Therm-Ex Grout and PowerTec is an engineered system for use as a backfill material in earth-coupled heat pump systems. Its elevated thermal conductivity and low permeability allow for excellent heat exchange while protecting groundwater supplies. Therm-Ex Grout and PowerTec should be pumped using a positive displacement pump capable of generating pressures in excess of 300 psi. Developed using high swelling Wyoming bentonite, this generation of grouting material offers efficient installation of closed-loop geothermal heat pump systems.