December 10, 2025, Planning Board Special Meeting - WEHI Transcript

01/14/2026 10:36:25 AM Page 61 to 64 of 144 16 of 55 sheets 61 Because it's a precautionary step that we take.1 A. And you would take the higher standard -- Factor2 Q. of Safety standard in some instances, right?3 If there were -- the name of the manual that4 A. you're referencing is Rock Foundations and there are no5 rock foundations on the slope that we're talking about.6 When you refer to seepage, seepage into what?7 Q. Seepage?8 A. Yeah. You say, "We agree" referring to the9 Q. analysis of seepage parallel to the slope. What are we10 seeping into?11 That's a worst case analysis.12 A. No, no, no. My question is, what are we seeping13 Q. into in this sentence?14 Into the soil primarily. Mostly -- primarily the15 A. soil overlying the rock.16 And you're saying the worst case analysis where17 Q. there's a 100-year storm?18 No, I didn't say that was the worst case.19 A. Well, you said an extreme event and when I asked20 Q. you what you're referring to, you referred to a 100-year21 storm. So what are you talking about?22 Well, that would be an extreme event.23 A. Okay. Thank you.24 Q. You should engineer to take into account25 62 something like a 100 year storm, which is really not1 that uncommon, isn't that correct?2 Well, I think the -- this is a situation we don't3 A. even know can occur.4 You just said in Plainfield we had the problem?5 Q. Well, you had the rain, yes.6 A. So you had rain and the rain is what leads to the7 Q. fear or risk of the collapse because it's an extreme8 rain event, isn't that correct?9 Extreme rain events can cause slope movements.10 A. And we had one two months ago?11 Q. Right.12 A. Right.13 Q. And I'm not aware that there was a slope movement14 A. associated with that storm.15 We don't evaluate the risk only if the crisis16 Q. occur's, do we?17 No, but it would indicate, it would indicate that18 A. the slope is resistant to that type of event.19 So you need to see a crisis in order to know20 Q. whether to use the higher safety factor?21 I'm sorry, repeat that. I need to see a22 A. crisis --23 I'll move on. Well, I guess I won't move on.24 Q. I'll be fair to you and ask the question again.25 63 Are you saying that you would evaluate this for a1 higher safety factor only if there was an actual2 catastrophe?3 No. A situation is likely -- situations like4 A. this, you know, are not, they're not long lasting. So5 you, it's considered

this for a1 higher safety factor only if there was an actual2 catastrophe?3 No. A situation is likely -- situations like4 A. this, you know, are not, they're not long lasting. So5 you, it's considered to by a lower factor of safety for6 events that are not -- for instance, this references7 here, last seismic event to use a reduced safety factor8 of 1.2 or 1.3.9 I'm not asking about seismic events, I'm talking10 Q. about this rain problem?11 Well, I'm just saying that's another infrequent12 A. and unlikely event.13 But in the event of heavy rain along the order of14 Q. a 100-year storm and rain that is proceeded by15 saturation earlier, a collapse could occur on what your16 calling a soil slope, isn't that correct?17 Correct.18 A. And shouldn't we be engineering in advance of19 Q. that, so that does not happen rather than only looking20 to see whether it has happened?21 No, no. It's not the rainfall, that's not going22 A. to happen. It's the development of the infinite slope23 seepage condition that's the unusual event.24 Which develops because of unusual rain events of25 Q. 64 an extreme nature preceded by infiltration?1 But I don't know that. That could occur on this2 A. site. When we looked at the slope we didn't see any3 evidence of that. This slope has been there for ions.4 Well, Princeton Hydro saw evidence.5 Q. No, they did not mention heavy rainfall6 A. conditions in their report.7 No, but they mentioned evidence of a higher water8 Q. table that Langan didn't see, isn't that correct?9 Right. But Langan --10 A. So they did mention it, didn't they?11 Q. CHAIRMAN BAGOFF: Let him finish, Mr. Afran.12 Let him finish, please.13 But Langan did assume a higher water level which14 A. was, which I believe they meant to address that.15 What does that mean?16 Q. They did a stability calculations with the water17 A. level about 3-feet below the surface.18 But you don't know the methodology they used,19 Q. right?20 Sorry.21 A. You told me you didn't know what methodology they22 Q. used, isn't that correct?23 I don't understand what that means.24 A. Do you know what methodology they used to25 Q.