Background
In March 1990 Pasminco resolved to replace and increase the capacity of the underground pumping system at the Southern Operations, Broken Hill. The existing pump station was built 23 years ago while the rising main had been in service for 38 years and was subject to frequent failure.
The old system was a conventional slurry/clear water separation and multi-stage pumping system. It was inadequate in the following areas:
insufficient capacity to handle current and expected future flows;
unable to consistently dewater lower production areas;
pumping capacity restricted sandfilling rates;
dirty water dams had insufficient settling capacity and were difficult to de-sludge;
the operating costs of dewatering were high;
it was labour intensive; and
it did not offer enough protection to the 25 level loading station.