• Persistent benzene contamination reduced from 530 μg/L to 4 μg/L
• Target Medium Specific Concentration (MSC) achieved within one quarter of treatment
• Application of PlumeStop® and ORC Advanced® successfully completed by REGENESIS® Remediation Services (RRS) within three days allowing for the project

Operation activities at the site of an active gas station resulted in contamination of the groundwater with low levels of benzene. The concentration of benzene fluctuated, reaching 530 μg/L before remediation efforts were undertaken. REGENESIS designed a remediation plan to address the persistent low levels of benzene that combined the application of PlumeStop and ORC Advanced for in situ sorption and enhanced aerobic biodegradation.

The sorbent properties of PlumeStop make it possible to successfully treat low contaminant levels by creating local areas of high contaminant concentration that can then be colonized by contaminant-degrading bacteria. This co-localization of the contaminants and bacteria on the PlumeStop surface greatly improves the contact between the two components, thereby enhancing the speed and efficiency of the degradative reactions. Addition of ORC-Advanced further supports aerobic biodegradation by providing a long-lasting oxygen source.

RRS injected PlumeStop and ORC Advanced into 12 points around MW-6R (Fig. 1) that showed elevated benzene levels. A total of 1,200 lb of PlumeStop were first injected via direct push technology followed by injections of 240 lb of ORC Advanced into the same 12 holes. Treatment of the site was completed over the course of two days without any complications.