13.-1106. Persian wheel.

Watsan matters
13.-1105. Permselective.
13.-1104. Permits.
13.-1103. Permeate.
13.-1102. Permeable, pervious.
13.-1101. Permeability.
13.-1100. Permafrost.
13.-1099. Peri-urban.
13.-1098. Perforated plastic sleeves.
13.-1097. Perfectly competitive market.
13.-1096. Percolation.
13.-1095. Perched aquifer.
13.-1094. Percentile.
13.-1093. Per capita use.
13.-1092. Pelagic.
13.-1091. Peak flow.
13.-1090. Pathways.
13.-1089. Pathogen.
13.-1088. Pathogen.
13.-1087. Pasteurisation.
13.-1086. Pasteurisation ( of sludge ).
13.-1085. Parts per million.
13.-1084. Parts per billion.
13.-1083. Particle size.
13.-1082. Participatory rural appraisal - ( PRA ).
13.-1081. Participatory planning tools.
13.-1080. Participatory Hygiene and Sanitation Transformation - ( PHAST ).
13.-1079. Participation.
13.-1078. Parasite.
13.-1077. Parallel pumps.