It all really depends. For liquid wastes, you probably want to get it close to neutral so that it doesn't mess up your plumbing if you pour it down the drain.

It all really depends. For liquid wastes, you probably want to get it close to neutral so that it doesn't mess up your plumbing if you pour it down the drain. For any complex organic or any inorganic stuff, you probably want to capture it and then send it to a chemical disposal facility.