1. Water quality - unknown at this stage. The water will...

1. Water quality - unknown at this stage. The water will probably be a combination of groundwater recharge plus rainwater inflow (depends how large the catchment area of the pit is). The pit was a low grade sulphide ore body, so depends if the rocks are acid forming or potentially acid forming - but there appears to be a lot of carbonate rock in the area, so this could buffer any acid.

2. Water - depending on water quality, most processing plants are designed to be closed loop, where mill water is recycled from tailings dam and reused, with any deficit being made up with water source from bores/dams etc. In most cases, if there is excess water, the water will be dealt with (cleaned up and discharged to environment, or evaporated [evaporation dams])

I would suspect that evaporation rates (other than in wet season) are very high in this area.

3. How long to dewater? - will depend on the recharge from the groundwater and the capacity of pumps you are using - more pumping capacity, faster dewatering.

4. Good question - depends on cost and time to dewater.