Tapcensus

Water quality for ZIP code 91748

ZIP 91748 covers Rowland Heights, Industry, West Covina, and South San Jose Hills 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

Rowland Water District CA1910194 · Community water system · Surface water purchased
Serves 56,100 people Rules violated, past 3 years 0 Last sanitary survey Apr 5, 2022 Distance 0.5 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
LA Habra Heights Cwd
 5,682 0 3.1 mi
LA Puente Valley Cwd
 8,276 0 4.3 mi
Walnut Valley Water District
 100,941 0 4.4 mi
Suburban Water Systems-San Jose
 170,523 0 4.6 mi
California Domestic Water Company
 0 0 5.4 mi
City of Industry Waterworks Systems
La Puente		 6,151 0 5.4 mi
Valencia Heights Water Co.
 7,775 0 6.2 mi
Suburban Water Systems-Whittier
 66,565 0 6.5 mi
Calif State Polytechnical Univ Pomona
 2,668 2 7.3 mi
Three Valleys Mwd
 0 0 7.5 mi
Covina-City, Water Dept.
Covina		 33,300 0 7.7 mi
Suburban Water Systems-Covina Knolls
 1,451 0 7.8 mi
Orchard Dale Water District
 25,000 0 7.8 mi
Whittier-City, Water Dept.
Whittier		 49,954 0 7.9 mi
Suburban Water Systems-La Mirada
 57,240 0 7.9 mi
San Gabriel Valley Water Co.-El Monte
 240,000 0 8.3 mi
Covina Valley Water Company Wholesale
 0 0 8.5 mi
Del Rio Mutual
 700 1 8.7 mi
Valley View Mutual Water Co.
 4,613 0 9.0 mi
Valley County Water Dist.
 68,871 0 9.2 mi
Gswc-San Dimas
 56,564 0 9.6 mi
Sterling Mutual Water Company
 198 2 9.7 mi
Azusa Light and Water
 110,044 0 9.8 mi
Santa FE Springs City, Water Dept.
Santa Fe Springs		 19,219 0 9.9 mi
Pomona City, Water Dept.
Pomona		 151,713 0 9.9 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
Irwindale Brewery Yard (iby)
 300 0 0
Plant Water Well Rockview Dairy
South Gate 		45 0 0
Rancho los Amigos Hospital
 3,200 0 0
Usfs-Chantry Flats-A16 Water
 113 0 0
Henninger Flats
 50 0 0
Young-Nak Presbyterian Church
 25 0 0
Usfs-Skyline Park / Mount Wilson A-4
 25 0 0
Millard Canyon Improvement Association
 42 1 0
Coldbrook Campground
 38 0 0
Usfs-Red Box Station A-3
 25 0 0
Usfs-Crystal Lake B-13 Water
 2,000 0 0
Clear Creek Outdoor Education Center
 105 0 0
Colby Ranch-United Methodist Camp
 180 0 0
Usfs-Chilao Main A-9
 50 0 0
Angeles Crest Christian Camp
 112 1 0
Usfs-Monte Cristo Camp T-4
 116 0 0
Huttopia Paradise Springs
 302 1 0
Rancho Ybarra Christian Camp
 73 0 0
Mount Kare Camp/kare Youth League
 59 0 0
Usfs-Big Pines V-2
 54 0 0
Mountain High East Ski Area
 150 0 0
Usfs-Jackson Lake V-4
 805 0 0
Usfs-Appletree Flats V-3
 25 0 0
Camp Elk
 121 0 0
Usfs-Valyermo Ranger Station
 25 1 1
Saint Andrews Abbey
 210 1 1
Angeles Shooting Ranges
 490 0 0
1000 Trails / Soledad Canyon Preserve
 812 1 0
Acton Four Square Church
 50 0 0
Acton-Agua Dulce Lds Church
 150 0 0
Acton la North KOA
 400 0 0
Acton Conservation Camp #11
 90 4 0
General Atomics Aeronautical Gray Butt
 405 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
Desert Aire Golf Course
 80 0 0
Shepherd of the Hills
 80 0 0
Living Springs Church
 50 0 0
Los Angeles World Airports
 180 0 0
LE Chene Restaurant Water System
 100 0 0
Lockheed Martin Skunk Works
 135 0 0
Antelope Valley Indian Museum State Park
 506 0 0
Northrop Grumman Corp.
 5,764 1 0
Texas Canyon Ranger Station
 30 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.