Hi We recently had our garage converted to a kitchen and utilty room.Now the sink with the waste is in the kitchen whereas the washing machine is 15 feet away in the utility.I plan to run a waste pipe behind the kitchen units the full 15 feet length for the washing machine waste.What I was wondering is firstly is this possible and secondly what angle should the pipe run at to drain the water but still be high enough to connect to the sink waste at the other end?