Fast Fact

Meters slow down as they age, not speed up.

Guide to Fire Service Lines

Press Enter to show all options, press Tab go to next option

A fire service line is the portion of a water line preceding the backflow prevention assembly (BPA), supplying water to the fire sprinkler or private fire hydrant. A fire sprinkler system is the portion following the BPA.

  • Fire protection systems should be protected with a minimum of a double check valve assembly (DC).
  • The fire department connection and private fire hydrant connections must be located downstream of the BPA.
  • The fire service line must be NSF61 certified to the backflow preventer.
  • Private fire hydrants must be painted red (or as approved by the fire service within the jurisdiction) to distinguish them from WaterOne’s hydrants, which are a standard yellow barrel with a black bonnet.

When your BPA is installed inside: It must be installed at the point where the potable water piping ends and the fire sprinkler system beings. The property owner must agree to follow WaterOne’s fire line annual flushing maintenance.

When your BPA is installed outside: The BPA must be located above ground in a heated enclosure or below ground in a vault on the property being served by the fire service. The entire heated enclosure or vault must be located at least 7 feet from the tap on the public water main. If the front edge of the enclosure or vault closest to the water main is located more than 12 feet from the tap on the public water main, the owner must follow WaterOne’s annual flushing maintenance.

Annual Flushing Maintenance

Annual flushing maintains water quality in the fire service line between the public water main and the backflow prevention assembly (BPA).

  • The fire service line must be flushed annually according to WaterOne specifications. WaterOne will notify the owner or the appointed agent when the flushing is to be performed.
  • The fire service line must be flushed through the system main drain or private fire hydrant.
  • When fire service line is fully opened, the amount of water to be discharged (from the tap on the public water main to the BPA) through the flushing apparatus is equivalent to five (5) times the volume of water in the fire service line. A standard floor drain would not be adequate to handle the amount of water being flushed.

WaterOne recommends that all main drains be discharged to the exterior of the building.


Free viewers are required for some of the attached documents.
They can be downloaded by clicking on the icons below.

Acrobat Reader Download Acrobat Reader Flash Player Download Flash Player Windows Media Player Download Windows Media Player Microsoft Silverlight Download Microsoft Silverlight Word Viewer Download Word Viewer Excel Viewer Download Excel Viewer PowerPoint Viewer Download PowerPoint Viewer