Civil Engineering December 2022 | Vol 30 No 11

16 December 2022 Civil Engineering M ine residue is the collective term for tailings, slimes, ash, slag, rejects, leached ore, gypsum, discards and similar post-processing wastes from ore bodies or mineral deposits. The majority of processed mine waste is referred to as tailings, with large volumes needing to be stored in tailings “dams”. The tailings often leave the plant as a slurry and are pumped to the dams where they need to be safely stored for many years, and in some cases become a low-grade future resource. The SANS 10286 code of practice for mine residue was originally drafted in 1998 in response to the 1994 Merriespruit Tailings Dam failure in the Free State town of Virginia, in which 17 people lost their lives, many homes were buried, and a water course was pol- luted. It has been in use ever since with two attempts to update it in 2008 and 2013, however both remained as draft versions. It has served not only South Africa very well, but also neighbouring countries that do not have an equivalent code. When compared to international standards it has stood up extremely well, but in recent years, the major tailings dam failures in Brazil have changed practices and requirements, and the code therefore required updating. In August 2020, the International Council on Mining and Metals (ICMM) together with the Principles for Responsible Investment and the United Nations Environment Programme published the Global Industry Standard for Tailings Management (GISTM). Since the ICMM represents the major mining companies, who all agreed to comply with it, it has been adopted as the new industry standard. Updating SANS 10286 In November 2020, the Tailings Sub- Committee of the Geotechnical Division of SAICE initiated an update of the code. A drafting or working group was formed comprising members from mining houses, consultants, academia, contractors, and the Minerals Council South Africa. The consultants include both tailings and environmental specialists. The drafting team took an early decision that the updated code should align with the GISTM. To do anything different would not only create confusion but also conflict. Even the terms used in the new code are the same, in particular the Accountable Executive (AE), Engineer of Record (EoR), Responsible Tailings Facility Engineer (RTFE) and Independent Tailings Review Board (ITRB). While the Mine Health and Safety appointments and delegation of responsibility will still apply on mines, these key persons must be appointed, and an organogram of their relationships set up. While the new code aligns fully with the GISTM, it also aligns with local regulations, proposes minimum factors of safety, and allows the design and construction of upstream tailings dams, provided that they comply with the ten rules (Vick (1992), Martin and McRoberts (1999)). By the end of March 2022, a draft code was completed. Since then, it has been entered into the SABS process for technical review and approval, then for editing and formatting into the SANS template, and lastly, in November 2022, it was issued for public comment. Due to the tragic failure of the Jagersfontein Tailings Dam on 11 September 2022, SANS agreed to shorten the public comment from 60 to 30 days. Subject to comments, the final code may be issued in December 2022. In the meantime, the industry is encouraged to start aligning with the GISTM requirements. Timing for compliance will need to be set in consultation with the industry Codes and standards Andrew Copeland Pr Eng, FSAICE Chairman of Tailings Working Group for Updating SANS 10286 Tailings Sub-Committee of SAICE Geotechnical Division acopeland@knightpiesold.com Updating the SANS 10286 code of practice for mine residue Aerial view of the Jagersfontein Tailings Dam after the failure