Risk assessment of groundwater and surface water contamination by waste leachate from the Guercif open dump, Morocco.

This study examines the physicochemical parameters of leachate from an uncontrolled landfill in the town of Guercif before its remediation, and its impact on the Tafrata aquifer located beneath the landfill and the adjacent Oued Moulouya surface waters. The results revealed significant organic pollution in the raw leachate, characterised by high levels of BOD5 (13,141.56 mg O2/l), COD (89,821.38 mg/L), nitrate, nitrite, and orthophosphate. Additionally, elevated concentrations of metallic elements (Co: 3 mg/L, Cr: 11.7 mg/L, Pb: 3 mg/L) exceeded recommended standards. The analysis also detected high pollutant concentrations in groundwater (e.g. BOD5 at P1: 176.65 mg O2/L), COD at P1: 589.25 mg/L), nitrate at P1: 57.08 mg/L, nitrite at P1: 0.86 mg/L, ammoniacal nitrogen at P1: 1.112 mg/L) and surface (BOD5: 420.14 mg O2/L, COD: 797.86 mg/L, nitrate, nitrite, orthophosphate). These findings indicate significant percolation of polluted leachate into the natural bedrock. [ABSTRACT FROM AUTHOR]