Hello
I am having a sealed holding tank installed at my cottage which will be attached to the two toilets. There is not venting in the plumbing system at the moment. How wold I vent the two toilets. There is minimal clearance under the cottage and would like to vent to run on the outside of the building. The distance from the toilets to the holding tank is 15' and 20'any help or suggestings would be appreciated

Thanks

Whether it's to city sewer, septic tank, cesspool or a sealed holding tank the toilets are all vented the same way. A tee on its back just after the toilet connects to the drain line and run out the roof. If your holding tanks are sealed air tight and not simply covered then they must have a pipe installed to exhaust the air the incoming discharge will produce otherwise you will have back pressure that will impede the drainage. Good luc k, Tom