What is backflow and how can it be prevented?

By June 12, 2018Uncategorized

Clean, potable water is the most important resource in the world. Fortunately, here in the U.S., having to deal with contaminated water is not something that the average person normally has to think twice about. This doesn’t mean that prevention is not an issue, however. From the common homeowner to commercial property owners, the potential problem of backflow is an issue that needs to be taken seriously.

What is backflow?

Backflow is when wastewater or other hazardous materials reverse their flow and end up in a previously potable water supply. It happens at a point in the water system known as a cross-connection, where the potable water supply is connected to a non-potable water supply. As you can imagine, this can be a very serious problem. The two most common causes of backflow are back pressure and back siphonage.

  • Back pressure: This is where high-pressure fluids are pushed into areas of relatively low-pressure fluids. This can be created by increases in boiler temperature, pumps in a water system, et cetera. It can be thought of in terms of blowing air through a straw and having air bubble appear in your drink. Direct cross-connections are subject to back pressure.
  • Back siphonage: This happens when higher-pressure fluids are pulled to a lower-pressure area. Imagine sucking liquid from a cup into a straw. This means that when there is a drop in pressure in a water system (which is not a rare occurrence), dangerous fluids or materials could actually be pulled into the system. Examples of this include water main breaks or the high usage of local fire hydrants. Indirect cross-connections cannot have back pressure introduced and are therefore susceptible to back siphonage.

The hazardous and potentially lethal consequences of backflow mean that having adequate prevention devices are imperative for your water system.

Backflow Preventers

A backflow preventer is a device designed to safeguard potable water supplies from dangerous backflow. They are necessary to be at cross-connections between water repositories. Here are a few of the most common backflow preventers used today.

Manually operated valves

These valves must be operated by hand and are not considered an acceptable way to prevent backflow. All methods that meet standard government regulations must be automatic in nature. This is so that nobody has to be alerted to stop dangerous water backflow and the system stops it automatically.

Air gaps

Air gaps mean that there is an open vertical area between a water dispenser and the flood level of the device. These are seen a lot in consumer and residential applications such as water faucets or dishwashing appliances. Since, in the example of a faucet, the water level of the sink never approaches the faucet dispenser, non-potable water never comes into contact with the faucet, and the potable water line is not contaminated.

Check valves

Check valves are automatic valves that prevent backflow by allowing fluid to only flow in one direction. There are different types, ranging from simple single check valves to the more complex reduced pressure zone valves. These are double check valves with another container in between that measures pressure. Extra pressure in this container is expelled through drainage discharge.

When should I have a backflow preventer?

For residences, you’ll need to install a backflow preventer if you’re putting in an in-ground irrigation system or if you have a separate irrigation meter. Commercial properties have more complex needs. Businesses that require backflow preventers include but are not limited to:

  • Restaurants.
  • Medical facilities.
  • Car washes.
  • Various forms of retail space.
  • Businesses with sprinkler systems.
  • Laboratories or other facilities where potentially hazardous materials could pose a threat to the water supply.
  • Tall buildings.

If you are unsure as to whether your business is required to install a backflow preventer, call Bieg Plumbing to schedule a consultation.

What is the process for installing a backflow preventer?

There are four steps for the proper, legal way to install a backflow preventer. Bieg Plumbing has the professionals and experience to go through each of these steps with you so that you can be confident that your backflow preventer meets all governmental regulations.

  • Installation. We recommend hiring a trained professional to install the device. Proper installation is extremely important and shouldn’t be left to those without the detailed knowledge necessary to do it correctly.
  • Inspection. This must be done by an experienced inspector. Let our technicians provide you with peace of mind.
  • Testing. Now that it has been inspected, it must be thoroughly tested by an individual approved by the State of Missouri.
  • Biannual inspection. The state of Missouri mandates that backflow preventers are to be inspected by a certified technician every two years. This ensures that they are in good working order and are not in need of repair.

The process may seem convoluted, but when you’re talking about something as important as keeping the water supply clean and free of serious contamination, it’s crucial to be as thorough as possible.

With 60 years of experience in this area, we are here to guide you through each part of the process and make sure that you’re up to code. Eliminate the need to procure professionals for each step and let us do it all! We’re truly a one-stop shop for all of your backflow prevention needs. Our red vans are ready to be dispatched, so give us a call!