GROUNDWATER QUALITY IN RURAL VILLAGES - A CASE STUDY: MALAWI 2006-2007

摘要

Water quality data in terms of biological, chemical and physical parameters has been developed for three districts in Malawi namely; Balaka, Chikwawa and Zomba. The results indicated that shallow well water was heavily polluted with both total and faecal coliforms. The pollution level was higher in the wet season compared to the dry season. All the wells tested failed to meet the total coliform (TC) guideline value of 50 TC/100ml for untreated drinking water in the wet season, while about 92% of the wells failed in the dry season. About 88% of the wells tested failed to meet the faecal coliform (FC) guideline value of 50 FC/100ml in the wet season, while 73% failed in the dry season. About 38% of the wells tested in Balaka and 50% of the wells tested in Chikwawa had fluoride levels >3.0mg/l. The results indicated a significant difference of fluoride concentration between the dry and wet season (p=0.048<0.05). In the region of 25% of the wells in Chikwawa had hardness values greater than the recommended 800mg/l for untreated water. Only 12% of the wells had turbidity values in excess of 25 NTU and around 4% had total dissolved solids and electrical conductivity in excess of 2000mg/l and 3500mg/l respectively.