|
Highlights
- Preliminary dewatering design
- Sizing of dewatering system
- Detailed design of dewatering well configuration
- Installation and testing of system
Background
The collapse of a load station trench was attributed to
high water table conditions which occurred during a cyclone.
An investigation into means of maintaining the water table
at a safe level was requested.
Comalco commissioned C. M. Jewell & Associates to undertake
the necessary field assessment and modelling of dewatering
options, and then to install the dewatering system.
Hydrogeological Environment
The superficial geology is unusual. Pisolithic bauxite gravels
overlie lateritic clays with a distinctive pipe feature.
The bulk hydraulic conductivity of the upper part of the
profile is very high; estimates of up to 350 metres per
day were made.
Scope
The design capacity of pumping equipment required to maintain
the water table at an artificial level was assessed in preliminary
studies. Subsequently, detailed design and costing of a
dewatering system employing twelve production wells was
undertaken. The wells and a permanent airlift pumping system
were installed in an intensive campaign prior to the onset
of the wet season. 
|
Projects