Worldwide, however, tailings failures occur at a frequency of about two or three a year and they’ve been known to cause companies to go bankrupt.

To bring the issue home, one need only hark back to 2000 when Perth-based Esmeralda Exploration’s joint venture Aurul gold project in Romania spilled some 100,000 cubic metres of cyanide-contaminated water.

The poisoning of the Danube river system resulted in Esmeralda going into administration and was decried as the worst environmental disaster in Europe since the Chernobyl nuclear power plant meltdown.

Worst case catastrophe scenarios aside, insufficient attention to tailings design can result in pesky cashflow inhibitors and invisible, long-term risks with expensive engineering ramifications.

Geochemistry issues related to sulphate or salt plumes might not be seen for 10-20 years but will ultimately become legacy items.

Miners are often guilty of failing to prepare tailings for closure and ineffectively integrating the system with the broader operation.

“One of the things about tailings dams is that, in the bigger picture of the mine, they don’t cost a lot of money but they certainly cover some of the biggest footprints and they are one of the biggest risks around an operation, both during operation and in closure,” SRK Consulting waste management head Dave Luppnow told MiningNewsPremium.net.

SRK claims expertise in mine tailings design since 1974, maintaining a philosophy of long-term planning, site-specific customisation and efficiency through better integration of a mine’s oft-ignored elephant in the room.

Luppnow identified one of the major problems in tailings as a market-driven tendency among cash-starved juniors to manage the system on the cheap.

“It’s our biggest challenge every single day to get people to spend money on something that doesn’t actually have an income,” he said.

“It’s seen as a waste. They want to dispose of it and they want to dispose of it as cheaply as possible.

“A lot of times the decision on the tailings is made at the feasibility level based on the lowest capital cost to get the thing started and it’s not necessarily the lowest cost or best solution in the long term.”

The problem, in some ways, breaks down to companies wobbling in the balancing act of pleasing investors.

Spending a lot of money on tailings isn’t particularly popular with many stakeholders but neither is a project burdened with too much operational and environmental risk.

Luppnow said addressing common waste management pitfalls with process designers, miners and hydro-geologists was the proactive approach.

With this in mind, improving compatibility between tailings and process plant systems is often simply a matter of communication.

Luppnow offered an anecdote of a beach slope designed by SRK where the uncommunicated deposition of finer-grained material resulted in innumerable problems with upstream raising of the dam and an “enormous” redesign expense.

“We’ve seen an enormous amount of cases where you do the design on a tailings product and at the last moment – or even after the design has been done – the tailings product changes,” he said.

“The people in the plant don’t understand the drivers and the repercussions of that impact on the tailings dam.

“If we’ve chosen a design that utilises coarse material and then they decide to overgrind the material such that they can get a better recovery, then first of all, they need to tell us.”

Communication can also be critical in relation to water issues.

“A lot of times, we find the plants have a particular process problem and they need to send excess water out to the tailings dam for disposal or you’ve got excess water from underground,” Luppnow explained.

“If these are not communicated to the tailings designer, there can be a major problem that ultimately results in a failure.”

In the eastern states, geochemical issues become water issues on the Great Artesian Basin – the world’s largest and deepest confined aquifier and a major national source of inland freshwater.

In dry Western Australia, water issues are heightened by salt build-ups in fresh water circuits, which either require water disposal into the tailings dam or expensive dedicated evaporation ponds.

“Water’s going to be the challenge going forward, getting enough of it and keeping it clean,” Luppnow warned with a hint at the immediate ramifications of climate change on mining.

“We’ve got a drying continent in Australia and there are pressures on water resources in places like India and China.

“It’s very precious and we only have a certain amount of it.”

Many of the emerging risk-mitigation and cost-saving techniques in tailings design are also aimed at conserving water.

These include dry stack tailings systems whereby the operator follows a concurrent closure plan, dewatering and closing tailings as they are stacked.

It’s a short-term method applied with a long-term view, increasingly demonstrated to save water, require a smaller footprint and reduce legacy issues.

“Five years ago the number of dry stacks was probably three or four in the word,” Luppnow said.

“Now it’s probably at 20 or 30 and gaining acceptance.”