The former Laplace Chemical Company located in Bergen County, New Jersey was historically operated as a chemical supply warehouse.  Very high levels of chlorinated solvents or cVOCs, predominately tetrachloroethene (PCE) and trichloroethene (TCE) were documented in ground water beneath the site (e.g. 137,000 micrograms per liter [ug/L] PCE, 166,000 ug/L TCE). Groundwater impacts at the Laplace main facility appeared to be a result of a commingled cVOC plume between upgradient sources and the LaPlace main facility.

From our inception in 2000, E&LP has been an early adopter of innovated environmental based technologies, microbial biological tools (MBTs) and sustained bio-augmentation.  E&LP received a NJDEP approval for combined use of In Situ Chemical Reduction (ISCR) and enhanced bio-remediation of the residual source materials.  The remedial technologies used included injections of nanoscale zero valent iron (nZVI) to cause in-situ chemical reduction coupled with In Situ Bio Reactors (ISBRs) to promote sustained bio-augmentation/stimulation. Each ISBR was equipped to inject four different commercially available emulsified electron donors to enhance anaerobic bioremediation. In addition, the sustained bio-augmentation via the ISBRs was compared to the traditional batch injection of EVO and bio-augmentation culture. The electron donors utilized at the site were Microemulsion ELS (Peroxychem), emulsified vegetable oil EVO (TerraSystems), EVO (EOS), and ERD Provectus.  During the period that the ISBR units operated, VOC concentrations dropped considerably.

The combination of multiple remediation technologies and approaches at the site produced success.  The following two figures (RIP-3 and RIP-4), which were close to the source area, show the cVOC concentrations over time where there was a gravity feed injection and where ISBRs were deployed.  All concentrations are µg per liter. 

The immediate impact of the ISBRs and gravity feed donor injection on the CVOC concentrations in the wells was robust.  Near complete dechlorination was occurring was the simultaneous decrease in all cVOC concentrations without the buildup of lower degradation products like DCE.  The combination of multiple remediation technologies and approaches at the site produced success, reducing the contaminant mass by approximately 85%.

The successful implementation of these innovative remedial technologies supported used of a long term Monitored Natural Attenuation final remedy.  Accordingly a restricted Response Action Outcome was issued for the site.