[Flickit]

Want to add drain line to a septic tank at the point outside the house where a vertical above ground cleanout and a below ground 'Y' or sanitary tee connects to the main house drain and is then outputted to the septic tank. Material is ABS and was wondering what the best way is to add the additional 'feed' without having one back feed into the other? Any other gotchas that might arise? Additional line is a long haul 100+ feet from detached garage with at least 4 feet of fall from garage to cleanout. Drain is 4 inch ABS with a sink, tub/shower combo and water closet attached. Usage is minimal and sporadic (detached garage is being converted into a guest house).

[speedball1]

Want to add an additional drain line to a septic tank at the point outside the house where a vertical above ground cleanout and a below ground 'Y' or sanitary tee connects to the main house drain and is then outputted to the septic tank. Material is ABS and was wondering what the best way is to add the additional 'feed' without having one back feed into the other? Any other gotchas that might arise? Additional line is a long haul 100+ feet from detached garage with at least 4 feet of fall from garage to cleanout. Drain is 4 inch ABS with a sink, tub/shower combo and water closet attached. Usage is minimal and sporadic (detached garage is being converted into a guest house).

If I were doing it I would cut in a wye and lay it on its back. I would connect by dropping to the wye with a 45 degree 1/8th. Bend. I would measure the line to the foot, (100 plus feet don't get it) and give make my slope/fall 1/4" to the foot. Too much fall on a long run and the solids are left behind to clog. Too little and the solids aren't carried to the septic tank. On a 100 foot run a 4 foot fall is twice as much as called for. A 2 foot fall is more like it Good luck, Tom

[Flickit]

If I were doing it I would cut in a wye and lay it on its back. I would connect by dropping to the wye with a 45 degree 1/8th. bend. I would measure the line to the foot, (100 plus feet don't get it) and give make my slope/fall 1/4" to the foot. Too much fall on a long run and the solids are left behind to clog. Too little and the solids aren't carried to the septic tank. On a 100 foot run a 4 foot fall is twice as much as called for. A 2 foot fall is more like it Good luck, Tom

... provide more insight into a problem than I would have thought possible.

Note the subject belonged in another forum but was afraid you and the other experts would miss it there.

Will place the correct slope as the highest priority on the to do list.

[speedball1]

Note the subject belonged in another forum but was afraid you and the other experts would miss it there

No Flick, You posted in the right place. Regards, tom