(Bloomberg) -- Eurasian Resources Group’s Boss Mining copper and cobalt project has been halted by the Democratic Republic of Congo’s government, which cites environmental concerns after flooding in March sent mine waste into a river and nearby town.

The suspension is the latest sign of strained relations between copper miners and the Congolese government at a time when output is booming. While the Boss operation is relatively small, the suspension highlights a broader push by Congo to hold miners accountable for environmental damage, Mines Minister Antoinette N’Samba Kalambayi said.

The project is set to produce an average of 21,600 tons of copper and 3,600 tons of cobalt hydroxide per year.

N’Samba Kalambayi suspended the project for at least three months and ordered an investigation into possible reparations for damages, according to remarks to a Senate commission Thursday sent by the ministry. The Boss project was restarted by ERG in November, after spending more than three years on care and maintenance.

“For some time now, there have been more and more incidents in mining areas relating to the overflow of effluents and the destruction of dikes causing significant damage to the environment,” she said. “Such was recently the case at the Boss Mining installations.”

The “enormous environmental damage” could have been avoided or reduced if the company had updated its environmental management plan when it reopened, N’Samba Kalambayi told Boss in a May 29 letter ordering the shutdown that was shared by her ministry. 

The miner will need to revise its social and environmental impact studies to resume operations or face further suspension, N’Samba Kalambayi told the senate commission.

ERG did not respond to emails or text messages requesting comment.

--With assistance from Mark Burton.

©2023 Bloomberg L.P.