Size drain pipe for a kitchen sink and clothes washer combination

[Scott W]

I was curious if 2 inch pvc is ok to drain out. No toilet or solids...just water from the kitchen washing machine. Or use 3 inch? Also I was thinking of taking it out about 160 feet from my house and the last 40-50 foot I was thinking of doing a split and having two lines on a bed of gravel with perforations on the bottom. If I do that how deep should the gravel be or does it really matter?

Any thoughts are appreciated.

[JGrout]

so you want a grey water drain?

[Mr_Mike]

Sounds like he wants a non-code compliant grey water leach line.

What precludes just hooking into the existing drain system? Most folks who do grey water actually want to use the grey water for something.

[Scott W]

It currently empties into a cesspool about 93 feet from the house. It pools up and attracts mosquitos. The existing drain is partial black corragcorrugated pipe and got clogged from squirrel nuts before. 

If I did it to code, according to a plumber I talked to, I would have to attach it to the septic and that would be a MAJOR deal with interference from my garage placement if I hired it out but as a homeowner I can do this. Plus I don't know about the septic capacity.  I currently have three drains from the house. One is for the washing machine, one for black water and one for kitchen.

[JGrout]

Sounds like he wants a non-code compliant grey water leach line.  

What precludes just hooking into the existing drain system?  Most folks who do grey water actually want to use the grey water for something.

I agree grey water in a septic has a purpose and it really needs to be there to help with the percolation of the septic field

[Scott W]

For the 60 or whatever years this house has stood it hasn't been going into the septic. The bathroom sink and the shower does go into the septic and of course the toilet. 

I'll use three inch.

[Bob10]

you might do well with a dry well type set up I am not going to respond with regard to what is and isn't code but something that might help get the water to drain without mosquitoes as a result.  My gutters drain into a drywell that was dug 4' square and 8' foot deep.  Drain rock wrapped in cloth with a christy box in place to allow for removing debris that might shorten the life of the well

[blackhat]

The more gravel the better. Kitchen grease tends to break down fairly slowly and you need a lot of room to allow that to happen.

[Robert Adams]

For the 60 or whatever years this house has stood it hasn't been going into the septic. The bathroom sink and the shower does go into the septic and of course the toilet. 

I'll use three inch.

       I would say 2" would be fine but it's hard to go too big on drain pipe. As for loosing grey water going into the septic... I don't see it as being a bad thing as it means you won't have bleach going into it which that isn't good for the bugs in there and it's really not much water going into the septic system anyway. Washers use way less water now and if like us where it's just the two of us we don't do a while lot of laundry. Also coupled with the fact that you don't have to wash everything seperate anymore you don't do many loads.
     Besides the shower provides way more grey water than anything else. 

       I had he thought of being able to divert the grey water from the washer to irrigate the yard but like I said it provides so little water it isn't worth the effort and cost.

[Scott W]

Thanks for the relpies. We did a dry well in the last house....it worked but I had access to bigger equipment and more money then. This option is cheaper. 

Regarding the code, most of my neighbors have some sort of non septic terminating grey water. I have had several people tell me the standard around here was to do this. In fact my parents should house doesn't empty into the septic. They, in 40 years, have never had a problem.