The Heavy Metals and Microbiological Profiles of the Major Drinking Water Supply System of Cagayan de Oro City, Philippines

This study characterized Cagayan de Oro’s major water supply system. Copper, chromium, lead, cobalt, manganese, nickel, and cadmium concentrations were measured in both raw and treated water along with two microbiological parameters (total coliform and Escherichia coli). The samples were composed of raw water from the Bubunawan River in Baungon, Bukidnon and processed water from selected households in Carmen, Cagayan de Oro City. The atomic absorption spectroscopy (AAS) found that most selected metals were present in raw and processed water at varying concentrations. The raw water was found to contain Cu, Cr, Pb, Mn, and Cd, while the processed water contained Cu, Cr, Pb, and Cd, with no Mn detected. The concentrations of these metals were within the PNSDW, USEPA, and WHO maximum allowable limits, indicating that the public is safe from the effects of these heavy metals. Too numerous to count total coliform bacteria indicated that the raw water sample was significantly polluted with coliform bacteria. This signifies that pathogen are present in the water supply, rendering it unsafe for human consumption unless regularly disinfected. On the other hand, the disinfected raw water or processed water had less than 1 total coliform count and no E. coli. The treated water met the PNSDW and USEPA microbiological criteria. In conclusion, the treatment process applied to Cagayan de Oro City’s major water supply system is effective in producing drinking water free of harmful heavy metals and microorganisms.