Chemical Injection Program at Former Gas Station

Chemical Injection program

Client: Engineering Firm
Location: New Brunswick
Industry: Oil & Gas

Project Overview

SCG Remediation Services was tasked with designing a chemical injection program to reduce benzene, toluene, ethylbenzene, and xylene (BTEX) impacts in groundwater at a decommissioned gas station site. The primary goal was to mitigate off-site migration southwest of the property boundary. To achieve this, SCG introduced Intrasorp® Colloidal Activated Carbon (CAC) for the installation of a permeable reactive barrier (PRB)—a first-ever application of Intrasorp in Canada. The material’s superior subsurface mobility and adsorption capacity made it ideal for establishing an effective reactive zone.

Key Challenges

  • BTEX Contamination: Groundwater impacted by multiple contaminants (BTEX) required a targeted, in-situ solution.
  • Off-Site Migration Risk: The remediation design needed to prevent contaminants from moving beyond the property boundary.
  • Budget Constraints: A multi-year, phased approach was necessary to meet the client’s financial parameters while ensuring thorough remediation.

Technical Execution

SCG developed a three-phase chemical injection program:

  1. Adsorptive/Reactive Zone: Forming a zone to trap and degrade contaminants.
  2. Subsequent Degradation: Introducing chemical or biological amendments for ongoing treatment.
  3. Phased Implementation: Allowing for adjustments based on site monitoring results over three years.
  • Phase 1: Intrasorp CAC was injected between 1.0 to 6.0 mbgs across approximately 600 m², using 15 injection locations. After confirming the radius of influence, additional points were selected to form a two-row PRB.

Results

By tailoring a multi-year strategy, SCG enabled the client to proceed with a cost-effective, adaptive solution. The phased approach provides flexibility for ongoing monitoring and refinement, ensuring long-term success in reducing BTEX concentrations and preventing further off-site migration.

Conclusion

This project exemplifies SCG Remediation Services’ innovative approach to environmental remediation, employing cutting-edge in-situ technologies like Intrasorp® CAC to address complex contamination challenges. Through a carefully planned, phased program, SCG delivered a sustainable, budget-conscious solution that safeguards surrounding areas and supports future site management.