What Do Backflow Prevention Devices Do?

Spread the love

A backflow prevention device is a common method of protecting our drinking water supplies from contamination.  Not all water authorities require backflow prevention devices, but if you live in an area where backflow prevention devices are required by local municipal codes, it is important to understand what role they serve and how to keep your backflow prevention device in good working order.

In general there are two types of municipal water supply systems:  open systems and closed system.  A typical municipal water supply system supplies water to homes and businesses through water supply lines connected to the municipal water main. Most of the time, the water pressure coming from the water supply is much higher than the water pressure in the home so water flows from the supply into the home.

However, under certain circumstances such as a broken water main or some other event that causes the municipal water pressure to drop, water can flow backwards from a home or business into the water supply.  A water system that can flow in either direction is called an open system.

In a closed system, a backflow prevention device prevents water from flowing backwards from the home or business into the water supply lines and helps protect the water supply from contamination.  In a home, water in irrigation sprinkler systems can become contaminated by pesticides and fertilizer.  In addition, if the home has an automatic pool filling device, the water can become contaminated with chlorine and other pool chemicals.

Backflow prevention devices can only do their job if they are regularly tested by a knowledgeable plumber.  Where backflow prevention devices are required by local ordinance, backflow testing is often required by law.  Even if it is not required by law, it is good practice to have your backflow prevention device tested annually.

Comments are closed.