The Investor Mining & Tailings Safety Initiative has requested that over 600 resource companies, including major miners, reveal the safety records of their waste storage facilities, following the collapse of Vale’s Brumadinho dam in Brazil in January, which killed hundreds.
Following the disaster, a group of 96 institutional investors (representing more than $10.3 trillion assets under management) have written to 683 extractive companies seeking greater disclosure on the management of tailings storage facilities.
The companies addressed, including major names in the mining industry such as BHP, Rio Tinto, Anglo American, Glencore and Vale itself, have been given 45 days to publicly disclose their dams’ size, construction methods and safety records.
About 100 investors, led by the Church of England Pensions Board and Sweden’s public pension fund, expect the companies to publish the answers to 20 questions sent, covering issues such as the height and type of dams they have, their capacity, engineering records and safety checks.
Industry group the International Council on Mining and Minerals (ICMM) said in March it was working with the United Nations Environment Programme (UNEP) and the Principles for Responsible Investment (PRI) to develop new standards.
Currently there are no set of universal rules defining exactly what a tailings dam is, how to build one and how to care for it after it is decommissioned.
There are about 3,500 tailings dams around the world. Unlike the ones used to build reservoirs or hydroelectric projects, tailings dams are not usually made from reinforced concrete or stone. They are mostly constructed from the waste material left over from mining operations, which — depending on the type of mine — can be toxic.
Only three countries in the world ban upstream dams — Chile, Peru, and now Brazil. Chile, the world’s No.1 copper producer, also regulates the minimum distance between dams and urban centres. But the nation still has 740 tailings deposits, only 101 of which are active, with the rest abandoned or inactive, according to data from mining agency Sernageomin.
Click here for complete coverage of the dam burst at Vale’s Córrego do Feijão mine.
What is an upstream tailings dam? Where I come from tailings dams are built across narrow valleys and they all lie upstream from something. What is the alternative to an upstream dam?
Toxicity is not the point…Stability is. Tailings are geochemically reactive and toxic or not…the leachate from them can eat holes in the underlying subgrade…and facilitate the development of saturated zones within the pile…much as Ice dams on a poorly insulated roof lead to failures. Same kind of thing….clay, ice…it interferes with drainage. Posted by Steve Johnson, geologist, Milena Resources LLC.
Toxic? Eh…not exactly…the reason mined wastes are in tailings piles is because they are considered “non-toxic” and “non-hazardous” and so exempt from landfill regulation (but not from water pollution regulation) at least by US regulatory officials. If they were “toxic” they would be regulated by the Toxic Substances Control Act. If they were regulated as “hazardous” they would be regulated under the Resource Conservation and Recovery Act…RCRA. They are not….yet. But if it were so controlled, just try to get approval for disposal. Once it is labelled Toxic or Hazardous…management will be doubly hard to do. I might be in favor of it but this is a Superfund issue par excellence. Going forth, everything will have to be moved and contained as if it were a “stacked leach pile”. The old piles? Well, they are a problem.
In the USA…the regulatory threshold tests (TCLP)…are not designed or applied to mined waste itself but there are stringent tests applied to any water coming from hazardous waste as part of the “derived from” rule So, if mined waste is regulated as “hazardous or Toxic”, water purification might be used in order to solve a problem that is as much a geochemical/mineralogical hydrogeotechnical soil stability dam safety issue as a “water quality” issue.
The “derived from” rule under RCRA is not user friendly. It is so tough on regulated material it can be used as an ax by agencies and political groups to shut projects down with too much water no matter how good the treatment plant. The city of Detroit did that once to us and we were the regulatory agency!
I regulated disposal of much less refractory material…PCBs in landfills for 25 years and it was very very hard to get innovative solutions to disposal partly because the regulations were so old and because innovation that would facilitate PCB destruction INSIDE a containment system was considered “post-processing” and frowned upon. Furthermore…nobody really knew how to deal with “perpetual care” issues very well, it became a Bond worthiness issue.
Companies were willing to consider treatment pre and post placement it but not the regulatory authorities I had to work with. For comparison, the actual environmental geochemistry of PCBs made landfill containment considerably more environmentally feasible than incineration…but still…much resistance against what the regulatory authorities believed was actually reasonable. So how will it be with mined waste? My experience is that It depends on the community…some went well when cleanup was on site…but the “commercial” offsite facilities were actively resisted so much it even split state agencies against themselves. Posted by Steve Johnson…ex TSCA permit geologist, USEPA Retired and currently, general partner…Milena Resources LLC, a mining exploration and development company.