Sembehun Geotechnical Site Investigations – Moyamba, Sierra Leone

Sierra Rutile Limited, is developing a new mining concession at Sembehun in the Moyamba District of Sierra Leone.

SRL, via their consultant DRA Global, requested PMI to submit a proposal for a geotechnical campaign comprising of borehole drilling SPT works and CPTu probing works in the dredging pit, tailing storage facility (TSF) and process water dam (PWD) locations.

PMI was commissioned to conduct the investigations after competitive analysis.

The Scope of Work included:

• 6 No CPTu tests
• 55 No geotechnical boreholes with SPT, for a total of 915 meter.

PMI Resources on Site:

• Geomil Truck mounted CPT rig.

Fraste Multi drill rig

Contract Execution

Upon contract award, PMI mobilized the equipment over land from the base in Ghana, to mining site in Sierra Leone. After a smooth mobilization, the teams passed site inductions and medicals, and started up the geotechnical campaign.

There was a close cooperation between the mine, their consultant and our team on ground, to ensure the highest Health & Safety measures were in place, as well as equipment maintenance and working condition were guaranteed and certified.

PMI concluded all boreholes with SPT’s within the dredging pit area, when due to COVID-19 measures, the mine decided to stall the remaining operations and demobilize all teams and equipment pending the end of the global pandemic. About 60% of the works had been completed at the time of demobilization

An intermediate Factual Report was prepared and issued to the client.

All teams were safely demobilized and as per guidelines from the WHO and local policies.

In close coordination with the Client, PMI will re-mobilize the teams and equipment, to finalize the balance Scope of Work on the project.