Funnel-and-gate vs innovative pump-and-treat systems: a comparative economic assessment

Based on a simplified hypothetical scenario of a PCE contaminated site, total remediation costs of a funnel-and-gate system are compared to the costs of innovative pump-and-treat systems which also include hydraulic barriers to minimize the required pumping rate. By means of a design optimization framework that combines groundwater flow modelling, hydrochemical treatment modelling, mathematical optimization and economic models, a cost-optimal design is provided for both alternatives, The results of sensitivity analysis show that the design of the cost-optimal configuration of the remediation systems depends not only on site-specific parameters but also on factors like the net interest rate. Since these economic factors are inevitably uncertain, the decision on which alternative to choose strongly depends on the underlying assumptions. Still, for the hypothetical scenario in this study, innovative pump-and-treat systems proved to be the lowest-cost alternative for quite a large range of relevant parameters.