Copper Refinery remediates historic Amsul Dam
The Amsul Dam, located on the western side of the copper refinery, was originally built in 1985 to store ammonia sulfate, a byproduct of operations at that time.
The dam was one of the first in Australia to be lined. In the 1980s, liners were an emerging technology used in dams and ponds, designed to prevent water seepage. However, the liner materials available 40 years ago lacked the durability of today's options, raising concerns that the liner might have degraded and was no longer providing an effective barrier.
In mid-July, a remediation project began to address these concerns. The project involved removing and disposing of the water and sludge sitting above the liner, followed by the removal and disposal of both the liner and the impacted soil beneath it.
After the decommissioning phase was complete, the area was backfilled with clean, high-quality materials. Corrective civil works then restored the site to its original ground level, with reprofiling efforts in place to mitigate potential impacts from future rainfall.
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Civil works during soil removal stages.
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Excavation of materials up to 1.5 metres below original dam ground level.
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Civil works during backfilling.
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Truck covers were used to avoid any potential dust emissions during unloading of imported backfill materials.
Wal Woodland, Senior Environmental Advisor said one of the main considerations during the planning stage was ensuring we had adequate controls in place to prevent environmental impacts during the remediation activities.
“We worked closely with several departments onsite as well as contractors McMahon’s who completed the civil works and suitable qualified contaminated land professionals to ensure the remediation works were planned and completed in line with the National Environment Protection (Assessment of Site Contamination).”
“Covered trucks and watering down of the area during drier periods kept dust emissions to a minimum. Despite some challenging external factors, such as wet weather and limited waste disposal options, the civil works for the project are now complete,” says Wal.
Regular updates and engagement with the Department of Environment, Science, and Innovation were also essential to the project’s progress.
Paul Taylor, Manager Townsville Copper Refinery and Port Operations, said Amsul Dam was one of the main historical legacy sources of contaminants at the refinery.
“Removing the contamination source is a major achievement for our operation.”
“Through careful planning and precise execution, we ensured that the project met regulatory standards, contributing to a more sustainable and resilient landscape for the future,” Paul added.