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-w \ <br /> Conestoga-Rovers & Associates <br /> i <br /> STANDARD FIELD PROCEDURES FOR ABANDONING MONITORING WELLS <br /> I <br /> I <br /> This document presents standard field methods for abandoning ground water monitoring wells. The <br /> objective of well abandonment is to destroy wells in a manner that is protective of potential water <br /> resources. The two procedures most commonly used are pressure grouting and drilling out the well. <br /> These procedures are designed to comply with Federal, State and local regulatory guidelines. Specific <br /> field procedures are summarized below. <br /> i <br /> Pressure Grouting j <br /> Pressure grouting consists of injecting neat Portland cement through a tremie pipe under pressure to the <br /> bottom of the well. The cement is composed of about five gallons of water to a 94 Ib. sack of Portland I/I1 <br /> Cement. Once the well casing is full of grout,it remains pressurized by applying.pressure with a grout <br /> pump. The well casing can also be pressurized by extending the well casing to the appropriate height and <br /> filling it with grout. In either case, the additional pressure allows the grout to be forced into the sand <br /> pack. After grouting the sand pack and casing, the well vault is removed and the area resurfaced or <br /> backfilled as required. <br /> Well Drill Out <br /> When well drill out is required, a hollow-stem auger drilling rig is used to drill out the well casing and <br /> pack materials. First, drill rods are dropped down the well and used to guide the augers as they drill out <br /> the well. Once the well is drilled out, the boring is filled with Portland cement injected through the <br /> augers or a tremie pipe under pressure to the bottom of the boring. The well vault is removed and the area <br /> resurfaced or backfilled as requi—rW <br /> Page I of I <br /> r <br />