Provo City Water Resources Division supplies drinking water to its customers that is safe and complies with all Federal and State requirements. However, no matter how well we treat and disinfect the water that we supply our customers, there is always the danger that the supply can be contaminated by means of a "cross-connection." A "cross-connection" may be defined as: Any connection or structural arrangement of pipe between a public or consumer’ s potable water system and anything else, through which backflow or backsiphonage may occur.

 

 

Backflow is simply the reverse flow of contaminated water or other substances from a consumer’s water system back into the public drinking water system. An example of a backflow potential is when a vacuum is formed in the water system in a building due to peak usage such as a fire flow or a shut-off for repairs. When this occurs non-potable or contaminated water can be drawn back into the potable water system.

  

 

Another common example is when a garden hose is used to spray lawn and garden chemicals. If a vacuum or siphonage condition occurs, it can draw the chemical solution back into the potable water supply. Other examples of potential cross-connection include landscape sprinkling systems and utility sinks.

 

Utah State Drinking Water Regulations require each water system to have a functioning cross connection control program. This program requires protection from the previously mentioned hazards as well as many others. A cross connection control program requires protection from any possible hazard, which includes various activities typically found in residences. Thus, a dual check valve should be installed on each residential service meter to protect the City system from any backfow from customers homes. In addition, any connection to equipment utilizing any type of chemical injection requires additional backflow protection at that point of use and is regulated by the State program, Provo's program, and plumbing code.

 

Anytime a backflow device/assembly is installed it creates a closed system, which creates a potential thermal expansion issue anywhere heated water is used. Thermal expansion raises pressure in a water system as the water is heated and must be compensated for. Several methods are available to install on your residence which will compensate for this issue. The most common is a thermal expansion tank which absorbs this increase in pressure. The thermal expasion tank is installed on the cold water feed line to the water heater. Typical cost to the owner is $100 too $200 for the installation of a thermal expansion tank.

 

Dual check valve devices have been required on new construction for several years in Provo and should have had thermal expansion protection installed during the construction of the residence. Service line renewals performed by the City will now require a dual check valve installed at Provo's expense, however, the installation of the thermal expansion protection and associated cost will be the customer's responsibility.

 

 

Backflow prevention devices and assemblies provide protection against contamination or pollution of the public drinking water system. Since most backflow incidents occur as a result of using a hose without proper backflow protection, a minimum of a hose-bib vacuum breaker (HBVB) should be installed to provide that backflow protection. The International Plumbing Code (IPC) requires all new potable water outlets with hose connections (threaded hose bib faucets) be equipped with HBVB’s or atmospheric vacuum breakers, and their use is strongly recommended. If your home does not have a built in unit, it will be necessary to purchase an after-market HBVB as per drawing 

   

Caution should be taken to drain after-market HBVB’s to prevent freezing in winter. This may be accomplished by simply removing the hose from the vacuum breaker and pushing the check valve open to drain the faucet. This will prevent water from being retained in the frost-free bib which extends back into the home.

  

Provo City Division of Water Resources has a Cross-Connection Control and Backflow Prevention program that is required and approved by the Utah Department of Environmental Quality-Division of Drinking Water and enforced by City Ordinance. This ordinance spells out the requirements for installation, operation, and maintenance of backflow prevention devices and assemblies. Provo Water Resources Division is doing its best to assure Provo citizens of a clean and safe water supply through an aggressive cross-connection control program.

 

 

If you have any questions concerning cross-connection control or backflow prevention, please contact the Provo Division of Water Resources at (801)852-6788.