8-3-11: VALVES:
There is no requirement to install a valve in a sewer lateral line. However, if a valve is installed in a sewer lateral line, it shall be accessible for maintenance and it shall be one of the following:
   A.   Resilient seated gate valve conforming to the latest edition of AWWA C509.
   B.   Backwater valve, Palmer type, service weight equivalent to that as manufactured by Tyler or U.S. Soil Pipe. (Ord. 173, 5-13-1983)