September 17, 2025, Planning Board Special Meeting Transcript - WEHI

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 62 1.5 number, I believe, and the number, the 2.0 number from Princeton Hydro. And I just want to make sure I understand you correctly. So if I understand you correctly you're saying that neither the 1.5 nor the 2.0 number guaranties that the slope won't collapse. That the difference is based on the amount of damage that would be done if the slope collapsed. So the U.S. Engineers base it on, because the damage, you said would wipeout a whole city, they require 2.0 and because if this slope happened to collapse it would only wipeout maybe half a dozen houses, 1.5 is an adequate number, is that what you're saying? THE WITNESS: No, that's not it. 1.5 -- a factor safety of 1.0 means that the forces that tend to drive failure are equal to the forces that tend to resist failure. So at 1.5 you're 50 percent higher, you know, 50 percent more resisting forces than you have driving forces. At 2.0 you have twice the number amount of driving -- of resisting forces relative to the driving forces. So in both cases the slope is stable. THE PUBLIC: So why would they U.S. Engineers have a different number than you, if that's the case? THE WITNESS: Well, the U.S. Core of Army Engineers they -- I suppose you have to ask them why