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California Water Quality
7,249 public water systems serving 42,404,883 people.
Water Systems
7,249
Total Violations
153,308
Violation Rate
89.2%
PFAS Detection
64.4%
447 of 694 tested
Largest Water Systems
LOS ANGELES-CITY, DEPT. OF WATER & POWER
LOS ANGELES, CA · 3,875,566 served
EAST BAY MUD
OAKLAND, CA · 1,442,800 served
SAN DIEGO, CITY OF
SAN DIEGO, CA · 1,385,379 served
SAN JOSE WATER
SAN JOSE, CA · 1,039,920 served
SFPUC CITY DISTRIBUTION DIVISION
BURLINGAME, CA · 848,019 served
EASTERN MUNICIPAL WD
PERRIS, CA · 666,581 served
CITY OF FRESNO
FRESNO, CA · 545,716 served
CITY OF SACRAMENTO MAIN
SACRAMENTO, CA · 520,407 served
LONG BEACH UTILITIES DEPARTMENT
LONG BEACH, CA · 466,772 served
IRVINE RANCH WATER DISTRICT
IRVINE, CA · 444,800 served
CITY OF ANAHEIM
ANAHEIM, CA · 348,593 served
ALAMEDA COUNTY WATER DISTRICT
FREMONT, CA · 344,000 served
CITY OF SANTA ANA
SANTA ANA, CA · 310,539 served
RIVERSIDE, CITY OF
RIVERSIDE, CA · 298,398 served
SANTA CLARITA VALLEY WATER AGENCY
NEWHALL, CA · 294,090 served
GSWC - SOUTHWEST
HAWTHORNE, CA · 277,740 served
HELIX WATER DISTRICT
LA MESA, CA · 277,668 served
COACHELLA VWD: COVE COMMUNITY
PALM DESERT, CA · 270,000 served
CWS - BAKERSFIELD
SAN JOSE, CA · 267,881 served
SAN GABRIEL VALLEY WATER CO.-EL MONTE
EL MONTE, CA · 248,000 served
Most Violations
#1 ROHNERT PARK, CITY OF ROHNERT PARK
561 #2 HANFORD, CITY OF HANFORD
454 #3 LAND PROJECTS MUTUAL WATER CO. LANCASTER
426 #4 ENCINAL RD WS #01 SALINAS
395 #5 JOHN HOVANNISIAN WATER SYSTEM FRESNO
378 #6 RIVERSIDE CSA #122-MESA VERDE BLYTHE
364 #7 CAMPERS INN - RV & GOLF COURSE DUNNIGAN
355 #8 HARRIS FARMS HEADQUARTERS COALINGA
343 #9 CYPRESS CANYON WATER SYSTEM LAKE ISABELLA
340 #10 ARVIN COMMUNITY SERVICES DIST ARVIN
331 #11 PAPPAS & CO (MENDOTA) FRESNO
310 #12 WASHINGTON SCHOOL WS SALINAS
310 #13 MORO RD WS #09 SALINAS
298 #14 ARMONA COMMUNITY SERVICES DIST ARMONA
292 #15 NPS-WOLVERTON THREE RIVERS
278 Counties in California
Los Angeles
276 systems · 10,109,089 served
· 3,972 violations
San Diego
197 systems · 3,744,323 served
· 4,832 violations
Orange
46 systems · 3,201,893 served
· 507 violations
Riverside
201 systems · 2,839,125 served
· 6,103 violations
San Bernardino
318 systems · 2,830,626 served
· 4,611 violations
Alameda
27 systems · 2,249,634 served
· 275 violations
Santa Clara
119 systems · 2,097,044 served
· 2,640 violations
Sacramento
166 systems · 1,685,812 served
· 2,206 violations
Fresno
340 systems · 1,053,609 served
· 11,624 violations
San Francisco
8 systems · 1,040,304 served
· 77 violations
Kern
341 systems · 1,032,343 served
· 11,890 violations
Ventura
95 systems · 882,799 served
· 1,507 violations
San Mateo
52 systems · 782,067 served
· 1,318 violations
San Joaquin
310 systems · 775,760 served
· 5,057 violations
Contra Costa
86 systems · 565,242 served
· 1,010 violations
Stanislaus
195 systems · 511,603 served
· 3,426 violations
Santa Barbara
152 systems · 490,541 served
· 2,187 violations
Sonoma
440 systems · 481,120 served
· 6,052 violations
Monterey
315 systems · 476,400 served
· 13,641 violations
Solano
61 systems · 470,297 served
· 530 violations
Tulare
296 systems · 446,656 served
· 12,135 violations
Placer
123 systems · 429,603 served
· 1,542 violations
San Luis Obispo
167 systems · 347,560 served
· 1,652 violations
El Dorado
129 systems · 294,812 served
· 3,192 violations
Marin
49 systems · 285,765 served
· 805 violations
Santa Cruz
96 systems · 274,174 served
· 2,563 violations
Merced
119 systems · 267,234 served
· 1,403 violations
Yolo
90 systems · 260,218 served
· 2,443 violations
Butte
88 systems · 231,825 served
· 1,512 violations
Shasta
180 systems · 211,056 served
· 2,130 violations
Showing top 30 of 58 counties.