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Drilling and Constructing Monitoring Wells with Hollow‐Stem Augers Part 1: Drilling Considerations
Author(s) -
Hackett Glen
Publication year - 1987
Publication title -
groundwater monitoring and remediation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.677
H-Index - 47
eISSN - 1745-6592
pISSN - 1069-3629
DOI - 10.1111/j.1745-6592.1987.tb00963.x
Subject(s) - casing , drilling , borehole , petroleum engineering , measurement while drilling , drilling fluid , drill , water well , auger , geology , hydrogeology , drill cuttings , groundwater , mining engineering , geotechnical engineering , engineering , mechanical engineering
Hollow‐stem augers are a widely used drilling method for constructing monitoring wells in unconsolidated materials. The drilling procedures used when constructing monitoring wells with hollow‐stem augers, however, are neither standardized nor thoroughly documented in the published literature. Variations in drilling procedures and techniques may occur as a result of the: (1) type of auger drill equipment and formation samplers used; (2) hydrogeologic conditions at the site, especially where heaving sands occur; and (3) known or suspected presence of contaminated zones, where there is a potential for the vertical movement of contaminants within the borehole. In a saturated zone in which heaving sands occur, changes in equipment and drilling techniques are required to provide a positive pressure head of water within the auger column. This may require the addition of clean water or other drilling fluid inside the augers. When monitoring the quality of ground water below a known contaminated zone, hollow‐stem auger drilling may not be advisable unless protective surface casing can be installed. Depending on the site hydrogeology, conventional hollow‐stem auger drilling techniques alone may not be adequate for the installation of the protective surface casing. A hybrid drilling method may be needed that combines conventional hollow‐stem auger drilling with a casing driving technique that advances the borehole and surface casing simultaneously.