The ROD identifies ex-situ treatment of the 1,4-dioxane and VOC plume as a remedial component of the RD/RA. Due to the mobility of 1,4-dioxane and an inherit threat to a downgradient municipal well, USEPA elected to accelerate the cleanup efforts through a Non-Time Critical Removal Action for Groundwater (GW NTCRA), effective July 2016. In order to isolate the plume and cutoff the migration towards Assabet 1A supply well, a temporary treatment system was installed in May 2017 and operated through May 2019.