PURPOSE: This rule sets standards for the placement of heat pump wells.

1. (1) A vertical heat pump well shall be located on a site which has good surface drainage and prevents the accumulation of water within ten feet (10') of the well and any buried pipes.

2. (2) Distances from pollution or contamination sources. A vertical heat pump well shall be at least—

   1. (A) Three hundred feet (300') from a storage area for commercial fertilizers or chemicals, landfill, lagoon, or above-ground or underground storage tank for petroleum, petroleum products or chemicals.
   2. (B) One hundred feet (100') from a below-grade manure storage area, cesspool, lagoon, unplugged abandoned well, subsurface disposal field (lateral field), grave, building or yard used for livestock or poultry, privy, or other contaminants that may drain into the ground.
   3. (C) Fifty feet (50') from an existing operating well, septic tank, buried sanitary sewer, rim of a sinkhole, a pit or unfilled space below ground surface, a sump, except that a closed-loop heat pump well may be drilled closer than fifty feet (50') to a basement or another heat pump well.
3. (3) Any heat pump well that encounters oil and/or gas must have a grout plug from fifty feet (50') below the oil and/or gas bearing zone to fifty feet (50') above the oil and/or gas bearing zone. The grout plug must be composed of neat cement grout with a two percent–six percent (2%–6%) bentonite additive and be placed via tremie. The well must be grouted pursuant to 10 CSR 23-5.050(7)(A), from the bottom of the neat cement grout plug to total depth and from the top of the neat cement grout plug to the surface. If the well terminates in the oil and/ or gas bearing zone, a grout plug composed of neat cement with a two percent–six percent (2%–6%) bentonite additive and placed via tremie must be placed from total depth to fifty feet (50') above the oil and/or gas bearing zone. The well must be grouted pursuant to 10 CSR 23-5.050(7)(A), from the top of the neat cement grout plug to the surface.

AUTHORITY: sections 256.606 and 256.626, 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 Nov. 1, 1995, effective June 30, 1996. Amended: Filed May 17, 2013, effective Dec. 30, 2013. Amended: Filed June 27, 2018, effective Feb. 28, 2019.

*Original authority: 256.606, RSMo 1991 and 256.626, RSMo 1985, amended 1991.