Backflow and Cross Connections

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Backflow is the undesirable flow of water that may have been contaminated back into your drink water supply lines.   Backflow is 100% preventable.  It is important to use anti-siphon hose bibs and either a testable double check or testable pressure vacuum Breaker device to protect you from your sprinkler system.  Only required if you don't have pressurized secondary water.  There are two types of backflows.

Backsiphonage: This phenomenon occurs when the supply pressure is reduced to 0 psi or below, which may cause a vacuum within the water supply system.  This could be a result of high usage demand, fire flows, line breaks, or turning off the main supply for maintenance and repair. 

Backpressure: This phenomenon occurs when the customer's pressure is higher than the supply pressure.  This could be caused by a cross connection between a drinking water supply and a pressurized irrigation connection, a boiler, a pressurized industrial process, elevation differences, air or steam pressure, use of booster pumps or any other source of pressure.  

Most new homes have the hose bib backflow preventer already built into hose bibs.  If you have one of these hose bibs it will have a plastic cap on the hose bib (see picture below).  If you do not have a backflow prevention device on your hose bib you can buy one for less than $20. If you are not sure and you live within the boundaries of Mutton Hollow Improvement District you can call or email us and we will verify your current backflow protection devices. 

Lawn irrigation systems if connected to the Mutton Hollow Improvement Districts water system are required to have a testable backflow prevention device installed after the main sprinkler system shut off valve.  If using a Reduced Pressure (RP) backflow assembly or Pressure Vacuum Breaker (PVB) they must be installed at least 12" above the ground and/or the highest sprinkler in your irrigation system.  Below are pictures of these two backflow protection devices.   

Cross connections can also cause a contamination of our water system.  Cross-connection means "Any actual or potential connection between a drinking (potable) water system and an unapproved water supply or other source of contamination. For example, if you have a pump moving non-potable water and hook into the drinking water system to supply water for the pump seal, a cross-connection or mixing between the two water systems can occur. This mixing may lead to contamination of the drinking water."  This connection can be from connecting an unapproved well or spring into our public water system.  A cross connection is also pumping water from a creek, stream or lake into a lawn irrigation system (sprinkler system) which is also connected to the Mutton Hollow Improvement District water system.   

Another common cross connection is if some ties into a pressurized irrigation system.  This happened in the summer of 2015 in Syracuse and Clinton water system.  The two cities received a boil order from the Davis County Health Department.  The boil order lasted until they could prove that they had contained the contamination and super chlorinated the water system.  

If you have questions about backflow or cross connections please feel free to contact one of your Mutton Hollow Board members or shoot us an email with your questions.  We'll try to respond as quickly as possible.