8e27de02_lls_in_Unconsolidated_Aquifers__1
[0] Sonic [2] Place CMT tubing into casing with anchor plate attached to bottom of tubing. Use tubing centralizers to center tubing inside of sonic casing. Add alternating lifts of sand and bentonite pellets* as casing is withdrawn, either by gravity placement, tremie methods. [3] Depths up to 300 feet. Use casing with an inside diameter (ID) of at least 4 inches. Addition of water to casing may be needed to prevent heaving as casing removed. [1] 
Advancing casing during drilling minimizes redistribution of contaminants in borehole. Steel casing prevents borehole from collapsing as CMT well is being built. Vibrating casing during removal reduces likelihood of bridging annular materials.
Summary of Drilling Methods & Techniques for Installing CMT wells in Unconsolidated Aquifers
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