JIM GORDON'S FINAL COMMENTS ON THE NORTH SPUR

THE NORTH SPUR – MY FINAL COMMENTS
Guest Post by James L. Gordon P.Eng.(Retired)

Way back in 2014, my interest in the North Spur started when I read a short book by Cabot Martin titled “Muskrat Madness”. It concentrated on the questionable stability of a natural side dam called the North Spur which contained layers of sandy silt and sensitive clay. I emailed Cabot, a member of the 2041 committee, on August 27th commenting on his book, and have commented several times on the Uncle Gnarley blog on the North Spur safety. NALCOR describes the Spur as -

The north spur forms a natural earthfill dam, with a crest elevation of about 60 m, and about one km long, which connects the rock knoll to the north bank of the valley……. The crest width varies from about 1,000 m at its north end to about 70m at its south end where it has been narrowed by erosion and landslide activity in the past. The head across the spur is presently 16 m from river level upstream to downstream. The impounding of the reservoir to El. 39 m will increase the hydraulic head across the spur to 36 m and stabilization measures are then necessary to ensure its long-term stability under both normal and extreme water levels. The soils forming the spur consist of a complex interbedded sequence of relatively low permeability silty sands and sands, and sensitive marine clays.

VARDY PUTS MINISTER'S NORTH SPUR POSITION ON PUBLIC RECORD

Guest Post by David Vardy

Response from Minister Disappointing

The Labrador Land Protectors presented a petition to government on May 9, 2017 calling for the appointment of an independent expert panel on the North Spur.  It was signed by more than 1000 people. There has been no response. Since that time the urgency of the panel has been raised. It has been raised by new research conducted in Sweden as well as by revelations flowing from the SNC risk assessment report released by the Premier.

The recently disclosed and disturbing SNC Lavalin risk assessment report of April 2013, released by the Premier on June 23, 2017, refers to the need for further geo-scientific information to guide remedial measures and assess overall safety and stability. SNC Lavalin rated the risk as “very high.” Whether Nalcor has successfully remediated these risks over the period from April 2013 to the present is as yet unknown. It will take the work of an independent expert panel to measure whether risks have been reduced or indeed whether they can be mitigated or eliminated.

“NORTH SPUR DESIGN UNSAFE” CONCLUDES HYDRO ENGINEER - INSISTS PANEL OF EXPERTS CONDUCT REVIEW

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

Marine clay, commonly known as “quick clay” and as “sensitive clay” by geotechnical engineers is clay deposited through salt water where the particles pick up salt, which alters the properties of the clay. The clay becomes “sensitive” since it has a propensity to liquefy when disturbed or saturated. It has been avoided by dam engineers due to its sensitivity.

Wikipedia defines marine clays as – “Marine clay is a type of clay found in coastal regions around the world. In the northern, de-glaciated regions, it can sometimes be quick clay which is notorious for being involved in landslides. Clay particles can self-assemble into various configurations, each with totally different properties. When clay is deposited in the ocean the presence of excess ions in seawater causes a loose, open structure of the clay particles to form, a process known as flocculation. Once stranded and dried by ancient changing ocean levels, this open framework means that such clay is open to water infiltration. Construction in marine clays thus presents a geotechnical engineering challenge.”

This explains the controversy surrounding the North Spur dam at Muskrat Falls since it will be the first hydro dam built on a quick clay foundation.

DAN CRUMMELL: THE PEOPLE OF MUD LAKE AWAIT YOUR ANSWER.

Guest Post written by Cabot Martin

My letter of September 11, 2015 to Minister Dan Crummell, on the perils of a North Spur collapse to workers both on the Spur and at the powerhouse site across the river, to downstream residents and to provincial finances alike has, so far, gone unanswered. Perhaps, that is not surprising. Despite the urgent nature of the matter, in the past he has usually taken about a month to reply.

One point not fully covered in my letter concerns the technical analysis on which Nalcor has based its “There’s no problem with the North Spur“ position. Seemingly, it has been adopted without critical analysis by Mr. Crummell.

NALCOR'S GILBERT BENNETT AS JUDGE AND JURY

Guest Post written by Cabot Martin

On VOCM BackTalk with Pete Soucy yesterday, Nalcor VP Gill Bennett, the regulator, examined  Gill Bennett the regulated and pronounced – risk of a North Spur Collapse during construction ? - no problem! Does not exist !

And repeated that assertion at the end of his call supposedly to really clinch the argument.

According to Bennett the risk of a North Spur collapse during construction was , not – acceptable risk; not -low risk; not – negligible risk;,  but 100% pure –unadulterated  NO RISK.

So go back to sleep people – no problem here.

All accompanied by a pious and disdainful  statement on the superiority of the engineering way of thinking and the high standards they hold themselves to – what tripe !

MINISTER WARNED RISK OF NORTH SPUR COLLAPSE

Guest Post by Cabot Martin

Work has recently started on Nalcor’s North Spur “stabilization” construction activities at the Muskrat Falls Project. So far, this has involved the stripping of trees on the upstream and downstream sides of the North Spur and the use of heavy excavation equipment .

The North Spur is known to be unstable and such activities can only heighten the risk of collapse.

As a result, there is presently a serious risk for a North Spur collapse.