Assessment of the Effect of Solid Waste Dump Site on Surrounding Soil and River Water Quality in Teppi Town, Southwest Ethiopia

Abstract

An increase in the urban population and the rising demand for food and other essentials perpetuate a rise in the amount of waste being generated daily by each household. In low-income countries, this waste is eventually thrown into open dump sites. It can cause severe impacts on human health and the surrounding environment. This study was aimed at assessing the effect of solid waste dump site of Teppi town on surrounding soil and river water quality. A total of three surface water, one leachate water samples and four soil samples were collected and were analyzed. Six heavy metals for surface water and leachate samples and four heavy metals for soil samples were measured by flame atomic absorption spectroscopy. Additionally, physical and chemical parameters such as pH, electrical conductivity for both soil and water samples, organic matter for soil samples, TDS, turbidity, nitrate, sulfate, fluoride, potassium, BOD5, and COD for stream and leachate water samples were analyzed using standard methods of ISO (1995 and 2015), APHA (1992 and1999), and WHO (2004). pH of soil was slightly basic (pH 8±0.1 up to 8.7±0.21) indicating the influence of solid waste dumped in the area. Similarly, EC was lower in 60 meters (1800±0.5μs/cm) and higher in the other sample sites (3490±0.66-4920±1.04μs/cm). The concentration of heavy metals such as cadmium (0.53±0.01-2.26±0.02 mg/kg), zinc (623.93±0.29-859.41±0.02mg/kg), lead (3.26±0.25-57.560.26mg/kg), and copper (204.06±0.06-337.11±0.01mg/kg) in the sample soils has been found to be higher than EEPA and USEPA guideline values. The concentration of heavy metals such as lead, cadmium, manganese, nickel, copper, and zinc in the leachate water and nickel and manganese in nearby river water, TDS, BOD, COD, and turbidity for both leachate and stream water samples were found to be higher than the EEPA and WHO standard guideline values. The finding suggested that solid waste open dump site adversely affect soil and water quality in the study area and probable source of human health risks via the food chain. The soil in the area requires Phytoremediation technologies. In addition, appropriate site selection, construction of geo-synthetic layer, erosion preventive brim, and sanitary landfill are recommended