Active Gas Station—Eastern Michigan

ORIN successfully implemented Free Product Removal (FPR) in-situ chemical oxidation using catalyzed sodium persulfate to treat LNAPL, contaminated soil, and groundwater. Treatment chemistry was injected while the Geoprobe rods were raised throughout the target interval. A vac truck was present to remove LNAPL
and desorbed contaminants while providing hydraulic control.

Approximately 2,400 gallons of 20% sodium persulfate catalyzed with PermeOx Plus was injected into 47 DPT injection locations. A second polish injection was needed to achieve site cleanup goals. In June of 2011, 24 DPT points were injected with approximately 1,200 gallons of 20% catalyzed sodium persulfate treatment.

The Challenge

The site presented complex operational requirements:

• Active gas station operations
• LNAPL contamination
• BTEX contamination
• Need for minimal business disruption
• Multiple contamination phases
• Need for sustained treatment

The Solution: Two-Phase Treatment Strategy

The team implemented a comprehensive approach:

1. Initial Treatment Phase:
   • 47 DPT injection locations
   • 2,400 gallons of treatment solution
   • 20% sodium persulfate
   • PermeOx Plus catalyst
   • Integrated vacuum extraction
2. Polish Treatment Phase:
   • 24 additional DPT points
   • 1,200 gallons of solution
   • Targeted problem areas
   • Enhanced treatment effectiveness

Implementation Strategy

Key operational elements included:

• Dynamic injection during rod withdrawal
• Continuous vacuum truck operation
• Active hydraulic control
• LNAPL removal
• Desorbed contaminant capture
• Minimal site disruption

Impressive Results

The treatment achieved multiple objectives:

• Complete LNAPL elimination
• 78% BTEX reduction in most contaminated well
• No measurable LNAPL in subsequent monitoring
• Continued oxygen release for bioremediation
• Maintained business operations

Key Success Factors

Several elements contributed to project success:

1. Strategic phased approach
2. Comprehensive injection coverage
3. Active contamination removal
4. Sustained treatment effects
5. Operational flexibility

Innovation Highlights

The project demonstrated several advantages:

• Effective during active operations
• Multiple contaminant phase treatment
• Long-term treatment benefits
• Minimal business impact
• Sustainable remediation

Practical Applications

This approach provides solutions for:

• Active gas station remediation
• Complex contamination scenarios
• Business-sensitive projects
• LNAPL/BTEX treatment
• Phased treatment programs

This case study shows how innovative treatment approaches can achieve environmental goals while protecting business operations.