Vientiane is the Capital City of the Lao People’s Democratic Republic (Lao PDR), recently upgraded from Vientiane Municipality to Vientiane Capital City. The population of Vientiane is 639,326 and more than eighty percent of the population now lives in the urban area. The increase in rural-urban migration and industrial sector growth will result in the rise of solid wastes, given the lack of an adequate drainage system, sanitation network and effective monitoring by national government agencies and local communities. The wastewater in the urban area of Vientiane Capital City currently stagnates in open roadside drains. The ground water has also been contaminated by on-site sanitation systems, such as septic tanks. In addition, there is a lack of data-sharing information, especially database generation using geographic information systems (GIS). The purpose of the research programme is to investigate wastewater management in households and buildings; to provide for wastewater collection with analysis systems and sampling stations using GIS; and to establish a GIS database system for monitoring and for disseminating wastewater management knowledge to stakeholders and increasing public awareness.
The research methodology involved: the exploitation of spatial and attribute data in combination with field interviews conducted with 100 villages on household wastewater management; and the overview of environment law and regulation. The geographic information system generated a wastewater database with spatial and attribute data, such as routes, buildings, villages with population distribution, sampling stations, wastewater quality monitoring data, etc.
The analysis techniques consisted of database generation and map visualization. Map overlay techniques were used to study the main sources of wastewater, wastewater distribution boundaries, verified selection and thematic mapping analysis by GIS software. Vientiane Capital City has no sewerage system, and most households use septic tank facilities. There are two type of toilet in Vientiane, namely the cistern-flush latrine linked to septic tank, and the pour-flush latrine with septic tank. About sixty percent of these urban households release wastewater into public drainage channels. About ninety-three percent of wastewater from the kitchen, bathroom, and washing are discharged without treatment. There has been little control or regulation of private facilities and no standard technology control. In addition, the infiltration of bacteria into the soil and groundwater will continue to affect human health and the environment. In order to correct this trend, the Government of Lao PDR has shown signs of renewed interest in the sector by assigning responsibilities and by planning for the provision of sewerage disposal facilities and the improvement of urban sanitation.
The research study provides an input for environmental reporting and decision-making on urban planning and monitoring. Its findings on the current state of household wastewater management and on-site sewage disposal practices in the urban area of Vientiane capital city are conducive to the improvement of wastewater management. The GIS database of wastewater management in the urban area of Vientiane capital city can also be used as a tool in environmental workshops and in future monitoring.
21 June 2005