Backflow Devices Are An Important Irrigation Component to You and Your Lawn
This article discusses the backflow and why it’s important to have. Most people know they need a backflow for their irrigation system. They just don’t know why. For instance, I’ll show what can happen if a backflow is missing or broken. Then I’ll tell you how they work and why you want one for your system. Click here to browse backflow preventers.
West Virginia Department of Health and Human Resources:
This section comes from the West Virginia Department of Health and Human Resources. “One of the most highly publicized cases of a backflow incident occurred in 1969 at Holy Cross University. The football season was canceled due to a large outbreak of infectious hepatitis among the team members. It was determined that backflow through an unprotected lawn sprinkler system at the practice football field caused the epidemic. Similarly, children carrying the hepatitis virus also that was routinely played in puddles around the sprinkler heads. Fire fighting demands in the vicinity caused negative pressures at the sprinkler heads back siphoning the contaminated water into the drinking water supply to the field.”
Environmental Protection Agency:
This article comes from the Environmental Protection Agency. In 1991, an atmospheric vacuum breaker valve was intended to protect a cross-connection between an irrigation system and the potable supply. However, it malfunctioned. This caused backflow of irrigation water into the public water system. The water system, located in Michigan, was contaminated with nematodes, rust, and debris.”
One of the most famous cases of backflow occurred in California. A laborer had been using an aspirator attached to a garden hose to spray a driveway with weed-killer containing arsenic. At some time during his work, the water pressure reversed. The man then disconnected the hose and unwittingly drank from the hose bib. Arsenic in the waterline killed him!
In 1981, chlordane and heptachlor were back siphoned through a garden hose that was submerged in a termite exterminator’s tank truck in Pennsylvania. An undisclosed number of illnesses occurred, and 75 apartment units were affected.
Types Of Backflow Devices:
- Pressure Vacuum Breakers (PVB)
- Double Check Assemblies (DCA)
- Reduced Pressure Zone Assemblies (RPZ)
- Atmospheric Vacuum Breakers (AVB)
The Basics Of Your Backflow Preventer
If you lose water pressure in your house, the water in the house will flow out to the main line. Because pressure is now reversed, going from house to the mainline, it creates a siphon effect and will pull anything in the sprinkler system and in the puddles around the sprinkler system with it. If your garden hose was on at the same time, it becomes a siphon hose. After that, all the fertilizer, insecticide, animal waste and many other things you don’t want are pulled into the drinking water.
Notice the two involving garden hoses? How many of us drink from a garden hose when working outside on a hot summer day? Ever use that same hose to put out pesticides or fertilizer? Put a backflow preventer on the hose bib. Cheap protection.
A backflow works by shutting down the irrigation water line when you lose water pressure. This works just like a stopper in your bathtub: a plug falls down and blocks the line. However, they get more complicated, depending on the application.
In conclusion, ask your city or county or your water provider. In my area a pressure vacuum breaker is plenty. Two miles away a new jurisdiction starts and they insist on double-checks. Above all, always verify local code requirements first.