WORK PLANS FILE 2 - Laserfiche WebLink

Home Browse Search

Geologfeal recklucs/Ac. Page 9 ' IRAP—Pilot Test Project No. 425.2 March 21,2005 ' 4.8 Soil Sampling ' Discrete soil samples will be collected in 6.0-inch brass liners using a 2.0-inch modified California split spoon sampler. All soil samples will be sealed with Teflon, capped with plastic end caps, labeled and placed in a cooler at 4° Celsius for transport to the laboratory ' following Chain of Custody protocol. Chemical Testing ' The soil samples will be analyzed for chemical appropriate constituents. 4.9 Sparge Point tThere are several commercially available sparge points to consider for use at the site. The apparatus selected will be chosen after consultation with the ozone equipment subcontractors. ' 4.10 Ozone Sparging Equipment ' The ozone sparging equipment will consist of an ozone generator, air compressor, manifold piping, pressure gauges and distribution valves. Three bids must be solicited for the project in order to stay in compliance with USTCFP requirements. The required injection pressures and flow rates utilized in the sparging system must be sufficient to overcome the head pressure of the overlying water column and the capillary ' pressure of the subsurface soil. The flow rates must be as high as possible to deliver ozone to the maximum possible area of the plume. The injection pressures will be lower than the pressures which may cause the lateral spreading of contamination plume. - k, Initially, air will be injected into the subsurface to open up the soil pore space. The pressurized air will be delivered through diffusers that will introduce fine bubbles into the ' soil. The bubbles will form micro-channels or preferential pathways through which the air will flow. While in the channels the air will allow the gasoline to undergo a phase transfer from dissolved to vapor phase. After the initial air injection, the ozone will then be ' introduced into the soil at a concentration of approximately 5% ozone & 95% oxygen. The system will operate in pulse mode to allow the micro-channels to repeatedly fill and empty which will cause a reaction chamber type response. The ozone will oxidize the MTBE as ' well as other constituents and unconsumed oxygen will serve to augment the bio-remediation capacity of the aquifer. ' The EPA has stated that 1 PSI of injection pressure is necessary for every 2.3 feet of hydraulic head. (USEPA: How to Evaluate Alternative Cleanup Technologies for ' Underground Storage Tank Sites, May, 1995). Water Table is at about 12 feet bgs. This would require an injection pressure of 4.4 PSI(10 feet divided by 2.3). 1