Safe Water Drinking Program/Backflow Prevention

The City of Florence ensures water that is treated and distributed to consumers is pure and healthful.  Public drinking water is collected at the source.  In Florence, our water source is from wells located in the dunal aquifer.  The water is treated at the Water Treatment Plant, and then it is distributed through the water distribution system to your home or business.  Below is information about Backflow and our Backflow Prevention Program. 

What Causes Backflow?

Your water could become contaminated when a water supply line is connected to equipment that contains a non-potable (non-drinkable) water source.  Connections like these can be permanent or temporary.  They are called Cross-Connections and contamination of the drinking water by these connections could be dangerous, however, there are several things we do to ensure such contamination does not happen.

Distribution systems are designed so water only flows in a certain direction; however, sometimes there are conditions within the system that causes the water to flow in the opposite direction—called backflow.  Backflow occurs when the pressure in the distribution system drops.  When the pressure drops, water could be siphoned (called backsiphonage) from a cross connection, causing possible contaminants to enter the distribution system.  An example of this is when there is a large fire or a main water line breaks.  Often you will hear of cities issuing a boil order after such events.  This is to ensure your drinking water is safe because there was the possibility of cross contaminants entering the water system.  Backsiphonage can occur through cross connections. For example, a hose connected to a faucet that is sitting in a mop bucket sitting in a maintenance sink.  Even a little water in the mop bucket could be siphoned back through the faucet and into the distribution system.

Example of Backsiphonage

Some water customers have non-potable materials on the premises that are under pressure.  If an unprotected water line is attached to the container or pipes holding the pressurized material, it could get “pumped” back into the water system.  This type of backflow is called backpressure.  Backpressure could occur when a water line is connected to a re-circulating system containing soap, acid, antifreeze, or any other non-potable substance.

Because of these potential dangers to the consumer, these cross-connections are controlled by mechanical assemblies called Backflow Preventers, which are designed to prevent contaminated water from entering water distribution systems.  There are different types of preventers and each type is designed to prevent backsiphonage or backpressure.  There are also types of preventers designed to work under different conditions—high hazard or low hazard, for example.

Backflow preventers have undergone stringent laboratory and field testing.  The Foundation for Cross-Connection Control and Hydraulic Research at the University of Southern California tests backflow preventers and ones that have passed their tests receive approval from the Foundation.  Approved backflow preventers are extremely dependable.

As a public water utility, the City of Florence must comply with federal laws to protect the drinking water system and consumers.  Throughout the year, we are constantly surveying the water to maintain high quality drinking level standards and determine the type(s) of backflow prevention necessary to protect the water system.  We have a cross-connection control program within our water department and a cross-connection control specialist as part of our utility crew. 

Consumers must be aware of cross-connections and prevent them, or protect cross-connections with the appropriate backflow preventer.  Backflow preventers need to be tested at least one time each year to ensure they are working properly, and when necessary, they must be repaired to assure proper operation.

With all of us working together, we can ensure the water distribution system is kept free from impurities and health hazards.  The City of Florence has a comprehensive cross-connection and backflow prevention program, which helps us to protect our valuable drinking water resource. 

If you have questions, or would like more information, please contact our Cross Connection Specialist:

Matthew Hiatt
(541) 997-7370
matthew.hiatt@ci.florence.or.us