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[,a <br /> 4.2.6 DETECTION LIMITS <br /> The detection limits for the various method analyses are presented in Appendix C. <br /> 4.3 FIELD PROCEDURES <br /> — 43.1 SOIL BORINGS AND MONITORING WELL INSTALLATION <br /> Soil borings will be drilled and sampled using 8-inch-outside diameter (OD), 3-inch- <br /> inside diameter (ID) hollow-stem augers. Soil borings will be sampled at five-foot in- <br /> tervals during boring advancement.to produce lithologic logs. Drill cuttings will be <br /> disposed as described in Section 3. Samples will be collected using a 2-inch ID split- <br /> spoon sampler lined with brass sleeves. Each sleeve will be capped with Teflon tape <br /> and a polyethylene cap, taped to the sleeve, and placed immediately on ice. Sample <br /> identification numbers will be marked on the outside of the sleeve using indelible <br /> markers. <br /> The well will be installed through 12-inch OD, 8-inch ID hollow-stem augers. If un- <br /> favorable conditions(sand locking, heaving sand,etc.) prevent or impede completion of <br /> the well using hollow-stem augers, air- or mud-rotary drilling may be used to prepare a <br /> borehole for well installation. <br /> The well casing and screen will be a 4-inch ID flush-threaded, Schedule 40, PVC. 'lie <br /> screen section will be factory slotted with O.U2-inch slots: The annulus around the '. <br /> screen will be filled with No. 3 sand (Lonestar or equivalent). The monitoring well will <br /> be screened across the water table with a maximum screened interval of 20 feet. The <br /> exact interval to be screened will be determined in the field, based on the first appear- <br /> ance of water in the boring and the first water-bearing permeable zone encountered. <br /> o <br /> The well installation procedures are as follows: <br /> • The proposed boring locations will be marked with stakes and cleared for <br /> s <br /> utilities. <br /> — The drill rig, drilling equipment, and brass sleeves will be decontaminated <br /> by steam cleaning or by detergenthvater/isopropanol/de-ionized water <br /> washings before and after drilling. <br /> • The drill cuttings and split spoon samples will be logged:by a CH21Vl <br /> HILL hydrogeologist or geologist._ <br /> SF031W4kA P14W.51 4-4 <br />