W. Va. Code R. § 47-60-15

Current through Register Vol. XLI, No. 50, December 13, 2024
Section 47-60-15 - Borehole Diameter
15.1. Boreholes in unconsolidated geologic formations. -- For all permanent monitoring wells in unconsolidated geologic formations, the borehole diameter shall meet the following requirements:
15.1.a. If hollow stem augers are used, their inside working diameter shall be at least two (2) inches greater than the inside diameter of the permanent well casing.
15.1.b. If solid stem augers are used, their outside diameter shall be at least four (4) inches greater than the inside diameter of the permanent well casing.
15.1.c. If an air or mud rotary method is used, the borehole diameter shall be at least four (4) inches greater than the inside diameter of the permanent well casing. If a temporary outer casing is used, the inside diameter of the temporary outer well casing shall be at least four (4) inches greater than the inside diameter of the permanent well casing. The temporary outer casing shall be pulled immediately before or as the annular space is sealed, depending on site specific geology.

Note: The dual-tube or triple-tube reverse rotary systems are rotary methods.

15.1.d. If percussion methods, including the rotary wash, wash down, and wash bore methods are used with a temporary outer casing in unconsolidated geologic formations, the inside diameter of the temporary outer casing shall be at least four (4) inches greater than the inside diameter of the permanent well casing. The temporary outer casing shall be removed during the sealing of the annular space.
15.2. Boreholes in bedrock geologic formations. -- For all permanent monitoring wells installed deeper than two (2) feet past the top of the bedrock, the borehole diameter shall meet the following requirements:
15.2.a. If an air or mud rotary method is used to construct the monitoring well, the requirements of subdivision 15.1.c of this rule shall be followed.
15.2.b. If percussion methods are used to construct the monitoring well, the requirements of subdivision 15.1.d of this rule shall be followed.

W. Va. Code R. § 47-60-15