Minimizing the Impact of Groundwater Pumping on the Environment: Optimization Strategies

Abstract

Long-term Groundwater pumping alters the environment and groundwater availability and thus affecting both the local and regional environment in a significant way. There are many purposes for which the groundwater has been abstracted in large quantity thus creating an unscientific way of management of the groundwater, leading to jeopardizing the sustainability of groundwater availability on a long-term basis. In this paper, we would be discussing one case study dealing with the groundwater modeling of open-cast mines with the development of an Integrated groundwater model to evaluate the impact of mining and the irrigated agriculture in the surrounding environs, on the groundwater status as well as to determine the time-period/year when the newly proposed mines without any increase in total pumping of groundwater. The study includes estimating groundwater recharge and developing a three‐dimensional steady‐state groundwater flow model exclusively for mine pumping simulation. The model has been utilized to evaluate the impacts of changes in groundwater pumping under the mine expansion scenario. In addition, simulation runs were made with the developed model to assess the impacts of recharging into the aquifer systems through the proposed recharge structures on groundwater and the surrounding environments and for various scenarios that vary depending upon the current as well as on the future conditions of water use. The other case study was in connection with the dewatering optimization in a metro rail tunneling construction. The requirement of maximum allowable drawdown necessitates the need for pumping and injection simultaneously and the optimal pumping wells and recharge wells location as well as the quantum of pumping and injection have been arrived at for 5 typical tunnel construction locations in a metro city of India. The engineering lessons learned, and the environment-friendly groundwater pumping plans are the major outcomes of these research works, which would be highlighted.