ARCHIVED REPORTS XR0000800 - Laserfiche WebLink

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C • Following sampling, boreholes will be tremae grouted to the surface using Oxygen Release Compound (ORCO) ORCO is used in this application to stimulate aerobic microbe activity by releasing oxygen into the surrounding soil Groundwater Monitoring Well Installation The borings will be converted to groundwater monitoring wells by installing 2-inch diameter, flush-threaded, Schedule 40 PVC casing with 0 020-inch factory-slotted screen Approxi- mately 20 feet of screen will be placed in the bottom of the boring An RMC 2/12 sand pack, or equivalent, will be placed in the annular space across the entire screened interval, and will extend approximately 2 feet above the top of the screen for the well A 2 to 3 foot bentomte transition seal will be placed atop the sand pack, and a Portland cement seal will extend from the bentonite transition seal to the ground surface The Portland cement seal will be emplaced by tremae pipe or through the center of the hollow-stem augers in one continuous operation from the bottom of the interval to be filled to the top Emplacement of the Portland cement grout specifically shall not be accomplished by "free fall' from the ground surface The boring logs will show well construction details The groundwater monitoring wells will be developed after completion The development procedure for each well will consist of pumping or balling water from the well until the water is visibly clear, the well goes dry, or until a maximum of ten casing volumes have been removed • Organic Vapor Procedures Soil samples collected at 5-foot depth intervals during drilling will be analyzed in the field for ionizable organic compounds using a flame-ionization detector (FID) or a photo- ionization detector (PID) with a 10 2 eV lamp The test procedure will involve measuring approximately 30 grams from an undisturbed soil sample, placing this subsample in a ziplock type bag or in a clean glass far, and sealing the far with aluminum foal secured under a ring- type threaded lad The container will be warmed for approximately 20 minutes (in the sun), then the head-space within the container will be tested for total organic vapor, measured in parts per million as benzene (ppm, volume/volume) The instrument wall be calibrated prior to drilling using a 100-ppm isobutylene standard (in air) and a sensitivity factor of 55 which relates the photo-ionization potential of benzene to that of isobutylene at 100 ppm The results of the field testing will be noted on the boring logs PID readings are useful for indicating relative levels of contamination, but cannot be used to evaluate hydrocarbon levels with the confidence of laboratory analyses Laboratory Procedures Selected soil samples collected from the soil borings and groundwater samples collected from the wells will be analyzed for the presence of total petroleum hydrocarbons calculated as • 9111-005 1S/WPLAN A - 2 June 10, 1998