Watsan matters

13.-1076. Palaeozoic - ( also Paleozoic ).

13.-1075. Ozonation.

13.-1074. Oxygen demand.

13.-1073. Oxidize.

13.-1072. Oxidation.

13.-1071. Oxidation ditch - ( OD ).

13.-1070. Overland relay.

13.-1069. Overland flow.

13.-1068. Overhung latrine.

13.-1067. Overexploitation.

13.-1066. Outlet.

13.-1065. Outflow.

13.-1064. Outfall.

13.-1063. Other water sources.

13.-1062. Osmosis.

13.-1061. Organics.

13.-1060. Organic.

13.-1059. Organic waste.

13.-1058. Organic Nitrogen.

13.-1057. Organic matter.

13.-1056. Optimisation of water use in industry.

13.-1055. Optimisation of water use in agriculture.

13.-1054. Optimisation of water use at home.

13.-1053. Operating costs.

13.-1052. Operation and maintenance of water distribution.

13.-1051. Operation and Maintenance - ( O & E ).

13.-1050. Operating expenses - ( OpEx ).

13.-1049. Operating condition.

13.-1048. Open planning of sanitation systems - ( OPSS ).

13.-1047. Open defecation.