Backflow Base / Every state / California
Backflow testing software for California.
Booking, scheduling, the field test, and the report to the water system, for testing companies in California.
California water systems
California has 2,783 active community water systems. Each test report goes to the one that serves the address. The largest:
- Los Angeles-City, Dept. of Water & Power3,875,566 people served
- East Bay MUD1,468,000 people served
- City of San Diego,1,408,937 people served
- San Jose Water1,039,920 people served
- Sfpuc City Distribution Division848,019 people served
- Eastern Municipal Wd659,923 people served
- City of Fresno545,970 people served
- City of Sacramento Main527,979 people served
- Long Beach Utilities Department466,772 people served
- Irvine Ranch Water District450,323 people served
Water systems: EPA SDWIS, active community systems, 2026-10-19. Population: Census Bureau 2024 estimates.
Testing companies in California
365 companies on the tester lists of 4 water systems, the most-listed first. The first 25:
- Backflow Team, LLClisted by 3 systems
- Bay Area Backflow Inc.listed by 3 systems
- Evergreen Landscapeslisted by 3 systems
- The Backflow Guy, INC.listed by 3 systems
- The Backflow Pro, INC.listed by 3 systems
- Therma, LLC.listed by 3 systems
- United Mechanical Inc.listed by 3 systems
- $125 Backflow Testinglisted by 2 systems
- 4th of July Backflow Testinglisted by 2 systems
- ABC Testing, INClisted by 2 systems
- ACCO Engineered Systemslisted by 2 systems
- Acme Bay Area Backflow, Inc.listed by 2 systems
- Agile Backflow Solutionslisted by 2 systems
- Backflow Prevention Specialists, Inc.listed by 2 systems
- Backflow Testing & Repair LLClisted by 2 systems
- Bay and Valley Backflow Serviceslisted by 2 systems
- Beasley Plumbinglisted by 2 systems
- Chris’ Plumbinglisted by 2 systems
- City Certified Backflow Prevention, INClisted by 2 systems
- City Mechanical, Inc.listed by 2 systems
- Got Backflow?listed by 2 systems
- L. J. Kruse Companylisted by 2 systems
- Lescure Co.listed by 2 systems
- Matrix HG, Inc.listed by 2 systems
- Salcido’s Backflow Serviceslisted by 2 systems
From San Francisco Public Utilities Commission (dated July 10, 2025), City of San Diego (dated August 26, 2026), East Bay Municipal Utility District (dated March 3, 2025), San Jose Water. Checked October 19, 2026. A list shows who may test, not who is good; ask the water system for its current list.
What a test costs in California
2 published prices for a routine annual test:
- Better Cost Backflow Service$135, San Francisco. Annual test, 1 assembly; $130 each for 2+; $140 new installed; $185 DCDA-II. San Francisco County.
- 415 Backflow Testing$185, San Francisco. Per tested backflow, includes electronic filing; $135 each for additional devices; includes SFPUC tag tax from 2025.
Prices as each company publishes them, checked October 19, 2026. Repairs, extra assemblies and trip fees vary; confirm before you book.
Cities
- Los Angeles →3,878,704 people
- San Diego →1,404,452 people
- San Jose →997,368 people
- San Francisco →827,526 people
- Fresno →550,105 people
- Sacramento →535,798 people
- Long Beach →450,901 people
- Oakland →443,554 people
- Bakersfield →417,468 people
- Anaheim →344,561 people
- Stockton →324,975 people
- Riverside →323,757 people
- Irvine →318,683 people
- Santa Ana →316,184 people
- Chula Vista →278,546 people
- Santa Clarita →229,159 people
- Fremont →228,192 people
- San Bernardino →224,775 people
- Modesto →220,592 people
- Fontana →218,455 people
- Moreno Valley →213,919 people
- Oxnard →200,616 people
- Huntington Beach →193,151 people
- Glendale →187,823 people
- Ontario →185,285 people
- Elk Grove →182,797 people
- Santa Rosa →177,524 people
- Rancho Cucamonga →176,675 people
- Garden Grove →172,361 people
- Oceanside →170,941 people
- Lancaster →167,426 people
- Roseville →163,304 people
- Palmdale →162,536 people
- Corona →161,540 people
- Salinas →160,783 people
- Hayward →158,440 people
- Sunnyvale →156,792 people
- Escondido →148,847 people
- Pomona →147,966 people
- Visalia →146,271 people
- Victorville →140,721 people
- Fullerton →140,054 people
- Torrance →139,576 people
- Orange →137,941 people
- Pasadena →137,195 people
- Santa Clara →133,132 people
- Clovis →127,993 people
- Simi Valley →125,778 people
- Thousand Oaks →124,229 people
- Concord →124,016 people
- Vallejo →123,475 people
- Fairfield →122,646 people
- Antioch →118,453 people
- Carlsbad →113,575 people
- Murrieta →112,539 people
- Temecula →112,431 people
- Santa Maria →111,346 people
- Downey →109,368 people
- Costa Mesa →109,131 people
- Jurupa Valley →108,154 people
- West Covina →106,920 people
- Rialto →104,918 people
- El Monte →104,639 people
- Vacaville →103,994 people
- Burbank →103,533 people
- San Mateo →103,006 people
- Chico →102,911 people
- Inglewood →102,774 people
- Hesperia →101,836 people
- Daly City →101,418 people
- Tracy →100,136 people
Testing in California
Who may test is set by the state, the water system, or both. Ask the water system you will test for which certifications it accepts before your first test.
The software
- Bookings from a booking page, your own website, and an AI receptionist on your phone.
- Schedule board and route for each tester.
- Field app that scores every test, even with no signal.
- Test reports sent to the water system that serves each address.
- Card payments to your own Stripe account, and yearly renewals that charge after the test.
- Client portal for HOAs, property managers and contractors.
- $50/month flat: no per-test fee, no cut of payments.
- Every feature →What the app does, part by part.
- Compare →Next to other backflow and field-service software.
- Start free →No card. $50/month or $500/year once you go live, 45 days free.
- Free exam prep →Study questions, practice exams, device tests, a VR wet lab.