Assessing a pre-treatment facility experimental prototype to enhance surface water runoff quality: a case study at Cali, Colombia

This study evaluated the performance of a pre-treatment facility for SuDS water quality improvement designed to handle the stormwater runoff of a 200 m² parking lot, using synthetic runoff and a statistical model of two levels of operation and four variables. The prototype consisted of an inlet ramp, sedimentation and filtration tank, and a recirculation system. The results showed that the removal efficiency of total suspended solids (TSS) and fats and oils concentration in the effluent are not affected by influent variations in flow rate, pH, temperature, TSS, fats and oils, and lead concentration. For the 32 measurements taken, an average of 82.9% (SD 3.6%) was obtained regarding total suspended solids removal. Lead retention possibilities were also observed. The TSS removal efficiencies were above 90.6% for precipitation events, generating peak flows of up to 5 L/s and a duration of 21 minutes, controlling the diffuse pollution peak.