Adding RO to island sink

[skrid216]

This probably is a stupid question, but my contractor installed a drain pipe rather high in my new island. I was able to hook up the garbage disposal by cutting down the black tail pipe to fit within the p trap.

I am now adding a RO system under the sink, which requires a 1/4" drain line to tap into the drain. The recommended installation is to tap into the waste line above the p trap, but as pictured, there is very little room to do so. Additionally, the bracket included to attach the 1/4" drain line is for 1-1/2" PVC (versus the 2" that my contractor installed).

Would there be any issues if I cut the 2" drain line down by about 4", installed a new elbow and trap adapter and added a longer tail pipe to the garbage disposal waste line? This would give me the additional room above the p trap to tap into for the RO drainage.

 

[Terry]

For starters your contractor left off the vent for the p-trap. For an Island like that you would have an AAV as the vent.
Yes you can cut the pipe shorter, add a santee with an AAV 4" above that.

The kitchen drain should also have a 2" cleanout.

 

[Sponsor]

 

[skrid216]

Thanks Terry! According to my contractor, he said the venting wasn't necessary as the waste line connected directly to the main 4" waste under the floor (<2' run), and the main drain line for the house was connected to a stack vent. Still a good idea to install the AAV anyway? I'll definitely include the cleanout...I see how that was missed as well.

 

[Reach4]

It is possible that unscrewing the AAV could serve as a cleanout.

That contractor is dodgy.

The RO unit should have an air gap, and a combo spigot with an air gap would be the easiest way to accomplish that. If you have not yet bought the RO unit, you want one with a permeate pump. That is non-electric, but increases the RO unit water efficiency.

 

[skrid216]

Thanks Reach4... I think I have room for both cleanout and AAV.

Not sure about the permeate pump... I have an Apec Water ROES-PH75 unit which has a pressurized water storage tank. I am not using the spigot that came with the RO system... My faucets had a matching spigot that just has one tube coming from it.

 

[Reach4]

Thanks Reach4... I think I have room for both cleanout and AAV.

Not sure about the permeate pump... I have an Apec Water ROES-PH75 unit which has a pressurized water storage tank. I am not using the spigot that came with the RO system... My faucets had a matching spigot that just has one tube coming from it.

You should put in a separate air gap, through another hole in the sink. I know that you don't intend to do that.

 

[skrid216]

You should put in a separate air gap, through another hole in the sink. I know that you don't intend to do that.

Does it matter that I am on a well pump and not municipal water?

 

[Reach4]

Does it matter that I am on a well pump and not municipal water?

It depends on who you ask. For me, it might be yes.