Performance Evaluation of Best Management Practices for Urban Storm Water Runoff

Non-point source pollutants in urban stormwater runoff depend mainly on land use pattern, human activities and rainfall characteristics. Studies on the characterization of street-dust and stormwater runoff in three different land use pattern show various effects of runoff pollutant loading on receiving waters. The evolved pollutant loading equations predicts an increasing trend for most of the parameters. The most problematic pollutant identified is phosphate. Experimental studies on modified Best Management Practices (BMP) in attenuating the phosphate revealed that infiltration trench (BMP-1) has a removal efficiency of 55%, detention basin (BMP-2) with 40%, partial ex-filtration trench (BMP-3) with 75%, vegetative swales (BMP-4) with 47% and horizontal flow filter drain (BMP-5) with 60%. In most of the cases, for economical reasons, time of attenuation and maintenance viewpoint, vegetative grass swales may become better option of best management practices for urban storm water runoff.