Domestic Water Availability in Vientiane, Lao PDR: The Water Quality Variation in the Rainy Season

Many of the water sources in Lao PDR are used for drinking and other domestic purposes. There are few reports on the domestic water availability in Lao PDR, which is composed of quality and quantity. The aim of this study was set to determine actual domestic water use and quality conditions during the rainy season in Vientiane, Laos to reveal seasonal variations in domestic water quality. In the target region, the supplied water and the deep and shallow well water were used for the domestic water sources. The different sources were taken depending on the purpose. On the whole, the quality of the supplied water was much better than that of the deep well water, which contrasted with the residents’ understanding. The quality of the shallow well water varied in the rainy season due to a dilution effect on many items except NH4+, TP, PO43- and coliform bacteria. Some shallow well with a very high NH4+ concentration implied contamination from a leaking sewer through the groundwater. The shallow well water used in the kitchens of some households may have bad health effects because of coliform contamination.