Influence of Seasonal Variation on Bio-Physicochemical Properties of Leachate and Groundwater in Cebu City Snaitary Landfill, Philippines

Characterization of leachate and groundwater composition in Cebu City Sanitary Landfill, Central Philippines has been studied during wet and dry seasons. Selected bio-physicochemical parameters were assessed for temperature, pH, electrical conductivity EC, TDS, TSS, TS, DO, BOD5, COD, coliform (total and fecal), and selected metals (Pb, Cr, Cd, and Cu). Results showed that coliform count were substantially high in both leachate and groundwater exceeding the national standards for drinking water. The determined average metal concentrations were found to be higher in leachate compared to groundwater. The relative order of heavy metals in the leachate regardless of seasonal variation is Cu>Pb>Cr>Cd. For groundwater it is Cr>Cu>Pb>Cd. Distinctively, concentration values for Pb and Cd in leachate and Pb in groundwater exceeded the national standards. Likewise, the mean BOD5 and COD values were relatively higher in leachate compared to groundwater. Comparable results were also obtained for TDS, TS, TSS, temperature, conductivity, and pH. Noticeable parameters for leachate during the wet season indicate high levels of both organic and inorganic pollutants as compared to groundwater brought about by rain dilution. However, quantification of groundwater contamination brought by landfill’s leachate is diverse, originating from anthropogenic and natural ecosystem cycles. Consequently, further monitoring is essential to ensure the environment and public health.