Skip navigation

Estimates are free!

24 hour Emergency Service


Northwest Vermont & Northeast New York


Why Does Backflow Happen?

The backflow preventer is a critical device for most commercial buildings, and is sometimes found I use homes and for larger residential structures. The backflow preventer is designed to protect the municipal water system from backflow, which is when waste water from the sewer system side of the plumbing ends up moving into the potable fresh water side, possibly contaminating the municipal fresh water supply. This isn’t something that’s a problem in most homes—there’s a simple air gap device to prevent backflow in the few places it can happen, such as a dishwasher—but it’s a major danger for commercial plumbing. Commercial plumbing has cross connections where there is the potential for backflow to occur and the fresh water becoming contaminated with bacteria and the microbes contained in waste water.

Why backflow might occur

So what exactly causes backflow and makes it necessary to have safeguards against it? There are two basic scenarios:

  • A drop in pressure on the fresh water side: This is the most common cause. It’s known as back siphonage. When the water pressure in the municipal system abruptly drops, the imbalance in pressure pulls the sewer water the other direction. There are a number of different reasons that fresh water pressure can suddenly drop, such as fire sprinklers coming on or the fire department using water from a fire hydrant. The huge draw on the fresh water system will cause a temporary pressure drop—and that means backflow unless there’s a backflow prevention device in place.
  • A rise in pressure from the waste water side: This is less common, although easier to understand. It’s called backpressure, a.k.a. downstream pressure along the sewage system. If pressure increases in the wastewater pipes, it will push contaminated water into the fresh water pipes. This can happen because of clogging and aging sewer line pipes.

When either of these situations occurs, the backflow preventer is there to stop it. Backflow preventers come in many sizes, but the basic job of the assembly is to detect when water moves the wrong direction and shut a valve to prevent it. Most commercial backflow preventers consist of a reduced-pressure assembly and a double-check valve assembly. This means the backflow preventers stops the water flow while also reducing the pressure.

Professional Backflow Prevention Services

You’ll need a licensed professional plumber in Plattsburgh, NY to handle services for backflow prevention—especially if it’s a commercial backflow prevention device, where a correctly working device is vital to keeping a business kept up to local health codes. Your business will periodically receive notice that the backflow prevention device needs to be tested, and you’ll have to call a certified plumber to do this.

In fact, any backflow prevention services, such as tests, repairs, and replacements, must have a licensed plumber. Our team of plumbers is qualified for all these jobs, as well as other important commercial work such as installing, cleaning, and replacing grease traps. We’re a family-owned and operated plumbing contractor with more than 23 years of experience in the area, so rely on us for backflow prevention services.

Red Rock Mechanical, LLC serves Northwest Vermont and Northeast York.

Comments are closed.