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What is water backflow?

Backflow is the flow of water from a building’s plumbing (or your home) back into the public water system. This reversal of flow can be caused by a drop in water pressure in the public system (such as from a water main break or hydrant usage) or an increase of pressure from within the building. Water pressure drops are not uncommon.

What dangers may arise from backflow?

This backflow of water may carry some contaminates from cross connections within a building (or your home) back into the public system. Some harmful substances such as chemicals used to fertilize your grass or the weed killer used on your lawn, and also the bacteria in the water from your wading pool. You can eliminate this from happening in your home by installing a backflow device and having it tested annually by a certified backflow tester.

What is cross connection?

A connection between drinking water pipes and any source of potential contamination is a cross connection. When the water pressure changes from internal usage or water system fluctuations, contaminated water may backflow into your plumbing from unprotected cross connections. Common household cross connections are garden hoses left in chemicals or in a pool and attachments to hoses used to apply lawn chemicals. Click here to review the City of Westerville Cross Connection Control Policy. 

What is a backflow preventer?

Backflow preventers protect the safety of the public water system by physically preventing the backflow of water and any potential contaminants from the consumer’s plumbing to the public system. The devices are installed by the consumer on their plumbing after the water meter. Keeping your customers, family, and water safe from these contaminants is easy with a backflow preventer.

Why do I need a backflow device on my lawn irrigation system?

Backflow preventers are required by the Ohio Environmental Protection Agency (EPA); State law (Ohio Administrative Code 3745-95) and the Ohio Plumbing Code (chapter 608) to be installed where there is a potential health or contamination threat within the consumer’s plumbing system. Most commercial buildings and residential properties with in-ground irrigation systems require a backflow prevention device. Further information can be found in the City’s Cross Connection Control Policy on the Water Division’s main web page (click on "Water" under "Services" to access this information).

Why does a backflow device have to be tested on an annual basis?

To ensure the device is working properly, the consumer is required to have annual testing done by a State certified backflow tester. Reports of this annual testing must be maintained by the consumer and forwarded to the Westerville Division of Water. Report forms are available on the Water Division's main web page (click on "Water" under "Services" to access this information). The water department sends out reminder letters 30 days before your backflow test due date.

Who do I contact to test my backflow device?

Contact a certified backflow tester. You can find a certified backflow tester in the phone book under plumbing contractors. Some lawn irrigation and fire protection companies employ certified backflow testers. Click THIS LINK to access the website for a list of Ohio Certified Backflow Testers. 

Please contact the Water Department if you have any questions at 614-901-6770.

Completed Backflow Prevention Test Reports may be sent as an attachment to:

Backflow Prevention Test Report [PDF]
Cross Connection Control Policy [PDF]
Ohio EPA Backflow Rules, Laws and Policies