All gravity building drains or building sewers connecting to new structures or modifications to existing structures requiring a plumbing permit, which drain plumbing fixtures at an elevation lower than the rim elevation of the closest upstream manhole of the public sewer main from where the building sewer is connected to the main, shall have installed on the building sewer or building drain a backwater valve to protect such fixtures from backwater either from the sewer connection or the public sewer main. The backwater valves shall be constructed to open to allow normal unimpeded use of the building drain and building sewer but shall insure a mechanical seal against backflow. The backwater valve shall be accessible for service and repair and shall meet the technical requirements of the North Carolina State Building Code, Volume II Plumbing, and latest edition.
(Ord. O-1996-11, passed 5-7-96; Am. Ord. O-1997-38, passed 9-16-97; Am. Ord. O-2008-11, passed 3-18-08; Am. Ord. O-2013-13, passed 5-21-13)