National Conference on Water Resources Management (WRM2019), March 15 - 16, 2019 Civil Engineering Department, AMU, Aligarh Long Term Management Plan for Pollutant Mass Reduction by Variable Withdrawal Rates in a Confined Aquifer Preetu Chandra 1 , RamanshBajpai2, Deepesh Singh 3 Department of Civil Engg. HBTU Kanpur India E-mail: chandrapreetu@gmail.com, ramanshbajpai786@gmail.com, dr.deepeshsingh@gmail.com Abstract: Groundwater, extracted from deep geological formations called aquifers through pumping wells, constitutes an important component of many water resource systems. Pollution of groundwater has become a major problem for its safe utilization. The flow of groundwater pollutants in an aquifer depends upon boundary conditions, initial conditions, hydrogeological information and wells.Long-term planning of groundwater usage requires analytical-based new decision support tools. These tools must be able to forecast the change in the groundwater storage with adequate accuracy, and must allow exploring management scenarios. The temporal and spatial distribution of pollutants from different fields can be studied by 2-D and 3-D groundwater modeling. A groundwater model provides a quantitative structure for synthesizing field information and for conceptualizing hydro geologic process. The analytical simulation model of transient pollute was used to develop a concentration response matrix. The model computes changes in concentration over time caused by the processes of convective transport, hydrodynamic dispersion, and dilution from fluid sources. This study aims to analyze the plume behavior with variation in pumping well discharge. The flow and transport simulation model MOC (USGS) is utilized for obtaining sets of pollution concentration realizations at potential monitoring locations. The pollutant concentration values at each node of the study area are found for a management period of 5 years and various cases along with scenarios are developed to find out best management plan for pumping schedule. Keywords: Groundwater, Pollute Transport, Method of Characteristics, 2-D Groundwater Modeling, Kriging. 1. Introduction Groundwater has been playing a major role in increasing food production and achieving food security. Groundwater, a renewable source of water, a highly dependable and safe source of water supply for agriculture, domestic, commercial and industrial needs. Increased use of chemical fertilizers coupled with improper water management practices has resulted in the deterioration of groundwater quality. Pollutant such as metals, pesticides, chlorinated solvents and other abandoned or buried chemicals are dissolved in and spread with the water and transport occurs mostly along preferential pathways that are typically inaccessible locations, which makes modeling challenging. Computer models for understanding and predicting hydraulics and pollutant transport in aquifers make assumptions about the distribution and hydraulic properties of geologic features. Subsurface water flows beneath the ground surface. Natural topographic and geologic systems control the occurrence of groundwater. Unconsolidated deposits of sand and gravel are favorable for groundwater occurrence due to their high permeability. The water content in the geologic formation varies with the depth below ground surface.Groundwater modeling aims at studying the temporal and spatial distribution of such pollutants in the aquifer and thus formulates sustainable groundwater strategies. It is essentially a tool to project the state variables of the groundwater system for an assigned pattern of forcing function and initial and boundary conditions and parameters. Especially during last few decades, the problem of design an optimal monitoring network under condition of uncertainty has been addressed by the number of researchers. Cieniawski et al. (1995) presented their methodology based on the work of Meyer and Brill (1988) on the optimal location of a network of groundwater monitoring wells under conditions of uncertainty. Gangwar and Singh (2017) suggested a model to design an optimal dynamic groundwater monitoring network for aquifer with varying thickness to determine the mass estimation error of pollutant concentration at different time intervals. Safaan et al. (2011) given MOGA model forthe maximum pumping rate and minimum operation cost as well as the prediction of the future changes in both pumping rate and pumping operation cost. Banks and Dillow (2001) was developed simulation- optimization model for the Old O-field area provided an optimal solution for flow system and amount of water needed to maintain capture.