The Agricola Experience... may it be a lesson

:: Overview of the Agricola situation

:: Gympie Times article - July 24, 2004

Overview of the Agricola situation

by Ian Mackay [CRC President]

The Conondale Ranges are an area of high conservation value. Areas of it are listed on the National Estate and yet, right in the middle, lies an ugly scar - and a reminder.

In the mid 1970s, a small mine operated at the site. When Astrik Resources took over in the eighties, a massive expansion took place. Mountains were literally moved in the search for gold, the ore being treated on site.

The Conondale Range Committee, formed in 1976 to press for a larger National Park, suddenly found itself facing a threat of a totally different kind. The massive depredations involved in clearing and earthmoving, not to mention the toxic nature of the cyanide used in the treatment process, posed enormous problems.

At a cost of nearly a million dollars, an electricity line was taken in through the forest, the cyanide tailings dam built, the mine pit dug and a treatment plant built. All this in an area which had recorded the highest 24 hour rainfall in South-east Queensland.

It seemed nothing would stop this insidious venture - after all, Queensland had been virtually founded on a series of gold-strikes and gold fever. This ‘rush’ seemed to reach into the speculative stock market as well.

There are times when the smallest of things bring down the greatest. The gold proved to be not quite as abundant as initially thought and high levels of copper made treatment more expensive. It became unviable to keep digging. Yet the plant had cost a lot to set up, and thus, in a desperate attempt to recoup some of the costs, a plan was proposed to truck ore in for processing. It stretched credibility that ore from all over South-east Queensland would be hauled up these narrow, winding roads to this de facto industrial zone high in top conservation value forest. Kenilworth Township faced the prospect of a 25 tonne ore truck passing through every quarter hour, the only respite being a few hours between midnight and dawn.

Then it happened. At Yednia, near Kilcoy, en route to the mine, six drums of cyanide fell off a truck and two burst open. It was downhill for the miners after that. State Cabinet vetoed the trucking proposal and soon after, in 1989, Astrik was declared bankrupt and announced that it wouldn't be able to carry out the necessary rehabilitation. The eventual cost to decommission the site was over one million dollars.

In 1991, the new Labor government put up a quarter of a million dollars to decontaminate the water and fill in the tailings dam. After five years of further agitation to complete the rehabilitation, an Agricola Consultative Committee was set up consisting of representatives of the various departments and involved conservation interests. A budget allocation of over $800 000 was eventually made and a committed Environment Officer appointed.

The acidified water in the open cut pit or “blue lagoon”, contaminated with various heavy metals, was treated, filled and capped; major earthworks were carried out and the site seeded and planted.

What was once a very hostile environment is now a totally different sight as the trees have grown so much that it’s possible to lose your way on this 16ha site. It will be years, though, before it returns to anything like its original state.

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Gympie Times article - July 24, 2004

Greening after the gold

Conondale Range Committee president Ian Mackay looks at how a previously controversial environmental issue has been resolved.

Progressive rehabilitation [above] has taken place at the abandoned Agricola gold mine near Kenilworth where the tailings dam and surrounding area was left denuded of vegetation and resembling a lunar landscape.

Conservationists are impressed with the way in which rehabilitation work at the abandoned Agricola gold mine has progressed. Part of the rehabilitation work has been the treatment of cyanide contaminated water and the waterproof capping over both the tailings dam and the mine pit [above].

Research scientists [some from overseas], Department of Natural Resources and Mines officers and conservationists inspected the progress of rehabilitation work at the abandoned Agicola gold mine near Kenilworth recently.

The open cut mine, with on-site cyanide treatment, was established in the 1980's, amid much controversy in State Forest southwest of Kenilworth. It was abandoned in 1989 after the company declared bankrupt. A small security deposit of $15,000 had been lodged with the government but the cost of the subsequent clean-up was in excess of $1.2 million at government expense.

It wasn't until after some years of pressuring by local conservation group, the Conondale Range Committee, that plans for the rehabilitation were drawn up and put into action with most of the work being carried out by contractors between 1995 and 1997.

Accompanying the recent inspection party was Dr Rob Savory, the Mines Department Environment officer who co-ordinated the bulk of the rehabilitation and revegetation work.

Land tenure changes in recent years mean that the mine site is now surrounded by National Park and plans are to eventually incorporate the revegetated site into National Park also. This sensitivity was reflected in the fact that an Agricola Consultative Committee was established at an early stage to work collaboratively toward rehabilitation. Apart from Dr Savory, this committee was made up of Forestry and National Parks officers and representatives from the CRC. As well as this, it drew on other expertise, notably from the University of Queensland's Centre for Mined Land Rehabilitation.

An important part of the work was the treatment of the cyanide contaminated water and the waterproof capping over both the tailings dam and the mine pit itself. A number of tests bores were sunk to test groundwater for contaminants, not just residual cyanide but also other metals dissolved from rocks exposed to the elements from the mining operation. These bores have been monitored on a regular basis since the rehabilitation and indicate that the operation has been successful.

A feature of the site was that in the six years between the mine being abandoned and the rehabilitation beginning, there had been very little natural plant recolonisation despite the surrounding area being an excellent seed source. The reason for this was determined to be the acid-forming rock exposed at the site. In 1994, a geology student in a research project had found that the 70,000 litres of water in the open pit had an acid pH of about 3 and had dissolved a host of heavy metals fron the surrounding rock.

The entire site was limed and the resultant change in plant growth is impressive. Many tree seedlings were planted at the site as well as it being seeded and hydro-mulched with pioneer species.

I took part in the recent inspection and was one of several speakers who outlined the difficulties faced by the rehabilitation project. I pay tribute to the diligent way the environmental sensitivity of the surrounding forest and particularly Booloumba Creek had been accommodated by the contractors.

It is now just over seven years since the revegetation stage was carried out and it's most satisfying to see the forest reclaiming what had previously been described as a 'lunar landscape'.