PURPOSE: This rule establishes criteria for the proper procedures to be followed when plugging a test hole.

1. (1) All test holes, except those that are converted to other types of wells are to be plugged in accordance with this chapter within sixty (60) days from the date that the well was drilled. Extensions of this time limit are available on a case-by-case basis from the division.

   1. (A) Plugging the Test Hole.

      1. 1. Test holes with no surface casing.

         1. A. Test holes must be filled with

grout via tremie to within two feet (2') of the ground surface. If the Davis Formation is penetrated, an expanding packer must be placed in the bottom portion of the formation and grouted to within two feet (2') of the surface.

1. B. The top two feet (2') of hole must

be filled with soil.

1. C. A registration report form must be

submitted to the division which documents the method of plugging the test hole.

1. 2. Test holes with removable surface

casing pipe.

1. A. If the Davis Formation is penetrat-

ed, an expanding packer must be set in the bottom portion of the formation.

1. B. The hole must be filled with grout

from the packer to the bottom of the interior casing pipe via tremie pipe. This grout plug must extend from near the bottom of the Davis Formation to at least fifty feet (50') above the top of the Davis Formation.

1. C. The hole must be backfilled with

chlorinated clean fill such as varied sized agricultural lime, gravel or sand to the base of the surface casing pipe, while the interior casing is being pulled.

1. D. A fifty-foot (50')-grout plug must

be pumped through the surface casing pipe as it is being removed, filling the hole to the top of bedrock.

1. E. Chlorinated clean fill must be used

to backfill the hole above the upper plug while the surface casing pipe is being removed. The clean fill must extend from the top of the grout plug to within two feet (2') of the surface.

1. F. The top two feet (2') of the hole

must be filled with on-site soil.

1. G. A registration report form must be

submitted to the division which documents the method of plugging.

1. H. The test hole may be filled from

total depth to surface with grout.

1. 3. Test holes with grouted nonremovable

surface casing.

1. A. Cut off casing three feet (3') below

ground surface making a hole at least two feet (2') in diameter larger than the surface casing.

1. B. Fill the hole from total depth to

within two feet (2') of the surface with grout.

1. C. Fill remaining hole with soil.
2. D. Submit a registration report form

to the division.

1. (2) Test Holes Drilled to Expand Quarrying and Surface Mining Operations. When test holes are drilled in the process of expanding quarrying and surface mining operations and are destroyed within one (1) year by the advance of the mine or quarry, they are required to be plugged by only inserting a temporary surface plug into the hole which will prevent surface water from entering the hole. Reporting requirements are not required for these temporary holes. If these test holes are drilled deeper than the quarry or mine floor, they must be plugged from the mine floor to the total depth of the hole with approved grout. If these holes are not destroyed by the mining process within one
2. (1) year then the requirements of subsection (1)(A) must be met. Extensions of this time limit will be considered on a case-by-case basis by the division.

3. (3) Test Holes Drilled in Association with Clay Mining Operations, Shallow Industrial Minerals Exploration and Miscellaneous Geologic Data Holes.

   1. (A) When the test hole is drilled that bottoms in an impermeable fire clay deposit a temporary surface plug must be inserted which prevents surface water from entering the hole. This type of well is exempted from reporting requirements.
   2. (B) When a test hole is drilled that bottoms at the bedrock-unconsolidated material contact or above, it must be plugged when no longer needed for exploratory purposes. If the test hole is less than one hundred feet (100') in depth and does not encounter a potable water horizon, the test hole must be plugged by filling the hole from bottom to top with the type of uncontaminated material removed from the hole or other approved grout. A registration report is required per site for holes drilled and plugged that are greater than twenty feet (20') in depth. One AUTHORITY: sections 256.606, 256.614,

4. (1) registration fee is required per report 256.615 and 256.626, RSMo Supp. 1991.* form for this type of hole. If a test hole is less Original rule filed Aug. 17, 1993, effective than twenty feet (20') in depth, it must be March 10, 1994. filled with the material removed from the *Original authority: 256.606, RSMo 1991; 256.614, hole as soon as it is no longer needed for RSMo 1985, amended 1991; 256.615, RSMo 1991; and exploratory purposes. Test holes less than 256.626, RSMo 1985, amended 1991. twenty feet (20') in depth are exempted from the rules. These wells can not be used in any way relative to monitoring well sites.

   1. (C) If a test hole is greater than one hundred feet (100') in depth, it must be plugged as stated in 10 CSR 23-6.050(1).

AUTHORITY: sections 256.606, 256.614, 256.615 and 256.626, RSMo 1994.* Original rule filed Aug. 17, 1993, effective March 10, 1994. Amended: Filed July 13, 1994, effective Jan. 29, 1995. Amended: Filed Nov. 1, 1995, effective June 30, 1996. *Original authority: 256.606, RSMo 1991; 256.614, RSMo 1985, amended 1991; 256.615, RSMo 1991; and 256.626, RSMo 1985, amended 1991.