The Backflow Prevention Program is a requirement of the Safe Drinking Water Act (1974, amended in 1986 and 1996), which was written to protect human health from contaminants in drinking water and to prevent contamination of existing groundwater supplies.
Requirements of the Safe Drinking Water Act
The Act, as amended, requires the installation and maintenance of an approved backflow prevention assembly at the water service connection whenever a potential hazard is determined to exist in a customer’s system. Without proper protection devices, cross connections can occur.
Under normal conditions, water from the public water main flows into a plumbing inside a home or business. When backflow occurs, the water flows from the plumbing in the home or business the back into the public water supply.
How Backflow Occurs
Backflow occurs when the water pressure in the home or business is higher than the pressure in the water distribution system. This condition can be caused by a drop in water pressure in the distribution system or by the presence of systems within a home or business that operate at higher pressures than that of the distribution system.
A cross-connection is a connection between a public water system and a non-potable (non-drinkable) source of possibly contaminated water or other fluid. If such a connection exists and is not properly controlled, contaminants could make their way from a non-potable source into the potable water supply should a backflow occur. Because of the risk of contamination, such systems typically require the installation and proper maintenance of a backflow prevention assembly.
Examples of common cross connections are: