Physicochemical quality of groundwater in suburban area - Impact of uncontrolled landfill in the district of Kitidjan in Agoe-Nyvé- Togo

Abstract

This study aimed to assess the quality of groundwater in the vicinity of an uncontrolled landfill in suburban of Lomé. Characterization of the leachate obtained by leaching test in lab scale (24 h) using solid waste from landfill (situated in Kitidjan district in Agoé-Nyvé Prefecture, Togo) as well as assessment on the quality of the local aquifer were carried out. The leachate pollution index (LPI) which a higher index value indicates a higher pollution threat and water quality index (WQI) were computed using physicochemical parameter analyzed on leachate and ground waters using AFNOR standards. Leachate obtained after 24 h was characterized with significant value of EC, nitrate, nitrite, chloride, sulfate, phosphorus and organic matter and the release factor about 10 indicates high capacity pollutant release from the landfill. This potential pollution was confirmed by LPI around 65.29 that indicate non-stabilized waste and significant pollution threat to surrounding environment including groundwater. The physicochemical analysis of groundwater samples shows high electrical conductivity and nitrate concentration respectively with 1263 μS/cm and 157.50 mg/L as mean value. The groundwater quality is unsafe for drinking due to nitrate concentration. Based on WQI values, groundwater falls into one of three categories: excellent water (5.8%), good water (53.3%), and poor water (41.2%). Poor water are encountered in borehole water located in vicinity of the landfill and in runoff the landfill leachate.