Utah Administrative Code
Topic - Natural Resources
Title R655 - Natural Resources, Water Rights
Rule R655-4 - Water Wells
Section R655-4-12 - Special Wells

a. The location of closed-loop heat pump wells must comply with applicable ordinances, regulations, or other enforceable instruments of local governments to ensure adequate protection of public water systems from encroachments or any impairment of the groundwater resource. During drilling and construction, provisions shall be made to reduce entry of foreign matter or surface runoff into the well or borehole.

b. Closed-loop system wells must be sealed from the bottom of the well or boring to ground surface using acceptable materials and placement methods described in Subsection R655-4-11 (11.4). Sand may be added to the seal mix to enhance thermal conductivity as long as the seal mix meets permeability and gel strength standards outlined in Subsection R655-4-11 (11.4).

c. Borehole Diameter: The borehole diameter of a closed-loop heat pump well must be of sufficient size to allow placement of the pipe and placement of a tremie to emplace the grout. In general, for loop piping with a nominal diameter of 3/4 to 1 inch, the borehole diameter shall be at least 4.75 inches. For loop piping with a nominal diameter of 1.25 inches, the borehole diameter shall be at least 5.25 inches. For loop piping with a nominal diameter of 1.5 to 2.0 inches, the borehole diameter shall be at least 6.0 inches.

d. Grouting of Vertical Ground Water Heat Pump Wells: Grouting the annulus of a heat pump well shall be completed within 24 hours from the time the borehole is drilled and loaded with the U-bend assembly and within at least 6 hours from the time the drill rig moves off the borehole. Full-length grout placement is required on all vertical closed-loop heat pump boreholes.

e. Placement of Grout Material: Full-length grout material must be placed by tremie from the bottom of the borehole to the top. The tremie pipe shall be continuously submerged in grout during placement. The tremie pipe must not be left in the borehole. The grout must fill the entire borehole. Grout must not be allowed to freefall. Once the grout has settled for at least 48 hours, borehole shall be topped off with additional grout as necessary to maintain seal material to ground surface.

f. Pipe: Pipe material, joining methods, and installation must meet the guidelines and standards referenced in the National Ground Water Association Guidelines for Construction of Vertical Boreholes for Closed-Loop Heat Pump Systems, which are copyrighted and available from the National Ground Water Association at 601 Dempsey Rd, Westerville, OH 43081-8978, Phone 614-898-7791, Fax 614.898-7786, email customerservice@ngwa.org, and in the Design and Installation Standards for Closed-Loop Geothermal Heat Pump Systems. Standards are copyrighted and available from the International Ground Source Heat Pump Association at 312 S. 4th Street, STE100, Springfield, IL 62701, www.igshpa.org, info@igshpa.org. Guidelines and standards may be viewed during normal business hours at the Division's main office at 1594 West North Temple, SLC, UT 84116. U-bend connections shall be factory jointed and piping shall not have any fusion joints below a depth of 30 feet.

g. Pressure Testing: Loop piping shall be filled with water and pressure tested before installation into the borehole. Loop piping failing this initial pressure testing shall not be installed. The installed system must be pressure tested at a minimum of two times the system operating pressure to ensure the integrity of the system. If a pressure loss is detected, the cause must be properly repaired or material replaced or properly plugged. The system shall be pressure tested again following any repairs. Pressure testing procedures shall follow the guidelines and standards in the National Ground Water Association Guidelines for Construction of Vertical Boreholes for Closed-Loop Heat Pump Systems, which are copyrighted and available from the National Ground Water Association at 601 Dempsey Rd, Westerville, OH 43081-8978, Phone 614-898-7791, Fax 614.898-7786, email customerservice@ngwa.org, and in the Design and Installation Standards for Closed-Loop Geothermal Heat Pump Systems. Standards are copyrighted and available from the International Ground Source Heat Pump Association at 312 S. 4th Street, STE100, Springfield, IL 62701, www.igshpa.org, info@igshpa.org. Guidelines and standards may be viewed during normal business hours at the Division's main office at 1594 West North Temple, SLC, UT 84116.

h. Heat transfer fluid, additives, and inhibitors. The heat transfer fluids, additives, and inhibitors used inside the closed-loop assembly must be non-toxic, safe to install, provide corrosion protection, not promote bacterial growth, and not produce an unacceptable risk to the environment in the event of a system leak. Potassium acetate or ethylene glycol shall not be used as a heat transfer fluid. Water used in the heat transfer fluid mix must be from a treated potable source or be disinfected in accordance with this rule. Use and placement of fluids, additives, and inhibitors shall be in accordance with the guidelines and standards in the National Ground Water Association Guidelines for Construction of Vertical Boreholes for Closed-Loop Heat Pump Systems, which are copyrighted and available from the National Ground Water Association at 601 Dempsey Rd, Westerville, OH 43081-8978, Phone 614-898-7791, Fax 614.898-7786, email customerservice@ngwa.org, and in the Design and Installation Standards for Closed-Loop Geothermal Heat Pump Systems. Standards are copyrighted and available from the International Ground Source Heat Pump Association at 312 S. 4th Street, STE100, Springfield, IL 62701, www.igshpa.org, info@igshpa.org. Guidelines and standards may be viewed during normal business hours at the Division's main office at 1594 West North Temple, SLC, UT 84116.

i. Abandonment: When closed-loop heat exchange wells are required to be permanently abandoned, the standards referenced in Subsection R655-4-12 (12.1.4.2) shall be followed. The state engineer shall be notified before loop field abandonment. All heat transfer fluids shall be flushed and removed from loop piping before abandonment. Below ground loop piping to be abandoned shall be filled completely with acceptable grout and the loop piping ends properly capped or sealed.