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Below: Riparian planting borders the Ohinemuri River with the slopes of the tailings impoundment in the background
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Environment: The tailings impoundment
It's a toxic waste dump, an environmental time bomb and will be a wasteland legacy for future generations. All wrong. Let's deal with some facts.
Variously called tailings dams, tailings impoundment, or 'toxic waste dumps' by those who don't understand, these large structures hold the ground-up rock after gold and silver has been removed. Our dams are carefully engineered load bearing rock structures, essentially built to the same specifications as a water dam. They are designed to withstand what engineers call the Maximum Credible Earthquake and to handle water from significant storm events (that's the Maximum Credible Precipitation).These are the 'inconvenient truths' about tailings impoundments in Waihi.
Are they full of toxic mud that could flow down into the river? No. Are they just giant areas of cyanide-laced water that poisons wildlife? No.
Is the Tui Mine tailings dam on the slopes of Mount Te Aroha an environmental disgrace and an embarrassment for the industry? Yes.
Built in a different century with different environmental, financial and engineering regulations (and certainly different attitudes) Tui is a mess. Can it be cleaned up? Yes, and it will be over the next two-three years now that funding has been sourced. Can it happen again? We don't think so. The laws have changed. Rules and regulations have changed. Mining technology and practices have changed. More importantly, attitudes have changed.
So, what's the truth about a modern tailings impoundment like those at Waihi? There is so much misinformation out there that it is difficult to know where to begin. Here are some of the frequently asked questions about our tailings impoundments. The links take you to individual pages on the Martha Mine website.
How are the dams built?
Geology of the Waste Disposal Area
Construction Control and Monitoring
Waste Rock and Tailings Characteristics
Embankment Design
Embankment Zoning
What happens to water?
Surface Water and Stormwater
Hydrogeology
Subsurface Drainage
Processes of Water Movement
What's acid drainage?
Acid Drainage Control
What happens when the mines close?
Long Term Management of the Tailings Storage Facilities