How to tie outdoor sink drain into homes sewage?

[Chris Milot]

Hello all,

I'm planning on building an outdoor bbq island and looking into the possibility of adding a sink to it. I'll be able to get water to it no issues by adding a tee to the main irrigation line before it reaches the valves. My question is in regards to drainage for the sink. I'm in Mesa, AZ and the house is on a slab. I have clear access to dig a trench to the side of the house where a kitchen sink is located which is about 30-40 feet away. Does anyone know if typically the drains go below the slab where I would be able to dig down and under the slab and tie in there or do these pipes usually run within the concrete slab? I know I will have to address venting it as well but first wanted to find out if this will even be feasible. Figured I'd ask before I start digging to see what is down there.

There is also a couple of cleanouts in my front yard that I may be able to tie into if that's an option.

Thank you!

 

[Cacher_Chick]

Depending on where the building drain is leaving the house, I would be looking at installing a wye into that.

Irrigation piping is often not rated for potable water, so I would not tie into that.

 

[Sponsor]

 

[Chris Milot]

That may be difficult to find where it leaves the house. Maybe when I have them come out to mark utilities they will know. For water supply I was planning on seeing off the main before it's gets to the valves. Wouldn't this be ok?