Remediation by 2-PHASE^TM Extraction--A 2-Year Success Story

Chris Koerner, James Siegfried, James Baxter, and Scott Huber

Radian has used the Xerox 2-PHASE^TM Extraction technology at several facilities worldwide to remove VOCs and petroleum hydrocarbons from subsurface soils and groundwater. The use of high vacuum with 2-PHASE^TM causes greater forces to be applied to the subsurface than do other dual-phase methods. 2-PHASE^TM improves dewatering, increases vacuum and groundwater radii of influence, deepens vadose zone development, enhances vapor stripping of soil contamination, improves vapor flow, and expedites remediation timeframes.

This paper describes the successful 2-year application of 2-PHASE^TM to remediate soil and several groundwater contamination. Contamination occurred under a floor slab near a former solvent spray booth and several underground storage tanks. Contaminants were primarily chlorinated VOCs and mineral spirits ranging to 330 mg/kg in soil and 1,070 mg/L in groundwater. The 2-PHASE^TM system was installed in October 1993; business constraints necessitated the completion of remediation within two years. The system was modified and expanded to optimize the removal effectiveness and extend the area of influence. Subsurface soil data obtained 8 and 11 months into the remediation program were used with soil gas data to predict future soil concentrations. VOC concentrations in he soil and groundwater were reduced by over 95 percent, and remediation goals were met within 18 months following start of in situ 2-PHASE^TM remediation. The system has been decommissioned following agency and landowner approval.

AAPG Search and Discover Article #91019©1996 AAPG Convention and Exhibition 19-22 May 1996, San Diego, California