Water Quality Response to Reductions in Waste Loading of Sitalakhya River, Bangladesh

Huge quantities of untreated domestic and industrial wastes are being released everyday in Sitalakhya River, flowing along the eastern side of Dhaka City. The water quality of this river is deteriorating rapidly, especially during the dry season at certain reaches of the river. A one-dimensional quasi-steady state water quality model has been developed and calibrated using primary field data. A number of load reduction scenarios have been developed to assess their impacts on the river water quality. The model results indicate that Sitalakhya River water quality near intake point of Saidabad water treatment plant may not improve appreciably through reduction of waste load from a single major point source and even if all the wastewater entering into the river system are treated according to the present national effluent standard, the water quality improvement is not significant during the dry season. A revision of the national standards for disposal of effluents seems necessary.