Newmont Ghana Gold Limited - Ahafo Mine Process Solution Overflow Event - Status Update December 2009
On Thursday, October 8th, an overflow of process solution containing low concentrations of sodium cyanide occurred within the processing plant site at Newmont Ghana’s Ahafo Mine. Newmont Ghana regrets and apologizes for the overflow and is committed to operating with high standards and accepts responsibility for any failure in meeting those standards.
The overflow occurred due to a pond-level instrument malfunction. The control room operator observed that the operations pond was overflowing into the event pond which was filled to capacity for planned maintenance activities. Once the situation was discovered, the source of the process solution overflow was stopped, but not before process solution overflowed from the event pond. The process solution within the plant site area was immediately contained and treated to neutralize the cyanide and laboratory analyses showed that all residual cyanide was destroyed.
On Saturday October 10, it was discovered that some process solution had entered the environment exiting the plant site area via a diversion channel leading to a series of seasonally swampy areas where a localized fish mortality was discovered. Employees, local communities, regulatory agencies and other key stakeholders were notified and updated about the overflow beginning Saturday October 10 when this condition was discovered Water quality samples collected after October 11 indicated residual process solution levels were below laboratory detection limits. Results of Ahafo’s internal testing were also made available to the regulatory agencies during their initial site visit.
Ongoing water quality sampling and analysis conducted by both the government agencies and Newmont Ghana following the incident have indicated no presence of cyanide. Water samples were sent to independent laboratories in Ghana and the United States to verify other tests showing that surface water drainages and groundwater remained safe. Sampling results continue to confirm that there is no threat from cyanide to human health and no residual environmental impact.
We deeply regret this incident and the anxiety it caused the local community. We are working with the regulatory agencies and interested parties to ensure restitution for any impacts. In addition, we continue working closely under the supervision of appropriate government agencies to modify our systems and implement corrective actions to ensure an accidental release of this nature does not happen again.
Newmont is conducting its own evaluation and has put interim measures in place to prevent any further releases. Newmont also has commissioned a third party review by qualified International Cyanide Management Code auditors to assess these measures and provide recommendations for long-term improvements.
Newmont Ghana has committed to publicly announcing our corrective actions for preventing any future releases of this nature. Similarly, the company is engaging with a regulatory panel established and managed by the Government to review causes of the overflow, its impacts and the corrective measures being implemented.
Newmont Ghana remains committed to demonstrating that the safety of our neighbors and employees and protection of the environment is our priority. Superior environmental performance of our operations is extremely important to Newmont Ghana and it will continue to be our focus going forward.
For further information or questions regarding the overflow event, please contact Adiki Ayitevie
