GA004 – Pneumatic Fracturing
Active Manufacturing Plant (Tank Farm) – Albany, Georgia
Pneumatic Fracturing (PF) was applied at a solvent recovery processing area and tank farm previously used to store spent and recovered ethyl acetate and methylene chloride. The site geology consisted of clayey sands and sandy clays from approximately 40-70 ft. in thickness. All processing equipment in the area is located in a diked Celicote-lined concrete pad with a floor drain connected to the plant’s chemical sewer. The tank farm initially contained thirteen underground stainless steel tanks used to store the solvents. The tanks were removed and appeared to be free of corrosion or holes. However, RFI studies discovered high levels of VOCs, primarily methlyene chloride in the soils of the tank farm. The higher concentrations were predominant at approximately 28-45 ft. below ground surface. Releases from flanges and pump seals, and operational overflows were suspected to be the primary sources of the contamination.
A 2-phase extraction pilot test was performed at the site to evaluate the effectiveness of the technology for VOC mass removal. Pneumatic Fracturing was initiated to enhance the existing 2-phase extraction pilot test. Two wells, in addition to one existing extraction well, were required to be installed. Two extraction wells, seven passive air inlet wells, and two air dissipation or relief wells were installed by the client.
A comparison of pre and post-fracture groundwater drawdown data from the 2-phase extraction testing shows that fracturing was effective at both increasing the rate of groundwater recovery and increasing the radial extent of vacuum influence around the extraction wells.