The annular space between the wellbore and casing of all public water supply wells and all other wells except those wells described in §§ 74:02:04:31, 74:02:04:35, 74:02:04:36, and 74:02:04:46, shall be pressure-grouted as follows:

1. (1) All wells completed into confined aquifers shall be pressure-grouted with bentonite grout or cement grout from the top of the producing aquifer to the ground surface or to the base of the pitless unit;
2. (2) All wells completed into unconfined aquifers shall be pressure-grouted with bentonite grout or cement grout from a depth no more than 4 feet above the top of the aquifer or to a depth of 20 feet below grade, whichever is nearest to ground surface, up to the ground surface or to the base of the pitless unit. Monitoring wells in which the well screen extends above the top of the unconfined aquifer shall be grouted from a depth beginning no more than 4 feet above the top of the well screen or to a depth of 20 feet below grade, whichever is nearest to the ground surface, up to the ground surface or to the base of the pitless unit;

3. (3) Any permanent casing installed for the purpose of stabilizing the upper wellbore so the drilling of the well can proceed to the intended total depth or any surface casing as required by §§ 74:02:04:35 and 74:02:04:36 must be pressure grouted with cement grout from the bottom to the top.

   See Appendix D at the end of this chapter.

   Notes: Bentonite manufactured for use as a drilling fluid does not meet the requirements for bentonite grout. The driller should be aware of the limitations inherent in bentonite grout. The low density of bentonite grout may make it inappropriate for use as a grout when higher hydrostatic pressure is required.

   Section 74:53:05:02 requires submission of plans and specifications for review and approval prior to construction of wells to supply community water systems defined by subdivision 74:04:05:01(3).

Source: 12 SDR 50, effective September 29, 1985; 13 SDR 129, 13 SDR 141, effective July 1, 1987; 18 SDR 224, effective July 16, 2992; 31 SDR 62, effective November 8, 2004.

General Authority: SDCL 46-2-5 , 46-6-20 , 46-6-27.

Law Implemented: SDCL 46-6-6.1 , 46-6-10 , 46-6-20 , 46-6-27.