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Question: 05-03 Code Section: 7 Date:

OBC 2006 Reference:

Question: Can a fixture (laundry tub) have its fixture drain connected to the 2" vent serving a sewage ejector?  All the requirements of the fixture drain have been met.

Interpretation: (On. Reg. 403/97) To connect a fixture drain to a vent pipe would imply that you are wet venting and should, therefore, comply with the requirements listed in Article 7.5.7.1.  After reading all the words of the Article, the committee is in agreement that the sewage tank is not a WC or a siphonic trap as stipulated in Clause (b) and it is not a P-trap as stipulated in Clause (c).  Therefore, you cannot drain a fixture through the vent.  You must go to the inlet of the tank and make your connection there.

Note:  One of our members has noted that such a discharge could have an effect on the floats of the pump, etc.

So why are we still refusing it ?  The problem is that one fixture flows through another before serving as the wet vent and although the interceptor is not referred to as a trap, it does act as one and we feel that the continuous waste is on the wrong side of the equation when it comes to wet venting the hub drain.  Usually, separately vented means that both fixture traps have their vents connected to their respective fixture drains (see 7.5.5.3.) and, in this scenario, the back vent for the interceptor is on the horizontal branch ( this is compliant with Sentence 7.5.4.2.(3)).

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