Tapcensus

Water quality for ZIP code 91770

ZIP 91770 covers Rosemead, South San Gabriel, Montebello, San Gabriel, El Monte, and Temple City in Los Angeles County, California, one of 295 ZIP codes in the county. 271 active public water systems serve the county; 66 had an EPA violation in the past three years.

Most likely your provider

Amarillo Mutual Water Company CA1910002 · Community water system · Ground water
Serves 3,134 people Rules violated, past 3 years 0 Last sanitary survey Feb 26, 2026 Distance 0.3 mi

Your location is within the outer bounds of this system's EPA service area.

View system details EPA facility report

Other community water systems in Los Angeles County

198 systems, nearest first
SystemServesStatusRules violated, 3 yrDistance
Gswc-South San Gabriel
 26,451 0 0.8 mi
San Gabriel County WD
 40,154 0 1.9 mi
Cal/am Water Company San Marino
 48,065 0 2.6 mi
EL Monte-City, Water Dept.
El Monte		 23,000 0 2.7 mi
San Gabriel Valley Water Co-Montebello 1
 5,205 0 2.7 mi
Monterey Park-City, Water Dept.
Monterey Park		 61,096 1 2.9 mi
City of Alhambra
Alhambra		 80,279 0 3.2 mi
Sunny Slope Water Co.
 25,252 1 3.3 mi
Del Rio Mutual
 700 1 3.7 mi
Montebello Land & Water Co.
 26,554 1 3.8 mi
San Gabriel Valley Water Co.-El Monte
 240,000 0 4.0 mi
Cal-Am Water Company East Pasadena
 9,963 0 4.2 mi
Sterling Mutual Water Company
 198 2 4.2 mi
Gswc-South Arcadia
 27,430 0 4.6 mi
Pico Rivera City, Water Dept.
Pico Rivera		 39,451 0 4.7 mi
Pico WD
 22,051 0 4.9 mi
Hemlock Mutual Water Co.
 686 2 5.0 mi
South Montebello Irrigation Dist.
 15,021 0 5.2 mi
City of South Pasadena
South Pasadena		 25,329 0 5.2 mi
California Water Service Co. Ela
 142,140 0 5.4 mi
City of Arcadia
Arcadia		 54,236 0 5.5 mi
San Gabriel Valley Water Co-Montebello 2
Montebello		 3,731 0 6.0 mi
Commerce-City, Water Dept.
Montebello		 3,598 0 6.1 mi
Valley View Mutual Water Co.
 4,613 0 6.3 mi
Whittier-City, Water Dept.
Whittier		 49,954 0 6.3 mi
All 199 community water systems in Los Angeles County
Non-community systems in Los Angeles County (72: schools, campgrounds, workplaces, restaurants)

These systems serve places you visit rather than homes.

SystemServesStatusRules violated, 3 yrUnresolved
Martin Marietta Southern Calif Aggregate
 51 0 0
Young-Nak Presbyterian Church
 25 0 0
Irwindale Brewery Yard (iby)
 300 0 0
Henninger Flats
 50 0 0
Plant Water Well Rockview Dairy
South Gate 		45 0 0
Usfs-Chantry Flats-A16 Water
 113 0 0
Rancho los Amigos Hospital
 3,200 0 0
Millard Canyon Improvement Association
 42 1 0
Usfs-Skyline Park / Mount Wilson A-4
 25 0 0
Usfs-Red Box Station A-3
 25 0 0
Clear Creek Outdoor Education Center
 105 0 0
Colby Ranch-United Methodist Camp
 180 0 0
Rancho Ybarra Christian Camp
 73 0 0
Usfs-Monte Cristo Camp T-4
 116 0 0
Angeles Crest Christian Camp
 112 1 0
Usfs-Chilao Main A-9
 50 0 0
Coldbrook Campground
 38 0 0
Usfs-Crystal Lake B-13 Water
 2,000 0 0
Angeles Shooting Ranges
 490 0 0
1000 Trails / Soledad Canyon Preserve
 812 1 0
Acton la North KOA
 400 0 0
Huttopia Paradise Springs
 302 1 0
Acton Conservation Camp #11
 90 4 0
Acton Four Square Church
 50 0 0
Acton-Agua Dulce Lds Church
 150 0 0
Saint Andrews Abbey
 210 1 1
Usfs-Valyermo Ranger Station
 25 1 1
Camp Elk
 121 0 0
Usfs-Jackson Lake V-4
 805 0 0
Usfs-Appletree Flats V-3
 25 0 0
Mountain High East Ski Area
 150 0 0
Mount Kare Camp/kare Youth League
 59 0 0
Usfs-Big Pines V-2
 54 0 0
Vasquez Rocks County Park
 30 0 0
Ilead Agua Dulce Charter School
 450 1 1
Agua Dulce Women's Club
 50 0 0
Lang Ranch Shopping Center
 28 0 0
Wagon Wheel Plaza
 55 1 0
Agua Dulce Water System
 493 0 0
Agua Dulce Winery
 113 0 0
Shepherd of the Hills
 80 0 0
Living Springs Church
 50 0 0
LE Chene Restaurant Water System
 100 0 0
Desert Aire Golf Course
 80 0 0
Texas Canyon Ranger Station
 30 0 0
Los Angeles World Airports
 180 0 0
Lockheed Martin Skunk Works
 135 0 0
Anchor Retreat Center
 202 0 0
Northrop Grumman Corp.
 5,764 1 0
Lancaster National Soccer Center
Lancaster 		500 0 0
All non-community systems
About this data

Water systems are matched to Los Angeles County, the county this ZIP code lies in, nearest to the ZIP code's centre first. Your exact provider depends on your address and connection; the largest community water system in a county is usually the city or town utility. Distances are measured to the centre of the service area EPA publishes for the system.

ZIP code areas and town boundaries come from the U.S. Census Bureau's 2020 ZCTA files.

Source: the U.S. EPA's Enforcement and Compliance History Online system (ECHO), which publishes the federal Safe Drinking Water Information System. EPA's terms and values are shown as published. The California records are from EPA's data refresh of Oct 7, 2026; EPA refreshes this data quarterly, and states report to EPA with a lag of three to six months, so the newest violations may not appear yet. Retrieved from ECHO on Oct 11, 2026.