All system materials and fluids shall meet or exceed requirements of Iowa Administrative Code 567.49. Geothermal piping shall have a 50-year warranty. Horizontal loops shall be installed with tracer wire. Heat transfer fluid used in exchanger lines must be a USP or food grade propylene glycol or calcium chloride solution. Ethylene glycol will not be accepted. System shall include a pressure-based leak detector that will stop the system circulating pumps, should a leak occur.