A Saprobic water classification is a biological classification of water quality according to five categories: (a) oligosaprobic: clear, with no or only slight pollution and high dissolved oxygen (DO) content, (b) p—mesosaprobic: moderately polluted with still high DO content, (c) x—mesosaprobic: polluted with not very high DO content, (d) polysaprobic: strongly polluted, with negligible DO content, and (e) antisaprobic: so polluted that no living organism is capable of living in the water