Group one is clean water, Group 2 is gray water, and Class three is blackwater. Clean drinking water refers to your source that doesn't lead to sizeable harm to human beings, though gray water may have some contaminants that could cause sickness or soreness. Blackwater is extremely contaminated with microorganisms https://remington3sajp.mybloglicious.com/51804313/the-best-side-of-how-to-clean-sewage-in-unaizah