WATER-QUALITY MANAGEMENT OF THE CHAO-PHRAYA RIVER (A CASE-STUDY)

The Chao Phraya River is the largest river in Thailand. It is formed from the four main rivers in the northern part of Thailand, the Ping, Wang, Yom and Nan rivers and drains an area of about 178,000 sq. km. This mighty river has been exhaustively used to its full extent for hundred of years for consumption, industries, agriculture, fisheries, transportation and worse than anything else, as a receiving body of liquid and solid wastes from all sorts of human activities. With the continuing growth of urban population and industrial outputs, the pressure on water quality is becoming intense in Thailand. The river water characteristics (dissolved oxygen, biochemical oxygen demand, coliform bacteria and etc.) especially in the lower part, are much inferior to the standard values. Thus, appropriate water quality management and an urgent mitigation plan should be implemented. The implications of pollution of the Chao Phraya River are wide ranging and could affect various socio-economic aspects of life. Likewise, the rapid urbanization and industrialization also require a dramatic increase in water demand, leading to water shortage. This problem is attributed mainly due to lack of an efficient water management system; discharge of untreated effluents from domestic and industrial activities; deforestation; lack of co-operation and co-ordination among private and government sectors concerned; no existing laws and regulations related to water resource conservation; and non-effectiveness of water quality standards, regulations and penalties. To effectively minimize the wastage of water resources and pollution in the Chao Phraya River, water conservation program should be adopted by the Bangkok Metropolitan Region while regulations and standards should be framed up in a practical and flexible way. Besides, there should be a permanent system of incentives based on appropriate regulations and economic measures and a rational and effective pricing system.