| CSLB #1045486 |

Safe Water Starts Here

Providing quality backflow services from Monterey to the Bay since 2016. AWWA & Cross - Connection Survey Certified.

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Our Family, Serving Yours

We’re Sergio and Alondra, and we started 4th of July Backflow, LLC in 2016 to keep our community’s water safe while treating every customer like family. With my background in landscaping and a degree in Environmental and Occupational Health, I focus on backflow testing, repairs, and installations while Alondra manages the backend and ensures every customer feels supported. Together, we bring certified, reliable, and family-run care to every job.

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Sergio Villegas & Alondra Haro | Founders
4th of July Backflow Testing LLC

Experience . Trust . Local Care

Proudly Serving our Local Communities:

Monterey | San Benito | Santa Cruz | Santa Clara | San Luis Obispo San Mateo | San Francisco

8 + Years Field Experience

Bringing 8 years of proven expertise in backflow services.

Licensed & Certified

Rest easy knowing that your service is in qualified hands.

Family-Owned & Operated

Caring for your backflow systems as if they were our own.

Report? Consider it Done

We'll submit your test result within 1-2 days after payment.

5 Star Reviews

Rated 5 stars for reliable backflow testing.

What We Offer

Backflow Installations

Annual Backflow Tests

Backflow Repairs & Replacement

Cross - Connection Surveys

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We Serve:

HOAs
Hotels
Malls
Military Bases

Airports
Attractions
Condos
Hospitals

Private Residences
Restaurants
Schools
Shopping Centers

Theme Parks
Water Agencies
& More!

Learn more about our services and let us know what you need help with!

5 Star Rated for Quality and Care

Where quality service meets genuine customer care.

Tom Muniz

Sergio arrived on time and completed work within estimated time period. He was professional and diligent with process.

Neil

It’s been a challenge to find a good and quickly reliable Backflow Certification company. Sergio from 4th of July Backflow Testing has been extremely professional and accommodating. I had a few last minute scheduling changes and Sergio was able to accommodate and work with us. I can’t recommend them enough!

Tarra Fluent

Sergio was fast in responding to our request for help on 2 separate properties for backflow help. Got results we needed and service!

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Got Questions About Backflow?
We've Got Answers.

How Much Will My Backflow Test Cost?

Most backflow tests range from $120–$250. The price depends on your device’s location and your water company’s rules. Some require a compliance tag, which only certified testers are able to purchase, and that may add a small extra cost.

Why Do I Need a Backflow Installed?

Water companies require backflows for high-risk properties. If the water system loses pressure, water could flow backward and bring contaminants - like chemicals, well water, or irrigation water into your drinking water. Backflows are designed to protect the public water supply and ensure everyone has safe, clean water.

How Often Should I Test My Backflow Device?

Most water companies require annual testing, though some areas may require it every six months. You’ll receive a notice from your water provider when it’s time for your backflow test.