A potable (drinking) water supply can become contaminated. It can happen by accident, through hazardous connections to the piping system known as cross connection. Water supply professionals know of such hazards - but many do not.
What is a Cross-Connection?
Cross-Connection is any temporary or permanent arrangement or connection between a public water system or consumer's drinking water system and any source or system containing non-potable water or other substances. One example of a Cross-Connection is the piping between a public water system and a customer's lawn irrigation sprinkler system. The most common Cross-Connection is caused by the garden hose.
What is backflow?
Backflow is the undesirable reversal of flow of non-potable water or other substances through a Cross-Connection and into the piping of a public water system or consumer's potable water system. There are two types of backflow: back pressure backflow and backsiphonage backflow.
What can cause backflow?
Backflow can be caused by a sudden drop in the water pressure in a public water main, which can create a sub-atmospheric condition. If a drop in pressure occurs while a hose is in a bucket of dirty water, for example, that water could backflow into the public water system, potentially contaminating the water for other users. A drop in pressure could be caused by a variety of things, including a water main break, loss of power at a pump station, etc.
Please contact Keith Dojaquez for more information:
Keith Dojaquez, CCI
Southwestern Utility Management, Inc.
Vice President of Compliance and Engineering
General Operations Manager|Certified Operator