Rulemaking for Submerged Closed Loop Heat Exchangers

The Minnesota Department of Health (MDH) is amending Minnesota Rules, chapter 4725 (Wells and Borings) to include requirements for the permitting and installation of submerged closed loop heat exchangers in water-supply wells. A submerged closed loop heat exchanger must not be installed in a water-supply well without a permit granted by the commissioner.

Minnesota Statutes, chapter 103I was amended during the 2023 Legislative Session authorizing the commissioner to adopt rules “to implement requirements for the permitting and installation of submerged closed loop heat exchangers…”

Submerged closed loop heat exchangers were also defined in the 2023 Legislative Session Law. Currently, Minnesota Session Law contains the amended language.

A "submerged closed loop heat exchanger" is defined as "a heating and cooling device that:

• is installed in a water-supply well;
• utilizes the convective flow of groundwater as the primary medium of heat exchange;
• contains water as the heat transfer fluid; and
• operates using a nonconsumptive recirculation.

A submerged closed loop heat exchanger includes other necessary appurtenances such as submersible pumps, a heat exchanger, and piping."

Revision documents

• Request for Comments - Request for Comments for the Possible Amendment of Minnesota Rules, Chapter 4725 (PDF).
• State Register Posting published on July 17, 2023 - Minnesota State Register Volume 48, Number 3 (PDF)(Pages 61-62).

Rulemaking contacts

Questions regarding the rulemaking process or the revised rules may be directed to:

Minnesota Department of Health
Environmental Health
Well Management Section
P.O. Box 64975
St. Paul, Minnesota 55164-0975

Avery Guertin or Corrie Floyd
wellrules.mdh@state.mn.us
651-201-4600 or 800-393-9808