Hi,

I want to put a sink in my basement, but I don't know where to drain it. Basically I have three pipes in my cement floor and I don't know what they are for.

1. There are two pipes that are coming up from the ground at a 45 deg angle. They both have a cap with a square bolt on it. One pipe is black the other is white. They are both covered with a piece of plywood.

2. The other pipe is a big black pvc pipe about 8" that is straight up and sort of flush with the floor. It has a lid.

What are these pipes and can I use one as a drain for the sink?

Good morning Steve,

The pipes with the caps are the clean out openings for the sewer line. The pipe with a lid sounds like it might be a pit for a sump pump.
To connect your bar sink you will have to drain into one of the mains connected to the clean-outs. This will mean jackhammering up the cement and cutting into a convenient drain line. Any one will do. But you'll also have to vent your bar sink. You have the option of running a vent up through the roof or installing a AAV,(Air Admittance Valve) on the top end of the drainage tee used to pick up the sink. If you're not familiar with AAVs you may check them out at; http://www.studor.com/homeowners.htm
See a picture of a Studor Vent below. Good luck, Tom