Don't let the hose run while washing your car. Use a bucket and a hose with a shut-off nozzle. Doing this could save 150 gallons of water!
-Henry the Water Drop
Water distribution systems are designed for water to flow in one direction, from the distribution system to the customer's water meter. Under certain conditions water can flow in the reverse direction. This is called backflow and this reversal flow in a water system is due to back-siphonage or back pressure. It can result in undesirable materials entering the municipal water system through a cross connection. Proper backflow prevention steps on your part will protect the water quality of our drinking water supply.
A cross connection is any temporary or permanent connection between a potable (i.e. drinking) water system and a source of contamination (sewage, chemicals, gas, etc.). Check your home for potentially hazardous cross connections and make sure your lawn irrigation systems, hose connections, boiler systems and water softeners are all properly protected against backflow. Follow the steps below to make sure your home is protected.
If your hose connection does not have one built in, no problem! Place a threaded vacuum breaker on your hose connection to protect against backflow.
Whether filling a pool or a soapy bucket to wash a car, be sure to not submerge the hose. In a backflow event this can cause contaminated, non-potable wash water, to flow back into the potable (drinking) water supply.
If you have a lawn irrigation system, it is required to have a backflow preventer on the water pipe that supplies water to the lawn irrigation system. Make sure your backflow prevention device is working by having the device tested regularly. The City of Kalamazoo - Protect Your Water recommends testing backflow devices on residential lawn irrigation systems no less than once every five years by a professional certified by the American Society of Sanitary Engineering in backflow prevention assembly testing. Other common residential hazards that require a testable backflow prevention device include sump pumps that are connected to the water supply and boiler systems with chemical additives.
During a backflow event chemicals that are connected to the end of a hose can flow backward into the potable (drinking) water supply.
Eliminating this direct cross connection is important to making protecting potable (drinking) water from possible contaminants in the floor drain. The diagram on the left represents a sufficient air gap.
Stormwater is water from precipitation that flows across the ground and pavement when it rains or when snow and ice melt. Stormwater eventually infiltrates through the ground (contributing to groundwater), runs directly into natural surface water features, evaporates or drains into systems of underground pipes or roadside ditches and may travel for many miles before being released into a lake, river, stream or wetland area.
A Cross Connection is an arrangement of pipes where undesirable water could flow backward into the potable (drinking) water system.
Backflow is the unwanted flow of water in the reverse direction.
Back-siphonage is the flowing back of used, contaminated, or polluted water into a potable (drinking) water supply because of negative pressure in the pipe.
Back pressure is a force opposing the desired flow of water through pipes.