Monday, 1 August 2016

HYDRO ENGINEER WRITES "OPEN LETTER" TO NALCOR CEO STAN MARSHALL

Guest Post Written by James L. Gordon, P.Eng. (Ret'd)


OPEN LETTER TO NALCOR CEO STAN MARSHALL 


Dear Mr. Marshall,

I write concerning safety issues with respect to the Muskrat Falls Project, and specifically concerning the North Spur.

You have probably been advised by your staff that, while the North Spur does indeed present significant technical challenges, they have been addressed by competent professionals, and so are no cause for concern.

In my professional opinion, such a conclusion is incorrect, and dangerously so.

Let me summarize the current situation at the North Spur, as I see it:

The North Spur Dam at Muskrat Falls will be the first dam ever built containing quick (or marine) clay in the dam body, and on a quick clay foundation.


To date, these clays have been avoided like the plague by dam designers, due to their propensity to liquefy if disturbed or fully saturated.

The dam design has been undertaken by SNC using the FLAC program, generally used on embankment dams.

The FLAC program has never before been used on a dam built on quick clay.

James L. Gordon, P.Eng. (Ret'd)
The design work has been reviewed by Dr. Serge Leroueil from Laval University. However, his review of a voluminous geotechnical document was confined to just over one page, and he admitted that “my knowledge on the dynamic behaviors of soils is rather limited”. He concluded that “the stabilization works increase the factor of safety from about 1.0 to 1.6 which is very significant”.  He did not express an opinion as to whether or not it is adequate, given the consequences of dam failure. 

Two other professors are known to have reviewed the North Spur, one was an earthquake specialist, but neither issued a report.

The North Spur dam design has also been reviewed by MWH, using the same FLAC program, with the same results.

One might argue that, since FLAC is the state of the art regarding soil stability, the concerns have thus been put to rest.  Unfortunately, this is not the case.

The scientific critique of the application of traditional methodologies to quick clays comes from an unlikely source.  Dr. Stig Bernander was, for many years, Chief Engineer for SKANSKA, an international Swedish contractor with over 55,000 employees. He and his team were asked by the Swedish government to determine the stability of several quick clay deposits being farmed in Sweden, due to the loss of life when several liquefied. Unfortunately, despite working on the problem for several years, they could not determine the safety with any precision, due to the lack of a reliable computation methodology.

When Dr. Bernander retired in 1991, he returned to the Lulea University of Technology to conduct research on quick clay stability.  In his doctoral research (Published in 2011 and updated in 2012), he developed a reliable computation methodology for determining quick clay stability, and successfully defended his 252 page thesis titled “Progressive Landslides in Long Natural Slopes”, before a geotechnical panel.

While I am not a geotechnical specialist, at times in my career I have worked with many geotechnical experts, including Dr. A. Casagrande from Harvard, and Dr. N. Morgenstern from U of A.  I have read Dr. Bernander’s thesis carefully, and I find its critique of applying traditional methodologies to quick clays to be persuasive. He demonstrates that the normal methods used to calculate the stability of embankment dams cannot be used where quick clay is involved, as they lead to inaccurate results. His methodology, which has accurately predicted instability in several cases, requires certain geotechnical data not normally obtained for dam analysis.

I called Dr. Bernander and asked him his opinion regarding the reliability of the FLAC analysis for quick clays. He said that he had compared results from FLAC with those of his own methodology, and found that they were not compatible, even after altering the FLAC program to account for a new variable.

Dr. Bernander has reviewed the reports and data made public so far concerning the North Spur, and finds it unpersuasive.  He visited the North Spur in October 2014. He has prepared a report, based on the data he has been able to consult, which has been filed with the Public Utilities Board in the context of the post-interconnection reliability review.  In this report, Dr. Bernander was unable to determine whether the proposed design was safe because there was insufficient geotechnical data and inadequate soil testing. One of his conclusions stated “The likely liquefaction of this kind makes the results of standard type soil investigations and the associated determination of the factors of safety in respect to slope stability, very unreliable. This applies in particular if calculations are based on the Plastic Equilibrium mode of analysis”, which underlies the FLAC program.

Dr. S. Bernander is currently working on a second report reviewing the SNC North Spur report issued this year. Unfortunately, he still cannot determine the safety factor due to the lack of the appropriate geotechnical soil tests.

The bottom line – the methodology used thus far to determine the safety of the North Spur Dam is not reliable for these types of soils. Until new analyses are performed by geotechnical engineers familiar with Dr. S. Bernander’s methodology, the possibility of catastrophic failure of the Muskrat Falls dam after impoundment cannot be ruled out.

Determining the North Spur dam safety factor is essential, in order to avoid both a financial disaster for NALCOR, and a fatal disaster engulfing the communities downstream of the Muskrat Falls Dam. Due to the deep deposit of quick clay below the North Spur, a failure would leave the Muskrat powerhouse high and dry, with no possibility of an economic repair.

Given the enormous human and economic cost of such an event, I strongly encourage you to give this issue your full attention.

The point I am trying to make is that the existing design is based on a discredited procedure. To bolster confidence in the design, it would be invaluable for someone familiar with Bernander's methodology review the work and determine the safety factor using the Bernander procedure. The cost, at something less than $50,000, would be insignificant compared to a failure.

For all I know, the design may be safe, but added reassurance would assuage the anxiety of the residents downstream, since they are convinced that the North Spur dam is not safe.


Sincerely,         
James L. Gordon P.Eng. (Retired)

19 comments:

  1. When respected engineers are making this type of public statement, about the engineering being completed on such a life safety issue it is time for the PEGNL to step in and make a comment. I doubt they will however, as they are a reactive type of organization.

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  2. My question is "Why are they not using sheet piling in addition to the bentonite curtain and armour Stone they are using?"

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  3. In my engineering studies I had one course on soil analysis, which would have have served me more if I had done civil engineering. I worked on dam construction at Churchill Falls as a student engineer. I eventually studied and graduated in electrical engineering and worked with Nfld Hydro in that capacity in high voltage system design and relay and protection systems. I am no expect in the risks of quick clay, but I appreciate the expertise and experience of both Dr. Bernander and Mr Gordon. I am also aware of Nalcor`s Gilbert Bennett`s and Ed Martin`s dismissal of concerns raised on this issue.
    Mr Stan Marshall now takes responsibility for the safety of this design. The risk and consequences are clearly stated here by Mr Gordon.
    President Truman always had a sign on his desk reading: THE BUCK STOPS HERE. As to Bennett,who continues in his capacity on the North Spur component, Mr Marshall has stated that what matters is the direction given by those in charge. Marshall, an engineer (a chemical engineer) he would appreciate the issue of changing stability of marine clay as salt content is reduced, that can lead to failure. As a lawyer also he would appreciate the liability of poor design. As a business manager he also understands the financial consequences of a failure of the North Spur and of unacceptable risk of failure. As a Nflder, he has accepted the burden to turn around this boondoggle, which is an engineering and financial nightmare in many forms. I very much support Mr Gordon`s appeal to Stan Marshall to publicly respond to the concerns raised. Indeed, safety is the highest standard expected from engineers by the public, and I expect Mr Marshall will give his careful attention to this issue in a timely manner.
    Winston Adams.

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  4. Mr. Gordon,

    This is a well informed plea to look at the inadequate spur engineering. The issue is clear and well presented. Stan Marshall and anyone who reads this can no longer claim they do not understand the risk to the project and the population downstream.

    Will Marshall care? He seems to have blinders on and is prone to the same lack of transparency.

    If polite pleas fail to bring a response, what then? Neither the media or political opposition are functional and even capable of defining the issue you have eloquently outlined James.

    I am shocked that the problem with the line manufacturing documented on this blog has yet to be documented in the "mainstream" media in detail. It seems the Marshall regime to date is more of ignore the facts and full steam ahead.

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  5. As I have stated on previous occasions, the Muskrat Falls project should be, at a minimum, halted for a full assessment. The North Spur element has gotten very little press and has been ignored by the government, both present and past.

    This letter should be a wakeup call that there are potential consequences that are much worse than even the grave financial distress this project will impose on the province. The PC's were the architects of this debacle but Mr. Ball's Liberals are the "builders" who will destroy the economic fabric of this place.

    I have written Mr. Ball to voice my concerns but thus far he has failed to respond. I urge every person with access to an email account to do the same and let him know the he, not Danny Williams, will ultimately take the fall for the folly that is Muskrat Falls.

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  6. I hereby endorse and support Mr. Gordon's sober call for scientific analysis of the North Spur dam Engineering Design.

    Robert G. Holmes, P.Eng. (Retired)

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  7. It is ironic that PEGNL is silent on this obvious danger, especially with senior engineering experts raising the alarm.

    It was disasters like the Quebec Bridge collapse that drove the creation of professional engineering societies and registration in Canada and the engineering iron ring ceremony here in Newfoundland has a long iron chain with the relics of many engineering disasters which serve as a reminder of the risks / dangers / and the duty to protect the public. Yet, here we have PEGNL that is bereft of professional leadership.

    I believe the spur will fail. Even with the finest mitigation measures, there are things we cannot control - like seismic activity. Having a reservoir behind unstable soil is like the sword of Damocles.

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    1. We must consider what "Catastrophic Failure" means with respect to earth Dam failure.

      https://en.wikipedia.org/wiki/Mount_Polley_mine_disaster

      The politically and environmentally risky Site C Dam in the Peace River is another.

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  8. Ms. May reports;

    http://www.cbc.ca/news/canada/newfoundland-labrador/elizabeth-may-slams-muskrat-falls-loan-guarantees-1.3703729

    Be careful what you wish for

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  9. Part of my interest in Muskrat, other than I was born a Jackytar, is the ongoing concern in my home province, BC. of Site C.

    http://www.cbc.ca/news/canada/british-columbia/site-c-dam-federal-approval-1.3703527

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  10. All this rushed preparation, phony cost/benefice analyses and lack of oversight so we can stick kit to Quebec; what a mess!

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  11. Has any acknowledgement and response to Mr. Gordon's letter been reported?

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  12. Mount Polley dam failure today

    http://www.huffingtonpost.ca/jacinda-mack/mount-polley-mine-disaster-bc-leak_b_11318498.html

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  13. Rumours abound that Uncle Gnarley is traversing the wilds of Labrador. Could it be a bit of Muskrat love? ;-)

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    1. The rumours are correct but the destination is much father north. A couple of weeks of kayaking and hiking awaits.

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  14. Is Lower Churchill a "Frack Free Zone?"

    http://www.thetyee.ca/Opinion/2016/08/16/Fracking-Threat-Peace-River-Dams/

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  15. Bertrand Russel said that ....the stupid are cocksure and the intelligent are doubtful. Wonder where Marshall fits in ?

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  16. Can a real journalist, (Justin Brake perhaps?.. do we have others?) publicly challenge Stan Marshall to respond to Mr. Gordon's, and the public's, request for information? Or is he just another muted fraud among a pack of them. At 600 "large ones" per year, he damn well owes it to the public to open the books on the fraudulent fiasco, let alone his mouth. Speak up or step down "Sir".

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