S.D. Admin. R. 74:02:04:67
All abandoned or forfeited wells or test holes that are completed into confined aquifers or that encounter more than one aquifer must be plugged with bentonite grout if the weight of the bentonite grout column is sufficient to overcome the bottom hole pressure or must be plugged with cement grout placed from the bottom of the well or hole to within eight feet of the ground surface. Cement grout must be placed from eight feet below ground surface to within three feet of the ground surface. The top three feet may be filled with native material. If a pipe cannot be lowered inside the well casing to place grout from the bottom to the top, the well may be plugged by making a tight connection to the top of the casing and pumping a volume of cement grout, sufficient to fill the well, under pressure into the well. Bentonite grout may not be used if the well must be plugged by making a tight connection to the top of the casing and pumping the grout in under pressure. If it cannot be verified that a well's casing was grouted in accordance with this chapter, an effort must be made to plug the annulus from the bottom of the annulus up to the ground surface with the same type of material or materials required for plugging inside the casing.
S.D. Admin. R. 74:02:04:67
General Authority: SDCL 46-2-5, 46-6-6.1, 46-6-9, 46-6-20, 46-6-27.
Law Implemented: SDCL 46-2-9, 46-6-6.1, 46-6-10, 46-6-14, 46-6-18, 46-6-20, 46-6-27, 46-6-28.
Note: Bentonite manufactured for use as a drilling fluid does not meet the requirements for bentonite grout. Bentonite grout may be used to plug wells at depths greater than eight feet. 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 plug when higher hydrostatic pressure is required.