PROJECT ARCHIVES:
Wilhelm Energy
Randallstown, Maryland

Between August 1997 and March 1998, twelve underground storage tanks (USTs) and one underground oil/water separator were removed from the Site. In response to the presence of petroleum impacts, MDE required completion of a subsurface investigation and in July 1998, five monitoring wells were installed. In October 1998, liquid phase hydrocarbon (LPH) was observed in one of the wells and LPH removal activities were initiated. Six additional monitoring wells were installed in May 1999 to complete the delineation of dissolved and liquid phase hydrocarbons.

In February 2000, a Corrective Action Plan (CAP) was submitted to the MDE proposing the installation of total fluids and soil vapor extraction (SVE) recovery systems to address liquid and dissolved phase hydrocarbon impacts. MDE approved the CAP and the remediation system was installed in September and October 2000. In November 2000 the total fluids extraction system was brought on-line. After several months of operation and reduction of the LPH thickness, the SVE system was brought on-line in May 2001. During the remediation system operation period semi-monthly site visits were conducted to check remediation system operation and gauge Site wells. Additionally, groundwater samples were collected quarterly from all wells not containing LPH.

Due to diminished LPH and hydrocarbon vapor recovery, Arc Environmental petitioned MDE Oil Control Program (OCP) to take the recovery system off-line and initiate the post remediation monitoring period. MDE approved and the system was turned off in May 2006. During its operation the total fluids recovery system a total of 5,724,572 gallons of groundwater and 203 gallons of LPH were removed from the subsurface and the SVE system recovered a total of 19,160 pounds of hydrocarbon vapors (approximately 3,090 gallons of hydrocarbons).

The MDE approved one-year post-remediation monitoring period was initiated upon system shutdown. Post-remediation monitoring consisted of monthly well gauging and quarterly groundwater sampling. The post-remediation monitoring period ended in April¬Ý2007. In June 2007, MDE granted approval to abandon the monitoring and recovery wells; this was completed in September 2007. MDE OCP issued a Notice of Compliance in January 2008 and the remediation system was dismantled in April 2008. The MDE OCP was actively involved throughout this project and has cited it as an example of remediation done right.