Knowledge Base

Understanding and Maintaining Your Backflow Prevention Device

Overview:

Backflow is the reverse flow of water in a pipeline, which can allow non-potable water to enter the public drinking water supply.

Normally, water under pressure flows in only one direction. If a water main breaks, pressure can drop and cause water to flow backward toward the area of lower pressure.

Backflow prevention devices help protect the drinking water supply by preventing harmful substances from entering the system.

Locating Your Backflow Prevention Device

Residential Properties

A backflow prevention device is required if the home has:

• An irrigation system

• A swimming pool

These devices are usually located:

• Near the curb in a separate box

• Next to or near the water meter

Commercial Properties

All commercial properties are required to have a backflow prevention device.

These devices are usually located:

• Near the curb

• Inside the building

Importance of Testing Your Backflow Prevention Device

Backflow prevention devices wear down over time and must be tested annually to ensure they are working properly.

For additional information, view the Backflow Device Testing webpage.

Note: Residential properties with pools or irrigation systems are currently required to have a backflow test only at the time of installation.