Workers have been trapped underground since the floods began on April 16.
Rescue teams, pumping water from a flooded zinc mine in Burkina Faso, where eight workers have been trapped for nearly a month, are approaching a refuge where they may have sought safety, the government said on Wednesday.
The six Burkina Faso nationals, one Tanzanian and one Zambian, have been missing since heavy rains caused flash flooding at Trevali Mining Corp’s Perkoa mine in Canada on April 16, forcing operations to be halted.
The company said that while most underground workers were able to evacuate safely, the eight missing persons were below level 520, which is 520 meters (1,706 feet) from the surface at the time of the flood.
Two shelters have been designed in case miners become trapped, but it is unknown if any of the missing workers were able to reach them.
One is on level 570, filled with food and water for three weeks, and a second smaller one is much deeper in the mine, reaching 710 meters below the surface.
Burkina Faso government spokesman Lionel Bilgo said on Wednesday that more than 38 million liters (10 million gallons) of water had been removed, leaving 10 meters of water above the first trap chamber.
“The vent is still working, so that allows us to keep hope,” Bilgo told reporters as he left a council meeting. “It’s a race against time.”
Trevali confirmed Bilgo’s update, adding that although a compressed air supply line to the room was still pressurized, there was no way of knowing if it was functioning.
“Important factors for survival are the availability of oxygen and how people use the water and any food reserves,” it said in an emailed comment to Reuters news agency.
Confused family members gathered every day at the Sanguie Province location in central Burkina Faso for updates and moral support.
“It’s not easy,” Antoine Bama, the brother of one of the missing workers, told Reuters.
“The more the number of days increases, the more fear there is,” he said over the phone.
The government of Burkina Faso has launched a judicial inquiry into the incident and said last week that mine operators should not be allowed to leave the country while the investigation is ongoing.
Trevali is also working to determine the cause of the accident.
“We initially underestimated the magnitude of the disaster,” said Ditil Moussa Palenfo, country director of Nantou Mining, the Trevali entity that owns Perkoa.