Impact evaluation with potential ecological risk of dumping sites on soil in Baglung Municipality, Nepal

Abstract

This study is focused on the analysis of the impact caused by the municipal solid waste (MSW) dumping sites in Baglung Municipality of Nepal. For assessment of pollution level, physicochemical parameters of the dumping site's soil and potential ecological risk (PER) index was determined. The nature of the studied dumping site's soil was weakly acidic with high EC and TDS value. The result evidenced the higher values of available nitrogen (N), phosphorus (P) and potassium (K) which signify disposed waste is with high organic content. The concentration of heavy metals in the soil of dumping sites is ranked as Zn>Cu>Pb>Ni>Cr>Cd for the older sites and Zn>Cu>Pb>Ni>Cd>Cr for newer sites. The correlation matrix visualizes that there are positive correlations between Cr-Cd, Pb-Cd, Cu-Zn and Zn-Cd. PCA analysis shows the strong associations of NPK and heavy metals which depict their common source of contamination. The estimated PER index of each and multiple heavy metals represent older dumping sites have a higher potential for causing risk to the environment than the newer ones. This reflects the prospect of environmental threats due to haphazard disposal of MSW. The major implication of this research outcome is the necessity of monitoring and management of possible source of toxic heavy metals in MSW which may contaminate the nearby source of waterbodies by the runoff and infiltration of leachate produced by the dumping site. Also, it is advised to ensure the intense segregation of the MSW prior to final disposal.