Lined Tailings Facilities - Consequential Risks Require Better Understanding

Lined Tailings Facilities - Consequential Risks Require Better Understanding

Publication: Mining Review Africa
Issue: October 2018

The mining industry in South Africa – which extends back more than a century – is grappling with historical legacies that have been put under the spotlight as the world becomes more environmentally conscious and responsible. Tailings management in particular, an area neglected in the past, is now a priority. While lining have become the preferred option to reduce possible environmental impact of tailings material they pose their own set of risks which urgently need to be monitored and addressed, Knight Piésold technical director for mining Andrew Copeland tells Laura Cornish.

Up until a few years ago, the mining industry in South Africa took a reactive approach to environmental impacts caused by mining activities. Unfortunately, tailings-related impacts are severe – and can result in loss of life, long-term damage to the environment and ground water pollution.

“The combination of legislation covered by the National Environmental Management: Waste Act, 2008, and Government Notice 332, May 2014 in which residue deposits were deemed as a waste unless de-classified or exempted by the minister, has seen the mining industry’s determination to make amends by complying. Together with government, consultants such as ourselves are working closely with the sector to improve our environmental image,” Copeland starts.

The mines have subsequently turned primarily to linings as a means to ensure seepage from tailings deposits does not come into contact with the natural environment. The government has also shown favour for this route as it considers it a proactive and trusted mechanism which guarantees protection of the environment.

“It is commendable that our industry is embracing the need to reduce its impact on the environment and we are undoubtedly heading in the right direction but few are aware that the solution we are now deploying has its own potential risks,” Copeland reveals.

The incorporation of linings for example is not a finite solution. Like most plastic-based products, they degrade over time (20–100 years possibly, depending on the quality of the lining and the material it houses) and will leak. This means they cannot be considered a long-term option on their own, and may only function well during the operational life of the tailings facility.

But there is a far greater risk at play, Copeland highlights. “The incorporation of a lining, be it traditional synthetic material the clean-up), there is the cost of having to prematurely build new facilities, an equally disastrous reality for the industry. “Considering that South Africa’s lined tailings facilities are <5 years in age, we are in a period of beginning to understand whether such designs are sustainable and if/when we reach the crossroad of having to build new tailings facilities to replace unsafe ones.”

 

Download the full article.

Download

Recent Insights

May 2023
Is the Implementation of Dry Stacking for Tailings Storage Increasing? A Southern African Perspective
February 2023
Canadian Consulting Engineer's Lifetime Achievement Awards: Jeremy Haile
February 2023
Geotechnical Characterization of Collapsible Salty Sands Subjected to Monotonic and Cyclic Loadings – A Case Study for Areas with High Seismicity
November 2022
Application of the 3D Limit Equilibrium Method in Tailings Dam Breach Analysis
November 2022
Evaluation of Tailings Behaviour for Dam Breach Assessments
November 2022
Tailings Improvement by Stress-Densification from Waste Rock Capping
November 2022
Transforming Tailings Management Systems toward Alignment with the GISTM: A Case History
October 2022
Managing Excessive Pit Wall Deformation of Weak Rock Mass
October 2022
State-of-the-art Method for Estimating Long-term Hydroclimatic Conditions for Tailing Dam Water Management and Dam Safety Planning
August 2022
Observed Subsidence Progression at New Afton Mine in Response to Lift 1 Mining
June 2022
Hydrometric Monitoring and Effluent Discharge Mixing in Challenging Natural Conditions
May 2022
Inundation Modelling of Non-Newtonian Tailings Dam Breach Outflows
May 2022
Video: Tailings Management Compliancy Picks Up Momentum
May 2022
A Catch up with...Richard Elmer
February 2022
Engineer of Record Services for Tailings Facilities
November 2021
Knight Piésold's Projects Commended at Prestigious Awards
November 2021
Advances in Ensuring Tailings Dam Safety
November 2021
Gearing Up for Growth in Zambia
October 2021
Climate Change Effects on Rainfall Extremes and Implications for Highway Drainage Structures
October 2021
Knight Piésold, aliado de la minería sustentable