ARCHIVED REPORTS XR0000575 - Laserfiche WebLink

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� r extend from the sand pack to the ground surface. The boring logs will show well construction details. The wells will be developed and sampled after completion. The development procedure for each well will consist of pumping or bailing 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. After development, water levels are allowed to partially recover. Groundwater samples are then collected using a disposable teflon bailer, placed into appropriate EPA-approved containers, labeled, placed on ice, and transported to the laboratory accompanied by chain-of-custody documentation. A California State Licensed Surveyor will survey the newly installed wells. The well casings will be surveyed to the nearest 0.01 feet in elevation to a known benchmark. Organic Vapor Procedures Soil samples collected at continuously during drilling will be analyzed in the field for ionizable organic compounds using a photo-ionization detector(PID) with a 10.2 eV lamp or a flame ionization detector(FID). The test procedure will involve measuring approximately 30 grams from an undisturbed soil sample, placing this subsample in a sealed container (either a zip-lock bag or a mason jar). The container will be warmed for . approximately 20 minutes (in the sun), then the head-space within will be tested for total organic vapor, measured in parts per million as benzene (ppm; volume/volume). The instrument will 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 and FID 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 will be analyzed for the presence of total petroleum hydrocarbons as gasoline (TPHg), benzene, toluene, ethyl benzene, xylenes (BTEX), and methyl tertiary butyl ether(MtBE) using EPA Method 8260. Collected groundwater samples will be analyzed for the presence of TPHg, BTEX compounds, and fuel oxygenates and lead scavengers including MtBE, tertiary butyl alcohol (TBA), di-isopropyl ether(DIPE), ethyl tertiary butyl ether(ELBE), tertiary amyl methyl ether(TAME), 1,2-dichloroethan, ethylene dibromide(EDB), ethanol and methanol using EPA method 8260.