| Comparative
Review of Drinking Water Quality from Different Rain Water Harvesting Systems in Sri Lanka Tanuja Ariyananda
Abstract The main constraints on using rain water for domestic use have been the water quality aspects. The quality of rain water collected depends on the cleanliness of the atmosphere, materials used for the catchment surface, gutters and down pipe of the storage tank and the water extraction device. In the hill country and in the north central province acid rain has been recorded and in the western province rain water has carried high nitrate levels. Compared to other industrialised countries in the region, however, acid rain is still not considered a serious problem in Sri Lanka. This study reviews the quality of rain collected throughout Sri Lanka from different types of storage tanks and roofs. It will compare the traditional rain water collecting methods with the present available technology of the Community Water Supply and Sanitation Project (CWSSP). It looks as the health aspects of drinking rain water related to biological contamination and indirectly due to disease vectors like mosquito and other insects/pest breeding in the stored water. Recommendations will be given on the different water treatment methods along with some suggestions for improvement. The result shows that the rain water collected and stored with adequate care meets the microbiological standards set by the WHO for total coliform in drinking. The data obtained reveal that the quality of the rain water collected depends on the storage and the management of the system. |
