Could you be contaminating your water supply?
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.
Back-flow 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 backflow 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.