A New Approach for Predicting Residence Time Distribution of Subsurface Wastewater Infiltration System

Hydraulic residence time (HRT) is one of the key design parameters controlling the removal efficiency of contaminants and nutrients in subsurface wastewater infiltration system (SWIS). A two-dimensional axisymetric finite element software called SEEP/W was used to simulate unsaturated and saturated flow within SWIS. The paper presents a methodology by example for estimating residence time distribution (RTD) at the design stage of SWIS.