Backwater Prevention Devices

BPDs should be installed on sewer laterals within two feet of where the pipe exits the foundation of a building and are sometimes located on a cleanout near the public sewer main.

If the BPD is below grade (Type 2) it should be enclosed in a suitable concrete utility box with a removable cover and shall be readily accessible for inspection and maintenance. It is critical that the top of a Type 2 BPD is installed at least six inches below the bottom of the box cover (see photo).

The owner is solely responsible for maintaining the BPD, ensuring it is periodically checked for debris and proper function.

BPDs must remain accessible and free from obstructions such as rocks, soil, vegetation, concrete, and other materials. Loose caps must not be buried or tightly screwed down or they will not relieve blockages. Regular maintenance prevents sewer backups in buildings.