In Situ Chemical Reduction of Recalcitrant Contaminants in a Low-pH/Elevated-Sulfate Pinelands Aquifer at a New Jersey Superfund Site

摘要

Background/Objectives. In order to accelerate groundwater remediation at a Superfund Site in the New Jersey Pinelands, an approach was established to supplement previous soil washing and in situ chemical oxidation remedies and supplant an 18-year-old groundwater recovery and treatment system (system) using in situ chemical reduction (ISCR). ISCR bench-scale and pilot testing programs were conducted to evaluate using ISCR to address various volatile organic compounds (VOCs) and heavy metals in a shallow Pinelands aquifer with low pH (4.0 to 6.5 standard units [SU]) and high natural sulfate levels (31,000 to 120,000 micrograms per liter [μg/l]). The significant compounds of concern (COCs) consisted of: tetrachloroethene (PCE); trichloroethene (TCE); 1,1,2,2-tetrachloroethane (1,1,2,2-PCA); 1,1-dichloroethane (1,1-DCA); 1,1,1-trichloroethane (1,1,1-TCA); ethylbenzene; beryllium; and chromium. As a result of residual source area impact and various groundwater hot spots, these COCs continued to exceed the applicable or relevant and appropriate requirements (ARARs) and projected timeframes for meeting ARARs using the current pump and treat remedy presented overall project endpoint and cost concerns.