Backflow Prevention

Backflow and its dangers

As your drinking water supplier, we are concerned about the possible introduction of contaminants to the drinking water from our users.  Most outside contamination takes place when the customer uses equipment that re-pressurizes the water supplied, or when negative pressures occur in the water supply mains, as with a water main that breaks.

Like most water suppliers, the District closely monitors commercial and industrial customers for backflow problems.  We often require special testable devices placed in these customers' water supply piping to prevent such contamination.

Residential customers can also cause contamination.  Permanent irrigation systems require the installation of a backflow prevention device.  Lawns are typically treated with composted materials and/or chemical fertilizers.  In the event of a flow reversal, these contaminants could be introduced into the household or the water distribution system.

Another potential source of contamination are the newer aspirator devices that are sold to apply insecticides and fertilizers.  Though they are often equipped with a check valve, they are easily fouled and often fail.  Vacuum breakers are the best protection in this situation and can be purchased at most hardware stores.  Many new outside sill cocks (outside faucets) have built-in vacuum breakers.  Never leave aspirator devices connected to your water supply when not in use.