Cross connections are physical connections between a drinking water pipe and something that is not safe to drink – such as a garden hose, swimming pool, lawn sprinkler, or boiler. Garden hoses are the easiest and most common source for a cross connection to take place.
Do not leave hoses submerged in any type of substance, regardless if a backflow prevention device is present or not.
Backflow often happens in the water system
Backflow can happen if there is a water main break, water line repair, fire, or during a period of high usage. These events may lower pressure in the street enough to reverse the flow of water from your house.
Back flowing water can suck bacteria, sewage, or chemicals from other parts of your plumbing system into your drinking water pipes or those of your neighbors. Unless you take steps to protect the cross connections in your home, your drinking water may become contaminated.
Prevention Strategies
The best way to protect yourself, your family, and your neighbors is to remove all cross connections in your pipes or protect them against backflow. Many plumbing fixtures have built-in backflow protection, but to ensure protection, a backflow prevention device such as a dual check valve, should be installed. This will stop water from going backwards from your house into the pipes in the street. All new residential structures and services MUST have a dual check valve installed after the water meter. All others are encouraged to do so. Be advised that if you have a device installed, your plumber should make sure that you also have a thermal expansion tank, so pressure does not build up and damage pipes.
Hose Bib Vacuum Breakers are simple, low cost devices that should be used on all residences to help prevent backflow of water when using water hoses. They are easy to install and available at many plumbing and hardware stores.
What You Should (and Should Not) Do
DO NOT:
- Submerge hoses in buckets, swimming pools, tubs, ponds, or standing water.
- Use spray attachments without backflow ention devices.
- Use a hose to unplug blocked toilets, drains, or sewer pipes.
- Connect an irrigation system to your plumbing without a backflow prevention device.
DO
- Keep the ends of hoses off the ground and clear of all possible contaminants.
- Install proper backflow prevention device.
- Look to see if your toilet and tub are ASSE certified.
- Contact your water supplier or Dept. of Health if you see any suspicious use of a fire hydrant.