Abstract
The Pasig River is the main river in Metro Manila, Philippines that connects Laguna de Bay with Manila bay. Due to lack of a proper sewage system, its 47 tributaries and creeks are contaminated by untreated sewage water. This paper sumarisez the characteristics and issues of the Pasig river tributaries. This study shows that BOD and COD of the Estero de Paco are affected both by rainfall and tidal change. Thus BOD load of the Estero is accumulated in the Estero due to adverse current. Moreover, the water mass where the average COD is over 100mg/L and BOD/COD is 1/2 indicates the high level of COD from sludge as COD is released from the sludge at the bottom throughout the year in addition to the continuous effluent of BOD (domestic waste).
