"The operations under Permit 491 are a research and development project to develop the technology for the production of low and medium Btu gas via a series of two in situ coal gasification tests. Test 1 ran for 35 days and was completed December 5, 1979. The Test 2 period ran for approximately 85 days, starting August 17, 1981, and was completed November 12, 1981. Coal is never brought to the surface during this process and, therefore, coal is neither surface mined nor deep mined per se. Surface facilities for UCG processes differ significantly from those of a true mining operation. In situ or underground coal gasification consists of drilling boreholes into the coal seam, linking the boreholes, igniting the coal and injecting an oxidant such as oxygen/steam or air down one of the boreholes. As the coal burns outward from the base of the injection well, the combustion gases, consisting primarily of CO2, Co and H2O react with the nonburning coal to form H2, more CO and pyrolysis products which exit through the product gas well."