ARCHIVED REPORTS PR0544112 - Laserfiche WebLink

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screened interval below the water table. Caution will be exercised not to drill through any aquitard below the'water table. If groundwater is not encountered before a depth of 40 feet below ground surface, or hard rock is encountered before 40 feet, then the boring will be completely filled from bottom to top with a grout mixture of 95% cement/5% bentonite, applied by tremie pipe under pressure: During soil-boring operations, soil samples will be collected at least every 5 feet with a split-spoon sampler. This will involve 3 1/2 feet of boring followed by 1 1/2 feet of sampler drive. In addition, soil samples will be collected at any significantly discernable change in lithology, and just above the water table, if possible. Samples below the water table will not be collected. During soil-boring operations, geological descriptions of the soil will be made by an on-site geologist, and an appropriate soil-boring log will be constructed and submitted ' with the final report. Soil samples will be collected in brass tubes by the split-spoon sampler. The ends of each tube will be covered with Teflon tape and then capped with plastic caps. The caps w • will be sealed with electrical tape. (�glneae t] The most contaminated soil sample and/or the deepest sample above the water table from each boring will be submitted for laboratory analysis. The most contaminated sample will be determined by field OVA. For each sampling point, soil will be preserved in glass jars filled approximately 1/2 full, and the jar mouth covered with aluminum foil and then capped. The jars will be allowed to sit for a minimum-of 20 minutes before insertion of an OVAp robe through the aluminum foil into the headspace of the soil sample. The sample depth with the highest OVA readings.'will be chosen as the depth for -�; sample analysis using the corresponding brass-tube sample. If all OVA readings in a well are zero, then the sample nearest to and above the water table will be analyzed. All soil samples submitted to the laboratory will be analyzed for BTX&E per EPA Method'8020, and for TPH per DHS/LUFT Method. Analytical results will be submitted in the final written report. Hollow-stem augers used in boring operations will be.decontaminated by steam- cleaning methods between each boring. Also, the split-spoon sampler will be decontaminated between each sampling point. I 3.4 Well Construction If groundwater is encountered, the soil boring(s) will be. converted to a monitoring well. Wells will be constructed (see Figure 4) using 4-inch diameter PVC casing designed with screw-type,flush joints. No solvent,cement, glue, screws, nor mechanical adaptors will be used at the casing joints. Each monitoring well will have a single screened interval of 15 feet, with 5 feet of screen above and 10 feet of screen below the water table. The screen slot size will be either 0.010-in. or 0.020-in depending on the size distribution of matrix materials. A PVC cap will be affixed to the bottom of the screened interval. -8- 172-32.R] 318191