Backflow Terminology for the Toronto Business Owner

What is backflow?

Simply put, this means water travelling back in the opposite direction it is supposed to. It can be caused by a drop in pressure on either side of your water meter. If everything is working correctly, water should only ever flow from the City side into your building. Backflow has been seen to cause widespread illness and even death. Almost all municipalities have written in a law mandating businesses to install devices and have them tested yearly.

Cross control survey

A cross control survey is required by some municipalities before a backflow device can be installed. This survey requires a plumber with special OWWA certifications to look at all the plumbing connections in your building. A report is generated and sent to the City outlining the hazard levels present in the building. If certain cross connections are not protected, contamination can happen very quickly.

For more information on how exactly a backflow preventer works, read our Backflow preventer Introduction page.

Zone, Premise and Fire protection

There are three key places that a backflow device is used to protect the water supply. Your fire system, your premise or main water supply line and any “zones” or areas that are a severe hazard will require a device. Areas that will require zone protection are areas like pool rooms, irrigation lines, cooling tower lines and other chemical feed lines. Any place where the backflow of water could potentially get someone sick is a liability and must be protected by law. Even in complex plumbing set ups with multiple zones like an industrial food manufacturing plant.