Quality Assessment of Stored Rainwater and Its Utilization in Dhaka City, Bangladesh

Monsoons provide Bangladesh with ample rainwater. However, many regions, both rural and urban, suffer from shortage of safe drinking water. While arsenic contamination of ground water affects many rural areas, some urban areas, including Dhaka City, also lack of sufficient potable water supply due to shortage of surface water. This research explored the quality of stored rainwater as well as the feasibility of harvesting monsoon rainwater as a source of drinking water. Rainwater had been experimentally harvested at Bangladesh University of Engineering and Technology in Dhaka using a simple traditional technology. The rainwater was collected using a small catchment area (4.57 m × 4.57 m) made of water-proof cloth and a 3.2 m³ capacity ferro-cement storage tank, attached with an automatic initial flushing device, for a family having five members for four months. Initial test results indicated that the stored rainwater had a slightly higher pH value (8.1 to 8.3) and presence of total coliform after three months of storage. The traditional filtering system removed contaminants completely and the total coliforms up to 60%. This research supports the viability of traditional filtering of harvested rainwater as a promising solution to potable water shortage in Bangladesh.