Plugging of Monitoring Wells

PURPOSE: This rule sets standards for the plugging of monitoring wells. (1) When plugging a monitoring well, the following minimum requirements shall be met: (A) Remove all pumps, sampling equipment, debris, or other substances; (B) Remove the surface completion from the borehole ensuring that the grout seal is not disturbed. Cut off riser pipe and/ or casing two feet (2') below ground surface; (C) Fill the well from bottom to within one foot (1') of ground surface with grout pursuant to 10 CSR 23-4.060(9); (D) After the grout is fully cured, check for settlement and top off if necessary. Fill remaining hole with soil or pave. (E) Flush mount completions in paved areas may be left in place and filled with asphalt or concrete; (F) A monitoring well may be completely excavated as opposed to being plugged with grout. If the well is over drilled, the borehole shall be completely filled with grout pursuant to 10 CSR 23-4.060(9); and (G) A non-restricted monitoring well installation contractor must be on site at all times during the excavation and plugging operations. (2) Temporary monitoring wells ten feet (10') or greater in depth must be plugged by removing any temporary pipe and filling the well from total depth to two feet (2') from the ground surface with approved grout, with the remainder of the well RESOURCES filled with compacted uncontaminated native material or grout. Temporary monitoring wells shall be plugged within thirty (30) days of the date of completion. AUTHORITY: sections 256.606, 256.615, and 256.623, RSMo 2016.* Emergency rule filed Nov. 16, 1993, effective Dec. 11, 1993, expired April 9, 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. Amended: Filed Nov. 18, 2010, effective July 30, 2011. Amended: Filed June 27, 2018, effective Feb. 28, 2019. *Original authority: 256.606, RSMo 1991; 256.615, RSMo 1991; and 256.623, RSMo 1985, amended 1991.