Human health and environmental risk assessment for closure planning of the Argyle Diamond Mine pit lake

Argyle Diamond Mine (Argyle) is a large open cut and underground mine in Northern Australia preparing for closure with the pit as a water management structure. Water quality will be pH 8-9, with solute concentrations increasing through evaporative concentration. However, poor pit lake habitat quality and restricted access to humans and stock limits exposure to potential receptors.

A risk assessment based on consequence and likelihood, found all risks from the pitlake water to be very low. A risk assessment offers a useful approach to assessing pit lake risk when specific water quality criteria alone may not be appropriate.