Nolan,
Originally Posted by
Patrick Martinez
If the drain is connected to another fixture trap this is not permitted as each fixture requires its own trap.
Pat has it right.
The reason your two compartment kitchen sink example did not play is that it is a "single" fixture, which only requires 'one trap'.
What you described were "two" fixtures trying to share that 'one trap'.
And, then (of course) the interior of a drain line or fitting is required to be smooth (so it does not collect debris and waste, least it: a) clog up; b) promote the growth of bacteria).
Now, *IF* the trap arms were the correct size and the trap arms did not exceed their maximum allowable length, one solution (*IF* those *IFs* worked out okay) would be to install a trap under the bar sink, tie it into the branch arm between the bathroom sink trap and the stack.
Even if it were a little off on the above *IFs*, it would still work much better than what is there, not that you could give it your blessing, but you could 'degrade it less'.
