Assessment of Groundwater Vulnerability to Contamination Using Capture Zone Delineation in Shenzhen City, China

As a result of the large risk associated with the contamination of aquifers, it becomes imperative to protect groundwater supply areas. One of the practical methods that is projected for the protection of aquifers is to zone a boundary around current production in order to control hazardous industrial practices close to the wells supply. Nanping Highway is proposed to be constructed over a mineral groundwater source area in Shenzhen city Guangdong Province in southern China. Using concrete pouring of Portland cement as a main component in Highway road structure does not interfere as a part of pollutants, so it has no impact on groundwater quality by its composition. However, rainwater run-off is often heavily contaminated by vehicles wear, brake wear, lubricants spillage and/or tyre debris which might discharge on both sides of the road and causes groundwater contamination. In this study two particle tracking simulations were performed using MODFLOW and MODPATH to analyze the long term effect of contamination from the base of the highway road. Model results show the vulnerability of the pumping wells to pollution. However because MODPATH program doesnpsilat take dispersive and chemical reactions processes during the flow of contaminant, this results indicate the worst scenario, so the contamination may be not significant to cause serious problem.