The More Things Change...

At the New Zealand Tunnelling Company descendants' gathering held in Waihi last Monday members of the Newmont Waihi Gold Mines Rescue Team explained the workings of their underground mine rescue apparatus.

Jake Croall demonstrated to the 75 people present how the Proto self contained breathing apparatus used underground in World War One differed very little in basic design from the BG4 used today. Troy Hargreaves modelled the equipment, even managing to get a quick lunch while wearing most of the gear.

Troy Hargreaves

Above: Mines Rescue Team member Troy Hargreaves grabs a hurried lunch.




The Newmont Waihi Gold community engagement line is attended 24 hours a day, seven days a week.


0800 NEWMONT (0800 639 6668)

In this Update we look at the waste rock embankment, join the craze for customising big V8s, and drop in on the New Zealand Tunnelling Company descendants' gathering.

Waste Rock Embankments

That big pile of rock and dirt you can see on your way out to Waihi Beach looks rather imposing right now. What is it? What is it for?

The mining process generates two byproducts. Waste rock contains no gold or silver, or too little to process economically. Tailings are the slurry that remains once the ore-bearing rock has been crushed and the gold and silver extracted.

In many mines throughout the world, waste rock and tailings are disposed of separately to form waste rock dumps and tailings dams. At Waihi the situation is different. Waste rock is used to form embankments that are progressively raised to store the tailings. The tailings settle and consolidate, the water is drawn off and either discharged or returned to the water treatment plant. There are no dams constructed out of tailings in Waihi; they are waste rock embankments that store the tailings. This is a crucial distinction.

Waste Rock Embankment

The two embankments are designed as earth/rockfill structures with enough strength to hold water. This is a very conservative design, as with time the tailings will consolidate and essentially become soils with similar inherent shear strength.

The waste rock embankments are carefully engineered; progressively constructed structures that must have a building permit and meet the requirements of the Resource Management Act. Each stage of the embankment's construction is carefully monitored. An independent peer reviewer carries out an annual inspection.

Pimp My Loader

Seddon Street will be buzzing tomorrow when Waihi hosts the Beach Hop Warm Up Party.

Newmont Waihi Gold is pleased to join with Go Waihi and local retailers in this initiative.

Come and join us at the Pumphouse. Bands. Cars. Gold Panning. And for the first time, our new minidigger will be available in conjunction with EXITO, the Extractive Industries Training Organisation.

Of course no Beach Hop is complete without the chance to show off your wheels. We'll be bringing a big piece of underground machinery up to the surface from Favona, and parking it on an Edwards Transport lowloader in Seddon Street. A great chance to get a very special photo.

It should be a great day. See you there.

Pimp my Bogger

Pimp my loader. A bit of playing with Photoshop and you get a real Hot Rod. Check the size of those mags! Look at those exhausts! It may not be the quickest machine off the line in a drag race, but we reckon we will have the widest tyres on the street tomorrow...

Victorian Bush Fire Appeal

Thanks to all those who contributed to the Aussie Bush Fire Appeal recently.

A total of $4380.40 was raised in Waihi. Newmont Asia Pacific matched the contributions from Australia and New Zealand Newmont mine sites 10:1, bringing the total to $271,711.00.

Ponds

Storage 2 (left) and Storage 1A

Could water flood over the top of the embankment?

The two waste rock embankments provide sufficient storage capacity to ensure that the water within the tailings ponds will be contained, even in extreme rainfall events.

Storage capacity is provided for a 1200 mm rainstorm - known as Probable Maximum Precipitation - plus an additional one metre minimum freeboard.

What about an earthquake?

The waste rock embankments have been designed to resist the effects of earthquake shaking from the Maximum Credible Earthquake (MCE) based on a seismic hazard study of the site in accordance with international guidelines. The MCE has been conservatively assessed to be a magnitude MW 7 earthquake at a distance of nine kilometres from the site.

Earthquakes have been felt in Waihi, but none in the last 150 years has caused high levels of shaking. Any earthquake capable of causing damage to the embankment would also cause significant damage to buildings and infrastructure in Waihi.

What would happen in an emergency?

Newmont Waihi Gold has a site-wide Emergency Management Plan. The plan covers all emergency and incident scenarios, and assigns specific tasks to staff on site. The plan is regularly updated. The most recent version was written in May 2008. Residents adjacent to the waste rock embankments are on a contact database and would be informed of any incident.

If you wish to be on this list please contact the Company Liaison Officer on 0800 NEWMONT.

On the web

For more information on large dams visit www.icold-cigb.net.

For information on large dams in New Zealand see www.ipenz.org.nz/nzsold