Moments ago Vale, BHP and Samarco concluded their press conference presenting the findings of their indepdendent panel on the causes of the Fundao Tailings dam failure . The report was commissioned by Vale. A full copy in English is up at http://www.fundaoinvestigation.com/ Users must register to access.
Within the narrow frame of “proximate causes” the report identifies three major inter related factors that combined to set up the failure events
Another central aspect is how their deposition was influenced by a series of unplanned occurrences during the dam’s construction and operation. Together, these incidents established the conditions that allowed the failure to take place. These included: (1) damage to the original Starter Dam that resulted in increased saturation; (2) deposition of slimes in areas where this was not intended; and (3) structural problems with a concrete conduit that caused the dam to be raised over the slimes.:Fundao Investigation Report
At its heart this means that the separation of slimes and sands was not achieved as intended and planned in the original design. This ineffective separation of slimes and sands , in combination with the sands not having adequate drainage on which efficacy of the design depended resulted in the liquefaction and failure..
The design was not adaptable to variation in the proportion of sands and slimes received. And most importantly, it depended on achieving adequate drainage of the sands.
A root cause was construction errors in the drainage system for dike 1 ( holding the sands) that became apparent through a leak almost immediately after the dam was placed in service in 2009. These construction errors were never fully corrected thus failing to provide from the outset the core elements on which the safety of the dam’s design depended
Engineering investigations later revealed serious construction flaws in the base drain and its filters, including a portion of the drain’s outlet that had never been completed. This allowed water pressure within it to build until causing the slope to erode and slump. As these investigations continued, the impending rainy season made it too late to fully restore the drainage features to their original condition, making it impossible to repair the damage. Instead, all of the drains were sealed. With this, the most important element of the original design concept became inoperative.
Both in the press conference and in the report the panel did an excellent job of presenting in plain English all could understand where and how the failure occurred, fulfilling.their two main mandates under the contract with Vale.
The failure occurred in the left abutment of the sands dam in an area that had been temporarily set back from the original design in an effort to relieve pressures while work to correct the draingae deficiencies discovered at the outset of operations at the Fundao were being undertaken. However, the set back section where the November 5, 2015 failure occurred was over unstable sands where prior problems had already been identified.
It became evident for the Main Gallery at the right abutment when in July, 2010 a vortex appeared in the reservoir above it, showing that tailings and water were entering. Inspections revealed cracking and structural damage from foundation settlement and construction defects. Were either of the galleries to collapse, uncontrolled release of tailings from the reservoir or failure of the dam would be possible. So in January, 2011 a program of jet grouting was initiated to repair the Main Gallery and return it to service. Similar conditions were discovered for the Secondary Gallery, and jet grouting was undertaken there as well. But by July, 2012, it was apparent that jet grouting had not cured these problems. After a sinkhole appeared in the tailings overlying the Secondary Gallery in November, 2012, repair efforts were abandoned. Instead, plans were made to plug both galleries by filling them with concrete from their outlets to a point beneath the projected crest of the 920 raise in order to prevent their collapse. Moreover, it was discovered from structural analyses that the Secondary Gallery could not support tailings higher than El. 845 m, some 10 m lower than the tailings already were at that time. Because the height of tailings at the left abutment already exceeded the load capacity of the Secondary Gallery, the dam could not be raised any further over this area until the plugging operation was completed. As a temporary solution, it was decided to realign the dam at the left abutment by moving it back behind the portion of the gallery to be filled with concrete so that embankment raising could continue. This realignment shown on Figure 2-10 became the “setback”. The setback would move the crest closer to the reservoir water and the slimes it contained, but it was anticipated that the dam would be quickly returned to its original alignment as soon as the plugging operations were done. At the same time, as will be explained more fully in Section 5, moving the crest back from its original alignment would also place it closer to, if not over, areas where beach encroachment and slimes deposition had already occurred.
The focus on “proximate cause of failure” is standard for dam failure reports so the limitations imposed by Vale on the panel are not substantially different from those imposed by Government commissioned cause of failure investigations.However, the narrow contractually defined focus on “proximate cause of failure “, masks avoids and obfuscates all questions of material relevance to a more comprehensive understanding of causes of failure and of the role Samarco, Vale and BHP played in fostering and furthering those root causes.
Although the carefully worded report does open avenues of inquiry to a more complete understanding of causes of failure, the impression left at the press conference was that the sudden liquefaction, that is where solids behave like liquids because of their saturation levels, was not detectable by conventional means of monitoring or to the naked eye. This impressions suggests , whether intentionally or not , that adequate supervision and oversight would not have detected the conditions that emerged continually from inception of operations of the Fundao which went on line in 2009.
Of course as this was not a Government report it in no way binds or limits what the Brazil Prosecutor and police from continuing their investigations and further pursuing the many criminal and civil actions still outstanding against Vale, BHP and Samarco. Panel members who are contractually constrained from saying more contractually can still say more under oath under compulsion of subpoena.The United Nations most likely will also not consider their issues resolved or addressed by this investigation report.
Meanwhile BHP and Vale, if not Samarco, will get a bit of a boost with investors from investment analysts who will be so excited by this report they won’t stop for a second before announcing BHP Vale and Samarco vindicated by expert panel. Watch. Inevitable.
The presentation was made by the elegant serene Dr Norbert Morgenstern,panel Chair and followed by questions from press . It was limited only to what they were contractually asked and allowed to address by Vale, their employer and a key contributor to the events. The carefully narrowly delineated scope, gives the impression as they did at Mt. Polley, that even though the failure was well advanced and inevitable ( my words but a fair summary of the carefully spoken Dr. M’s) it was not detectable by any customary monitoring equipment or by the human eye.
Dr.. Morgenstern, also chaired the Government commissioned Mt Polley Investigation Commission . Samarco panel member Dr.Steven Vick also served on the Mt Polley panel and has served on numerous other failure committees often managimg to speak beyond the contractual limitations .to deviation from best knowledge and best . On the Mt Polley report the panel also managed to speak more fully to underlyig causes that was perhaps intended by the Government opening pathways toward solutions that are still being explored and advanced throughout the industry..
It is not explicitly stated at the press conference or stated in the framing of the Fundao failure report that this was beyond the panels scope pro but there is a disturbing absence of context for causal events in best practice, best knowledge best available technology both n the press conference presentation and in the written report.
This can still be added by the Brazilian prosecutor sand police.
Rate of Raise
The quiet dignified immaculately groomed Dr. Morgenstern ducked the rate of raise question as a contributing cause.many times. The first time he straight out papered over it stating what the maximum design height was and that the TSF was receiving what was generated and moving towards that planned height. The rate of raise and the design height, as he very well knows violates the 10 commandments for upstream dam construction . I have to look ..wasn’t he a co author on that and an original contributor to those 10 commandments?
It is a huge huge failing that the panel did not speak to that when specifically asked several times. To the second question on rate of raise as a contributing factor Dr. Morgenstern said the full record was in the report and gave the exact location. In another comment he noted that the right abutment had the same rate of raise and showed no deformation .
In the report however the panel points out that the safety and efficacy of the planned rate of raise depended on dry sands stack and clear separation of slimes as intended in the original design but never realized in the construction of the dam.in the orginal design.
Additionally, the balance between sands and slimes crucial to the dam raising plan was changed. Filling of Dike 2 had begun earlier than anticipated, making its slimes level higher, not lower, than the projected sands in Dike 1. At the same time, reduction in pellet production reduced the amount of sand available while delivery of slimes continued. This required construction of yet a third dike between Dikes 1 and 2, designated Dike 1A, to provide additional slimes capacity. It was November 2010 before all of the measures made necessary by the piping incident were finally completed. It remained to devise a new design concept to replace the old one.
(dike 2 is the slimes dike intended to mainatn the essential separation between slimes and sands.) At the press conference Dr. Morgenstern had many opportunities to explain this in answer to the several questions on rate of raise as a contributing factor.
In the report Dr. Morgenstern seems to be backing away from the 10 commandments on safe upstream construction and suggesting that conventional slurry deposition at very large very high upstream dams can be done safely if adequate drainage is maintained and adequate separation of slimes is maintained throughout. Or perhaps in this context he wanted to keep the focus clearly and mainly on the importance of of a dry sand stack to dam safety and that of course is pre eminent over height and size considerations in any earthen impoundment using slurry deposition.
A surprise were the findings and questions on the earthquake. Panel ( as spoken for by Dr. Morgenstern) said the earthquake definitely preceded the failure and they had examined the records carefully on that ( have to read the report to see how they established the time of failure). In the 1937 Mexico failure where the failure precipitated the earthquake a very loud clap preceded the actual break and the clap was the start of the big slide which triggered the earthquake. He said the panel found that the role of the earthquake was only as an accelerant of an already advanced failure condition.
He did note though that the right abutment showed no deformation nor other “adverse response” to the little tremor.
I was surprised that in discussing the relative effect of the small tremors he did not bring out that under the undrained conditions of the Fundao a hair trigger even from construction vibrations could set off a liquefaction slide. Also he did not offer any guidance or information on the procedues for USA ( undrained stability analysis) or the importance of using that analysis especially when a dam design depends so critically on a totally dry and stable state as the panel itself noted. Instead of referring to USA and the absence of any USA at the Samarco operations he said that the type of monitoring needed to detect the growing saturation within the stack were not customary.
Design, Or Implementation of Design at Fault
At the outset of the press conference Vale’s Press Secretry said that press questions were to be limited to the content presented and that all questions of fault or otherwise outside the spefic material in the report ” would be disregarded”
Dr. Morgenstern specifically ducked all questions about whether the failure in the drainage was a result of design of the drainage system or a flaw in the construction of a good design saying it was not in their scope to address beyond proximate cause of failure the standard limitation in all dam failure reports.
Left Abutment a Deviation from Design.
On the same basis he ducked very well researched and very well informed questions about whether the left abutment was a deviation from original design and whether the original design would have held ( the failure was at that abutment to which one time engineer in charge Pimenta De Avila had referred many times as an unstudied deviation from the original design). The report is very clear that the left abutment was a deviation and that its intent was t compensate for noted drainage problems.
All in all I’d say the report. not unlike the Mt Polley report is a sort of red herring taking analysis away from a more comprehensive analysis of root causes of failure and if it is allowed to stand unchallenged in that regard gives BHP Vale and even Samarco a big hall pass.
Ducked All Questions About Vale’s Illegal Dumping At The Fundao
Several press asked about the documented amounts Vale desposited in the tailings dam without authority from Minas Gerais Offcials and whether that contributed to the failure or escalated the risk. To all Dr. Mogenstern calmly said their scope was limited only to the sequence of geophysical events leading to failure.
No Examination of Deviation From Advice of Inpdependent Panel & Advisors
There were no questions and no answers would have been forthcoming anyway on what the mine independent panel chaired by Angela Kuipers had advised in any of these matters nor on what the advisory board including Dr. Andrew Macgrgeor Robertson, head of Info mine and of Mining.com had to say. The report indicates that the panel had complete access to all these records.
All in all I guess I am saying the use of some very distinguished people in the field to pull off a giant white wash of the real issues and a full examination of the real causes of failure is an insult and perhaps injury to the public interest unless the bold Brazilian prosecutor acts to make sure this hall pass does not stand.
I was very very impressed by the in depth knowledge all press had and it is shameful that unapologetically so many good questions directly relevant and key to a more thorough examination of root causes were met with “that was not in the purview of our commission”( my summary phrase of the many different ways Dr .Morgenstern responded to key questions.
I think Dr. Morgenstern and Dr. Vick owe the world. They should never have accepted a commission to do this for Vale knowing full well what constraints would attend. No doubt they are also contractually required to be silent forever in all these other questions and to not speak publicly ever beyond what is on the contract given to the panel and the report they generated pursuant to that obfuscating scope.
A subpoena trumps that contractual obligation and the elegant Dr. Morgenstern may yet have to answer those questions as a key expert witness.
Lindsay Newland Bowker, CPCU ARM
Bowker Associates, Science & Research In The Public Interest
PRESS COVERAGE ON REPORT & PRESS CONFERENCE FROM WITHIN AND UTSIDE THE MINING INDUSTRY
Very encouraging to see this level of competence, also very evident in the press conference, in mainstream media and press and also among business and investment analysts. Mining proponents have traditionally had nearly complete control of information including the collective witholding of public information about very serious failures. These wonderful accurate and technically proficient accounts of what the report said and didn’t say are the seeds of change from which mining reform will spring. These journalists are holding the light on the path to zero failure and serving the public interest with excellence.
Perhaps 9 months ago when the eminent Dr’s Morgenstern and Vick agreed to work for Vale on this it wasn’t clear how much of the story would ever be told or understood. Both have worked all their careers for responsible mining and for research which has created the enduring foundations of best knowledge and best practice. Perhaps they thought that even with the extremely narrow mandate of their commission the truth would be obvious.
This impressive list of main stream media and press coverage on their work certainly has accomplished that, whatever their still unspoken intent and hopes..The Brazilian Prosecutor has gone on record as citing the report as useful to their continued move to rejection of the settlement agreement and toward an ultimate settlement amount of $45 billion under for which by law BHP, Vale and Samarco are already jointly and severally liable. The police investigation pursuing criminal charges including against a Vale engineer who falsified records has also stated publicly to these journalists that the report reaffirms and exactly parallels their own investigations and conclusions.
It is heartening to me to see the individual impressions, questions and analysis in each of these accounts. These articles are all more than just a competent cut and paste of bits and pieces of a report and situation they don’t understand. Each fully understands the larger context and implications and each offers a valuable insight for a framing that yields insight.
To each and all..thank you for your important work in the public interest.
Lindsay Newland Bowker September 1, 2016 Stonington Maine
Wall Street Journal has a similar take on the report headlining that it adds little new to either understanding the causes of failure or leading us to solutions.http://www.wsj.com/articles/companies-report-on-brazil-dam-failure-adds-little-new-on-causes-1472512948 Paul Kiernan ( who lives in Brazil) and Rhianon Hoyle(Reuters), both main stream press/media have followed the Samarco failure from the first day and have each attained a level of competence and understanding of mining and its social, economic and environmental foot print on the world. This coverage is far more insightful ( and accurate that what appeared in Mining.Com.
FORTUNE http://fortune.com/2016/08/30/samarco-disaster-investigation-cause/ accurate and well presented..echoes Wall St Journal Observation that the report added little to what was already known and already the basis for the Barzil Prosecutors $45 billion against BHP, Vale and Samarco and of the police investigations seeking criminal indictments against Samarco’s former President and a Vale Senior Engneer.
https://translate.google.com/translate?hl=en&sl=pt&u=http://infraestruturaurbana.pini.com.br/solucoes-tecnicas/noticias/relatorio-independente-diz-que-rompimento-da-barragem-de-fundao-aconteceu-372445-1.aspx&prev=search excellent Portuguese language ( English translation) account of the reprt in a professional engineering magazine.. Overstates the reports finding on the original design as “robust”. The report in fact said the dam was dependent on the drainage system for keeping sands dry and the dkes for for keeping slimes separate but was not flexible enough to handle the slimes vlume that actually emerged. The drainage failure, as accurately explained in this piece, was due to a construction error from which the project never relay recovered. This lead to several deviations from the original plan,including the set back of the left autent after it was determined the elevation was already too high for safety.
https://translate.google.com/translate?hl=en&sl=pt&u=http://www.valor.com.br/empresas/4691183/relatorio-aponta-falha-de-construcao-em-drenos-da-barragem-da-samarco&prev=search Another very accurate account based on an acutal reading of the report more than the press conference. Clearly got the drift that this started wth a deficiency in implementation of the design as the dam was being built detected in 2010 through a leak of running water through the face of dike 1, the sands dam. The dam had to be drained to investigate and attempt to fix but when it was excavated it was apparent it wasn’t just broken it was missing entire sections that were called for on the dam design. . This article accurately summarizes the series of mis steps and ad hoc adjustments made thereafter which finally and irrevocably culminated in failureaccrding to the expert panel.
BBC summarizes the report as a series of design and construction errors cited cause of failure. This includes a statement by the Brazil Prosecutor that essentially the report just adds details to what their investigation, now asserting a claim of $43 billion, already showed.
REUTERS (Stephen Eisenhammer) http://www.reuters.com/article/us-brazil-mining-samarco-idUSKCN114259
BLOOMBERG MARKETS .. no mincing words here http://www.bloomberg.com/news/articles/2016-08-31/bhp-ceo-mackenzie-s-bonus-axed-after-fatal-samarco-dam-failure and headline is BHP CEO’s slahed bnus owing to the Samarco disaster.
PANARMENIAN NEWS http://www.panarmenian.net/eng/news/219674/ straight talk here as well with quotes from Brazil Prosecutor http://www.panarmenian.net/eng/news/219674/