RESPONSE TO SIGNIFICANT RAINFALL AT THE DARGUES MINE
In March 2022, record rainfall and associated run-off filled the TSF at our Dargues Mine to its operational storage capacity. The possibility water would be released into downstream waterways was a real threat if the rain continued. To ensure this didn’t happen, our Trigger Action Response Plan decided to halt production for four days.
The production halt prevented an offsite release from the TSF. Production resumed based on a favourable weather outlook, expert advice from our Tailings Engineer, and amendments to the TSF’s operating controls and monitoring regime.
The decision to halt production and the actions following the event highlight our Value of courage and our unwavering commitment to environmental responsibility.
The Dargues TSF is designed and built-in accordance with the ANCOLD and NSW Dam Safety Guidelines. It has an emergency spillway that allows for the release of excess water to downstream waterways without impacting the integrity or stability of the dam walls. However, as a conduction of our development approval, Dargues is a zero-discharge site.
At the time of the event, our Managing Director and CEO Dan Clifford spoke to the media about what we were doing to address the situation.
“At Aurelia Metals, we take our environmental responsibility very seriously. We have notified the appropriate regulators about the impact of the rainfall and continue to work closely with them to manage the situation.
“Independent accredited laboratory testing of the accumulated water shows it satisfies the requirements for use as stock water. Additionally, we are conducting extensive water quality sampling of the immediate downstream environment in the event of an offsite release,” Dan said.
While production was halted, representatives from the NSW Environment Protection Authority (EPA) inspected the TSF and assessed the relevant risks. An out-of-cycle Community Consultative Committee meeting was also held to brief the community.
Members from our Board also inspected the facility to ensure appropriate measures were being taken to mitigate the situation.
As a result of the actions taken at our Dargues Mine, we successfully contained excess water within the TSF and have so far avoided the need to discharge to downstream waterways. We will continue to work closely with the relevant government authorities and the community to reduce the likelihood of this occurring.
Since the incident, a number of controls have been implemented to reduce the likelihood of a release. These include:
Accelerating the TSF embankment raise to increase the TSF’s excess water holding capacity.
Progressing the approvals required for the construction of a ‘turkeys nest dam’ that will be used to store excess runoff water that would otherwise report to the TSF.
Extensive consultation with the relevant government authorities about using the excess runoff water for dust suppression onsite and irrigation of pastures used for stock grazing.