Second Massive Mine Tailings Dam Collapse in 3 Years

Brazil’s Worst Environmental Disaster and over 300 Dead

For the second time in three years, a mine tailings dam in Brazil holding millions of tons of mud and sludge has collapsed cascading its toxic contents into local towns, killing scores of people and devastating the local environment. The Waihi and nearby Waitekauri mining companies say their tailings dam are safe but might they too collapse in a large earthquake?Read More »

Damnable Council Dithering on Tailings Dams

In an earlier blog, I questioned whether the tailings dams at Waihi are earthquake safe

I have now received the latest reports on hazard/earthquake risk for all tailings dams. The reports are perfunctory and/or rely on obsolete research.  Waikato Regional Council has failed to properly regulate these critical structures.  The reports have strengthened my opinion that a fully independent reassessment of seismic safety is urgently required.Read More »

How earthquake safe are the mine tailings dams at Waihi?

The two tailings dams near Waihi are some of the largest structures in the country.

edenpark1
Size of Martha Mine Waihi tailings dam compared to Mount Eden suburbs Auckland

Should either of these dams fail in an earthquake, we could be facing potentially New Zealand’s worst ever environmental disaster, and loss of life and livelihoods on a significant scale.

Therefore it is perfectly reasonable to ask the question – would these structures withstand a large earthquake?  The question is even more pertinent because –

  • the Kaikoura quake unleashed thousands of huge landslides
  • a new GNS Science report on the nearby Kerepehi fault suggests a 7.4 magnitude  earthquake is possible near Waihi, and also estimates that the interval between large quakes is 1000 years rather than 6000-8000 years  as previously assumed.
  • the catastrophic failure of a tailings dam in Brazil in 2015 was due in part to a very small 2.6Mw quake acting as a triggering mechanism for the dam collapse

Read More »