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WASTE DISCHARGE REQUIREMENTS ORDER NO.R5-2004-0160 CONTIGROUP COMPANIES,INCORPORATED 3 FRENCH CAMP GRAIN ELEVATOR ENHANCED REMEDIATION PILOT STUDY SAN JOAQUIN COUNTY 9. Hydraulic fracturing is a process whereby a fluid is pumped into a boring at a rate and pressure high enough to overcome the in-situ confining stress and the material strength of a formation(i.e. soil or rock) resulting in the formation of a fracture. The slurry mixture is pumped under pressure into the subsurface soils to create a fracture. During pumping, downhole pressures and flow rates are monitored against time via logging computers. After'pumping, the GZVI holds the fracture open while the enzyme breaks down the viscous fluid. The fluid subsequently drainsout of the fractures, leaving multiple, overlying fractures radiating from the borehole. 10. The Discharger will use the FRAC RITETm process,which was developed in 1995 specifically for geo-environmental applications in unconsolidated, low permeability sediments for the hydraulic fracturing. Fracturing is conducted using proprietary down hole fracturing equipment designed for various soil types at shallow depths and low operating pressures. The pollutants are treated as a result of moving into the fractures. _ 11. Afler injections are completed, the Discharger will abandon the borings bygrouting. The expected lateral extent of the GZVI is about 33 feet following the fractures created,which the Discharger will verify by fracture mapping on each boring. The mapping will be done by using tiltmeters, which are instruments that measure the minute ground surface deformations created during the fracturing process and can determine direction and magnitude of the ground surface deformation. The Discharger will set out about 12 to 20 titlmeters in a grid or concentric configuration to measure the ground surface deformations. After the first boring is completed, the remaining two boring locations may be adjusted based on the results of the fracture mapping from the first boring. 12. Within two days of completing the three borings with GZVI injections,the Discharger will install two groundwater monitoring wells screened from 60 to 80 feet bgs in the B water bearing zone (MW-9B and MW-IOB). MW-9B and MW-1OB are being installed after the GZVI injections to prevent possible damage from the fracturing activities and so that the lateral extent of GZVI can be determined, allowing the wells to be installed in the appropriate locations. MW-9B will be installed at the downgradient edge of the furthest reach of the GZVI from the second boring but also outside the upgradient lateral extent of GZVI from the third boring. MW-1OB will be installed at the downgradient edge of the furthest extent of the GZVI from the third boring. Based on this proposed spacing of the monitoring wells,the Discharger anticipates seeing effects of the GZVI injections in MW-9B and MW-1 OB within the first month after the injections. 13. The Discharger will monitor MW-3B,MW-9B, and MW-1 OB to evaluate the effectiveness of the GZVI injections. The Discharger will monitor MW-4B to determine whether increases in pollutants,byproducts, and breakdown products occur downgradient of the treatment area. The treatment area is the area of the GZVI injected into the three borings and 10 feet downgradient of the furthest reach of the GZVI, since the average groundwater flow at the Site is about 10 feet per year. 14. The Discharger has conducted two sampling events for baseline parameters and will collect additional baseline groundwater samples from MW-3B and MW-4B a minimum of four weeks