Using MFA to Analyze the Balance of Organic Matters and Suspended Solids in the Tamshui River Watershed

River pollution is one of the environmental issues concerned gravely by scientists and engineers. Due to the excessive wasteload received, the water quality of the Tamshui River deteriorated for many years. This study was made to establish a basin-wide MFA framework to calculate the manmade mass flow of BOD5 and SS in the watershed. Also evaluated in this study were the removal efficiencies of the sewage treatment plants under operation.
With certain assumptions, this study showed that in the year of 2003, the basin-wide inflows of SS and BOD5 were 1,031,830 kg/day and 363,460 kg/day, respectively. The existing sewage treatment plants could only remove 51.7 % of the BOD5 and 18.8 % of the SS. Therefore the remaining proportion of the polluted flows to the basin should be carefully examined for their sources.
Because the majority of BOD5 and SS was known to come from the domestic source, a follow-up management program should be planned to reduce the pollutional loads contributed by the watersheds with no sewer systems provided.