418.6, Special Provisions, is hereby created by the addition of the following provisions:

In group “R” occupancies, individual floor drains shall not be required to be vented, unless the length of the trap arm exceeds fifteen (15) feet from a vented line. In all other occupancies, individual emergency floor drains shall not be required to be vented unless the length of the trap arm exceeds fifteen (15) feet from a vented line with a maximum of four (4) unvented floor drains per building waste system. When combination waste and vent systems are being utilized, this provision shall not apply.