What Is Backflow Testing?

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Backflow testing helps prevent water contamination or pollution.

When the pressure in a water system isn't maintained, the risk for water to flow backward into the water system and become contaminated is greatly increased. Backflow testing monitors the health and safety mechanisms designed to protect water purity.


The function of a backflow prevention device is to keep dirty water from pools, storm drains and other external water sources from flowing backward into clean, uncontaminated water or into your home. It also keeps any water from cross-connecting with the drinking water in your home.


Backflow prevention devices or strategies are required in most local building and plumbing codes. The most common types of backflow prevention devices are air gaps, which is a space in your water storage area that connects to your plumbing system and a check valve, which prevents water from flowing backward into your home by only allowing water to flow in one direction.

Prevention and Testing

To prevent backflow, most water districts are required to have a backflow prevention program and plan in place, along with backflow prevention devices, where necessary according to local plumbing and building codes. Most cities and counties in the United States require yearly testing of each water district by a certified backflow testing agency.


Arin Bodden

Based in the Pacific Northwest, Arin Bodden started writing professionally in 2003. Her writing has been featured in "Northwest Boulevard" and "Mermaids." She received the Huston Medal in English in 2005. Bodden has a Master of Arts in English from Eastern Washington University. She currently teaches English composition and technical writing at the university level.