A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science, School of Environment, Resources and Development

Thesis (M.Eng.) - Asian Institute of Technology, 1997

Waste stabilization ponds are suitable for tropical developing countries because of low cost of construction, and simple operation. A combination of anaerobic, facultative and aerobic ponds together with wetlands and fish ponds have been applied in Battambang town. The Battambang sewage treatment plant (STP) was installed in 1993 with funds from the European Community (EC) within the Cambodia Rehabilitation Program (CRP) in cooperation with Consultants for Development (SAW A) and International Development Research Committee (IDRC). This research study includes a literature review, data collection on the geographical and meteorological situation of the area, secondary and primary data indicating the river quality of the Sang Ke river and operations of the Battambang STP. An evaluation and comparison of results with results from other tropical countries considering environmental compatibility together with recommendations for the operation and maintenance of the ponds is given. The study found that the Battambang STP removal efficiency for fecal coliform is 99.9 %, for suspended solids 95 % and total dissolved solids 36 %. The effluent from Battambang STP meets the WHO standards for irrigation. Farmers using the effluent for irrigation of vegetables, fruit trees and other crops could improve the yield of their agricultural products. The water quality in the Sang Ke river was improved by establishing the pond systems. There is no sign of environmental deterioration except an increase of mosquitoes and some skin irritation for the farmers. The comparison with results from other ponds in tropical countries are satisfactory. Recommendations for further constructions, improving the maintenance and operation and some suggestions for public health aspects are given.