Vent piping shall be permitted to be
omitted on an interceptor where such interceptor acts as a primary
settling tank and discharges through a horizontal indirect
waste pipe into a secondary interceptor. The second
interceptor shall be properly trapped and vented.
Traps serving
sinks that are part of the equipment of bars, soda fountains,
and counters need not be vented where the location and construction
of such bars, soda fountains, and counters are such as
to make it impossible to do so. Where such conditions exist,
said sinks shall discharge using approved indirect waste pipes
into a floor sink or other approved type of receptor.