Avaliação da água subterrânea e superficial na área de entorno do antigo lixão de resíduos sólidos

Abstract

The irregular disposal of solid waste in areas of inadequate disposal, such as landfills, is still a reality in Brazil, generating impacts on the environment (in the soil and in groundwater and surface waters) and public health risk. In this sense, the objective of this research was to evaluate the quality of groundwater and surface water adjacent to the old dump of Tangará da Serra-MT. The methodology consisted of performing physical, chemical and microbiological analyzes of groundwater and surface water in the rainy and dry period between September 2019 and June 2020. Four monitoring wells (P1, P2, P3 and P4) were evaluated with a distance of 100 and 2,000 meters from the dump. The assessment of surface water occurred in Córrego do Meio, (P5) close to the dump (source) and (P6) downstream. Water quality assessment was carried out using the Water Quality Index (WQI). The results obtained showed higher values in all parameters (real color, apparent color, electrical conductivity, nitrite, nitrate, phosphorus, total hardness, BOD5,20 and COD) in the dry season, in all monitoring wells, showing that with the reduction the volume of water in the drought increases the concentration of nutrients. In the surface waters, the data of nitrate, solid residues and Escherichia coli, showed higher values downstream, due to the altered vegetation by anthropic actions influencing the carrying of particles, while in the spring area the best water quality was found due to conservation vegetation in the area. Consequently, the values of (WQI) of the Córrego do Meio classified the waters of the spring (P5) as Good and those of the downstream (P6) as Medium. The results obtained infer that there is no carrying of pollutants from the old dump in the study period capable of impacting the quality of groundwater and surface water.