Illinois Administrative Code › Title 77 - PUBLIC HEALTH › Part 920 - WATER WELL CONSTRUCTION CODE › Section 920.180 - Closed Loop Wells

Current through Register Vol. 48, No. 28, July 12, 2024
a)
			 Construction. For each closed loop well, the borehole, containing the heat
			 exchanger piping, shall be grouted from the bottom of the borehole to the
			 bottom of the header-piping trench and, in the case of directional bores, the
			 surface of the ground. When karst conditions are encountered, disinfected clean
			 pea gravel or limestone chips may be used to bridge karst zones, limited to 5
			 feet above the karst zone. When more than one karst zone is encountered a
			 bentonite plug a minimum of 5 feet thick must be installed above each karst
			 zone. The Department will maintain a list of approved closed loop well grouts
			 on its website at
http://www.dph.illinois.gov/
. Closed
			 loop wells that are constructed in a manner that leaves a casing in the ground
			 shall be grouted in a manner consistent with water wells. Closed loop wells
			 shall not be located closer to water wells and sources of contamination than
			 the minimum separation distances specified in Table C.
b) Borehole Piping. Piping shall be
			 watertight with a minimum of 160 psi pressure-rated high density polyethylene
			 or equivalent manufactured for the purpose of use in a ground heat exchange
			 system. All copper piping and joints used in direct expansion heat pump systems
			 shall be watertight and conform to UL 1995.
c) Heat Exchange Fluid. The heat exchange
			 fluid that is pumped through the closed loop well piping shall be compatible
			 with piping in the borehole and shall be water or a mixture of water and one of
			 the following: methanol, or ethanol, or United States Pharmacopeia propylene
			 glycol that meet U.S. FDA Food Contact Substance (FCS) Requirements.
d) Refrigerant. When refrigerant is used with
			 copper piping in a direct exchange system, the refrigerant shall be R-134a or
			 R-290.
e) Sealing Requirements for
			 Closed Loop Wells.
1) Heat Exchange Fluid or
			 Refrigerant. All heat exchange fluid or refrigerant shall be removed from the
			 closed loop well system and disposed of in accordance with State and local
			 laws.
2) Piping. All piping left in
			 place in closed loop wells shall be sealed with neat cement grout or any
			 bentonite product manufactured for water well sealing by pressure grouting. The
			 sealing material shall be pumped into the supply of the loop until the sealing
			 material is flowing out of the return of the loop.
3) Open or cased wells shall be sealed
			 according to Section
			 920.120.
4) Abandoned closed loop wells shall be
			 brought into compliance with this Section or sealed within 30 days after
			 abandonment.
5) Closed loop wells
			 constructed for thermal conductivity testing shall be incorporated into a
			 system or sealed within one year after borehole completion. The Department will
			 grant an extension of this time if the owner submits a written request to the
			 Department indicating the reasons for the request and an estimate of the time
			 in which the closed loop well will be either sealed or used. The request for
			 the extension shall be submitted not less than 11 months nor more than 12
			 months after borehole completion.