Evaluating the Water Quality Contribution of Estero de Paco to Pasig River and Manila Bay, Philippines

Abstract

The clean-up of the river system feeding into Manila Bay is crucial in addressing the current Manila Bay water quality. Since Estero de Paco is a feeder into Pasig River which enters the Manila Bay, its clean-up is imperative to sustain Manila Bay water quality. This research gathered information on the water quality Estero during both the dry and the wet season. Initial survey of the stretch showed that there are bridges and residential areas as potential sampling points. Using the Streeter-Phelps model an assessment of the water quality during different meteorological conditions shows that almost no DO is available during the dry season, while some have a DO > 5 mg/l (standard) during the rainy season. Unfortunately, based on the other critical parameters, Biochemical Oxygen Demand (BOD) was high due to discharge of septic waste directly into the river during the heavy rains. Sludge near populated areas were characterized and found to contain high levels of Oil & Grease, Organic Matter. The Streeter-Phelps equation used to evaluate the oxygen deficit shows that at the Pasig River junction DO is negligible even during the wet season. It is recommended that regular monitoring and community engagement be actively pursued.