Adding bathroom to detached garage.. Sewer line?

[Evader53]

Hello, new to the forum and looking for some advice.

We have a detached garage behind our house with a finished room above. We’re looking to add a bathroom, and the biggest obstacle is going to be sewer connection which is in front of the house. The total line distance will be 100’. I’m in the process of trying to make sure I’ll have enough slope to make the connection. We have a cleanout right by the front patio, and there is a small (roughly 1’ wide) circular concrete cover stamped sewer about 6’ away towards the street (still in our yard). Removing it exposes the top of black capped pipe about 5” in diameter if I remember correctly.

What is the best way to do this? Do I need to dig around this capped pipe and find how deep the sewer line is, then use a laser level to measure depth? Would the new line be connected between the cleanout and this pipe?

FYI, I’m not tackling this myself, just trying to make sure it’s feasible before calling in a plumber/GC

Thanks

 

[OLD TIMER]

Dig up that clean out by the front patio and see what you got. depending how deep it goes you could tie right into the drop. I hope you have 4" pipe going to the city sewer because when your done i'm guessing you'll have more than two toilets on your property.

 

[Sponsor]

 

[54fighting]

I'm probably not visualizing this correctly, but would an ejection pit be a solution? I have a room above a garage at the back of the property. We installed an ejection pit, and it has worked pretty well over the last two decades.