Abstract:

Solute transport simulation is one of the most reliable approaches for groundwater pollution risk assessment. In this paper, to understand the effect to the reservoir from an organic contaminated site as the source of pollution, a precise flow simulation and a solute transport model of organic pollutant leaked from the chemical plant were built based on accurate measurement of flow field in the study area to estimate and analyze the change of groundwater flow and pollution migration after the reservoir built. The simulation results showed that, after the reservoir and two seepage intercepting ditches which had different water levels were built, groundwater flow would change to two kinds of groundwater flow fields, in one condition of which the reservoir would discharge to ditches and the ditches would discharge to vicinity area, while in the other condition the reservoir and vicinity area would both discharge to the ditches. In the two cases, some contaminant plume diffusion were farther than normal condition, but all the diffusion lengths in the direction of reservoir were less than 300 m, so it indicated that the contaminated site will pose no pollution risk to the water quality of reservoir.

Key words: groundwater, pollution risk assessment, solute transport, numerical simulation