S.D. Admin. R. 74:11:08:07.02
Bentonite chips may be used in place of bentonite grout to plug test holes with a diameter four inches or greater, that are not deeper than 500 feet and that have no more than 100 feet of standing water unless the chips have been coated by the manufacturer to delay hydration. Bentonite chips shall be poured slowly into the top of the test hole to prevent bridging in the casing or borehole. Fine bentonite particles or dust that accumulate in the shipping container may not be used for plugging. Upon completion of the plugging operation, water shall be placed into the casing or borehole to promote expansion of the bentonite above the static water level. A maximum of four gallons of water shall be added for every 50 pounds of bentonite chips added above the static water level.
If bridging occurs during pouring of the bentonite chips, the point of bridging must be broken to allow the bentonite chips to fall to the bottom of the test hole. If the bridge cannot be broken, the test hole must be drilled out and replugged with bentonite or cement grout. Bentonite chips may not be used in test holes drilled into loose or broken strata if hole collapse and bridging is likely.
S.D. Admin. R. 74:11:08:07.02
General Authority: SDCL 45-6C-29, 45-6D-34.
Law Implemented: SDCL 45-6C-29, 45-6D-34.