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SOP: Monitoring <br />Well Installation <br />Direct-Push Method <br />The direct-push drilling method may also be used to complete soil borings and monitoring wells. Examples of <br />this technique include the Diedrich ESP vibratory probe system or AMS Power Probe® dual-tube system. <br />Environmental probe systems typically use a hydraulically operated percussion hammer. Depending on the <br />equipment used, the hammer delivers 140- to 350-foot pounds of energy with each blow. The hammer provides <br />the force needed to penetrate very stiff/medium dense soil formations. The hammer simultaneously advances an <br />outer steel casing that contains adual-tube liner for sampling soil. The outside diameter (OD) of the outer casing <br />ranges from 1.75 to 2.4 inches and the OD of the inner sampling tube ranges from 1.1 to 1.8 inches. The outer <br />casing isolates shallow layers and permits the unit to continue to probe at depth. The double-rod system provides <br />a borehole that may be tremie-grouted from the bottom up. Alternatively, the inside diameter (ID) of the steel <br />casing provides cleazance for the installation of small-diameter (e.g., 0.75- to 1-inch ID) micro-wells. The <br />procedures for installing monitoring wells in soil using the direct-push method aze described below. <br />1. Locate boring/well location, establish work wne, and set up sample equipment cleaning azea. <br />2. Advance soil boring to designated depth, collecting samples at intervals specified in the Work Plan. Samples <br />will be collected using dedicated, disposable, plastic liners. Describe samples in accordance with the <br />procedures ouflined in Step 2 above. Collect samples for laboratory analysis as specified in the Work Plan <br />and/or FSP. <br />3. Upon advancing the borehole to the desired depth, install the micro-well through the inner drill casing. The <br />micro-well will consist of approximately 1-inch ID PVC slotted screen and blank riser. The sand pack, <br />bentonite seal, and cement/bentonite grout will be installed as described, where applicable, in Step 4 above. <br />4. Install protective steel casing or flush-mount, as appropriate, as described in Step 5 above. During well <br />installation, record construction details and tabulate materials used. <br />5. After completing the well installation, lock [he well, clean the area, and dispose of materials in accordance <br />with the procedures outlined in Section VII below. <br />Driven Well Point Installation <br />Well points will be installed by pushing or driving using a drilling rig or direct-push rig, or hand-driven where <br />possible. The well point construction materials will consist of a 1- to 2-inch-diameter threaded steel casing with <br />either 0.010- or 0.020-inch slotted stainless steel screen. The screen length will vary depending on [he <br />hydrogeologic conditions of the site. The casings will be joined together with threaded couplings and the <br />terminal end will consist of a steel well point. Because they are driven or pushed to the desired depth, well <br />points do not have annular backfill materials such as sand pack or grout. <br />VII. Waste Management <br />Investigation-derived wastes, including soil cuttings and excess drilling fluids (if used), decontamination liquids, <br />and disposable materials (well material packages, PPE, etc.), will be managed as specified in the Work Plan or <br />FSP. <br />tt~sros <br />SOP04A/onito, WeN Installation-Mine.tlOc <br />