The mine is situated in the northern Freestate, south of the town of Vereeniging. The Dwyka and overlying Karoo sediments, which host the economic coal seams exploited at New Vaal Colliery, rest unconformably on dolomites of the Chuniespoort Group. A combination of chemical and physical weathering of these dolomites has resulted in a highly undulating floor nonto which the Dwyka and Karoo sediments have been deposited. Consequently, the morphology of the coal seams is complex.

Basement highs (dolomite ridges and pinnacles) and lows (doline features), of varying scales, result in the strata changing dip, strike and gradient very rapidly over relatively short distances. The resulting structures (joints and faults) imparted to the strata have a major impact on both high- and low-wall stability. New Vaal Colliery was investigated to determine the causes and effects of geotechnical factors on high- and low-wall
stability.

New Vaal Colliery is a surface mining operation that uses truck and shovel for pre-stripping soft overburden i.e. sand. The colliery has three different pits: namely North, South, and West pit with a dragline in each pit. The draglines remove the hard overburden from the pit and place it on the spoil heap. The mining operation at New Vaal Colliery is divided into three sections: namely Sand Stripping, Draglines, and Coaling.

To pre-strip the sand both the bucketwheel excavator (sand system), which moved 1.5 million bank cubic metres (BCMs) during 2009, and the truck and shovel fleet, which moved 4.0 million BCMs in the same year, are used. In October 2010, the bucketwheel excavator was scrapped after reaching a life of 25 years. The soft overburden is now removed using truck and shovel only. A fleet of seven Euclid R170 rear dump haul trucks and three P&H rope shovels are used for sand stripping operations, with one of the shovels on standby. The coaling fleet consists of five Hitachi EH 3500 and five Cat 789 rear dump trucks, combined with four Demag 285 hydraulic shovels (front end loaders) and one rope shovel. In total there is a fleet of eight shovels at New Vaal Colliery, consisting of four rope shovels and four Demags. The hard overburden and the top seam are drilled and blasted together, followed by the interburden and the middle seam, and finally the parting and the bottom seam. New Vaal Colliery uses the dispatch system to monitor, record, and direct mining operations.

New Vaal also operates a washing plant, where the coal is crushed, screened and, if required, sent to the dense medium separation plant, which consists of two large Drewboy washing vessels, 7 m in diameter, containing a mixture of magnetite and water. The heavier stone sinks and is removed back to the mine, while the coal is skimmed off the surface by the rotating paddle wheel and joins the crushed coal as it is transported to the stockyard by a system of conveyor belts.