Capture Zone Comparison for Photovoltaic Microgrid-Powered Pump and Treat Remediation

Abstract

Pump and treat groundwater remediation systems typically rely on utility power to continuously pump contaminated groundwater to an above-ground treatment unit. The use of renewable energy for a pump and treat remediation system reduces the output of harmful greenhouse gases and the need for coal-based utility power. This paper describes a hypothetical renewable energy-powered pump and treat remediation system that uses an off-grid photovoltaic array to power a submersible solar water pump. The pump operates on an intermittent schedule predicted by available solar irradiance. The intermittently operated pump generates an effective capture zone defined by multiple transient capture zones. Effective capture zones are modeled using Visual MODFLOW and MODPATH and compared against a continuously pumped steady-state capture zone. The comparison showed that a renewable energy-powered intermittently pumped remediation system performs 90% as effectively as a utility-powered continuously pumped remediation system and is cost effective when the capital cost and annual costs of the utility-powered system exceed the capital cost of the renewable-energy powered system.