Section 710.1.1 is added to read as follows

710.1.1 Backwater Valves. In every case where the outlet of a trap for a plumbing fixture is installed or located at an elevation which is less than two feet (2') above the rim of the nearest manhole uphill from the point of connection of the building sewer to the public sewer in any new or existing drainage system, approved types of backwater valve, relief vent and cleanout shall be installed in the building sewer at the point of lowest elevation of the ground surface of the building site outside of the building or at such other location as is permitted by the Building Official, providing that any such location, the elevation of the ground surface is not less than two feet (2') below the lowest trap outlet served by the building sewer.

The installation shall consist of an approved fresh air inlet and a Y branch or combination fitting installed in sequence in the line of the flow from the building. The vent from this fresh air inlet shall be piped to the ground surface and capped with a vent cap. Provision shall be made by elevation above the ground or by other means for preventing the obstruction of the vent opening or the flow of water therein. The cleanout shall be placed as close to the valve as is practical and shall be piped to within one foot (1') of the ground surface and closed with an approved cleanout plug. Every existing installation which includes a plumbing fixture trap outlet which is less than two feet (2') above the rim of the nearest manhole uphill from the point of connection of the building sewer to the public sewer is hereby declared to be dangerous, unsanitary and a menace to life, health and property. Whenever it shall come to the attention of the Building Official that such an installation exists, he or she is hereby empowered to order and require that such plumbing outlet be immediately plugged or capped, or that the equipment described in the preceding paragraph of this section be installed immediately. (Topographical finding)