Contamination of soil and groundwater in area of urban solid residual disposition in state of Minas Gerais

Abstract

The irregular disposal of urban solid waste generates several environmental impacts resulting from its decomposition, whose product contains toxic and persistent substances that can contaminate the soil and groundwater. Thus, the objective of the work was to evaluate the contribution of urban waste deposits in the State of Minas Gerais as a polluting source of soil and groundwater, analyzing the risks of propagation of contaminants according to local pedology and lithology, as well as evaluating the natural vulnerability of the aquifer to contamination. The survey of contaminated areas was carried out from 2009 to 2020, the elaboration of pedological and lithological maps, the determination of hydraulic loads and contamination flows and the application of the GOD method. It’s already been noted that urban solid waste deposits represent less than 1% of the total contaminated areas in Minas Gerais. The vulnerability to aquifer contamination indicates that the areas studied – Contagem and Itueta waste dumps and Itabira and Uberaba landfills, show low vulnerability, with the exception of the Nova Lima waste dump, which is highly vulnerable. Among the studied areas, the Nova Lima area presented the worst situation due to the shallow soil and low pollutant retention capacity, the low depth of the aquifer and for presenting highly toxic substances; while Uberaba has greater protection both because it has a deeper water level and because it has an aquifer covered by a layer of rock (dacite), which hinders the access of the pollutant to the aquifer.