1.2.2.1.17 Liddell

Liddell Coal Operations (Liddell) is an open-cut mine operated and managed by Liddell Coal Operations Pty Limited, a wholly owned subsidiary of Glencore Coal Pty Ltd, on behalf of a joint venture between Glencore (67.5%) and Mitsui Matsushima Australia (32.5%) (Glencore, 2014e). Liddell Colliery has had continued mining, either open-cut or underground, since the 1950s (Liddell Coal, 2002).

Liddell Coal is located at Hebden, 25 km north-west of Singleton in the Upper Hunter Valley (Liddell Coal, 2014). Pits currently mined are South Pit and Entrance/Barrier Pit (Xstrata Coal, 2013, p. 12). The mine operates a truck and excavator, and dragline and highwall operation (Glencore, 2014e). Mining is expected to continue until approximately 2023. Coal resources as at December 2013 were reported to be 100 Mt (measured), 210 Mt (indicated) and 350 Mt (inferred) (GlencoreXstrata, 2014, p. 49). Potential economic extraction at Liddell Coal is from the Lemington, Pikes Gully, Arties, Liddell and Barrett seams (Glencore, 2014f). Proved marketable reserves as at end of 2013 were 20 Mt and total marketable reserves were 36 Mt (GlencoreXstrata, 2014, p. 49).

Both semi-soft coking coal and thermal coal are mined at the Liddell Colliery (Glencore, 2014e). The coal seams targeted by the current and planned mining operations range from 0.7 to 9.5 m in thickness and include the Lemington, Pikes Gully, Arties, Liddell and Barrett coal members (Glencore, 2014e) in addition to the Hebden Gully Coal Member (Glencore, 2014e).

The water management system at Liddell Colliery manages surface water runoff to existing pits and operational areas, groundwater seepage in open-cut and old underground workings, mine operation water for the CHPP, dust suppression, and off-site discharges and water sharing arrangements (Xstrata Coal, 2013, p. 5). Liddell Colliery consumes approximately 4.9 ML/day of water in the CHPP (at a rate of 7 Mt/year ROM production) (Xstrata Coal, 2013c, p. 5). The main water storage onsite is the raw water transfer void with a capacity of approximately 500 ML which receives water from both open-cut pits (South Pit and Entrance/Barrier Pit) and other dams, as well as the Liddell underground mine (Xstrata Coal, 2013c, p. 12). Surface water storage totals 2473 ML and underground water storage in old workings totals 7160 ML (Xstrata Coal, 2013, p. 5, p. 14). Water is stored in underground workings because a barrier to groundwater flow exists between the Hazeldene and old Liddell workings. This allows water levels in the Hazeldene underground workings to be maintained as groundwater levels are reduced in the Liddell underground mine (Xstrata Coal, 2013c, p. 7).