Plugging of Test Holes

PURPOSE: This rule establishes criteria for the proper procedures to be followed when plugging a test hole. (1) All test holes, except those that are converted to other types of wells shall be plugged in accordance with this chapter within sixty days from the date that the well was drilled. Submit plugging registration records pursuant to section 256.614.1, RSMo. Test holes are exempt from submitting construction certification records. (A) Plugging the Test Hole. 1. Test holes with no surface casing. A. Fill the test hole from total depth to within two feet (2') of ground surface with grout. B. If the Davis Formation is penetrated, a grout plug shall extend from the bottom of the formation to within two feet (2') of ground surface. C. A mechanical packer may be installed at the bottom of the Davis Formation or emplace clean fill from total depth to the bottom of the Davis Formation to hold the grout plug in place. D. Fill the top two feet (2') of hole with soil. 2. Test holes with removable surface casing pipe. A. Remove the surface casing and any interior casing if used. B. Fill the test hole from total depth to within two feet (2') of ground surface with grout. C. If the borehole has collapse potential, add grout as casing is withdrawn. D. If the Davis Formation is penetrated, a grout plug shall extend from the bottom of the formation to within two feet (2') of ground surface. E. A mechanical packer may be installed at the bottom of the Davis Formation or emplace clean fill from total depth to the bottom of the Davis Formation to hold the grout plug in place. F. Fill the top two feet (2') of hole with soil. 3. Test holes with grouted nonremovable surface casing. A. Cut the casing off two feet (2') below ground surface or three feet in an agricultural area. If bedrock is encountered, cut the casing flush with the top of bedrock. B. Fill the test hole from total depth to within two feet (2') of ground surface with grout. C. If the Davis Formation is penetrated, a grout plug shall extend from the bottom of the formation to within two feet (2') of ground surface. D. A mechanical packer may be installed at the bottom of the Davis Formation or emplace clean fill from total depth to the bottom of the Davis Formation to hold the grout plug in place. E. Fill the top two feet (2') of hole with soil. (2) Test holes drilled to expand quarrying and surface mining operations. (A) Test holes completely destroyed within one (1) year of the advance of the mine or quarry shall have a ten foot (10') surface grout plug and are exempt from plugging registration requirements. (B) Test holes that are not destroyed within one (1) year of the advance of the mine or quarry are subject to plugging requirements pursuant to 10 CSR 23-6.050(1). (C) Test holes that penetrate the quarry or mine floor which are not completely destroyed by the quarry or mine operation shall be plugged with grout from total depth to the bottom of the quarry or mine and are subject to plugging registration requirements. (3) Clay mining operations. Test holes that do not penetrate beneath an impermeable fire clay deposit shall have a ten foot (10') surface grout plug and are exempt from plugging registration requirements. (4) Unconsolidated material test holes less than one hundred feet (<100') deep. (A) Test holes less than twenty feet (<20') in depth may be plugged using clean fill or uncontaminated native material and are exempt from plugging registration requirements. (B) One (1) registration report and fee is required per site for test holes that are twenty feet (20') in depth or greater. All test holes plugged may be reported on one (1) form. (C) Test holes where no ground water is encountered, may be plugged using clean fill or uncontaminated native material. (D) Test holes may not be used for monitoring. AUTHORITY: sections 256.606, 256.614, 256.615, and 256.626, RSMo 2016.* 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. Amended: Filed June 27, 2018, effective Feb. 28, 2019. *Original authority: 256.606, RSMo 1991; 256.614, RSMo 1985, amended 1991; 256.615, RSMo 1991; and 256.626, RSMo 1985, amended 1991.