Alternative Formulations for Optimal Ground-Water Remediation Design

Abstract

This paper presents alternative formulations of optimal pumping design for contaminated ground-water cleanup. Remediation-efficiency indicators are proposed for evaluating well performances in terms of contaminant removal. For a selected remediation period, the alternative objective functions are: (1) Total volume of the extracted and/or injected water; (2) total contaminant removal; (3) total residual contaminant; and (4) any weighted combination of the first and second or first and third items. With the introduction of a field variable, referred to as the temporal accumulative contaminant concentration, the contaminant removal by any remediation well is computed directly by solving a temporal-integrated contaminant transport equation. Ground-water-quality constraints can be placed on the residual average and/or maximum concentrations in selected aquifer zones and the concentrations at specified locations. The state sensitivities to the injection and extraction components of the pumping rates are computed using formulations derived analytically from the state simulators.