Potential contamination of groundwater quality in west Algeria by non-biodegradable effluents from public discharges

The aim of this work is to study the environmental impact of the municipal landfill in the town of Sidi Bel Abbes (western Algeria), in particular on the water table, which circulates at a shallow depth (Max. 20 m) under permeable soil. The huge quantities of putrescible waste discharged into this landfill generate highly polluting leachate water, rich in organic matter (COD up to 1300 mg/L, 209 mg/L in BOD5), salts and micro-organisms. A physico-chemical study of well water in the region reveals a significant deterioration in the quality of the underlying groundwater. In fact, electrical conductivities (on average 5.75 mS/cm) are common in wells, especially those located close to the landfill site. This indicates heavy contamination of the water in these wells by leachate. As for the organic and metallic load, abnormally high levels (82 mg/l in COD, 40 mg/l in BOD₅, 0.74 mg/L in Cr, 0.45 mg/L in Cd, 0.24 mg/L in Cu, 0.85 mg/L in Ni) were observed, mainly in the wells located near and downstream of the landfill, in the direction of groundwater flow.