Section 920.180  Closed-Loop Wells

a)         Construction.  Each closed-loop well shall be grouted as required in Section 920.90(h). Closed-loop wells shall not be located closer than 200 feet from a water well, except when the well is a private water system well and when the owner is the same for both the water well and the closed-loop well, in which case the water well shall not be closer than 75 feet from the closed-loop well.

b)         Piping Pressure.  The liquid in the closed-loop piping shall be maintained under pressure.  The equipment shall be designed to shut down if there is any pressure loss in the system.  The system must be pressure tested at a minimum pressure of 20 pounds per square inch by the installer after installation to ensure that there are no leaks in the piping or in the equipment system.

c)         Coolant.  The solution used as coolant or the liquid which is pumped through the closed-loop well piping must be methanol, ethanol, propolene glycol, calcium chloride or ethylene glycol.  These chemicals may be used only in concentrations of 20% or less. When copper piping is utilized, the coolant shall be hydrochlorofluorocarbon-22, or any equivalent refrigerant with less ozone depletion potential.

d)         Piping.  All plastic piping shall be watertight and shall conform to ASTM D2666-89, D2447-89, D3035-91. All copper piping system and joints shall be watertight and conform to UL 1995. All joints in plastic piping shall be heat fusion welded.

e)         Abandonment.  All vertical piping in closed-loop wells which is abandoned shall be physically disconnected from the horizontal piping and sealed with neat cement grout or any bentonite product manufactured for water well sealing by pressure grouting.   All horizontal piping which is abandoned shall be removed or the coolant must be drained from the piping and disposed of off-site in accordance with State and local laws.

f)         Horizontal Piping Distances to Water Wells.  Horizontal piping in a closed-looped system shall not be closer than 25 feet to any water well.

g)         Distances to Sources of Contamination.  Closed-loop wells shall not be closer to the sources of contamination listed in Section 920.50(b)(1) than the distances to water wells specified in this Section.

(Source:  Amended at 22 Ill. Reg. 3973, effective April 1, 1998)