State rankings
California water-system rankings
Lowest-scoring systems in California
Ranked lowest score first. Population shown for context.
1 RUNNING SPRINGS WATER DISTRICT RUNNING SPRINGS, CA · ~5,268 served 1 2 HELENDALE COMMUNITY SERVICE DISTRICT HELENDALE, CA · ~6,347 served 15 3 PORTERVILLE, CITY OF PORTERVILLE, CA · ~63,487 served 19 4 CERES, CITY OF CERES, CA · ~54,513 served 19 5 YOSEMITE SPRING PARK UTIL CO COARSEGOLD, CA · ~5,300 served 20 6 RIVERSIDE HIGHLAND WATER COMPANY GRAND TERRACE, CA · ~20,188 served 24 7 RUBIO CANON LAND & WATER ASSOCIATION ALTADENA, CA · ~9,215 served 24 8 CITY OF ORANGE ORANGE, CA · ~120,770 served 26 9 CITY OF GARDEN GROVE GARDEN GROVE, CA · ~174,226 served 28 10 PLEASANT VALLEY MUTUAL WATER CO CAMARILLO, CA · ~5,000 served 28 11 LOS OSOS COMMUNITY SERVICES DISTRICT LOS OSOS, CA · ~7,086 served 29 12 CITY OF PLEASANTON PLEASANTON, CA · ~76,689 served 30 13 LIBERTY UTILITIES - BELLFLOWER-NORWALK DOWNEY, CA · ~72,624 served 30 14 NORCO, CITY OF NORCO, CA · ~25,068 served 30 15 CITY OF CLOVIS CLOVIS, CA · ~130,130 served 31 16 TRACT 349 MUTUAL WATER CO. CUDAHY, CA · ~8,700 served 31 17 CITY OF GRIDLEY GRIDLEY, CA · ~7,269 served 31 18 HESPERIA WD HESPERIA, CA · ~100,744 served 32 19 CAL AM WATER COMPANY - MONTEREY PACIFIC GROVE, CA · ~92,450 served 32 20 MONTEBELLO LAND & WATER CO. MONTEBELLO, CA · ~26,554 served 32 21 CITY OF REDDING REDDING, CA · ~89,628 served 33 22 CITY OF SACRAMENTO MAIN SACRAMENTO, CA · ~527,979 served 34 23 CITY OF SANTA ANA SANTA ANA, CA · ~310,539 served 34 24 CITY OF FULLERTON FULLERTON, CA · ~139,461 served 34 25 DOWNEY - CITY, WATER DEPT. DOWNEY, CA · ~110,556 served 34
Highest-scoring large systems in California
Systems serving 10,000+ people with the best scores.
1 LOS ANGELES-CITY, DEPT. OF WATER & POWER LOS ANGELES, CA · ~7,751,132 served 100 2 EAST BAY MUD OAKLAND, CA · ~1,442,800 served 100 3 SAN DIEGO, CITY OF SAN DIEGO, CA · ~1,385,379 served 100 4 SFPUC CITY DISTRIBUTION DIVISION BURLINGAME, CA · ~848,019 served 100 5 EASTERN MUNICIPAL WD PERRIS, CA · ~666,581 served 100 6 LONG BEACH UTILITIES DEPARTMENT LONG BEACH, CA · ~466,772 served 100 7 IRVINE RANCH WATER DISTRICT IRVINE, CA · ~444,800 served 100 8 ALAMEDA COUNTY WATER DISTRICT FREMONT, CA · ~344,000 served 100
Scores reflect EPA public records (violations, enforcement, PFAS), are system-level, and can’t account for your home’s plumbing. See the methodology.