The Tarrawonga Coal Mine is located in the Gunnedah Basin, in the Gunnedah Coalfield, which contains sedimentary rocks, including coal measures, of Permian and Triassic age. Regionally, there are two coal-bearing sequences in the Gunnedah Basin, namely:

- Early Permian Bellata Group (comprising the Maules Creek sub-basin and Mullaley subbasin, separated by the Boggabri Ridge);
- Late Permian Black Jack Group.

The Tarrawonga coal resource is located within the Maules Creek sub-basin of the Early Permian Bellata Group. The target coal seams within the Maules Creek sub-basin are contained within the Maules Creek Formation. They subcrop on low hills to the west of theTarrawonga area and dip towards the east.

Target coal seams within the open cut extent are Braymont, Bollol, Creek, Jeralong, Jeralong Lower, Merriown, Merriown Lower, Velyama, Nagero.

Individual coal seams range up to approximately 4.5 m thick, and average 1.5 m. They onlap the Boggabri Ridge to the west of the Tarrawonga area and thicken towards the east.

During the MOP term, open cut mining will continue eastward within ML 1579, ML 1693, and ML1685 and ML1749.

The current truck and shovel mining methods will be utilised for pre-stripping and coal recovery. Excavators will be used to load haul trucks to remove overburden and interburden. Coal will also be loaded into haul trucks with excavators.

Used tyres from mining equipment will continue to be stockpiled prior to being safely disposed of in the backfilled mine void as the open cut advances.

Conventional drill and blast techniques are used for the removal of competent overburden and interburden material. Blast designs and sizes will vary over the life of the mine and will depend on factors such as the depth of coal seams and the design of benches. As the open cut mining operations advance to the south- east, some sections of Goonbri Road will be temporarily closed during blast events that are within 500 m of the public road.

Blast design will ensure that burden distances and stemming lengths are such that an adequate level of fragmentation with acceptable environmental impact is achieved.

In accordance with condition 16 of Schedule 3 of PA 11_0047 blasting will be limited to one blast per day; unless an additional blast is required for safety reasons. The total number of blasts per week will not exceed four, averaged over a calendar year. PA 11_0047 does allow additional blasts provided that such blasts do not generate ground vibration of more than 0.5 millimetres per second (mm/s) at any residence on privately-owned land. Additional blasts required to ensure the safety of the mine or its workers are also permitted.

Overburden Emplacement
Overburden and interburden mined during the MOP period will continue to be used to in-fill the mine void behind the advancing open cut, as well as being placed in the two adjoining out-of-pit mine waste rock emplacements (Northern Emplacement and Southern Emplacement).

The waste rock emplacements at Tarrawonga will be progressively shaped for rehabilitation activities, including final re-contouring, topsoiling and revegetation.

During the MOP term, the majority of ROM coal will be trucked to the ROM pad and ROM stockpiles where it will be transferred to a 40 t hopper and conveyed to the on-site coal crushing and screening facility. ROM coal will then be sized and conveyed to the coal load-out bin for loading in to on-highway haul trucks for transport to the Whitehaven (Gunnedah) CHPP or Boggabri CHPP for further processing prior to being railed to the Port of Newcastle via the Werris Creek Mungindi Railway for export customers.

Tarrawonga will continue to use an on-site mobile crusher to selectively process domestic specification coal per annum. Sized coal will then be transported via road to domestic customers.

Subject to commercial agreement, TCPL and BCPL will handle and process Tarrawonga’s ROM coal at the upgraded Boggabri Infrastructure Facilities and private rail spur. Tarrawonga product coal would also be separately loaded into trains for transport to the Port of Newcastle via th ........