Quantification of Groundwater Infiltration into Urban Drainage Networks Based on Marker Species Approach

Abstract:

A methodology was proposed to estimate its quantity and the corresponding pipe defect grade. This method was applied to estimating the groundwater infiltration into three separate sewer and storm systems of the City of Shanghai, China. Here, hardness and total nitrogen were used as markers to indicate groundwater and domestic wastewater into sewer pipes and storm pipes with inappropriate sewage entry. Absolute flows of groundwater were estimated in conjunction with MonteCarlo entryexit mass balance simulation. The apportioned groundwater flows fell within the allowable designing requirements, and the assessed pipe defect grades fit the anticipated pipe conditions, proving the proposed method feasible and applicable to pipe maintenance assessment. Information also showed that actual allowable groundwater inflow was larger for the study site in comparison with German and US standards, and hence pipe construction and maintenance technologies in China need improving.