Building 100 Groundwater Bioremediation at the Former DOE Pinellas Plant, Florida: Review of Progress and Opportunities

Abstract

Weapons research, development, and production operations at the former Pinellas Plant, which includes the Building 100 area, released chlorinated organic solvents into the subsurface, contaminating the underlying soil and groundwater. The site was sold to Pinellas County and is now home to a thriving industrial park known as the Young - Rainey Science, Technology, and Research (STAR) Center. The US Department of Energy (DOE) has applied bioremediation at the Building 100 Area as a key technology to clean up the chlorinated volatile organic compound (cVOC) contamination in soil and groundwater. The monitoring data indicate significant progress toward remedial objectives over the past two decades. Starting conditions in the 1980s-1990s included areas containing residual undissolved dense nonaqueous phase liquids (DNAPLs) and the associated presence of an extensive high concentration plume in the groundwater. The original parent cVOCs were primarily tetrachloroethene (PCE) and trichloroethene (TCE). After several informative pilot studies, bioremediation was implemented at the Building 100 Area of the site and relies on reductive biological pathways and the sequential removal of chlorine from the parent cVOCs forming dichloroethane (DCE) and chloroethene (vinyl chloride, VC). As bioremediation sites evolve toward cleanup, the trends in VC concentrations often serve as a critical indicator for progress and remediation timeframe because VC typically has a lower concentration target remedial objective (nominally 1 to 2 μg/L) compared to PCE and TCE (nominally 3 to 5 μg/L).