SITE INFORMATION AND CORRESPONDENCE

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• Explain in the text what size drill bit will be used to drill through the 12-inch casing. 24 . Again, the use of compressed air, potable water or drilling fluids is mentioned in the drilling procedures for all wells. • Explain if an in-line filter be used for the compressed air. • State if there will be analyses of the potable water and drilling fluids for the constituents of concern. • State what type of "drilling fluid" is to be used. • State how the drilling fluids and water will be contained. 25. In Section 4 . 1. 6, it is stated that water or drilling fluids used in drilling and any water displaced during grouting of the wells will be collected in bins. • Explain how will this be accomplished. • State whether the water and drilling fluids will be contained in a lined pit and pumped into the bins. 26. In Section 4 . 1. 7, it is stated that "once total depth of each well is achieved, the drill stem will be withdrawn from the hole to allow performance of geophysical logging. " In Section 3 . 3 , it was stated that video logging of the boreholes would be performed after the retrieval of groundwater samples. • Explain in the text the actual planned sequence of sampling and logging. • State if the wells will be purged after geophysical logging if the logging is to precede sampling. (If not, then the drilling fluid and potable water added to the well, could have an impact on the quality and reliability of the data obtained from sampling. ) Page 4-3 . Section 4 . 2 27 . According to Section 4 . 2 . 1 samples of cuttings will be analyzed for purgeable halocarbons and purgeable aromatics, while the other samples, groundwater and waste drill cuttings and waste water will be analyzed for a wider range of constituents. • Explain in the text why all samples are not to be 8 of 12