Thread by @Lidsville

"Suspect timing for latest update on problematic holes at #SiteC" - @VaughnPalmer

"Opinion: Sooner or later the public and ratepayers will discover what BC Hydro and the NDP have been hiding all these months" vancouversun.com/opinion/column… #bcpoli

@VaughnPalmer ..This BCUC Q to BC Hydro is esp. interesting: "Discuss which geotechnical studies were used to inform the initial design of the powerhouse, spillway & dam core foundations.” Interesting that BCUC would go back that far - possibly as far back as 2010-11 design of L-shaped dam

@VaughnPalmer I'm chatting with my engineer pal right now and he's saying "No idea how BC Hydro can answer these q's. Anything they say will create more q's, & they will have to come up with design data & input values for all the parameters used in the calculations.." cont'd

@VaughnPalmer .. "& the values won't match between lab tests & data used." Me: "You're saying this will reveal negligence & that they should never have gone ahead?" Engineer: "Both, & maybe criminal actions if they show shear values that for shale should have been zero but obviously weren't"

@VaughnPalmer .."KCB [Klohn Crippen Berger] said Hydro provided the shear values. This dam depends on shear strength of the shale it sits on, so what value did they use for shear strength? The shale has 2 diff values, a satisfactory one when tested dry, & another when saturated, that is zero."

@VaughnPalmer .."The worst value, which is zero, has to govern their design, so #SiteC can't be built on this shale. If they knew it was zero, why did they not use that? If they used another value so they could go ahead, that seems criminal..."

@VaughnPalmer .."Conway [Dave Conway, BC Hydro Site C spokesperson] said the shear values were suitable. He works for Hydro. Where did he get that info? The anchor bolts falling out in the tunnels were ignored. Why wasn't that investigated? They just went & changed to drilling the holes dry."

@VaughnPalmer .."KCB also said the shale swells when exposed to water in the shale (via fissures), but didn't state it has no strength when it swells. Why? If the shale can rebound & move around under water pressure, what design values for shear & compression are used on material like that?"

@VaughnPalmer "No matter what happened after they began, they just kept going. This dam has to be solidly in place for next 100+ years. It can't be guaranteed to do that if the foundation material shifts w water in it. It has to hold back a reservoir with a force on it of several million tons"

@VaughnPalmer .."The same force will also be applied to the buttresses when the approach channel is filled and the water fills in behind. Not to mention how that shale bank will hold up the weight of the water.

So many discrepancies...where do we start." #SiteC

"KCB also measured a compression strength that was too low to be rock, but that was ignored also."

Sorry, that was all a bit of a digression from Vaughn's article, but that one question from BCUC to BC Hydro set us off.

..Oh, and this related BCUC Q: "Discuss the reasons for any discrepancies between the geotechnical studies used to inform design of the foundations and subsequent geotechnical studies.” That's a minefield for BC Hydro. But the biggest issue:

..Part of what the @BCUtilitiesCom asked for from from Hydro is listed as "confidential" and is only referenced. What was in it? We demand transparency.

And as for the Milburn review, its terms of reference & its final report MUST BE MADE PUBLIC. #SiteC #bcpoli

@BCUtilitiesCom And @daveunger3 makes a good point: what about this question raised by Ben Parfitt in this amazing exposé from October 8: policynote.ca/troubled-site-…

https://twitter.com/daveunger3/status/1322034833405534208

@BCUtilitiesCom @daveunger3 ..And as Norm points out, here is what Vaughn Palmer guesses the BCUC confidentially asked BC Hydro, and it's one of the most pressing questions I have had:

https://twitter.com/Norm_Farrell/status/1322043131957633024

#SiteC #bcpoli