Characterization of a river at risk: the case of Sapangdaku River in Toledo City, Cebu, Philippines

Abstract

Sapangdaku River in Toledo City, Cebu is a freshwater source found near a copper mine operating for more than 50 years. The river has been one of the major rivers identified by the Environmental Management Bureau to be at risk, that needs monitoring and more empirical studies. This paper assessed the water quality of the Sapangdaku River through physicochemical, metal, and microbial analyses. Five (5) samples were collected from the downstream, midstream, and upstream sites, and were immediately tested in a water laboratory. Findings revealed that the pH, DO, BOD and COD registered within the acceptable range. Conductivity, turbidity, TDS, and TSS have fluctuating results where the midstream area recorded the highest measurement for the first three and upstream for the latter. Hg and Pb are present in little amounts while Cu in high concentrations. Total coliform counts are low in midstream and upstream while fecal coliform counts are high in all sites. Higher conductivity, higher turbidity, slower flow rate, and cooler condition in the midstream, as well as the presence of more pathogenic bacteria and Cu across sites, indicate poor water quality. Though there is poor quality, the DO, BOD, and COD levels of the river show promising results that aquatic life can still thrive. Educating communities, decreasing means of erosion, and establishing strict policies and ordinances on the use of river resources are recommended.

Keywords

• sapangdaku river
• physicochemical assessment
• metals
• coliform
• river rehabilitation