1. Young-Rainey STAR Centre
Ross Towler & Robert Leather

2. Introduction Site Description Contaminants
Alternative Remediation Techniques
Remediation Adopted
Conclusion

3. Site Description Location History Environmental Restoration
Pinellas County, Largo, Florida
History
Formerly US DoE nuclear weapons research and development centre
End of the Cold War; stewardship and maintenance of the nation’s nuclear weapons
1999; Young-Rainey Science Technology and Research (STAR) Centre
houses more than 20 businesses that range from administrative to light manufacturing
Environmental Restoration
Full cleanup of soil and groundwater contamination

4. Contaminants Non-aqueous phase liquid (NAPL)
Trichloroethene (TCE) 360 mg/l
Dichloroethene (DCE) 450 mg/l
Volatile organic compounds (VOCs)
Vinyl chloride
Methylene chloride
Toluene
Petroleum Hydrocarbons
Area 10,000 sq ft, 35 ft
Volume of 13,000 cubic yards

5. Alternative Remediation Techniques
In-situ Remediation
Techniques
Soil treatment without excavation and transportation
Cost savings
Longer time periods
Non-uniformity of treatment
Less certain results
Ex-situ Remediation
Techniques
Contaminant treatment after excavation of soil
Shorter time period
Uniformity of treatment
Greater costs
Engineering Problems associated with excavation

6. Biological Remediation Processes
What is it?
Stimulation of micro organisms
Contaminant used as food source & broken down
Contaminant destroyed or transformed
Organic contaminants only
Low cost
Why not for YRSC?
Contaminant concentration too high (Initially)
However… reduced current levels make Bioremediation a viable option.

7. Physical/Chemical Treatment
Physical/Chemical treatment uses the physical properties of the contaminants or the contaminated medium to destroy (i.e., chemically convert), separate, or contain the contamination.
Examples…
Chemical Oxidation
Electrokinetic Remediation
Soil Flushing
Solidification/Stabilisation
Soil Vapour Extraction

8. Containment & Offsite Disposal
Migration of contaminant in soils/ground water prevented or significantly reduced
Used in absence of realistic treatment option
Does not lessen toxicity, mobility or volume of contaminant
Offsite Disposal
Contaminated material removed & transported to permitted off-site treatment and/or disposal facilities.
Pretreatment usually is required
Costly
Disposal facilities uncommon
Engineering problems associated with excavation

9. In Situ Thermal Treatment Techniques
Steam/hot air injection, electrical resistance or other means used to increase the volatilisation rate of semi-volatiles and facilitate extraction
Quick cleanup times, but generally costly
Thermally enhanced SVE uses temperature to increase the volatility of the contaminants in the soils
Similar to standard SVE , but requires heat resistant extraction wells.

10. Remediation Adopted Soil Media
In-situ thermal enhanced soil vapour extraction technique
Steam Enhanced Extraction and Electro-Thermal Dynamic Stripping Process (ET-DSP™)
Steam injection wells
Extraction wells
ET-DSP™ electrodes

11. Remediation Adopted (2)
Preheat the perimeter of the remediation area
Steam injection was used to form a steam barrier around the perimeter
Evacuation of vapourised effluents from the system
Treatment included heat exchange, separations, and carbon adsorption
Why this technique?
Low permeability sediments
Presence of TCE, NAPL etc.

12. Conclusion Goals Results Costs Soil cleanup; TCE – 20.4 mg/kg
Groundwater cleanup; DCE – 50 mg/L
Results
After 4.5 months of operation all soil and groundwater cleanup goals had been met
Costs
total project subcontract cost was approximately $3,800,000