There are several ways to dispose of the glycerol by-product. If you are using NaOH the glycerol makes an excellent weed killer. If you are using KOH the glycerol will make a great fertilizer. It can also be used as a dust suppressant for gravel or dirt roads. KOH based glycerol may also be used as a livestock supplement( after the MeOH is recovered). The glycerol can also be used as a heat source with the proper burner. I don't have any wash-water problem because I use Magnesol dry-wash.