SSR Mining (SSRM.TO, SSRM) was at last look up 1.3% in after-hours Nasdaq trading Wednesday as it provided an update on the deadly February, 2024 collapse of the heap-leach pad at its Copler mine in Turkey, citing a review that puts it down to a "deeply-rooted flaw in the third-party engineered design of the heap leach pad."

SSR noted that following the Copler Incident, it commissioned Call & Nicholas, Inc (CNI), an international mining consulting firm that specializes in geological engineering, geotechnical engineering and hydrology, to conduct an independent review of the pad failure at the project. It said after analysis of the engineering design, construction, and operation of the heap leach facility, and comprehensive reverse-engineering of the failure, the consultants determined the most likely cause of the Copler Incident was a "deeply-rooted flaw in the third-party engineered design of the heap leach pad."

SSRM said: "The review found that in the third-party engineered design, the assessment of the test data overestimated the shear strength properties of the liner system at the base of the heap leach, which inflated the calculated factor of safety values in the third-party engineered design. This error resulted in insufficient shear strength along the liner interface to support the as-designed heap leach facility."

"Importantly," SSRM added, "CNI also determined that in all material respects, the heap leach pad construction and operation was carried out in conformance with the issued-for-construction engineered design parameters. In addition, CNI's review did not find any substantiation that excess water, ground vibrations from blasting, nor stacking beyond the design caused the event."

Rod Antal, Executive Chairman, in a statement said knowing now that the failure was the result of an engineering design flaw, and not the result of a failure in SSRM's operation or construction of the pad, "provides clarity and some reassurance to the team on the ground as we seek to restart the Copler mine." Antal added the company remains committed to Copler, the local communities and Turkiye."

SSR Mining said it continues to work closely with the relevant authorities to advance the required permits for the restart of the Copler mine. At this time, it is not able to estimate or predict when and under what conditions we will resume operations at Copler.

SSR shares were last seen up US$0.10 to US$7.50 after hours. They closed unchanged at $10.59 on the Toronto Stock Exchange.