What type of pipe is good for sewer system in building PVC or UPVC?

As far as I know, uPVC (unplasticized polyvinyl chloride) sewer pipe is still a very costly specialty item, and currently only used for gutters and the like. PVC and uPVC are essentially the same thing expect for one difference. uPVC is not plasticized. The plasticizers in PVC are the main thing by which it causes enviromental damge. Mechanically speaking though, it would make no difference. PVC is very common and works quite well in all its applications. If you want to save major cash though, use ABS.