County Park 1,200 19 -
McSwain Elementary School 1,046 11 -
Liberty Packing Company LLC 1,020 7 -
John Latoracca Correctional Facility 800 11 -
San Luis Hills 779 46 -
Cdpr Four Rivers District-San Luis Creek 653 14 -
The Morning Star Packing Company 650 7 -
Ingomar Packing 600 17 -
Planada Elementaryschool 567 4 -
Delhi Kingdom Hall 452 11 -
Joseph Gallo Cheese Co. 407 8 -
Volta Community SD 406 9 -
Sensient Natural Ingredients LLC 400 12 -
Black Rascal Water Company 367 15 -
Cdpr Four Rivers District-Basalt 363 10 -
Cdpr-Hatfield 352 18 -
Turlock Golf & Country Club 350 26 -
Washington School 338 9 -
Charleston School 325 8 -
Saputo Dairy Foods USA, LLC 320 0 -
Lds Church Atwater 300 0 -
Schelby School 290 4 -
Cdpr-McConnell 286 14 -
Yosemite Wholesale 285 9 -
Merquin Elementary School 284 5 -
Hagaman County Park 280 19 -
Lds Church Merced 257 0 -
Firebaugh Travel Plaza (SW) 250 24 -
E & J Gallo Winery 245 6 -
Foster Farms Delhi Feedmill Collier Road 244 56 -
Ballico Csd 238 1 -
Henderson County Park 230 18 -
Classic Yam Water System 224 10 -

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
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

Drinking Water Guides

Frequently Asked Questions

How many water violations are in Merced County? ▼
Merced County has 1,403 total drinking water violations across 119 water systems, of which 887 are health-based violations. 79.8% of systems have at least one violation.
How many people get water from Merced County systems? ▼
Water systems in Merced County serve approximately 267,234 people through 119 public water systems.
Has PFAS been detected in Merced County water? ▼
Of 11 water systems tested for PFAS in Merced County, 7 had PFAS detected (63.6% detection rate).
What types of water sources supply Merced County? ▼
Water systems in Merced County use GW (43 systems), SW (7 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. 63.2% of Merced 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.