During the first few months of 1985, field investigations were undertaken at Leigh Creek by consultants Golder Associates to provide quantitative data on the strength and permeability characteristics of the geological profile of the Main Series coal measures in Lobe B of the Telford Basin coal deposit. This data was required to inform engineering concerns around the proposed development of underground coal gasification (UCG) there. For a trial UCG project, an area of investigation was selected which was believed to contain, in a single block at 200 m depth, the required coal reserves of 30 Mt which would provide the gaseous fuel supply needed for a pilot 60 MW gas turbine electricity generating system. During January-February 1985, 3 partly HQ3 cored appraisal boreholes were drilled by SADME to depths of 260.2 m, 396.8 m and 403.7 m respectively, at sites located on two seismic lines crossing the area of investigation. A total of 158.18 m was cored. Two more shallow rotary mud holes were also drilled, for later installation of near surface piezometers. Permeability tests and geophysical logging were undertaken in the three deep holes, and sealed piezometers were subsequently installed in them for monitoring the ground water potentiometric surface (water table) level over time. Permeability values were determined for the UCG target coal seam, and for its roof and floor rocks. Indentor tests were used to assess rock strengths. The new drillhole data generally confirmed the thickness and continuity of the target Main Series coal seam, established by previous SADME and ETSA work, with good agreement seen between seismic survey and drillhole data. An average coal thickness of ~14 m, with seam dip varying from -16 to -22 degrees, was determined. Subsequent modelling was done by the consultants in relation to groundwater inflow and water table drawdown, and seam roof stability. Consideration of all data then to hand concluded that underground gasification of the coal in the selected target area of Lobe B at Leigh Creek could be both technically and economically feasible to provide energy for local electricity generation. The consultants also made an initial appraisal of the feasibility of using UCG to access the energy value of the complete inaccessible coal resource in Lobe B, with the purpose of assessing the best technical approach to achieve such a development. Lobe B is the largest and most deeply extensive coal occurrence at Leigh Creek, with the highest possibility of containing coal reserves that will be inaccessible to conventional open pit mining methods.