03/24/2015
What is a backflow prevention assembly?
We see them all the time… Sometimes mammoth, strange looking pipe configurations, with handles and valves that come out of the ground, and go right back into the ground.
A backflow prevention assembly prevents contaminated water from returning into the public water supply by backpressure or backsiphonage.
My favorite example is this:
In the movies… when a fire sprinkler system is activated by fire in a building, it appears like lovely rain, right?
Not in reality… That water has been standing for a long time in those pipes. It’s black, smelly and really unhealthy.
So, let’s say there is a fire down the street…
Believe it or not, fire hoses need way more pressure than what comes from an open fire hydrant to fight a big fire. So, when the fire pumper truck connects to a nearby fire hydrant to draw the water at high volumes, it will literally suck water from everywhere it can.
It will pull the water from those nasty fire sprinkler pipes, in every building in that neighborhood…
It will suck yucky water right back into the clean public water supply… if there is not a “backflow prevention assembly” protecting it!
There are many common cross connection hazards similar to the above as well as the following:
• Lawn Sprinklers: Chemicals common to landscaped areas and pet waste can flow into sprinkler piping through sprinkler heads or cracked piping.
• Pools and spas: Chemicals used to keep pools and spas sanitary can also be harmful to drinking water.
• Heating and cooling systems: Many common systems in use today have chemicals that stop algae growth or keep fluids from freezing. These chemicals can be a hazard if allowed to enter the public water system.
• Ice makers and soda fountains: Soft drink dispensers (post-mix carbonators) use carbonated water mixed under pressure with syrup and water to provide soft drinks beverages. Many, if not most, water pipes are made of copper. When carbonated water comes into contact with copper it chemically dissolves the copper from the pipe. This copper-carbonate solution (i.e. Carbonic Acid) has been proven to be a risk to the digestive system.
