Evaluation for the contribution of different surface runoff to the pollution of wet weather flows in storm sewers

AbstractIn recent years, the pollution of surface runoff has raised increasing concern. However, its contribution to the contamination of wet weather flows (WWF) in storm sewers is little evaluated. A simplified mathematical method named Contribution Partition Mathematical Method for Storm Sewers was proposed, which would help small-scale residential communities to learn the contribution of different surface runoff (including roof, internal road, lawn, external road runoff and so on), mistakenly discharged wastewater (MDW) and sewer deposit erosion (SDE) to WWF pollution load in storm sewers. In a case study, internal road was found to be the greatest contributor of WWF pollution, while provided about 50% of organic compounds and total phosphorus (TP), 40% of suspended solids (SS), volatile suspended solids (VSS) and heavy metals. Meanwhile, MDW and SDE also supplied sufficient pollutants to WWF, including about 30% of TP, SS and VSS. Some suggestions were thereby proposed to better assist the local communities on their runoff pollution control.