Tui mine

The Tui mine is an abandoned mine on the western slopes of Mount Te Aroha in the Kaimai Range of New Zealand. It is considered to be the most contaminated site in the country, following the clean up of the former Fruitgrowers Chemical Company site at Mapua, Nelson.[1]

Contents

History

In the 1960s, the Tui mine extracted copper, lead and zinc sulphides.[2] The mine was abandoned in 1973, after the mining company Norpac Mining went bankrupt.[1] Waste, rock ore dumps and mine tailings were left behind. The tailings have significant amounts of zinc and cadmium.[2] The mine tailings are stored behind a dam in a large pool-like area which has an oxidised, solid surface layer.[1]

Environmental issues

The tailings dam is considered to be unstable and is leaching various minerals, including heavy metals, into neighbouring waterways and this adversely affects the stream ecology. According to Environment Waikato, the Tui mine has three major environmental impacts;

  1. The heavy metals lead and cadmium are leaching from the tailings dam into the Tunakohoia stream, which flows through land managed by the Department of Conservation and through the centre of the town of Te Aroha
  2. The separate Tui catchment is also contaminated with heavy metals from the tailings dam;
  3. The abandoned mine tailings dam in the Tui catchment is at risk of collapsing in a moderate seismic event or an extreme weather event. That could cause 90,000 cubic metres of mine waste to liquefy and to flow down the Tui stream near to Te Aroha.[3]

Remediation

In 2007, the New Zealand Government announced that $9.88 million will be made available to clean up the site with the work scheduled to be completed by 2010.[4] In April 2010 it was reported that the estimated cost of the clean-up would be $17.4 million[5] and in 2011 a sum of $16.2 million was allocated to the cleanup with most of the funding from central government.[6]

See also

References