The old gold mine of “Agricola” is located within the boundaries of Conondale National Park, near the town of Kenilworth, approximately 100 kilometres North West of Brisbane. Kenilworth lies on a tourist route through the Sunshine Coast hinterland, in pristine mountainous rainforest. The area had been the site of a previous gold mine, in the seventies, under the designation Unnamed -638521. The site was purchased by Astrik Resources NL., and after many months of consultation with Queensland Government and the Department of Mines, work on the site was started in June of 1987.
Rigid construction and operational requirements imposed by the Queensland Government have been designed to minimise the impact on the forest and water supply in the local area. Mainly Booloumba Creek, which crosses the lease and Boondaroo Creek, on the leases northern boundary. A tight reign had to be kept on a lease of only 16 hectares, measuring 800 metres by 300 metres, within Kenilworth State Forest.
Construction progressed quickly, and by October, nearly 100 construction workers and Astrik staff were working two shifts a day, seven days a week. Opening production was set for November. Construction included building potable water storage tanks, a gold room building, leach tanks, a ball mill, and a reagent mixing plant.
Photograph on left: Top. Leaching tanks, with the ball mill, being assembled above and to the left.
Second left: No.1 pit. The drill at the left is being used for further exploration of the ore body.
Bottom left: Gold room under construction at left. The squat tank will hold catholyte (pregnant solution). Reagent mixing plant is to the right.
Hoped For Output.
Testing on site looked promising. Lode 1: Measured Mineral Resource: 82,000 tonnes of ore @ 4.50 g/t of Gold, for 369 kilograms gold.
Lode 2: Measured Mineral Resource: 174,000 tonnes of ore @ 5.50 g/t of gold, for 957 kilograms gold.
Lode 3: Measured Mineral Resource: 150,000 tonnes of ore @ 5.00 g/t of gold, for 750 kilograms gold.
It was hoped that an output of 30,000 ounces a year could be achieved in a closed circuit situation, with the tailings from the carbon-in-pulp plant stored on site, and the process water being recycled.
Local community initially supported the development of the mine, on the basis of employment and business opportunities. A power line was even driven over the mountains to supply electricity for the mine, at a cost of over a $1,000,000.00.
Eventually things began to go downhill for Astrik, the gold was not quite as abundant as hoped for, and the high level of copper in the ore made it more expensive to treat. It became unviable to continue digging the ore.
A new plan was proposed, to truck ore in from all over South-east Queensland for treatment at Astrik’s state of the art plant, high in the Conondale National Park. Kenilworth faced the prospect of a 25 tonne ore truck passing through town every quarter hour, the only respite between midnight and dawn.
Then the accident happened. A truck transporting drums of cyanide up the winding roads near Kilcoy, on route to the mine, lost six drums. Two of the drums burst open, spilling cyanide into the local waterways and residential area. Rumours abounded that the Conondale Range Committee, had bribed the truck driver to lose the drums.
Government inspectors began to find defects in the containment walls to the pits. No.2 pit was crumbling and there was unstable structure on the southern wall and below the cyanide mixing tanks.
State Cabinet vetoed the trucking proposal and soon after, in 1989, Astrik was declared bankrupt and announced that it would not be able to carry out the necessary rehabilitation of the mine site.
Astrik had been allowed to start work and run the Agricola Gold Mine with only a minimal security deposit, for rehabilitation, of $80,000.00. Now, left with 16 hectares of toxic lunar landscape, deep inside Conondale National Park, beside a popular camping ground, Queensland Department of Minerals and Energy (DME) accepted responsibility for the site.
In April 1991, DME detoxified the cyanide solution in the tailings storage facility and pumped the treated water into the open pit. The tailings storage facility was capped and several monitoring bores were installed. Natural revegetation of the site was occurring only slowly due to the acidic, salty nature of the exposed surface material. No more rehabilitation was under taken until 1995.
The Criminal Justice Commission, investigation into “The improper disposal of liquid waste in south-east Queensland”, shows statements by Senior Environmental Officer Curly, who at the time of the report, had last inspected Agricola in December 1993, there was:
“A possible danger of overflow of polluted waters from the now abandoned pit to Booloumba Creek, 50 metres away, which may contain cyanide.”
“Significant erosion and slumping of the tailings dam cap has begun to take place, with the result that water is ponding onto the top, of the once domed cap and overflowing into the creek, 50 metres away.”
“In 1990 drilling revealed cyanide readings well over 0.1 parts per million (ppm); the minimum level found to kill wildlife and pose a threat to people. Agricola site is showing levels testing at 300ppm, the acceptable level is less than 1ppm.”
In 1995, the DME commissioned a rehabilitation plan and funding of $850,000.00 was approved. The incorporation of the Agricola mine site into the Conondale National Park considerably raised the political profile of the rehabilitation program.
The decommissioning project was undertaken over a period of 15 months, and has been considered highly successful, from a number of perspectives.
“Revegetation- Many trees grew to over 5 metres within two and a half years.”
“Water Quality- Apart from localised silting in Booloumba Creek, the rehabilitation works caused no apparent effects on downstream water quality.”
“Community Relations- Once rehabilitation work started there was an improvement in attitude from the community in general and for the Conondale Range Committee and Forestry Rangers in particular.”
“Safety- No accidents were recorded during the 15 month rehabilitation program involving more than 600 person-visits to the site.”
The Agricola mine site is accessible by walking trail, situated near Booloumba Creek camping and day-use area, and between the Cairn and the Artists Cascades.
Queensland parks and wildlife service
Exploreconondales.com (the Agricola experience…May it be a lesson)
Cmc.qld.gov.au (report on improper disposal of liquid waste in south-east Queensland)
Ret.gov.au (Mine Decommissioning- Case Study 7)
Dme.qld.gov.au (Queensland Government Mining Journal. Volume 88, No. 1031)
I’ve travelled the logging roads through the State forests and National Parks, between Jimna and Kenilworth. Dozens of old gold mines are in the area, all locked away, no access to fossickers. Across the top of the range, Rainforest so thick, the sunlight can not hit the ground. Steep gullies border the twisting gravel road. Around each corner is a new wonder. I walked down to Peter’s Creek, beautiful spot. Picked up at least a half dozen leeches just walking the 600 metre trail to Peter’s Creek.
Trying to move through the area in the old days must have been torture. Living there even harder, let alone working the area for gold.
Explore a little, live a little.