The proximity of Lake Superior is the primary environmental driver for a historical, industrial site contaminated with heavy coal tars. Given the limited mobility of coal tar in the subsurface, the existing pump and treat system has extracted diminishing amounts of NAPL overtime. Data indicated recalcitrant presence of NAPL in the subsurface. ORIN conducted in-situ treatment using a sonic method of drilling into a tight lithology of well graded sands, silts, and gravels.
Chemical oxidation targeted the heavy hydrocarbons to catalyze soil desorption, breakdown, and mobility. A second approach of BAM and calcium peroxide was injected near the perimeter of the ISCO area to target dissolve phase PAH impacts. A vac truck was onsite to assist in simultaneous extraction and influence of the injection interval.
The Challenge
The site presented multiple complex challenges:
- Proximity to Lake Superior
- Recalcitrant coal tar contamination
- Diminishing pump-and-treat returns
- Complex geology:
- Well-graded sands
- Silts and gravels
- Tight lithology
- Environmental sensitivity
The Solution: Multi-Technology Approach
The team implemented a sophisticated treatment strategy:
- Primary Treatment Zone:
- Sonic drilling methodology
- Chemical oxidation treatment
- Targeted heavy hydrocarbons
- Enhanced mobility promotion
- Desorption acceleration
- Perimeter Treatment:
- BAM technology deployment
- Calcium peroxide addition
- Dissolved phase PAH targeting
- Buffer zone creation
- Active Management:
- Vacuum truck extraction
- Simultaneous injection/extraction
- Treatment interval control
- Continuous monitoring
Innovation Highlights
Several breakthrough approaches:
- Sonic drilling in challenging geology
- Combined treatment technologies
- Strategic perimeter control
- Enhanced extraction methods
- Adaptive treatment protocols
Success Indicators
The project achieved key objectives:
- Significant surge in free product removal
- Improved contaminant extractability
- Successful treatment in tight geology
- Client requested additional treatments
- Enhanced system performance
Key Success Factors
Critical elements included:
- Advanced drilling technology
- Strategic treatment combination
- Active extraction integration
- Comprehensive site understanding
- Environmental protection measures
Technical Advantages
The approach demonstrated:
- Superior geological penetration
- Enhanced reagent distribution
- Improved contaminant mobility
- Effective treatment in tight soils
- Environmental safety maintenance
Practical Applications
This success provides solutions for:
- Historical contamination sites
- Environmentally sensitive areas
- Complex geological conditions
- Recalcitrant contamination
- Pump-and-treat optimization
This case study demonstrates how innovative technology combinations can overcome traditional treatment limitations while protecting sensitive environmental receptors.
