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Kellogg Garden Products ECOLOGIC Engineering Groundwater Monitoring Well Installation Work Plan KELG04-001 11/10/2004 304 E Weber Ave.3rd Floor Stockton,CA 95202 (209)468-3420 Fax: (209)464-0138 The monitoring wells will be drilled with a truck mounted sonic drill rig. The nominal diameter of the boring will be eight inches. Boreholes will be probed on five-foot intervals for the presence of standing water. A continuous core of the boreholes will be collected and logged pursuant to the Unified Soil Classification. WELL DEVELOPMENT The drilling contractor will develop the wells using a combination of methods. Where practicable and where formation stability permits, well development by gently swabbing the well with a surge block will be initiated before the installation of the sanitary seal or cement grout to ensure settling of the filter pack prior to sealing the annulus. Once the seal has been installed and sets up (no less than 12 hours), further development by vigorously swabbing the well with a surge block and manual bailing will ensue and continue until the concentration of suspended solids in the water bailed from the well is sufficiently low to permit pumping with a portable submersible pump. Accumulated fill shall be removed from the bottom of the well screen. Development will continue until the turbidity of the discharge measured in the field is 5 n.t.u.,or less. Water discharged from the wells during development will be disposed of to the Contact Water Pond. No water discharged during development will be allowed to enter a surface water drainage course. Equipment shall be cleaned according to field sampling method cleaning prior to introduction to the well and shall be cleaned between wells. WELL/PIEZOMETER MODIFICATIONS The existing monitoring well/piezometers numbers MW-2 (P-2) and MW-4 will be converted to an above ground completion according to the details presented in Figure 5. WELL DISINFECTION After well development and prior to sampling(with sufficient time for completion of the following procedure), the wells shall be disinfected according to AWWA C654-03. Calculated volume of water in the filter pack shall be included in determining the chlorine concentration for disinfection according to AWWA C654-03 assuming porosity of 0.20. Chlorine solution shall be placed in the well using a tremie pipe starting at the bottom and working upward. Under no circumstances shall granular chlorine be used without fust dissolving in potable water. Commence by installing the tremie pipe at the bottom and insert enough chlorine solution via the tremie pipe to displace 5-10 ft of the water in the well and filter pack. Raise the tremie an appropriate distance(5-10 ft),then repeat until all of the well water has been displaced. Surge the well with a swab to mix the solution and force it out into the filter pack and the formation/borehole interface. Surge block or swab can be constructed of lengths of all thread,washers and neoprene gasket material. Allow the solution contact time according to AWWA C654-03. After contact time, pump from the well a minimum of three well volumes and until a minimum of 15 minutes with zero chlorine residual(including filter pack water volume in well volume calculation). Place pump immediately below water surface such that suction is not broken. "Chase" the pumping level to keep suction if water level falls below pump. Sample well for total coliform (10 tube method)and Trihalomethanes. Install cleaned and disinfected compression cap after pumping and sampling. All equipment used in well disinfection shall be clean. Equipment shall be cleaned according to field sampling method cleaning prior to introduction to the well and shall be cleaned between wells. 6