Development and Validation of Technologies for Remediation of 1,2,3-Trichloropropane in Groundwater

Purpose of Review 1,2,3-Trichloropropane (TCP) is a synthetic chemical with known and suspected human health effects associated with exposure. In response to the identification of TCP in environmental media, several states in the United States (US) have set maximum contaminant levels (MCLs) for TCP in drinking water and guidance values for TCP in groundwater. Current treatment methods for TCP in groundwater are limited and can be cost prohibitive. The purpose of this review is to summarize the state of knowledge on TCP remedial technologies and describe efforts to develop and validate promising treatment methods. Recent Findings In situ chemical reduction (ISCR) and in situ bioremediation (ISB) have shown the most potential for TCP remediation. ISCR of TCP by zero-valent zinc (ZVZ) has been evaluated for several years through bench-scale testing, field-scale column testing, and a pilot-scale ZVZ injection program. Additional injections are ongoing to assess the long-term efficacy of ISCR. ISB under anaerobic conditions has been evaluated in laboratory studies and at the field scale with bioaugmentation. Field-scale evaluation of ISB is also ongoing. This review provides an overview of TCP, including use, physicochemical properties, fate and transport, health effects, and current regulation. The states of treatment technologies for TCP are detailed, including granular activated carbon (GAC), ISCR, ISB, and chemical oxidation. Case studies and notable findings are described for ISCR and ISB. While knowledge gaps remain for ISCR and ISB, results to date for these technologies are encouraging.