Bored Geothermal Heat Exchanger (BGHE) Construction Permit Application
Well Management Program
Instructions for Obtaining a BGHE (Earth-Coupled Heat Loop) Construction Permit
Minnesota Statutes, chapter 103I authorizes the commissioner of health to issue permits for the construction of bored geothermal heat exchangers. This includes any earth-coupled heating or cooling device consisting of a sealed pipe system installed vertically in the ground for the purpose of transferring heat to or from the surrounding earth. Minnesota Rules, chapter 4725 "Wells and Borings" establishes the permit application requirements and the standards for the construction, maintenance, and sealing of the bored geothermal heat exchanger.
Conditions of the permit approval include the following:
- A completed application form must be submitted, accompanied by the appropriate fee (the fee is nonrefundable).
- The bored geothermal heat exchanger must be constructed by a licensed well contractor or licensed bored geothermal heat exchanger contractor.
- The construction, maintenance, and sealing must be in compliance with Minnesota Rules, chapter 4725.
- The owner agrees to allow inspection of the system during regular business hours by the Minnesota Department of Health (MDH).
A completed application must be submitted to MDH, along with the appropriate fee and the required documentation, which includes:
- the name and license number of the well contractor and the certified representative;
- the name and address of the owner of the property on which the bored geothermal heat exchanger will be constructed;
- the township number, range number, section, and one quarter, and the property street address, if assigned;
- a plan diagram showing the location of the bored geothermal heat exchanger, property lines, and structures on the property;
- the number, diameter, and depth of all bore holes drilled to install the bored geothermal heat exchanger piping;
- the grout materials and grouting method;
- the type of heat transfer fluid to be used;
- the system operating pressure, and
- the location of water-supply wells, utilities, and property lines.
In order to protect the quality of the groundwater resources of the state, MDH will review permit applications to determine compliance with the following standards:
- Piping used must be a minimum 160 psi pressure-rated, SDR 11 high density, polyethylene meeting ASTM Standard D3035-03a.
- Connections to bored geothermal heat exchanger piping must use socket fusion or butt fusion joining methods.
- Piping must be pressure tested with air or potable water for 15 minutes at a pressure of 1.5 times the system operating pressure or 75 pounds per square inch, whichever is greater, after installation in the bore hole.
- The annular space between the bored geothermal heat exchanger piping and the bore hole must be grouted according to the procedures in part 4725.3050, subpart 2. Rock portions must be grouted with neat-cement or cement-sand grout. Portions of the hole in unconsolidated formations must be grouted with bentonite grout, thermally enhanced bentonite grout, neat-cement grout, or cement-sand grout.
- Only food-grade or USP-grade propylene glycol must be used as heat transfer fluid. No other materials or additives must be used except for potable water. A permanent sign must be attached to the heat pump specifying that only approved heat transfer fluids must be used.
- A water make-up line to the bored geothermal heat exchanger must be protected with a backflow prevention device as required by the Minnesot Plumbing Code, Minnesota Rules, chapter 4714.
The owner of the bored geothermal heat exchanger must notify the commissioner of health of heat loop fluid leakage or loss of pressure within 24 hours after the owner becomes aware of the loss or leak.
The contractor must contact Ms. Kara Dennis at 651-201-4589 or email@example.com at least 48 hours prior to beginning construction.
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- BGHE Construction Permit Application Memo (PDF)
- BGHE Construction Permit Application Form (PDF)
- Credit Card Payment Information Form (PDF)
Contact the MDH Well Management Section
651-201-4600 or 800-383-9808
Minnesota Department of Health