Impacts of Physical and Chemical Heterogeneities on Aquifer Remediation Design

Abstract

The impacts of physical and chemical aquifer heterogeneities on optimal remediation design, costs, and time to compliance are investigated by linking a genetic algorithm with a contaminant transport simulation model. Physical and chemical aquifer heterogeneities were grouped into three levels as follows: (1) hydraulic conductivity (K) heterogeneity only; (2) combined heterogeneity of K and the distribution coefficient (Kd); and (3) combined heterogeneity of K, Kd, and the mass transfer rate (α). Various degrees of heterogeneity were considered, ranging from slightly heterogeneous to strongly heterogeneous. Impacts were evaluated using two different optimization models: the optimal design model and the time-to-compliance model. The first model focused on finding optimal aquifer remediation designs and costs under various heterogeneity conditions, and the second model optimized the time needed to meet the water quality goals for a fixed pumping schedule. Results show that the variability in the remediation ...