S.D. Admin. R. 74:11:08:04
Test holes that encounter no water or only low-permeability formations such as clays, shales, and till must be backfilled to restore natural conditions as nearly as possible. Except as provided in §§ 74:11:08:05 to 74:11:08:07.02, inclusive, the minimum acceptable test hole plugging method is the return of the excess drill cuttings to the drill hole to a point not less than eight feet below the ground surface. Backfill material must be free of contamination and have a permeability equal to or less than the permeability of the formations encountered in the borehole. A nondegradational, nonslip plug shall be placed at a point not less than eight feet below the ground surface, and a five-foot column of cement grout shall be placed above the plug. Topsoil or material representative of the undisturbed surface material shall be tamped into the upper three feet of the drill hole.
Bentonite chips may be used as an alternative to cement grout in the top eight feet of the test hole if bentonite grout or bentonite chips are used to plug the test hole.
S.D. Admin. R. 74:11:08:04
General Authority: SDCL 45-6C-29, 45-6D-34.
Law Implemented: SDCL 45-6C-29, 45-6D-34.