Water catastrophe in the offing

Allan Seccombe | Tue, 08 Dec 2009 08:26
[miningmx.com] -- GAUTENG, South Africa’s richest and most populous province that was built on gold, is close to running out of water – and fast.

Gauteng’s authorities say it will run out of water by 2013 unless “drastic measures are implemented immediately”. That’s a dramatic bit of news for anyone to digest, especially for the 10.5 million people living in the province.

One such measure could be supplementing supplies with water treated from mines – also known as acid mine drainage (AMD).

Some may find the proposal unpalatable because of the content of such untreated water includes uranium and heavy metals. However, Western Utilities Corporation (WUC) is pushing hard for the South African government approval before year-end 2009 of a process it claims will treat mine water to drinking water standards and avert two crises at once.

Asked about the warning issued by Gauteng’s authorities, Jaco Schoeman, CEO of WUC, said: “Additional urgency is required.”

An environmental catastrophe is slowly but surely unfolding around Johannesburg as defunct gold mines fill with water, which then becomes heavily polluted with uranium, heavy metals and salts.

There comes a point when that water will reach a level when its starts polluting ground water sources and then finally overflows or decants, streaming out of shafts and causing serious environmental damage.

'Take drastic action'

There are four compartments within the Wits Basin, the world’s richest single known source of gold. Those have been mined over the past century, creating massive underground voids that miners kept dry while working there but have been allowed to fill with water when mining stopped.

The smallest basin, the West Rand Basin, decanted in 2002 and releases 15 megalitres (Ml) of water/day. Mining companies are treating that water, extracting the heavy minerals. But the sulphates, or salts, remain behind. That water is released into the Tweelopies Spruit, a process that’s attracted the wrath of environmentalists infuriated by the damage to the water course.

WUC has a stark warning for authorities: Take decisive action on two of the other three basins or face disaster.

The Central Basin will decant 60Ml/day in little more than two years; and the Eastern Basin could decant 82Ml/day within three years if pumping there stops.

Pamodzi Gold, now liquidated, was pumping and treating water in the Eastern Basin. The towns of Nigel and Boksburg are at real risk of being inundated with AMD if nothing is done soon.

The action that authorities need to take, said Schoeman, is to approve WUC’s environmental impact assessment study, clearing the way for a critical off-take deal with Rand Water, South Africa’s largest water provider, before year-end and allowing the construction of the plant to start.

R1.5bn in funding required

Timing is critical. It will take a year to build the plant to treat 155Ml/day of mine water pumped in from the three basins, generating 75Ml of potable quality water and 80Ml of industrial grade water for mines and other industries. The by-product of elemental sulphur can be sold to chemical companies to make sulphuric acid, which South Africa imports.

Not only that, but WUC has yet to raise R1.5bn, which it will conduct through its AIM London-traded parent company Watermark Global, with the split being 75% debt from the Development Bank of SA and South African commercial banks, with the remainder via equity, possibly with a listing on the JSE.

Mining companies – including DRDGOLD, Rand Uranium, Central Rand Gold, Mintails and Pamodzi – have contributed R500m with infrastructure, tailings facilities and land and, of course, as much polluted water feedstock as WUC wants.

This proposal – which is hampered by red tape and apparent dithering by the government – contrasts strongly with what’s happening on the coalfields, where Anglo Coal and BHP Billiton have an extremely successful joint venture plant to treat 25Ml/day of water extracted from four coal mines.

After three years of talking, the eMalahleni plant now supplies 20% of the drinking water to the eMalahleni municipality, which includes the coal mining town of Witbank.

Anglo/Billiton eMalahleni joint venture "extremely successful"

The attraction of the process is that it extracts a waste product called gypsum, which has already been used to build a comfortable house. The plant’s capacity will be doubled from July next year, with potential to raise throughput to 75ML/day later, said Peter Günther, Anglo Coal’s regional manager of hydrology.

A prefabricated three-bedroom, 60 square metre (squ m house requires about six tons of gypsum. The plant generates up to 200t/day of the material. Anglo plans to use those homes to help relocate workers from hostels, setting up villages made of gypsum homes that cost around R145 000 each to build.

The plant has been such a success that BHP Billiton is looking at building a similar process at Middleburg, but nothing has yet been finalised.