B A C K F L O W

PROTECT YOUR WATER FROM CONTAMINATION

Normally, your water supply is under 40 to 80 pounds of pressure when it enters your home or business. On rare occasions, this pressure is interrupted—perhaps by a water main break, a power failure, fire fighters battling a nearby blaze, or some other disruption in water service. When there is a significant loss of pressure, water can flow back into the public water supply system. When water flows backward into the public water supply, it is called “back-siphonage” or “backflow”. Backflow can also occur when the customer’s water system has a higher pressure than the water system.

In rare instances, backflow can contaminate the public water supply. Contamination occurs when a water supply line is connected to equipment containing a non-potable (unsafe to drink) substance. Such connections are called cross connections and they are dangerous if no protective measures are taken.

Here are a few examples of common cross connections:

• A hose is submerged in polluted or contaminated water
  

• A secondary source of irrigation water (from a well or pond) is pumped into an irrigation system that is directly connected to the potable water supply system 
  

• A heating boiler with treatment chemical added to prevent internal corrosion is connected directly to the water supply for make-up water
  

• An underground lawn sprinkler system is directly connected to the water supply system
  

• A fountain or swimming pool has a direct connection with the water system for filling
  

• In all of these examples, a sudden drop in water pressure could draw contaminants – chemicals, fertilizer, soapy water or even bacteria -- back into your pipes and your drinking water supply. Any of these contaminants could be hazardous to your health if ingested.
  

The best way to prevent this potential contamination is to eliminate the cross connection. This could mean simply making sure that you never leave a hose submerged in a tub of water or that you never apply fertilizer to your lawn with a hose-aspirator device. In some cases (such as the lawn sprinkling system example noted above) the cross connection cannot be eliminated and the only means of protection is by installation of an approved backflow prevention device.