Evaluation of the impact of landfill on floodplain water quality in a tropical monsoon region

Nowadays, a deterioration of floodplain water quality in the Lower Mekong River Basin in Cambodia is expected because of urbanization/industrialization by landfilling. This study aimed to evaluate the impact of floodplain landfilling on basin water quality. Field observations of total phosphorus (TP), chemical oxygen demand and heavy metals were conducted in the Mekong River Basin in Cambodia and the Chao Phraya River Basin in Thailand. In the Mekong River Basin, TP was 2.05 mg/L in the floodplain where large-scale landfill was carried out using waste, with iron (Fe) at the factory site 6.54 mg/L. In comparison, in the Chao Phraya River Basin, TP and Fe concentrations were low. A degree of floodplain water quality management commensurate to the level of economic development was confirmed from water quality conservation efforts, among others, in Thailand.