PlainWater

Merced County, California

SDWIS compliance plate

Sheet CA047 · Merced County 119 sys · 1,403 viol · #262/3254

VIOL-SEVERE · HEALTH-HIGH · RANK-TOP · PHOTO-FINISH · PFAS-MID · SRC-GW · SYS-MID · BOOK-FULL

  • VIOL-SEVERE 79.8% flagged
  • HEALTH-HIGH 63.2% health
  • RANK-TOP #262/3254
  • PHOTO-FINISH ±0.2 pp
  • PFAS-MID 45.5% detect
  • SRC-GW GW lead 91%
  • SYS-MID 119 systems
  • BOOK-FULL 7/7 fields

Nearest flagged-rate peer: Plumas County (+ 0.2 pp flagged-rate)

According to EPA SDWIS county population served used on /counties, Merced County ranks #262 of 3,254 counties by people served, and #27 of 58 counties in California. See methodology · corpus placement.

Merced County standing, lower-flagged corpus third

Flagged-system rate 79.8% is at or below the corpus lower third (≤ 92.7% flagged) across 2,973 counties with ≥3 SDWIS systems . Health-based share 63.2% is health-based share above the upper third (> 24.5%) . UCMR5 detect rate 45.5% is UCMR5 detect rate above the tested-pool upper third (> 33.3%) . Population served ranks #262 of 3,254 · #27 of 58 in California.

Flagged-rate neighbourhood around Merced County

Lowest/highest poles plus in-state counties nearest Merced County on % of SDWIS systems with ≥1 violation. Full ladder: /counties.

0% 20% 40% 60% 80% 100% Alpine · lowest Marin · near Plumas · near Sutter · highest 70% 79.1% 79.6% 79.8% 80% 80.3% 97.1%

Source: EPA SDWIS (county aggregates) As of 2026-05-15

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 -

Compare beyond California

Lower-flagged peers for Merced County

Cross-state counties nearest Merced County on flagged-system share (79.8%) and cumulative violation count (1,403). In-state neighbours stay on the compliance plate above.

Similar flagged-system rate

Nearest cross-state counties by % of SDWIS systems with at least one violation on record.

4 peers

Similar violation load

Nearest cross-state counties by cumulative SDWIS violation count (all systems in the county).

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

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.