Faulty pumps to blame for Husab waste leak
Investigations into a leak in the Husab Mine's tailings dam located in the Namib Naukluft Park in May, has finally been completed.
Photos of the leak surfaced on social media, which sparked fears that dangerous waste material was leaking into underground water sources. Particular concerns were raised that groundwater in the Kahn and Swakop rivers will be contaminated.
The vice-president of human resources at Swakop Uranium, Percy McCallum, however, said that investigations by the department of environmental affairs, the National Radiation Protection Authority, Ministry of Agriculture, Water and Forestry and an external environment consultant, found that the spillage took place in a small localised area.
“The pumps at some of the lined seepage collection ponds partially failed and with the continuous inflow of the seepage water, resulted in the lined seepage ponds overflowing onto the unlined surroundings,” said McCallum.
The spillage area is still within the perimeter of the tailings storage facility fence, which is not accessible to the public or animals according to him.
McCallum also confirmed that the incident was reported to the authorities within days and inspections were conducted.
“The inspections confirmed that the spillage incidences were directly caused by the pump failures at some of the seepage ponds. When the external regulators examined the area, there was no longer any overflow of the seepage ponds as corrective action had already been taken to repair the pumps timeously, and additional mechanical pumps were used to pump the water back over the wall into the tailings dam.”
“In addition to the water analysis done by the mine itself, the ministry of agriculture also took independent samples for verification purposes. The company also continues to frequently monitor the tailings storage facility and surrounding boreholes. Rehabilitation measures were taken by the company to neutralise the sand patches where the spills occurred, and subsequent rehabilitation of the areas started and is continuing. The company also reviewed reasons for the pump failures and has ordered new pumps,” said McCallum.
The president of the Namibia Uranium Association (NUA), Hilifa Mbako, said that the NUA concurred with the findings of the regulators.
According to McCallum the tailings dam contains the treated slurry from the processing plant. The bulk of the water from the slurry is returned via the decant system to optimise water recovery.
“Due to commissioning activities at the storage facility initially higher seepage rates can be expected which it was designed for, which is subsequently drained into lined seepage collection ponds from where it is pumped back to the processing plant via the return water ponds or over the wall into the tailings dam for re-using purposes to save water,” he said.
JESSICA BOTES
Photos of the leak surfaced on social media, which sparked fears that dangerous waste material was leaking into underground water sources. Particular concerns were raised that groundwater in the Kahn and Swakop rivers will be contaminated.
The vice-president of human resources at Swakop Uranium, Percy McCallum, however, said that investigations by the department of environmental affairs, the National Radiation Protection Authority, Ministry of Agriculture, Water and Forestry and an external environment consultant, found that the spillage took place in a small localised area.
“The pumps at some of the lined seepage collection ponds partially failed and with the continuous inflow of the seepage water, resulted in the lined seepage ponds overflowing onto the unlined surroundings,” said McCallum.
The spillage area is still within the perimeter of the tailings storage facility fence, which is not accessible to the public or animals according to him.
McCallum also confirmed that the incident was reported to the authorities within days and inspections were conducted.
“The inspections confirmed that the spillage incidences were directly caused by the pump failures at some of the seepage ponds. When the external regulators examined the area, there was no longer any overflow of the seepage ponds as corrective action had already been taken to repair the pumps timeously, and additional mechanical pumps were used to pump the water back over the wall into the tailings dam.”
“In addition to the water analysis done by the mine itself, the ministry of agriculture also took independent samples for verification purposes. The company also continues to frequently monitor the tailings storage facility and surrounding boreholes. Rehabilitation measures were taken by the company to neutralise the sand patches where the spills occurred, and subsequent rehabilitation of the areas started and is continuing. The company also reviewed reasons for the pump failures and has ordered new pumps,” said McCallum.
The president of the Namibia Uranium Association (NUA), Hilifa Mbako, said that the NUA concurred with the findings of the regulators.
According to McCallum the tailings dam contains the treated slurry from the processing plant. The bulk of the water from the slurry is returned via the decant system to optimise water recovery.
“Due to commissioning activities at the storage facility initially higher seepage rates can be expected which it was designed for, which is subsequently drained into lined seepage collection ponds from where it is pumped back to the processing plant via the return water ponds or over the wall into the tailings dam for re-using purposes to save water,” he said.
JESSICA BOTES
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