ARSD Article 74:11 — MINERAL EXPLORATION

AGRICULTURE & NATURAL RESOURCES AGRICULTURE & NATURAL RESOURCES

Chapter 74:11:08 Capping, sealing, and plugging exploration test holes

ARSD 74:11:08:01 Void

Standards for mineral exploration.** Void

ARSD 74:11:08:02 Void

Permit area size.** Void

ARSD 74:11:08:03 Void

Exemptions for small equipment.** Void

ARSD 74:11:08:03.01 Definitions

Terms defined by SDCL chapters 45-6C and 45-6D have the same meanings when used in this chapter. In addition, terms used in this chapter mean:

(1) "Bedrock," any geologic formation or sediment of Pliocene age or older of solid unweathered rock, including solid limestone, dolomite, sandstone, shale, and igneous and metamorphic rocks;

(2) "Bentonite," a highly plastic when wet, colloidal clay composed primarily of sodium montmorillonite;

(3) "Bentonite chips," angular fragments of bentonite that have been commercially processed and graded according to size for use in plugging test holes. The fragments range in size from 1/4 to 3/4-inch;

(4) "Bentonite grout," a mixture consisting of water and a high solids, bentonite material, that has been commercially manufactured and specially formulated for use to plug a test hole. The bentonite grout must contain a minimum of 20 percent solids by weight and have a minimum slurry density of 9.4 pounds per gallon when mixed according to the manufacturer's recommendations. Bentonite manufactured for use as a drilling fluid does not meet the requirements for bentonite grout;

(5) "Cement grout," a mixture consisting of a high-sulfate-resistant type Portland cement and no more than six gallons of water for each 94-pound sack of cement, and which may have up to 75 pounds of drilling-grade bentonite per 10 sacks of cement to reduce shrinkage;

(6) "Confined aquifer," an aquifer in which the groundwater is isolated from the atmosphere by geologic formations of low permeability and that produces water levels above the top of the aquifer in test holes penetrating it;

(7) "Flowing artesian test hole," a test hole that has penetrated a confined aquifer whose potentiometric surface is above the land surface resulting in water flow at the surface;

(8) "Formation pressure," the fluid pressure within an aquifer or formation; and

(9) "Top of the aquifer," the uppermost point at which saturated conditions are found.

History

• Source: 34 SDR 323, effective July 2, 2008.
• General Authority: SDCL 45-6C-29, 45-6D-34.
• Law Implemented: SDCL 45-6C-29, 45-6D-34.

ARSD 74:11:08:04 Minimum acceptable plugging method

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.

History

• Source: 5 SDR 69, effective February 20, 1979; transferred from § 12:04:08:04, effective July 1, 1981; citations replaced effective July 1, 1982; 13 SDR 129, 13 SDR 141, effective July 1, 1987; 34 SDR 323, effective July 2, 2008.
• General Authority: SDCL 45-6C-29, 45-6D-34.
• Law Implemented: SDCL 45-6C-29, 45-6D-34.

ARSD 74:11:08:05 Plugging and sealing confined aquifers or more than one aquifer

Test holes that penetrate confined aquifers or that encounter more than one aquifer may be plugged with bentonite grout only if the weight of the bentonite grout column is sufficient to overcome formation pressure. If the weight of the bentonite grout column is not sufficient to overcome formation pressure the test hole must be plugged with cement grout. The bentonite or cement grout must be placed from the bottom of the hole to within eight feet of the ground surface. The upper eight feet of the hole shall be plugged in accordance with the specifications set forth in § 74:11:08:04.

History

• Source: 5 SDR 69, effective February 20, 1979; transferred from § 12:04:08:05, effective July 1, 1981; citations replaced effective July 1, 1982; 13 SDR 129, 13 SDR 141, effective July 1, 1987; 34 SDR 323, effective July 2, 2008.
• General Authority: SDCL 45-6C-29, 45-6D-34.
• Law Implemented: SDCL 45-6C-29, 45-6D-34.

ARSD 74:11:08:05.01 Plugging and sealing single unconfined aquifers

Test holes that penetrate a single, unconfined aquifer may be backfilled with drill cuttings or clean sand or gravel from the bottom of the hole to the top of the aquifer. Above the aquifer, bentonite grout or cement grout shall be used to plug the test hole from the top of the aquifer to within at least eight feet of the ground surface. The upper eight feet of the hole shall be plugged in accordance with the specifications set forth in § 74:11:08:04.

History

• Source: 34 SDR 323, effective July 2, 2008.
• General Authority: SDCL 45-6C-29, 45-6D-34.
• Law Implemented: SDCL 45-6C-29, 45-6D-34.

ARSD 74:11:08:06 Plugging in unconsolidated granular material

Test holes that penetrate water-bearing unconsolidated granular material above bedrock and that continue into the bedrock shall be plugged by placing a column of bentonite or cement grout from the bottom of the hole to a point not less than five feet below the bedrock surface. A column of cement grout shall be placed between the bentonite grout and three feet below the ground surface. Upon initial settling of the cement grout, the remainder of the test hole shall be plugged with topsoil or a suitable material in a manner consistent with the specifications set forth in § 74:11:08:04.

Test holes that penetrate nonwater-bearing unconsolidated granular material above the bedrock surface shall be plugged by returning all excess drill cuttings to the hole to a point not less than eight feet below the ground surface. The upper eight feet of the hole shall be plugged in accordance with the specifications set forth in § 74:11:08:04. If drill cuttings are not available in quantities sufficient to fill the hole to within eight feet of the ground surface, that portion of the hole remaining to be filled may be plugged with either cement grout or free-flowing mineral aggregate.

History

• Source: 5 SDR 69, effective February 20, 1979; transferred from § 12:04:08:06, effective July 1, 1981; citations replaced effective July 1, 1982; 13 SDR 129, 13 SDR 141, effective July 1, 1987; 34 SDR 323, effective July 2, 2008.
• General Authority: SDCL 45-6C-29, 45-6D-34.
• Law Implemented: SDCL 45-6C-29, 45-6D-34.

ARSD 74:11:08:07 Plugging flowing artesian test holes

All flowing artesian test holes shall be plugged with cement grout from the bottom of the hole to within three feet of the surface. Upon initial settling of the cement grout, the remainder of the test hole shall be plugged with topsoil or suitable material in a manner consistent with the specifications set forth in § 74:11:08:04.

History

• Source: 5 SDR 69, effective February 20, 1979; transferred from § 12:04:08:07, effective July 1, 1981; citations replaced effective July 1, 1982; 13 SDR 129, 13 SDR 141, effective July 1, 1987; 34 SDR 323, effective July 2, 2008.
• General Authority: SDCL 45-6C-29, 45-6D-34.
• Law Implemented: SDCL 45-6C-29, 45-6D-34.

ARSD 74:11:08:07.01 Alternate plugging plans

Alternate plugging plans may be approved by the department if they are determined to be as protective of groundwater as the methods specified in this chapter. Alternate plugging plans must be approved by the department in writing before the plans are implemented.

History

• Source: 34 SDR 323, effective July 2, 2008.
• General Authority: SDCL 45-6C-29, 45-6D-34.
• Law Implemented: SDCL 45-6C-29, 45-6D-34.

ARSD 74:11:08:07.02 Plugging with bentonite chips

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.

History

• Source: 34 SDR 323, effective July 2, 2008.
• General Authority: SDCL 45-6C-29, 45-6D-34.
• Law Implemented: SDCL 45-6C-29, 45-6D-34.

ARSD 74:11:08:08 Temporary plugging and capping

If a delay in plugging and capping is approved by the department, the hole shall be securely capped with a tapered concrete plug or suitable equivalent that is of sufficient diameter to prevent it from slipping below the surface. The temporarily plugged and capped hole shall be marked with a sturdy steel fence post with a minimum height of 42 inches above the ground surface. All test holes shall be capped and permanently plugged as soon as practical and may not be left unplugged for more than 30 days without approval of the department.

History

• Source: 5 SDR 69, effective February 20, 1979; transferred from § 12:04:08:08, effective July 1, 1981; citations replaced effective July 1, 1982; 13 SDR 129, 13 SDR 141, effective July 1, 1987; 34 SDR 323, effective July 2, 2008.
• General Authority: SDCL 45-6C-29, 45-6D-34.
• Law Implemented: SDCL 45-6C-29, 45-6D-34.

ARSD 74:11:08:09 Void

New road and trail standards.** Void

ARSD 74:11:08:10 Void

Surface restoration of drill sites.** Void

ARSD 74:11:08:11 Void

Wells used for fresh water.** Void

ARSD 74:11:08:12 Void

Notification required of aquifer penetration.** Void

ARSD 74:11:08:13 Void

Submission of general geologic information.** Void

ARSD 74:11:08:14 Void

Preservation of cores and samples.** Void

ARSD 74:11:08:15 Void

Reporting schedule for general geologic information.** Void