The Influence of Rainfall on the Characteristics of Historic Acid Mine Drainage on the Denniston Plateau, NZ Jewiss, C. S. 1 , Craw, D. 1 & Pope, J. 2 University of Otago 1 , CRL 2
The Influence of Rainfall on the Characteristics of Historic Acid Mine
Drainage on the Denniston Plateau, NZ
Jewiss, C. S.1, Craw, D.1 & Pope, J.2
University of Otago1, CRL2
Denniston Plateau
Stream Flow Data
pH/Specific Conductance v Flow Rate
Specific conductance is the measure of the conductivity of the dissolved load, which can be correlated to the concentration sulphate and other ions in solution.
Precipitation and Neutralisation
Conclusions• Increased flow rate occurs during rainfall events, with a lag of
approximately one-two hours• Varied water chemistry occurs within the historic runoff at
Cascade Mine• pH and SPC have an overall dilution effect during rainfall, with
the exception of heavy rainfall events that propagate aflushing event, causing a sharp decrease in pH and increase inSPC
• Fe-oxyhydroxides ± schwertmannite + Al-mineral precipitatein mixing zones in Cascade Creek, consistent with geochemicalmodelling
• Partial acid load of Cascade Mine– Ca. 463 t CaCO3/yr
• Bathurst Resources Limited for providing access to Cascade Mine• WCRC for providing the pH/EC sonde• Education Endowment Trust, AusIMM NZ Branch – Postgraduate Scholarship• My field assistants, Hana Christensen and Aaron Dutton (CRL), Emma Scanlan, Jason Jewiss and Christine
McLachlan