Lessard Environmental, Inc. [logo]
Innovative Solutions, Effective Results, Professional Relationships
About LEI Services Bio-Rem OX SM Case Studies Resources Alliances Careers Contact Us Site Map  
Case Study #6

Case Studies

Case Study #1

Case Study #2

Case Study #3

Case Study #4

Case Study #4

Case Study #6

Case Study #7


Remedial Case Study


This high volume retail gasoline station is situated upgradient of a public drinking water reservoir. Lubricating oil NAPL (Non-Aqueous Phase Liquid) was periodically detected in a particular site monitoring well. LEI delineated the limited area of impact and initiated treatment by eliminating the NAPL via dual phase extraction administered by a vacuum truck. A series of 3 Chemox (chemical oxidation) injection events were then conducted within the plume area over a 5 month period to address residual dissolved phase contaminants. Post treatment sampling revealed that the stringent clean up goals were met for this site


Assessment and remedial activities were conducted as a Release Abatement Measure (RAM) Modification . The following assessment activities were performed to adequately delineate the NAPL plume and any related soil impact.
  • Advanced 3 soil borings and completed as monitoring wells to provide additional data on soil and groundwater conditions proximal to the affected well
  • Field screened and laboratory analyzed selected soil and groundwater samples

Response Activities:

A two tiered approach was selected for this site. The first tier addressed the NAPL while the second tier addressed residual dissolved phase contaminants:
  • A dual phase extraction event (recovering vapors and liquids simultaneously) performed by a vacuum truck removed over 50 gallons of NAPL and groundwater, leaving the impacted well free of NAPL
  • 3 separate Chemox injection events were administered in September 1999, October 1999 and January 2000.
  • Compared site specific standards to actual groundwater quality indicating that groundwater did not require any further remedial actions
  • Performed a method 2 Risk Assessment which concluded that No Further Remedial Actions were required
  • Completed a RAO (Response Action Outcome)

Key Monitoring Results:

Current Site Status:

  • Site Closed — No Further Remedial Actions required

All content © 2003 Lessard Environmental Incorporated.