At a manufacturing facility HRC was injected into a crystalline bedrock aquifer contaminated with TCE and its daughter products. Groundwater flow at this site is controlled by fractures in the crystalline rock with little or no permeability present beyond these fractures. The industrial facility had been in operation for over 30 years. Contamination levels reached 220 ppb of TCE so an HRC pilot test, along with excavation, took place.
Injection of HRC was accomplished using single and double packer arrays and an appropriate delivery pump. The packer application method allowed HRC to be focused on the fractures controlling groundwater flow. A single packer system was used to apply HRC to the lower fracture (32 ft. bgs.) and a double (straddle) packer system was used to apply HRC to the upper fracture zone (22-28 ft bgs). HRC was injected at volumes that ranged from 120-160 pounds per injection well.