ABSTRACT
This chapter addresses the formation of pumping sumps and associated gravity drainage channels for the control of surface water, groundwater. Sump pumping can be a very effective and economic method to achieve modest drawdowns in well-graded coarse soils in hard fractured rock. The initial discharge water from any pumping operation will be discoloured due to the presence of fines. Continuation of the discolouration of the water can be tolerated only if the pumped water is entirely derived from surface run-off. A very common approach to sump pumping uses suction pumps of the vacuum-assisted self-priming centrifugal type or reciprocating diaphragm type, typically powered by diesel engines. In shallow excavations, the sump pump can be located outside the excavation at ground level with a suction hose laid from the pump down into the sump. Sump pumping forms an important part of the groundwater control strategies for many open pit mines, although in that industry, the method is referred to as ‘in-pit pumping’.
