Concerns about the safety of the Site C dam are mounting in some downstream communities along the Peace River, despite the B.C. government’s assurances that the project can be completed safely after two independent experts approved BC Hydro’s proposed fix for the dam’s weak foundation.
The fix involves driving as many as 125 concrete-filled pipes 25 metres into the ground — the height of an eight-storey residential building — to extend the foundation of the dam, its powerhouse and spillways.
Additional instrumentation will also be installed to monitor any movements beneath the dam for the duration of its projected 70 to 100-year lifespan “as a continued precaution [to] help ensure safety,” following ground movements detected in August 2018.
The fix will be the first of its kind in the world, as there are no other earthen L-shaped dams.
“I am confident that the Site C dam can proceed safely and will be built to the highest dam standards,” Premier John Horgan told reporters at a Feb. 26 news conference, where he announced the troubled project will continue with a new price tag of $16 billion — making it the most expensive dam in Canadian history with nearly five years of construction still to come.
Terry Ungarian, Reeve for the County of Northern Lights, a municipal district in northwest Alberta that stretches along the west side of the Peace River, said the county’s concerns about the safety of the dam have heightened since Horgan’s announcement.
In a long-awaited summary report on the Site C project, released on Feb. 26, former B.C. deputy finance minister Peter Milburn said BC Hydro has consistently underestimated the geotechnical risk in building the dam and noted “the risk of additional geotechnical issues on this project continues at the time of writing.”
“When they admit themselves that there’s still potential for further problems, well what does that mean?” Ungarian asked. “That’s leaving themselves fairly open for interpreting that as ‘the fix isn’t bullet proof. It isn’t totally solid.’”
“I’m not a geologist or an engineer … But what I’ve read indicates that it’s being built on a very poor type of material. What is the solution? I don’t know that they even know themselves. They throw another $6 billlion at it, and say they’ve resolved it. Well, have they?”
“I don’t think we’re ever going to get reassurances that this is nothing to worry about.”
A dam failure or overtopping would cause extensive damage and flooding in the County of Northern Lights, including to a pulp mill and recreational and agricultural properties, Ungarian told The Narwhal.
He said Peace River MLA Dan Williams will be attending a March 8 council meeting and the county will ask Williams to bring safety concerns to the Alberta government, in the hopes that the two provincial governments will discuss the matter.
“We’re turning to our provincial government to try to find us those answers.”
Top B.C. government officials knew in May 2019 that the Site C dam faced geotechnical problems due to its “weak foundation,” according to documents obtained by The Narwhal. Photo: Jayce Hawkins / The Narwhal
Horgan’s announcement ended months of speculation about whether or not the Site C project would continue, following the disclosure last July — after BC Hydro and the B.C. government withheld information from the public — that the foundation for the earthen dam, powerhouse and spillways required shoring up after 1.7 million cubic feet of aggregate concrete had been poured.
BC Hydro said at the time that it did not know how to fix the problems, how long it would take or what the cost would be.
In January, Horgan surprised reporters with the news that two independent dam safety experts had been commissioned to examine the fix proposed by BC Hydro.
Steep slopes along the banks of the Peace River in the Site C dam flood zone. The dam will flood 128 kilometres of the Peace River and its tributaries – about the distance of driving from Vancouver to Whistler. Photo: Jayce Hawkins / The Narwhal
Kaare Hoeg, a Norwegian engineer, and John France, an independent consultant from Colorado who worked for 25 years for Aecom, a California company that has received hundreds of thousands of dollars in Site C project contracts, were tasked with determining if it was safe to proceed with the dam.
The pair found the dam will be “safe and reliable” and will meet safety guidelines established by the Canadian Dam Association, the government said.
While Hoeg and France approved BC Hydro’s fix, they said their opinions were based on information provided by the Site C project team and that the ultimate decisions and responsibilities for design rests with BC Hydro.
Read more: Active Peace Valley landslide renews questions about slope instability and B.C. government secrecy
“Our review services were performed within the limits prescribed by BC Hydro in a manner consistent with the level of care and skill normally exercised in the current standard of professional engineering practice,” they wrote in a geotechnical safety overview report.
“No other representation to BC Hydro, expressed or implied, and no warranty or guarantee is included or intended.”
Scott Campbell, a construction worker who has lived in the B.C. community of Old Fort for 20 years, said he and others in the riverside settlement, two kilometres downstream from the Site C dam, continue to fear for their safety.
“I have tried to get the attention of BC Hydro about the safety concerns of the dam and what they will be after the dam is built as well — if it even works, which many of us are afraid it will not,” Campbell said in an email to The Narwhal.
“I think about it every day, if not several times a day. It is not fair that we live so close to a dam that has this many geotech issues. Who would feel safe?” He said Horgan should be true to his word about engaging in a meaningful dialogue with local communities and come to Old Fort to speak with worried residents.
Old Fort has experienced two major landslides since 2018, which cut off the only road into the community of 150, forcing Campbell and other residents to evacuate during the first landslide. Several homes remain under evacuation alert.
The road to Old Fort, crumpled by a November 2018 landslide on the notoriously unstable slopes of the Peace River. Photo: Jayce Hawkins / The Narwhal
A December 2020 report from B.C.’s chief inspector of mines found the root cause of the landslides could not be determined. In January, 35 Old Fort residents filed a lawsuit against the B.C. government, BC Hydro and three other parties, alleging in part that construction of the Site C dam has had adverse consequences on their safety and the value of their homes, and claiming damages.
Lawyer Malcolm Macpherson, who represents the residents, pointed out that 32 million cubic metres of soil is being excavated to build the dam.
“That’s gargantuan in size,” he said in an interview. “My clients are saying ‘look, how do you realistically move 32 million cubic metres of structures and not affect waterways and not affect nearby soil support?’”
Old Fort residents remain concerned about their safety following the news that construction of the Site C dam will proceed, Macpherson said.
“The announcement has not addressed their underlying concern for their safety, the well-being of their families and their right to have the soil under their family homes supported in a natural state.”
Read more: Top B.C. government officials knew Site C dam was in serious trouble over a year ago: FOI docs
Former BC Hydro CEO and president Marc Eliesen, who was at the helm of BC Hydro when its board of directors rejected the Site C dam in the early 1990s — in large part due to geotechnical concerns — said no independent review can provide a satisfactory level of comfort that the Site C dam will be safe.
“BC Hydro has studied this area for years and years and years,” said Eliesen, who is also the former CEO of Ontario Hydro and the Manitoba Energy Authority.
“They know what kind of turf they’re dealing with — sedimentary shale. Think mud. It’s prone to erosion and it’s prone to landslides. It’s prone to water seepage. The bottom line, in the context of what has taken place, is you should not build there. There are too many risks.”
“The ground is too unstable. There are too many surprises … No amount of review will give you a greater comfort level of ensuring that it will be safe and it will be operational and there will be no additional expenditures.”
Eliesen said the final tab for the dam could reach $20 billion.
“There’s never been this kind of a problem before. They’ve never had this kind of design before for a powerhouse and spillways, at a right angle. It’s never been done. This is all brand new.”
The B.C. government said Hoeg and France, along with the Site C technical advisory board — a panel of engineering and construction experts — reviewed the unconventional L-shaped design of the earthen dam and “all reviews concluded that the main dam design is safe.”
However, Hoeg and France acknowledged in their report that there is uncertainty about the foundation conditions for the dam structure “as that area has yet to be excavated, mapped and grouted.”
Additionally, the safety report the B.C. government commissioned Hoeg and France to write doesn’t follow all safety review guidelines established by the Canadian Dam Association, which state that a site visit must take place during a review.
At a Feb. 26 technical briefing for reporters, a government official, who cannot be named due to the protocols for technical briefings, confirmed that Hoeg and France met virtually with the Site C design team and the project’s technical advisory board to review BC Hydro’s proposed solution to the dam’s foundation problems, but they did not travel to the site.
In an emailed response to questions, Canadian Dam Association president and engineer Terry Oswell said a dam safety review, which includes a review of a dam’s design and construction, “has the overall goal to protect people, property and the environment from harmful effects of mis-operation or failure of dams and reservoirs.”
“A safe dam is one that performs its intended function under both normal and unusual conditions, does not impose an unacceptable risk to people, property or environment, and meets applicable safety criteria.”
In 2016, the association published a technical bulletin on dam safety reviews, outlining the process for carrying out a review and the roles and responsibilities of the dam owner and review engineer.
“The essential conclusion of a dam safety review is a statement on the safety of the dam,” Oswell said.
She said an independent qualified dam review engineer must understand the dam safety management system and the risk controls in place to halt the progression of failure modes — such as overtopping, foundation defects and cracking — or to mitigate consequences.
A dam safety analysis is carried out by identifying hazards and failure modes, performing or reviewing analyses for dam performance for each of the hazards and failure modes and assessing the adequacy of risk controls, she said.
In addition to a site visit, a safety review must include interviews with staff who have responsibilities for dam safety.
Oswell said that because the Canadian Dam Association does not collect records of safety reviews, it is unable to say whether the Site C review meets its guidelines.
The B.C. government said it commissioned Hoeg and France to write the safety report because they have considerable global experience with earthen dams and neither had “any involvement with the Site C project to date.”
Hoeg was one of three international experts in embankment dams who conducted an extensive safety review of the WAC Bennett dam after a sinkhole was noticed by a tourist in 1996.
The three experts were asked to conduct “their own, fully independent, bottom-up review of the dam design and performance,” which took about one year and involved several site visits.
According to France’s online bio, he served on an advisory board to review BC Hydro’s planned dam safety modifications of the Strathcona dam on Vancouver Island and on an advisory board to review planned dam safety modifications of the Ruskin and Blind Slough dams in Mission, B.C.
Aecom, France’s former employer, has received at least $674,000 in no-bid Site C dam contracts for providing the services of Site C dam “independent construction advisor” Steve Summy and the services of its program manager Joe Ehasz, who sits on the Site C project’s technical advisory board.
Updated March 5, 2021, at 12:15 p.m. PST: This article has been updated to say that Aecom received hundreds of thousands of dollars in Site C contracts, not hundreds of millions as previously stated. A paragraph mentioning the company Aecom and the AFDE partnership has been removed from the story. John France worked for Aecom, not Aecon.
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