Groundwater contamination transport through modeling approach: a case study in Kasur, Pakistan

Abstract

Assessment of contaminated sites having an anthropogenic source of contamination from industries is the need of the hour to properly investigate and search for mechanism of contamination, that is, how the pollution is spreading out and how much the life in those areas is at risk due to complex environmental scenarios existing at site. In this background Kasur tannery area was selected to explore the environmental situation regarding industrial pollution mainly caused by major pollutants being released from tanneries, that is, chromium. FEMWATER model was used to conduct contaminant transport simulations in the area. Three main scenarios were developed to simulate the site for contaminant flow. The first scenario was considered with adverse condition with a stagnant pond in the tannery area in operation with no treatment plant and drains in the area and this scenario was conserved for a duration of 20 y from 1980 to 2000, the second scenario was for no contaminant release into the environment due to properly collected wastewater systems and treatment plants. Furthermore, the third scenario was based on an existing situation, when the treatment plant was not working efficiently due to the release of excessive tannery effluent from the tannery units. The result of simulation showed very slow movement of contaminant plume indicating that stagnant pond in the tannery area has not affected the downstream side. After the year 2004, the generation of stagnant pond 2 due to heavy overflow also could not cre-ate any farther contaminant transport horizontally. Therefore, it has been suggested that, once the source of contamination has been stopped and controlled by focusing on the chemical treatment of the tannery effluent and the seepage prevention of the untreated effluent from the drains or leakages, the groundwater contamination might reduce by exhibiting natural attenuation.