HR: 1330h
AN: H12E-1022    [PDF]
TI: Analysis of the impact of soil heterogeneity on optimal policies for groundwater remediation
AU: * Bau, D
EM: dabau@mtu.edu
AF: Department of Geological and Mining Engineering and Sciences, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931 United States
AU: Mayer, A S
EM: asmayer@mtu.edu
AF: Department of Geological and Mining Engineering and Sciences, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931 United States
AB: Typical groundwater remediation problems involve the design of the number, location and flow rate schedule of pumping and injection wells. Simulation models combined with optimization models are used to rank alternatives while considering management objectives, e.g. minimizing remediation cost and/or maximizing cleanup efficiency, and constraints, e.g. the maximum permissible concentrations at selected compliance sites. Mostly due to both high computational effort required and lack of data, the simulation models often are based on simplified 2D homogeneous hydrogeologic settings. The purpose of this work is to investigate how simplifying hypotheses may affect the final optimal remediation policy. In particular, the analysis addresses the case of a heterogeneous layered aquifer versus an homogeneous one with an equivalent (lumped) hydraulic conductivity. To simulate groundwater flow and contaminant transport, use is made of a fully 3D finite element unsaturated flow model along with a particle tracking transport code. The flow and transport code is then coupled to a genetic algorithm model to optimize the specified objective function. The problem considered is the remediation of a hypothetical aquifer-contaminant system using pump and treat. The objective is to minimize the cost of the remediation system. The cost function is a nonlinear function of decision variables (pumping rates) and state variables (hydraulic heads and contaminant concentrations). Constraints include limits on hydraulic head and the contaminant mass remaining in the aquifer at the end of the remediation. The results of homogeneous and heterogeneous simulations are compared in terms of cost and values of the decision variables.
DE: 1829 Groundwater hydrology
DE: 1832 Groundwater transport
SC: Hydrology [H]
MN: 2003 Fall Meeting