Using a PV-Powered Pump to Remediate Contaminated Ground Water at a Dry Cleaning Site

Green and sustainable remediation techniques sometimes involve the substitution of renewable energy systems for utility-provided power. Such a use of renewable energy may be attractive in terms of resource conservation, ease of installation, reduced installation costs, and limited disruption of facility operation. This project includes the installation of a single-axis tracking photovoltaic (PV) array at a former dry-cleaning site that is undergoing remediation under Missouri\u27s Drycleaning Environmental Response Trust (DERT) program. The PV array was used to power a piston pump that extracted shallow ground water and circulated the contaminated ground water through granular activated carbon units prior to discharge to the local publicly owned treatment works (POTW). The PV system included a linear current booster that eliminated the need for batteries but meant that the system would only pump water when there was adequate solar insolation. The system was instrumented to collect insolation and flowrate data, and water quality samples were regularly collected to quantify the mass of PCE (the primary contaminant of concern) that was removed from the aquifer. There were several challenges encountered during the project, the greatest of which was the low aquifer yield and the greater than anticipated GAC consumption rate. A stochastic analysis was performed to characterize the average daily flowrate as a function of the power consumed by the pump, and a comparison of the actual insolation relative to publically-available insolation estimates for the site were conducted. The data provide a means for predicting PV-powered pumping rates at other sites