Water Quality Monitoring and Management in Lao PDR: The Case Study of Nam Ngum River Basin Souphasay Komany Head of Water Resources Policy and Legislation Division Department of Water Resources Water Resources and Environment Administration Lao PDR Introduction Lao PDR is in the midst of relatively rapid economic growth and natural resource development. Hydropower, mining and forestry are major areas of activity, while tourism, agriculture and fisheries are also developing and changing. Urban areas are also growing as population shifts and commercial and industrial development takes place. As a result there are increasing pressures on the environment and an increasing need to manage natural resources in a sustainable manner. The country is generally rich in water resources. Total available surface water resources (including the flow of the Mekong River and its tributaries) are 55,000 m3 on an annual per capita basis, the highest in Asia. However, little of the national water supply has been developed. Total storage capacity of large reservoirs is less than 3% of annual surface flow. Up to the present time the focus of water quality work in Lao PDR has been on general environmental monitoring, project-related environmental protection (EIAs, EMPs, etc) and public awareness and education. The current rapid development of water resources and impacts on watersheds is now bringing about greater risks for water quality deterioration. Recommendations have been made in various contexts for improved water quality monitoring, modeling and other technical strengthening. However, rather than addressing individual areas of weakness, there is a need for a more systematic approach. The objectives of this discussion paper are to: ? give a brief description of general situation and the issues affecting water quality in Lao PDR and particularly in the Nam Ngum River Basin; ? make recommendations regarding institutional arrangements on water quality monitoring and management, and other water quality related activities for further technical strengthening. Water Quality Situation in Lao PDR The Water Quality Laboratory of the Ministry of Agriculture and Forestry reports that over the past 15 years of monitoring, water quality in Lao PDR has generally been good and is not significantly affected by human activities. This is in agreement with a Mekong River Diagnostic Study by MRC which indicated that “water throughout the Mekong River Basin is generally of good quality, but there are localized exceptions.” However, with the pressure of rapid demographic growth, economic development and urbanization, water quality is increasingly likely to deteriorate. The major issues which may arise include: ? The installation of hydropower schemes pose some important water quality problems or risks. In most deep-water reservoirs in the tropics, in the first few years following impoundment, oxygen depletion will take place in the lower part of the reservoir. This situation is mainly due to thermal stratification and the decomposition of submerged biomass or organic matter (overhead vegetation and carbon contained in the soil). Water quality in the downstream river is strongly affected by water quality variations in the reservoir. If the turbined water comes from a single, low-level discharge from the reservoir, it will be low in dissolved oxygen (anoxic) and may be high in noxious compounds (methane, mercury, etc). ? Lao PDR is rich in mineral resources and is increasing its exploitation of these resources. In a number of parts of the country exploration, planning and actual mining are underway. Mining uses water in both the mining and ore processing stages, although little information is currently available on the amount of water which is consumed. Water use is not included in mining licenses. In some cases mines, processing areas and mine tailings (waste) storage areas are close to rivers and reservoirs. ? Population growth in cities, towns and villages leads to extensive municipal waste and organic matter release to waterways. No urban centers have access to comprehensive piped sewerage systems. Treatment and disposal of urban waste water is generally not satisfactory; most households rely on soak pits for wastewater disposal. Urban drains act as secondary sewers, carrying industrial discharges and septic tank seepage and overflow in the rainy season. As a result, water in the drainage system is invariably contaminated with faecal matter from latrines and coliform from septic tank effluent. ? The growing number of industries has increased the incidence and risk of pollution. The larger mills and industries of concern in Lao PDR are pulp and paper, timber, food processing, garment manufacturing and cement factories and gravel pits. Most of these have only limited wastewater treatment systems for reducing waste concentrations and loads in the final effluent disc。