The Tui mine site is situated on the NW flank of Mt. Te Aroha, at approximately 400 m altitude. During underground
mining operations two lead-copper-zinc ore bodies were exploited and processed on site. The legacy of the mining
operation is a barren dam containing over 100,000 m3 of sulphide-rich tailings. The Tui mine site is arguably the worst
case of environmental degradation resulting from past mining activity in New Zealand. Although the impacted area
(approximately 4 ha) is extremely small by international standards, acid mine drainage (AMD) emanating from the
abandoned tailings dam and mine adits has severely contaminated local streams and prevented natural plant
recolonisation of the site for more than 20 years.