September 11, 2024 Engineering Criteria Review Board Meeting

Jenn Hyman, BCDC: muted. Can everybody mute?

Jenn Hyman, BCDC: the script that we have? It’s fine fine!

Jenn Hyman, BCDC: Oh, I know. Sorry! That’s me.

Temazcal Room: We can go ahead and start right. Rod

Temazcal Room: the microphones.

Temazcal Room: Okay. Good afternoon. Welcome to this hybrid in person and online Ecrb meeting.

Temazcal Room: My name is Rod Iwashta. I am the chair of the Ecrb, and I have a few announcements.

Temazcal Room: Our 1st order of business is to call the roll board. Members, please

Temazcal Room: unmute yourselves to respond and then mute yourselves again after responding. Jen, please call the roll

Temazcal Room: okay, and actually make sure to

Temazcal Room: microphones for

Temazcal Room: for speaking and pushing the buttons to turn it on and off.

Temazcal Room: rod you want to share here.

Temazcal Room: Jim French vice chair. Sure.

Temazcal Room: Bob Natalia.

Temazcal Room: Here.

Temazcal Room: Jima Kasali.

Temazcal Room: Yeah.

Temazcal Room: Chris may

Temazcal Room: here

Temazcal Room: Rameen Gosarky.

Temazcal Room: Here.

Temazcal Room: Nick Sitar.

Temazcal Room: Present.

Temazcal Room: Gail Johnson. Hello.

Temazcal Room: Patrick Ryan.

Temazcal Room: Here.

Temazcal Room: Cherry Washta. We have a forum of at least 5 present.

Temazcal Room: Okay, thank you. Jen. We have a quorum present. So we are duly constituted to conduct business.

Temazcal Room: we may have some alternate board members who may be participating as members of the public.

Temazcal Room: Names I see listed are Thalia, Travaceru, Philip Trevetti.

Temazcal Room: Justin Van Diever, and Bill Tremaine and I now call the meeting to order.

Temazcal Room: I wanna

Temazcal Room: Carrie Washer Robert Batali would like to speak. He has his hand raised.

Temazcal Room: I’m sorry I didn’t know how I had my hand raised. I was trying to figure out how to get myself on the

Temazcal Room: video on Zoom, oh, yeah. Okay.

Temazcal Room: okay, okay. Thank you.

Temazcal Room: Okay. I want to start with some instructions, and how we can best participate

Temazcal Room: in this meeting, so that it runs as smoothly as possible.

Temazcal Room: First, st everyone, when you are not involved in the active discussion. Please make sure

Temazcal Room: you have your microphones or phones muted to avoid background noise

Temazcal Room: for board members. If you have a camera, please make sure that it is on during the meeting. So everyone online can see you.

Temazcal Room: Every now and then I may refer to the meeting host Margie, who is working behind the scenes

Temazcal Room: to ensure that the technology moves the meeting forward smoothly and consistently.

Temazcal Room: And

Temazcal Room: please be patient with us if it’s needed.

Temazcal Room: Ex parte communications

Temazcal Room: as set forth in the Bcdc’s regulations. A member of the Ecrb.

Temazcal Room: Shall not have any oral or written communication regarding a proposed

Temazcal Room: project or other matter that has been noticed

Temazcal Room: to be considered at an Ecrb meeting with a project proponent permit applicant, prospective applicant

Temazcal Room: or member of the public, except on the record during an Ecrb meeting

Temazcal Room: Board members, in case you have inadvertently forgotten to provide

Temazcal Room: the staff with a notice on any written or oral ex parte communications.

Temazcal Room: I invite you to report on any such communications at this point by raising your hand and unmuting yourself.

Temazcal Room: Okay, I don’t see any.

Temazcal Room: for the record. No hands have been raised.

Temazcal Room: And

Temazcal Room: Jen, are you going to talk about the timing of this, the room and and all of that? Okay.

Temazcal Room: then let’s have a staff update

Temazcal Room: from senior engineer and board. Secretary, Jen Hyman.

Temazcal Room: Thank you, Cherry Washta.

Temazcal Room: I would like to provide an update on upcoming meetings

Temazcal Room: on September 25, th the Ecrb will have a second meeting with the Representatives from the San Francisco International Airport on their shoreline protection project.

Temazcal Room: On October 23, rd the Ecrb will review and discuss the updated regional shoreline adaptation plan or Rsap guidelines.

Temazcal Room: At the end of that meeting, Bcdc. Council, Michael Ng. Will give a legal training to Ecr Ecrb members on regulations and policies of the Ecrb

Temazcal Room: and board members. I would like to

Temazcal Room: let everyone know and app permit applicants today that we building management asked us to vacate the room at 5 o’clock sharp, because, that’s the end of their workday, and we’re getting their assistance in running this meeting, and they have to leave so hopefully, we can try to, if possible, wind the meeting up by around 4 30 today.

Temazcal Room: yeah, if need be. If we have to go beyond 5 o’clock, then we’ll

Temazcal Room: probably all just log into zoom without any of the screens or anything.

Temazcal Room: if if need be.

Temazcal Room: Those are all my announcements, Cherry Rashta.

Temazcal Room: Okay, thank you, Jan.

Temazcal Room: Before we move on to the presentation. Are there any announcements from board members.

Temazcal Room: Okay? Seeing none. Let’s let’s move on

Temazcal Room: to agenda. Item, 3

Temazcal Room: Cargills, solar sea salt system, maintenance and operations project firm stability.

Temazcal Room: So the main agenda item related to the permit application for Cargill Cargills.

Temazcal Room: solar sea salt maintenance or system, maintenance and operations. Our discussion will focus on the stability of the berms surrounding the mixed sea. Salt or Mss. Ponds.

Temazcal Room: p. 12, p. 2, 12, and p. 2, 13.

Temazcal Room: Mixed tea salts are also referred to as Bittern

Temazcal Room: Jen, the Board Secretary and Senior engineer for Bcdc. Has a slide presentation for us

Temazcal Room: with an introduction and a bit of background

Temazcal Room: since is. This is this is the 3rd meeting on this topic

Temazcal Room: during the presentation. It is fine for board members to ask clarifying questions.

Temazcal Room: I would like to ask board members and presenters to please turn on your cameras for any discussion

Temazcal Room: during or after the presentation.

Temazcal Room: and I will now turn it over to Jen to begin her presentation.

Temazcal Room: I’m just going to give some brief introductory slides on the Project

Temazcal Room: and the Permit history and the history of the Ecrb meetings for this project.

Temazcal Room: Cargill salts, current maintenance and operation activities are regulated by Vcdc. By a 10 year permit

Temazcal Room: that was issued by Bcdc. In 1,995.

Temazcal Room: This permit has been extended numerous times.

Temazcal Room: Cargill has applied to renew the 10 year Permit and staff plan to present the new permit to the Commission. In December of this year

Temazcal Room: Bcdc. Has prepared a draft environmental assessment

Temazcal Room: to comply with Ceqa assessing the potential impacts from Cargill’s maintenance and operational activities.

Temazcal Room: The draft Ea is currently out for the 30 day public comment period right now.

Temazcal Room: and that comment period will be ending on September 21, st

Temazcal Room: the Ea can be accessed at the Bcd Bcdc. Website.

Temazcal Room: The link is provided in the slide. But there’s also a link on Bcdc’s homepage.

Temazcal Room: The Engineering Criteria Review Board’s review

Temazcal Room: has been.

Temazcal Room: and today we’ll focus on the stability and safety of the earth and berm surrounding ponds. P. 212 and p. 213. At Cargill’s Newark plant number 2.

Temazcal Room: These ponds store mixed sea salts, which

Temazcal Room: we you will hear the acronym Mss. For these mixed sea salts

Temazcal Room: due to its high salinity, and the fact that its Ionic balance differs from bay water.

Temazcal Room: Mss.

Temazcal Room: Could contribute to potential environmental impacts if overtopping scour and erosion caused a release of brine to the bay.

Temazcal Room: Important to note, however, that once Mss. Is diluted with seawater.

Temazcal Room: it no longer exhibits toxicity.

Temazcal Room: The static and seismic stability of the berms is also a concern.

Temazcal Room: The Ecrb’s engineering review today has prompted some draft permit conditions, and Bcdc. Is in the process of drafting

Temazcal Room: the updated permit. Right now.

Temazcal Room: these are some examples.

Temazcal Room: Argill will be raising the berms around the Mss. Ponds to an elevation of 11.5 feet.

Temazcal Room: nabbed 88 by the end of the 10 year permit period.

Temazcal Room: Cargill has also proposed to raise the external berm at Pond, p. 212 to 11.5 feet at a slightly earlier date. Because that’s the berm

Temazcal Room: of all the of the of the 2 ponds that is facing the bay.

Temazcal Room: They’re proposing to do that earlier by 2029

Temazcal Room: cargo will track and report potential seepage from the Mss. Ponds annually.

Temazcal Room: The permit

Temazcal Room: will present the Ecrb’s concluding assessment of the Mss. Burn safety to the Commission.

Temazcal Room: The other

Temazcal Room: function that Ep, the Ecrb’s input has had on the permit is Cargill’s technical reports that were requested by the Ecrb have informed portions of the environmental assessment.

Temazcal Room: This map shows a location of the Mss. Ponds, p. 2, 12 and p. 2, 13,

Temazcal Room: close to Newark.

Temazcal Room: and along the shores of San Francisco’s South Bay, south of the Dumbarton Bridge.

Temazcal Room: The Ecrb meetings on the topic of stability of the mixed sea. Salt Pond berms

Temazcal Room: were previously held, first, st on November 16, th 2022,

Temazcal Room: and a second meeting was held on August 30, th 2023.

Temazcal Room: The remaining issues to discuss today are as follows.

Temazcal Room: updated sea level rise, risk assessment focusing on wave run up and wave induced firm erosion

Temazcal Room: results from the geotechnical investigation of the berms

Temazcal Room: using Cone penetrometer testing.

Temazcal Room: also known as Cpt.

Temazcal Room: that was performed just this summer.

Temazcal Room: Updated stability analyses for the Mss. Berms based on the new geotechnical data.

Temazcal Room: including

Temazcal Room: post slope and non-circular failure surfaces.

Temazcal Room: seismic and funny scenario

Temazcal Room: firm keying and layering scenarios.

Temazcal Room: firm displacement and settlement, analysis

Temazcal Room: a consideration of settlement

Temazcal Room: of the Nss. Palm berms

Temazcal Room: and questions regarding seepage of the Mss. Out through the berms.

Temazcal Room: Those were all the results

Temazcal Room: that all the comments that the Ecrb had made

Temazcal Room: on the issues at the last meeting.

Temazcal Room: So

Temazcal Room: I’ve put together these questions for the Board to consider for this 3rd meeting.

Temazcal Room: Number one is Cargill’s plan to maintain the berms to a crest elevation of 11.5 feet.

Temazcal Room: plus inspections and maintenance adequate to address the risk posed by sea level rise and and waves

Temazcal Room: did the field investigation adequately characterize the subsurface. Geology and geotechnical parameters

Temazcal Room: are the scenarios and criteria in the static and seismic berm stability analysis adequate for assessing the risk of berm failure at the Mss. Ponds

Temazcal Room: do the updated static and seismic stability calculations for the berms adequately characterize and model the berm stability.

Temazcal Room: including any berm raising

Temazcal Room: possible subsidence and sea level rise predicted for 2030, and 2040

Temazcal Room: for the stability analyses that indicate areas where the berms do not meet. The 1.1 factor of safety are the risks adequately addressed?

Temazcal Room: Does the presentation on Mss. Seepage and Berm coring adequately address the concerns and comments from the Ecrb?

Temazcal Room: Do the do the results of the updated berm stability, modeling, utilize adequately conservative assumptions and meet adequate levels of safety, so that an ecological and human health risk analysis is not needed.

Temazcal Room: This was a statement made by Cargill in the second Ecrb meeting.

Temazcal Room: responding to the Ecrb’s request in the 1st meeting to provide a risk assessment.

Temazcal Room: And lastly, does the Board have any other concerns regarding burn stability that have not been addressed.

Temazcal Room: and that’s the end of my

Temazcal Room: presentation.

Temazcal Room: Okay, thank you, Jen.

Temazcal Room: Now Jeremy Mull, of Aecom will make a presentation on behalf of Cargill.

Jeremy Mull (AECOM): Hey, everybody! Can you hear me? Okay.

Temazcal Room: Yes.

Jeremy Mull (AECOM): Okay, great.

Jeremy Mull (AECOM): I’m gonna share my screen.

Jeremy Mull (AECOM): And someone confirm that they’re they can see a Powerpoint presentation up on the screen.

Temazcal Room: Yes.

Jeremy Mull (AECOM): Okay, great, thank you.

Jeremy Mull (AECOM): My name is Jeremy Mull. I’m a coastal engineer with acom. Thank you. Everybody for attending and listening. Today I’m going to give a brief presentation on the

Jeremy Mull (AECOM): The wave run up

Jeremy Mull (AECOM): and overtopping analysis that we perform for Cargill.

Jeremy Mull (AECOM): I’ll note that Justin Vannever was the coastal engineering lead for this project. But because he’s part of the the ecrb that I’m presenting.

Temazcal Room: Excuse me, Jeremy, can you? Do you mind turning on your camera.

Jeremy Mull (AECOM): Not at all.

Temazcal Room: Thank you.

Jeremy Mull (AECOM): Can you guys see me now?

Jeremy Mull (AECOM): Yes, okay, thanks.

Jeremy Mull (AECOM): Okay. So just a a quick background on the project. I know some of this was outlined by Jen and her presentation.

Jeremy Mull (AECOM): In 2,020 and 2,021, Cargill prepared a sea level rise assessment

Jeremy Mull (AECOM): to support his long-term operations and the Bcdc. 10 year operations and maintenance permit renewal.

Jeremy Mull (AECOM): This assessment included a mapping of the shoreline and the England berms, including some assets of the site.

Jeremy Mull (AECOM): An evaluation of sea level rise impacts for the year 2,100

Jeremy Mull (AECOM): the identification of vulnerable berm segments. That could be

Jeremy Mull (AECOM): vulnerable to us, overtopping from storm surge.

Jeremy Mull (AECOM): vulnerability and risk assessment, for you know, some of the assets on Cargill side, including operations and and the environment.

Jeremy Mull (AECOM): And then a conceptual phase, sea level rise, adaptation, approach.

Jeremy Mull (AECOM): That included adaptation considerations.

Jeremy Mull (AECOM): Then, in December 2022 Bcdc. Requested that Cardio evaluate. The impacts of wave run up and overtopping, including future sea level, rise on the bayfront berms. So those are the berms between the ponds and shoreline of San Francisco Bay, and this was based on requests from the Ecrb.

Jeremy Mull (AECOM): In August 2023, Cargill presented preliminary wave run up methods and findings to Dcrb.

Jeremy Mull (AECOM): worth noting that the the methodology and the results largely haven’t changed since this presentation.

Jeremy Mull (AECOM): And then in 2023, through 2024 we run up an overtopping analysis. Memo was prepared and then submitted

Jeremy Mull (AECOM): to the the Bcdc

Jeremy Mull (AECOM): So these slides are just going to be a high, level overview of the project. It’s my understanding that

Jeremy Mull (AECOM): the presentation that was done previously had a pretty detailed overview of the

Jeremy Mull (AECOM): the methods and findings, and then those are also included in a lot of detail in in the technical memo

Jeremy Mull (AECOM): so prior sea level rise assessments, those focus on impacts of of high tides and combined the storm surge and more of a overtopping from the still water level of the berms.

Jeremy Mull (AECOM): This assessment evaluated the potential for way run up and overtopping on those bayfront berms. For existing conditions, and then future conditions with sea level rise under a no action scenario. And what that means is the analysis assumed that the berms would not be elevated from their their current elevations.

Jeremy Mull (AECOM): we developed 2 kind of metrics to evaluate the impacts of waves.

Jeremy Mull (AECOM): The 1st included the duration of the berm toe exceedance

Jeremy Mull (AECOM): by the total water level with a wave height greater than one foot, and we calculated the average hours per year that this might occur. So this was kind of a proxy for the amount of time that the waves

Jeremy Mull (AECOM): excuse me that the berms would be exposed to significant wave energy in a year we then looked at the frequency of berm crest overtopping and we evaluated this, based on the return period,

Jeremy Mull (AECOM): for different storm events.

Jeremy Mull (AECOM): So these results are helping Cargill identify and prioritize maintenance

Jeremy Mull (AECOM): for the burn segments that may experience, increased exposure

Jeremy Mull (AECOM): to wave impacts due to sea level rise. It also can help inform the development of a long term adaptation management plan for these Burns.

Jeremy Mull (AECOM): Okay, so just a quick overview of the technical approach. This, the approach is detailed or presented more detailed report.

Jeremy Mull (AECOM): This slide just conceptually shows each of the steps in the technical analysis.

Jeremy Mull (AECOM): starting with step, one on the top left, and then all finishing up

Jeremy Mull (AECOM): with the

Jeremy Mull (AECOM): the firm.

Jeremy Mull (AECOM): sorry I have something on the screen, the firm exposure metrics on the bottom. Right? So,

Jeremy Mull (AECOM): starting in step one, we applied a 1-dimensional transact based analysis.

Jeremy Mull (AECOM): Where transects are spaced.

Jeremy Mull (AECOM): perpendicular

Jeremy Mull (AECOM): perpendicularly to the the berm, we place transacts

Jeremy Mull (AECOM): based on segments of berm with different

Jeremy Mull (AECOM): exposures to wave energy.

Jeremy Mull (AECOM): Then all of our empirical equations to calculate over top and run up and overtopping were applied in in one dimension.

Jeremy Mull (AECOM): In step 2. We extracted

Jeremy Mull (AECOM): cross shore profiles from topographic and bathymetric data, and then identified the key features of the berms that were used in our our engineering calculations.

Jeremy Mull (AECOM): In step 3. We assigned representative transects to each berm segment. So the berms

Jeremy Mull (AECOM): we’re divided into short segments.

Jeremy Mull (AECOM): and the results of the analysis were then compared to the elevations of each burn segment.

Jeremy Mull (AECOM): So each berm segment came with a representative transect.

Jeremy Mull (AECOM): As it’s described in the report, we rely primarily on

Jeremy Mull (AECOM): a a multi decatal wave and water level model that was used in a fema coastal flood. Study of San Francisco Bay.

Jeremy Mull (AECOM): Model was built by dhi and had waves and water levels, I believe, every 15 min for over 50 years.

Jeremy Mull (AECOM): So each transect was paired with a model output station.

Jeremy Mull (AECOM): We then calculated

Jeremy Mull (AECOM): the total water level at each of those time steps

Jeremy Mull (AECOM): for the entire hindcast and use statistical extreme value analysis

Jeremy Mull (AECOM): to come up with the conditions for storms for different return periods.

Jeremy Mull (AECOM): Finally, with the results of the total water levels at each transect, we map those spatially onto the the berm segments with different different elevations and presented those results as

Jeremy Mull (AECOM): as results. Maps.

Jeremy Mull (AECOM): Okay, so just a quick like overview of what the total water level is this is just a conceptual slide and hopefully helps orient Orient people to the total water level because it drives a lot of flooding in San Francisco Bay, so the total water level consists of several different components.

Jeremy Mull (AECOM): It includes the astronomical tide sometimes referred to as predicted tide, which ranges about 6 to 8 feet in the bay

Jeremy Mull (AECOM): and includes storm surge, which is composed of

Jeremy Mull (AECOM): yeah atmospheric pressure events, winds, atmospheric pressure effects, wind setup, and El Nino effects. It ranges on the order of like one to 3 feet in the bay.

Jeremy Mull (AECOM): It also includes wave components like wave setup and wave wave run up.

Jeremy Mull (AECOM): and those range about 2 to 5 feet.

Jeremy Mull (AECOM): and then you add that all up and you get the total water level. Extreme total water, total water level events on the Bay range from about 10 to 15 feet

Jeremy Mull (AECOM): any vd, 88, depending on the storm conditions you’re looking at. And each, you know.

Jeremy Mull (AECOM): areas exposure to wave energy and things like that.

Jeremy Mull (AECOM): In the cartoon on the bottom. You can see how all these components add up. You see the tide.

Jeremy Mull (AECOM): How time and storm surge add up to the still water level, and then, if a segment of the berm is exposed to wind waves, those waves usually propagate up.

Jeremy Mull (AECOM): propagate through the marsh, and then

Jeremy Mull (AECOM): break

Jeremy Mull (AECOM): near, or at the Bernto, and the uprush

Jeremy Mull (AECOM): of water can come up the outward side of the berm, and then potentially over top levee

Jeremy Mull (AECOM): so we did incorporate future sea level rise, and that would be that was incorporated into the still water level in which we

Jeremy Mull (AECOM): Then we ran all of our total water level calculations.

Jeremy Mull (AECOM): Okay, so just an overview of some of the results. These figures are all

Jeremy Mull (AECOM): presented in the report.

Jeremy Mull (AECOM): and

Jeremy Mull (AECOM): we’re focused on Pond 12 today. Which is shown in the upper left of all the figures. It’s highlighted in the 1st figure.

Jeremy Mull (AECOM): The 1st figure is the baseline conditions, which are

Jeremy Mull (AECOM): approximately from the year 2,010, and then the results.

Jeremy Mull (AECOM): The different figures show the results for 6 inches, 12 inches and 36 inches of sea level rise.

Jeremy Mull (AECOM): We are using the sea level rise estimates from the Ocean Ocean Protection Council report.

Jeremy Mull (AECOM): From 2,024 you can see the timing of those different amounts of sea level rise in the bottom right there. This table.

Jeremy Mull (AECOM): so

Jeremy Mull (AECOM): just as an example for 12 inches of sea level rise that could occur as early as the year 2,050. If you’re looking at the intermediate high scenario, it’s likely by 2,055, if you’re using the intermediate scenario.

Jeremy Mull (AECOM): So these the slides show the results for the berm toe exceedance. Remember, this is the average number of hours per year that the total water level

Jeremy Mull (AECOM): would exceed the burnt tow with a wave height

Jeremy Mull (AECOM): of at least one foot.

Jeremy Mull (AECOM): So it’s kind of a measure of how often the outboard the bayfront firm is being impacted by waves.

Jeremy Mull (AECOM): Up in the upper left. You have the baseline conditions, and you can see all. Jeremy.

Jeremy Mull (AECOM): Yeah, go ahead.

Temazcal Room: Can I ask? This is Bob Battaglio. Hi, Jeremy.

Jeremy Mull (AECOM): Hey! Bob!

Temazcal Room: I’d like to ask a question.

Temazcal Room: so

Temazcal Room: I was a little surprised by this slide, because if I understand it correctly.

Temazcal Room: Under existing conditions the toe of the berm, which is the base

Temazcal Room: on the bay side.

Temazcal Room: is exceeded by the total water level.

Temazcal Room: Less than 1 HA year is, am I interpreting this correctly?

Jeremy Mull (AECOM): Mostly. So remember it’s 1

Jeremy Mull (AECOM): hour per year, combined with a wave height greater than one foot.

Temazcal Room: Okay?

Temazcal Room: So the toe of the berm is in places is fronted by Marsh, which is around me. High water, I mean higher high water.

Temazcal Room: so just the still water level alone should exceed the tow

Temazcal Room: of the lev of the levy like 8% of the time, or something like that is that

Temazcal Room: just just because of the tide, not including non tidal residuals. So

Temazcal Room: it just seems like this is.

Temazcal Room: there should be waves

Temazcal Room: during some of those 8% of the time. So

Temazcal Room: it seems like the total water level would be

Temazcal Room: higher. So I have a concern about that. I don’t know if you wanna

Temazcal Room: address that now or.

Jeremy Mull (AECOM): Yeah, I mean, I I guess I can just speak conceptually to that. It’s it’s it’s a good question. And I think

Jeremy Mull (AECOM): you have to.

Jeremy Mull (AECOM): I imagine it’s through a combination of

Jeremy Mull (AECOM): high tides combined with

Jeremy Mull (AECOM): exposure. So waves approaching at the right angle to attack. You know the burn you kind of think about like

Jeremy Mull (AECOM): every firm has a little bit different. Exposure in this firm.

Jeremy Mull (AECOM): you know, is really only vulnerable to ways that are

Jeremy Mull (AECOM): coming in, you know, a bit from maybe the South Southwest here. So it would be those times when you have a combination, the high tide. So the

Jeremy Mull (AECOM): sorry advance the slide, so the

Jeremy Mull (AECOM): the tide, like you said, is coming up above the berm toe, but then that also has to coincide with a wind event, where the wind’s approaching from the right direction to to generate those waves.

Temazcal Room: Yeah, so it sounds like the way you’re filtering it. The waves are not above one foot

Temazcal Room: when the tide is above the marsh in her high water

Temazcal Room: more than 1 HA year, if I understand that correctly. And again, that just seems

Temazcal Room: less than I would expect.

Temazcal Room: So I you know I just have a concern there. Can I? Ask you another question?

Temazcal Room: How was the wind setup computed? Was it

Temazcal Room: extracted at the offshore wave location.

Temazcal Room: or was it

Temazcal Room: recomputed, based on the profile

Temazcal Room: towards shore, towards the tow.

Jeremy Mull (AECOM): Are you asking about the wave set.

Temazcal Room: By the wind. The wind set up.

Jeremy Mull (AECOM): Okay. Sorry.

Temazcal Room: Start with. The wind setup.

Jeremy Mull (AECOM): Yeah, it’s good question.

Jeremy Mull (AECOM): I would have to go

Jeremy Mull (AECOM): back into the

Jeremy Mull (AECOM): dhi methodology for the model. What?

Jeremy Mull (AECOM): I? So we didn’t

Jeremy Mull (AECOM): adjust

Jeremy Mull (AECOM): the still water levels at all. We took them straight from the model output.

Jeremy Mull (AECOM): They ran my

Jeremy Mull (AECOM): my 21

Jeremy Mull (AECOM): about the the water level wave conditions.

Jeremy Mull (AECOM): And so we extracted those from, you know, each each output station in the transects I would have to

Jeremy Mull (AECOM): not familiar enough with to say offhand exactly how they handled when set up in the model.

Temazcal Room: Yeah, no, that’s okay. I I just I’ll make a point here that

Temazcal Room: The wind setup increases with

Temazcal Room: proximity to the shore, because the wind blows the water on shore, and as it gets shallower the return flow

Temazcal Room: is suppressed. So you get a setup.

Temazcal Room: So the wind setup profile is not horizontal, it should actually increase as you get closer to the levee

Temazcal Room: and your offshore way of reference point is not

Temazcal Room: close to the total levee, so I think the water depth would be higher.

Temazcal Room: Then, perhaps, is being modeled, which, of course.

Temazcal Room: allows larger waves to propagate

Temazcal Room: landward to reach the toe.

Temazcal Room: which may also be contributing to this very low

Temazcal Room: wave total water level exceedance at the toe of the berm. I think I’ve made my point, but I had. That’s that’s 1 of the concerns I have. And we can discuss more.

Temazcal Room: In the discussion.

Temazcal Room: Is is that okay?

Temazcal Room: Okay? Thanks. Jeremy.

Jeremy Mull (AECOM): Sure.

Jeremy Mull (AECOM): so let’s see, we this slide. We’re looking at the berm tail exceedance.

Jeremy Mull (AECOM): and that’s the average number of hours per year, where the total water level is exceeding the berm tail with a wave height greater than one foot.

Jeremy Mull (AECOM): So under baseline conditions, you can see in the upper left. The levee is completely colored and green, and that’s

Jeremy Mull (AECOM): for

Jeremy Mull (AECOM): entire berm. Sorry.

Jeremy Mull (AECOM): And so that’s less than 1 h per year. The legends, the color legends here.

Jeremy Mull (AECOM): to interpret the different colors. You look at

Jeremy Mull (AECOM): the 6 inch sea level Rise scenario, which is what we’re considering to be the the 10 year sea level rise amount

Jeremy Mull (AECOM): the berm is still mostly green with some yellow, so that would bump the segment of berm up into the one to $12 per year.

Jeremy Mull (AECOM): That it’s been impacted by these waves, and then you can look at the results for the higher sea level rise scenarios of 12 inches and 36 inches sea level rise.

Jeremy Mull (AECOM): The next thing we looked at was the frequency of crest overtopping by waves.

Jeremy Mull (AECOM): And we looked at the approximate return period. Total water levels.

Jeremy Mull (AECOM): That would result

Jeremy Mull (AECOM): in in overtopping. So these would be

Jeremy Mull (AECOM): from events as frequent as 2 years. So a total water level with 2 year term period

Jeremy Mull (AECOM): through 1050, and then on up to

Jeremy Mull (AECOM): 100 years.

Jeremy Mull (AECOM): I’m

Jeremy Mull (AECOM): and same as before. Baseline conditions are shown here in the

Jeremy Mull (AECOM): upper left, and then

Jeremy Mull (AECOM): on 36 inches of sea level rise. Most extreme scenario shown here on the bottom right? So for baseline conditions. You can see here. Most of the the berm is shaded in orange, which

Jeremy Mull (AECOM): indicates that it’s vulnerable to

Jeremy Mull (AECOM): overtopping from a storm with a roughly 10 to 50 year return period. There is a small segment in red which is more vulnerable to the light red, so that’s vulnerable to

Jeremy Mull (AECOM): to 10 year. Total water level with 6 inches of sea level rise. More of the berm here is colored in red meaning. It’s more vulnerable. Obviously, to to storms

Jeremy Mull (AECOM): with lower return periods. So it happened more frequently.

Temazcal Room: Hey, hey, Jeremy? This is Bobby again. Sorry.

Jeremy Mull (AECOM): Yeah.

Temazcal Room: Ha! The dynamic water level, or the wave set up, you know, like the wind setup is

Temazcal Room: sloping upwards towards shore.

Temazcal Room: A lot of the same physics.

Temazcal Room: The wave setup? Was it

Temazcal Room: associated with

Temazcal Room: the wave height at the toe of the levee, or with the wave, the largest wave breaking farther offshore.

Jeremy Mull (AECOM): That’s a great question. And

Jeremy Mull (AECOM): it really I I guess it depends on the wave condition. So I’ll kind of walk you through what we did.

Jeremy Mull (AECOM): We generally follow the the engineering guidance, and that the Fema

Jeremy Mull (AECOM): Pacific Islands. So

Jeremy Mull (AECOM): guidelines for the west coast, and so for

Jeremy Mull (AECOM): the 1st step in the run up calculation. We use the

Jeremy Mull (AECOM): the Bim equation, the direct integration method equation to calculate both

Jeremy Mull (AECOM): wave setup

Jeremy Mull (AECOM): and we run up

Jeremy Mull (AECOM): and then we looked at the

Jeremy Mull (AECOM): the dynamic water level so that would be

Jeremy Mull (AECOM): the still water level plus static wave set up, and the dynamic wave set up.

Jeremy Mull (AECOM): and then, if that exceeded the berm toe, we switched to

Jeremy Mull (AECOM): the tar equation, which is a wave wave wrap equation for steep

Jeremy Mull (AECOM): coastal barriers.

Jeremy Mull (AECOM): And then we did a check. So we use the the near shore wave height

Jeremy Mull (AECOM): shoaled to the depth of the toe. If that exceeded

Jeremy Mull (AECOM): the depth limited wave height we would use the depth limited wave height, until, if it did it, we would use that wave height to calculate

Jeremy Mull (AECOM): way round up with tall.

Temazcal Room: Yeah. So I I think that all sounds good. I’m I’m familiar with that methodology. It makes.

Jeremy Mull (AECOM): Yeah.

Temazcal Room: So I mean, I think the question is, where was the what wave was used? At? What pansec location offshore

Temazcal Room: to calculate the way it’s set up.

Temazcal Room: The dynamic water level.

Jeremy Mull (AECOM): Sorry. So you’re are you asking what wave I was used in tall, or what? What wave height.

Temazcal Room: I know.

Jeremy Mull (AECOM): Extracted from the the model to start the calculations.

Temazcal Room: No, I think I understand that the wave height for the run up calculation using the paw equation

Temazcal Room: was the maximum expected.

Temazcal Room: That’s limited or otherwise wave height at the toe of the levee.

Temazcal Room: But the question is.

Temazcal Room: what wave height was used to compute

Temazcal Room: the way it’s set up.

Temazcal Room: which may be a wave that’s bigger farther offshore.

Jeremy Mull (AECOM): Yeah, I I think I get what you’re saying. So we use the near shore wave. I extracted from the the dhi model.

Temazcal Room: Okay.

Jeremy Mull (AECOM): Yeah, so it wouldn’t be an offshore wave. And people are being a nearshore wave.

Temazcal Room: So it’s the offshore. It’s at the extraction point.

Jeremy Mull (AECOM): Right.

Temazcal Room: Okay.

Jeremy Mull (AECOM): Yeah.

Temazcal Room: Thank you.

Jeremy Mull (AECOM): Sure.

Temazcal Room: Maybe. Can I? Ask one question as well, Jeremy?

Temazcal Room: I don’t know if it’s you, but we’re using. You’re using overtopping

Temazcal Room: as kind of the measurement metric for

Temazcal Room: for the hazard. And can you maybe just explain what

Temazcal Room: that that

Temazcal Room: what that does to the the bittern? And

Temazcal Room: ultimately, I think we’re concerned about release

Temazcal Room: of the bittern from into the bay, right? And so

Temazcal Room: is there like a sequence of that happens.

Temazcal Room: That you know that that causes you to use the overtopping as

Temazcal Room: the

Temazcal Room: the measurement of the risk.

Jeremy Mull (AECOM): So I I think what you’re asking is like, what’s the impact of wave over topping to the the the contents of the Mss. Fund.

Temazcal Room: Yes, what I mean. I assume that’s the hazard that we’re that we’re all concerned about, right.

Jeremy Mull (AECOM): Right. So we so we considered.

Jeremy Mull (AECOM): I I guess. We looked at Wave, overtopping as really

Jeremy Mull (AECOM): the

Jeremy Mull (AECOM): the the risk from like a flooding standpoint. And as I guess, really, for just a like a

Jeremy Mull (AECOM): a metric on how vulnerable upon

Jeremy Mull (AECOM): would be to

Jeremy Mull (AECOM): storm conditions and then future sea level rise. We didn’t do any

Jeremy Mull (AECOM): detailed analysis on, like what the actual impacts of the overtopping would be.

Temazcal Room: Yeah, so my name is Matt Pitcher. I’m the operations guy for Cargill. So the overtopping can scour the top of the berms so it wouldn’t be. One wave wouldn’t do anything right. And one wave going into the pond is just a drop, right, you know. I mean. So there! There’s plenty of free board in the pond, so it would take many waves

Temazcal Room: scouring the top to erode the top of the berm, so that then the level in the pond was higher than whatever got scoured, so that that would be the risk.

Temazcal Room: Okay, thank you. And and then it’s just the release of the bittern into the bay, and I’m understanding that

Temazcal Room: the dilution it dilutes. But there is still

Temazcal Room: is there like a time, hazard, or or a hazard in

Temazcal Room: a short period of time, as the the matrix is released.

Temazcal Room: Yeah. So the the hazard would be. Yes, the bitterin getting out of the pond and getting onto the vegetation, or coming in contact with a aquatic species out there, or or whatever but it dilutes.

Temazcal Room: you know, with all the water out there, so it dilutes quickly. But it it all depends on how much of a release. It is right.

Temazcal Room: The the majority of the Mss. Pond is a solid

Temazcal Room: salt

Temazcal Room: or different types of salts, but there is a liquid component in it, too. That’s in inside the matrix. And so that’s really what you’d be worried about is that liquid component because it would take a lot to dissolve the salt and then get

Temazcal Room: that high of a concentration.

Temazcal Room: Thank you.

Temazcal Room: Yeah. I’d I’d like to follow up on that discussion. I I understand what you were saying that.

Temazcal Room: The ponds are very big, and so if there’s a couple of waves that come over, it really doesn’t provide that much

Temazcal Room: water volume, and it doesn’t necessarily raise the water level that much, yet

Temazcal Room: I think I understand that the plan is to continue to

Temazcal Room: increase the the amount of what is it? Mss.

Temazcal Room: Whatever in these ponds, so that the water level is going to go up over time. Right? Correct. We are still using the the ponds for the Mss. To to store the Mss. So so the water level is going to go up over time, and then with sea level, the amount of wave overtopping is going to increase over time. And so

Temazcal Room: I think what Rod’s question is, you know, how does all this translate to the

Temazcal Room: threshold? Criterion for

Temazcal Room: the ponds not overflowing, or

Temazcal Room: you know, it’s hard for us to have a feel for that. It doesn’t seem like that was analyzed. Yeah, there’s a there’s. There’s

Temazcal Room: feet of free board, you know, a couple of feet at least at the minimum inside the pond, so it would take a large amount, and your accumulation per year is

Temazcal Room: less than a half inch.

Temazcal Room: Okay, yeah. So I think it sounds like it’s apparent to you. I guess it’s just not apparent to us. But I appreciate. Thank you for the answer. I I understand.

Temazcal Room: Yeah, this is Chris.

Temazcal Room: My understanding is the purpose of what Jeremy is presenting is less

Temazcal Room: accumulation of bay water in the Mss. Ponds. But looking at the risk to these berms of being

Temazcal Room: eroded or made less stable by the wave overtopping, so it’s the risk of damage to these

Temazcal Room: which would then allow for a larger release.

Temazcal Room: So that’s why we’re looking at like the wave impacts. And the overtopping is that going to damage

Temazcal Room: these burns and cause a larger release.

Temazcal Room: Is that is that right?

Temazcal Room: Yes, that’s correct.

Temazcal Room: Yeah, yeah. I mean, yeah, to to get a large release of it. You would need a lot of scouring

Temazcal Room: which would take

Temazcal Room: it would take a lot of waves, and all those waves would have to happen at a high tide

Temazcal Room: with surge to to get there, because you’ve got you’ve got a large amount. It’s hard to see in the picture, but there’s a large amount of marsh in front of here, so the marsh, the only time the marsh gets covered would be like a king tide.

Temazcal Room: so it would have to happen during a king tide. All the other high tides, you know, or the majority of the high tides during a year don’t even cover the marsh.

Temazcal Room: so you’d have your waves would break up before they ever got through the mark.

Temazcal Room: Okay, yeah, I mean I. And then I understand that you’re looking at

Temazcal Room: into the future with different rates of sea level rise right? So that the risk increases as you move forward in time.

Temazcal Room: Correct? Yes.

Temazcal Room: Okay. Sorry for the interruption. Please please continue.

Jeremy Mull (AECOM): No, no problem at all.

Jeremy Mull (AECOM): I let’s see. I think that I had covered the results for the the baseline conditions. Here, and then the 6 inch sea Level Rise scenario which we’re considering that the sea Level Rise scenario for the next 10 years.

Jeremy Mull (AECOM): And see that

Jeremy Mull (AECOM): roughly. I mean, there’s there’s different spots. But roughly, we’re switching from

Jeremy Mull (AECOM): overtopping, occurring from a

Jeremy Mull (AECOM): 10 to 50 year.

Jeremy Mull (AECOM): return period total water level. Then to one with a

Jeremy Mull (AECOM): the term period of 2

Jeremy Mull (AECOM): to 10 years.

Jeremy Mull (AECOM): so this slide has a little bit of the same information. But it’s just kind of more of a focus on on

Jeremy Mull (AECOM): or a summary of the results, I guess, for point 12. So we’re obviously focused on. Here’s 1 12. Here’s the the bayfront. Berm and

Jeremy Mull (AECOM): So if you’re reading the report, you’re curious what transects were used for this section. We looked at transacts. 2122. Well, 21 through 24, and they’re shown here in the snapshot

Jeremy Mull (AECOM): on the right.

Jeremy Mull (AECOM): The existing Bay front crest elevations for this firm range generally from 11 to 12 feet. Any vd, 88. See that in the picture and also in the report, there’s a

Jeremy Mull (AECOM): color index here shows that the different elevations you’ve got some high spots, some low spots.

Jeremy Mull (AECOM): The majority of the pond. 12 burn crops are above the 100 year. Still water elevation, which is roughly around 11 feet

Jeremy Mull (AECOM): and DVD 88

Jeremy Mull (AECOM): and just a summary set for baseline conditions. Wave overtopping.

Jeremy Mull (AECOM): Generally occurs for a 10 year storm and greater

Jeremy Mull (AECOM): and as a reference, the 100 year

Jeremy Mull (AECOM): total water level is 11 to

Jeremy Mull (AECOM): 13 feet. Any vd, 88

Jeremy Mull (AECOM): just as a note, we’ve been referring to storms in terms of return period.

Jeremy Mull (AECOM): The 10 year storm is actually a 10, a storm with a 10%

Jeremy Mull (AECOM): annual chance of occurrence. And so

Jeremy Mull (AECOM): on average, we would expect it to occur once

Jeremy Mull (AECOM): every 10 years.

Jeremy Mull (AECOM): so for future conditions, that’s 6 inches of sea level rise, wave overtopping roughly occurs, and for a 5 year storm. So it’s more frequent.

Jeremy Mull (AECOM): That has about a 20% annual chance of occurrence, and under your total water level is

Jeremy Mull (AECOM): 12 to 13 feet. Any Bd 88. With that amount of sea level rise.

Temazcal Room: Hey, Jeremy? Sorry to interrupt again. This is Bob again.

Temazcal Room: So you’re saying that the the levee crest elevations are somewhere around the 100 year. Still water level SW. EL.

Temazcal Room: Of about 11 feet in Avd.

Temazcal Room: So that means there’s really no free board.

Temazcal Room: Essentially

Temazcal Room: so with sea level rise.

Temazcal Room: Wouldn’t it be possible that

Temazcal Room: at that 100 year water level water would

Temazcal Room: spilled over the levee.

Jeremy Mull (AECOM): Yeah, so that right now.

Jeremy Mull (AECOM): the the bird crests are above the 100 year. Still water level elevation, the majority of them. It’s around 11 feet. So nothing.

Jeremy Mull (AECOM): If if there was no raising of the firms, yes, there would be

Jeremy Mull (AECOM): potentially subject to to flooding

Jeremy Mull (AECOM): but a hundred years still water level.

Jeremy Mull (AECOM): So what happens.

Temazcal Room: Okay? And then my other comment is, it seems that the total water level 100 year listed there of 11 to 13 feet

Temazcal Room: doesn’t seem to be

Temazcal Room: that much higher than the 100. You’re still water level of 11 feet, and I understand that the bigger winds and waves don’t happen necessarily during the 100, you’re still water level. But still.

Temazcal Room: or even so

Temazcal Room: again, the total water levels seem a little low to me.

Temazcal Room: And I don’t know if that’s because of the wind setup computation or other computation. But

Temazcal Room: And furthermore, usually you would like to have free board unless

Temazcal Room: there’s no consequence to, I guess, the overtopping in terms of

Temazcal Room: the internal water levels or the levee erosion, etc. So I know.

Temazcal Room: So

Temazcal Room: I think that’s still a concern that I have, both in terms of the total water level, seeming a little low to me.

Temazcal Room: and also the implications of the apparent overtopping that will will occur.

Jeremy Mull (AECOM): Yeah, I I think, it’s a it’s a good comment. And you know it. It could potentially be due to yeah, the exposure like we talked about different orientation of the

Jeremy Mull (AECOM): that

Jeremy Mull (AECOM): you know, segments of berm. And then how much

Jeremy Mull (AECOM): Windfash they’re exposed to. And then the frequency that you actually get big wind events time with those high still water levels that

Jeremy Mull (AECOM): we’re actually able to generate waves.

Temazcal Room: Thank you.

Temazcal Room: Rod, can I ask a question? Too?

Temazcal Room: Sure. Yeah, Jeremy, this is Gail Johnson

Temazcal Room: actually had a similar question to Rod about the

Temazcal Room: what are the actual

Temazcal Room: hazards associated with the overtopping?

Temazcal Room: And Chris mentioned about erosion?

Temazcal Room: maybe this is a question for Cargill. We saw photographs from Jen’s staff. Report of

Temazcal Room: that. You trench in the center of the berm

Temazcal Room: and put some kind of a slurry mix.

Temazcal Room: And and you’ve created kind of a

Temazcal Room: interior wall, if you will.

Temazcal Room: Yeah. So it we’re just putting dirt in there. So it’s it’s just. It’s nothing, nothing that. No, it’s not. It’s not hardens it, so to speak. No, okay, no.

Temazcal Room: And but we are compacting it. And his

Temazcal Room: oh, sorry and historically, when you have had

Temazcal Room: overtopping in the past.

Temazcal Room: is it? Has it been in the form of

Temazcal Room: massive breaches or over extensive lengths? Or what what is it? What’s what’s the his history of

Temazcal Room: of damage that’s occurred.

Temazcal Room: Yeah, from from single, from single storms. Assuming you can do repairs.

Temazcal Room: It’s been very minor. I I mean you can. You can tell where some water has gone over, you know, but it’s not. I mean, we haven’t even lost.

Temazcal Room: I wouldn’t even see an inch

Temazcal Room: of material off the top of it.

Temazcal Room: Just you can. You can just sort of see where the where the waves came over.

Temazcal Room: Okay. Yeah. Cause I was, I was having a hard time envisioning

Temazcal Room: what would cause them.

Temazcal Room: Ms. Has to

Temazcal Room: come out of the levee. Because just water going in

Temazcal Room: isn’t the hazard. As far as I can see, that’s what that’s why, I was a little confused.

Temazcal Room: Thanks.

Temazcal Room: My name is Don Brown. I’m the land resources manager for Cargill. So

Temazcal Room: they asked me to cover this slide.

Temazcal Room: What we’re going to do with this information that we received. It really allows us to.

Temazcal Room: you know, identify those specific areas for inspection and maintenance.

Temazcal Room: and that allows us to

Temazcal Room: work our maintenance plan to prioritize, you know, working on those.

Temazcal Room: perhaps more vulnerable segments of of those firms.

Temazcal Room: And and this is in addition to what we already do with regard to you know, we’re we’re out there.

Temazcal Room: you know. Matt’s team is out there inspecting the berms all the time, especially after storms identifying any area that may need some additional maintenance

Temazcal Room: and inspection.

Temazcal Room: And again, this the the study here was under what Jeremy explained as a

Temazcal Room: no action scenario.

Temazcal Room: Well, we’re we’re planning on increasing the height of those berms. So we’ll increase it to 11.5.

Temazcal Room: Nabbed

Temazcal Room: 88 by 2034.

Temazcal Room: We’ve worked with BC. Bcdc staff on on how we’re going to do that.

Temazcal Room: We are going to prioritize the pond. 12 firms.

Temazcal Room: We’ll have that

Temazcal Room: up to that 11.5 by the end of 2029, and, in fact, we’ve already started working on it. Matt’s team is out there already

Temazcal Room: is is increased

Temazcal Room: small segments of those berms

Temazcal Room: already to that that height. So

Temazcal Room: and and we’ll continue to.

Temazcal Room: you know, evaluate any impact that overtopping might have as far as scouring or having any impact to to the berms.

Temazcal Room: So and anything that might anything that might impact firm stability.

Temazcal Room: You know, we’ll be closely monitoring.

Temazcal Room: And and then during the next 10 year period, we’ll have a longer term

Temazcal Room: adaptation plan. How do we? How do we make sure that those those berms around those mixed sea salt palms

Temazcal Room: remained

Temazcal Room: stable and and safely

Temazcal Room: hold that that Mss.

Temazcal Room: Can I ask? Can I ask a question. Oh.

Temazcal Room: oh, you go ahead.

Temazcal Room: So we should see a 5, 6 inches of sea level rise by 2,034. So it seems like you would be building a system that would be

Temazcal Room: too short by 2,034, since we’re supposed to have, it’s highly likely that we would have 11 inches of sea level rise by 2,050

Temazcal Room: so it would seem like it would be more prudent to build now for a 2050 condition instead of building. Now

Temazcal Room: for a condition that you’re going to start exceeding already by 2,034 with that 100 year. Fill water

Temazcal Room: something we’re going to look at in the next 10 year. Permit period the issue would be, you start getting too high. You might have to build horizontally out in order to support the height.

Temazcal Room: So one thing that we’ll be looking at the next 10 years is

Temazcal Room: is really that long term adaptation plan. This is just a commitment we want to do to stay ahead of sea level rise. But

Temazcal Room: we will. That will be part of a long term plan that we look at. How do you actually.

Temazcal Room: make sure that those berms, you know, withstand again, even higher sea level rise?

Temazcal Room: I think you would need to start implementing your long term plan by 2,029. So I, yeah, that that just concerns me. I guess. Yeah, I I had a follow up. I had a similar question. So how was the 11.5 elevation

Temazcal Room: that you’re going to raise the levies to?

Temazcal Room: How was that selected?

Temazcal Room: I was 11.5.

Temazcal Room: It was just based on sea level rise projections, on what

Temazcal Room: you know, as far as the vulnerability of having wave overtopping

Temazcal Room: so that that was based on, I guess.

Temazcal Room: a projection from the existing condition which you consider to be

Temazcal Room: okay.

Temazcal Room: And then

Temazcal Room: a certain amount of sea level rise like half a foot or something like that.

Temazcal Room: I’m sorry. So it sounds like you’re using the existing condition, plus

Temazcal Room: something like half a foot of sea level rise. Is that? Or how?

Temazcal Room: Yep. Yeah. So that

Temazcal Room: I think that’s what we’re struggling with a little bit. What are the criteria for? The initial

Temazcal Room: levee crest elevation rise.

Temazcal Room: and

Temazcal Room: it sounds like it might actually be limited by geotechnical factors rather than

Temazcal Room: something that was developed, based on the hydraulics, the hydraulic exposure. You mentioned the concern that if you raised it higher than that now, which is what Chris was suggesting.

Temazcal Room: That that might be problematic, necessarily problematic. But it’s something that we’re just not permitted to do in our our current maintenance. So it’s that’s why we want to spend the you know.

Temazcal Room: during that 10 year permit period

Temazcal Room: term. And you know, if we want to, if we need to build it even higher or raise them even higher, how would you go about doing that because you know that we can raise it to 11.5 under. You know, that’s part of our existing maintenance that we

Temazcal Room: that we do every year. Thank you. Appreciate it. Thank you.

Jeremy Mull (AECOM): That is all that we have for this live presentation, unless there’s any more questions.

Temazcal Room: Okay, thank you, Jeremy.

Temazcal Room: Are there any

Temazcal Room: further comments from the board?

Temazcal Room: Oh, Jen, yes.

Temazcal Room: I have a comment question. Do these analyses depend? Did they take into account the dampening

Temazcal Room: effect from the tidal marshes that are there.

Temazcal Room: so that if the tidal marshes, for example, either eroded or were not able to create, to keep up with sea level rise. Would that change the outcome of the modeling.

Jeremy Mull (AECOM): So the answer to your 1st question is, no, that

Jeremy Mull (AECOM): on

Jeremy Mull (AECOM): the analysis did not.

Jeremy Mull (AECOM): did not account for the dampening of of the marsh, except for the

Jeremy Mull (AECOM): You know the elevation of the marsh, so that

Jeremy Mull (AECOM): the way we

Jeremy Mull (AECOM): calculated way to set up and run up is purely.

Jeremy Mull (AECOM): purely based on

Jeremy Mull (AECOM): I guess, depth and and elevations only. So it considered. Like the you know, the the flooded depth of the the toe of the berm

Jeremy Mull (AECOM): which is impacted by the marsh elevations. But it didn’t account for

Jeremy Mull (AECOM): any any kind of like future

Jeremy Mull (AECOM): changes to the marsh.

Jeremy Mull (AECOM): like the marsh, potentially rising to keep pace with sea level, rise.

Jeremy Mull (AECOM): A marsh actually potentially dampening the waves a little bit to drag and friction

Jeremy Mull (AECOM): stuff like that.

Temazcal Room: This is this is Chris again.

Temazcal Room: When I look at figure one of your wave analysis. Memo. It looks like you are accounting, at least in that figure for the dampening

Temazcal Room: of the wave height. Under existing conditions. That’s what the figure shows. But I think then, when you’re adding the 6 inches of sea level rise or

Temazcal Room: higher. In your analysis, I’m assuming you’re just keeping that marsh plain edits

Temazcal Room: existing condition. So, not accounting for the rise that it could have.

Jeremy Mull (AECOM): Yeah, that’s a good point. So that we’re accounting for the dampening that might occur. Due to shallow water of the marsh. So as the waves come in. You know they could potentially break

Jeremy Mull (AECOM): you know, and the the shallow water and you get death limited waves at the tail of the firm.

Jeremy Mull (AECOM): and the marsh elevation is not changed for the with future sea level rise, so it stays the same, and we add sea level rise into the calculations.

Jeremy Mull (AECOM): But there’s no dampening like to the marsh.

Jeremy Mull (AECOM): or from the marsh grass.

Jeremy Mull (AECOM): right like providing friction and stuff like that

Jeremy Mull (AECOM): that make any sense, Chris.

Temazcal Room: Yeah. Got it? Thank you.

Temazcal Room: Okay. Thank you, Chris. Any any other questions from the board?

Temazcal Room: Okay.

Temazcal Room: thank you, Jeremy. You

Temazcal Room: see next page of the script.

Temazcal Room: Now Michael Whalen, of Anchor Qea will make a presentation

Temazcal Room: on behalf of Cargill.

Temazcal Room: Hello!

Temazcal Room: Yes.

Temazcal Room: Well, hello! My name is Michael Whalen. I am with the firm anchor. Qea. I’m a principal geotechnical engineer. I will be leading this

Temazcal Room: presentation.

Temazcal Room: should I

Temazcal Room: log in and do it from my screen, or is there a more? What would be the most practical way to go through the

Temazcal Room: okay? I haven’t actually

Temazcal Room: logged in. So let let me let me do that.

Temazcal Room: and I’m I’m joined on the virtually by my colleagues, Andrew Barrett and Cole bales.

Temazcal Room: I’m a i’m Andrew performed a lot of the analyses under my direction.

Temazcal Room: and Cole and I have been

Temazcal Room: the folks to review it and put it all together.

Temazcal Room: So let me

Temazcal Room: let me get get myself logged in to this.

Temazcal Room: Yeah, I got. I got that.

Temazcal Room: I have 45 slides. I do, and I will. I do want to be conscious of time. And I know folks may have comments as I go.

Temazcal Room: Okay.

Temazcal Room: yep, okay. I’m I’m getting. I’m getting in there.

Temazcal Room: Oh, yeah.

Temazcal Room: just

Temazcal Room: okay.

Temazcal Room: And there’s me.

Temazcal Room: okay?

Temazcal Room: Oh, join as panelists. Right?

Temazcal Room: Okay.

Temazcal Room: there’s me. Okay.

Temazcal Room: And then if I share my screen.

Temazcal Room: we

Temazcal Room: we’ll be good

Temazcal Room: share screen.

Temazcal Room: Mike, yeah, let us know when you’re ready, Michael. But I think we want to wait for the board members to okay to show up. Sure.

Temazcal Room: Yep, okay, I I will. That’s I’m all set. And I will.

Temazcal Room: I will hold up.

Temazcal Room: Okay, Michael. I think we’re we’re back now. So

Temazcal Room: okay.

Temazcal Room: very good.

Temazcal Room: Okay, thanks again. Yeah. Michael Whalen, principal geotechnical engineer, anchor. Qea. I. I spoke in the in our last 2 engagements on this topic.

Temazcal Room: and I will go through our updated analysis of

Temazcal Room: static and seismic stability for the for the Pond, p. 2, 12 and p. 2, 13. Firms.

Temazcal Room: And I will start

Temazcal Room: with a short recap of what you heard from us last summertime.

Temazcal Room: where we had obtained all the available information on the sub service conditions that existed at the time performed by other parties.

Temazcal Room: Several borings 24, and, to be exact, were had been done. We had access to that information.

Temazcal Room: I’m including 2 deeper ones to 80 feet.

Temazcal Room: We had quite a few cone penetration tests or cpts to use

Temazcal Room: many of them with hydraulic profiling tools.

Temazcal Room: although those tended to go to depths of like around 20 feet. So there were some limitations on how deep into the subservice we could obtain information, but we used what we had.

Temazcal Room: and developed a model

Temazcal Room: of the subsurface and performed stability analyses for the berm for the berms.

Temazcal Room: And you’ll remember our technical memo. We discussed it. Our conclusions at the time was that the berms showed an adequate level of

Temazcal Room: stability, factors of safety under static and seismic conditions.

Temazcal Room: and we did the analysis for 2 distinct earthquake

Temazcal Room: magnitudes a 50 year earthquake and a 475 year earthquake

Temazcal Room: and

Temazcal Room: We discussed it, and one of the takeaways from our engagement with the Board was that you’re at. You were recommending that

Temazcal Room: a a

Temazcal Room: further series of field investigations be performed

Temazcal Room: specific to this type of analysis.

Temazcal Room: focusing on Cpts, getting to greater depths, etc.

Temazcal Room: And so that’s what we put together. And you saw our work plan

Temazcal Room: right at the end of the year last year.

Temazcal Room: and, as was mentioned early in this conversation in this meeting.

Temazcal Room: we performed that work plan. The investigations described in that work plan

Temazcal Room: late this spring. We got out there as soon as we could, and we we had to wait through difficult weather and rain conditions, but we got out there and did the work. We’re finished by May 3, rd

Temazcal Room: and again consistent with the work plan that we prepared. We did

Temazcal Room: 24 Cpts

Temazcal Room: to as much as 100 feet below below ground surface. Oftentimes, though, they didn’t actually get that far.

Temazcal Room: they got to 64 to 65 feet, and then kind of refusal, but significantly deeper than what we had before.

Temazcal Room: 2 of them were seismic cones, which is, which is a useful way to get an understanding of

Temazcal Room: some of the seismic properties that came into our analysis, as you’ll see in a in a few minutes.

Temazcal Room: We did one deeper boring to help us understand seismic properties. In the subsurface

Temazcal Room: we obtained a handful of undisturbed samples by pushing Shelby tubes.

Temazcal Room: and used those as well as

Temazcal Room: the samples we obtained

Temazcal Room: from the deep boring to perform a series of laboratory tests

Temazcal Room: strength test for the triaxial equipment. You’ll see that comes into play in some of this presentation, and some various index properties of the subsurface, elasticity, grain, size, moisture, content. So all in all, we’re able to successfully execute the program that was described in our

Temazcal Room: in our work plan.

Temazcal Room: And this is a map

Temazcal Room: of

Temazcal Room: the 2 ponds in question.

Temazcal Room: and I could zoom in if folks, and maybe as we go through this, there may be opportunities to zoom in and take a look closer. But there’s a number of things that are depicted on this map.

Temazcal Room: You see, a whole string of little circles, and that is, showing both

Temazcal Room: the preceding existing explorations that we had used for last year’s analysis

Temazcal Room: as well as

Temazcal Room: in the, in the darker color. I I realize that

Temazcal Room: they’re a little small here, but

Temazcal Room: the new ones that we did.

Temazcal Room: and I guess the the takeaway I wanted to show all of you is that we

Temazcal Room: we got information all along these these berms

Temazcal Room: around these ponds. On the bayward side, and between ponds 12 and 13 on both sides of plumber slough. So

Temazcal Room: we were able to get to all these places and get our information. Another thing that appears on this map in our report is

Temazcal Room: the fact that as we discussed a few minutes ago in the in the preceding presentation.

Temazcal Room: Cargill has performed the keying process where the the trench is excavated and then imported, fill, controlled fill is put back in a in a compacted fashion.

Temazcal Room: and

Temazcal Room: This map includes the areas that were

Temazcal Room: keyed over the last 5 years, and our series of explorations included going right through some of the keyed areas and also going through places that had not been

Temazcal Room: need. So we’re able to, you know. Look and compare. And I’ll I’ll talk about that in a

Temazcal Room: in a few minutes. What what did we learn from that?

Temazcal Room: Can I ask a question before you change the slide?

Temazcal Room: when you get further in the presentation section CC is, gonna be kind of right on the line. It looks like

Temazcal Room: and so my question is, can you tell us a little bit more about how you selected these critical sections. Yeah. And how do you know there isn’t 1 that’s worse.

Temazcal Room: And just from a very simplistic perspective, it looks like down to the right of CC. The berm gets narrower.

Temazcal Room: which would seem to indicate, you know, more vulnerable. So can you tell us a little bit about that. Sure? Yeah, thanks that I really should. As a matter of fact, because you do see the 5 sections that we selected on these maps

Temazcal Room: the what we used to select these 5 sections was,

Temazcal Room: a combination of things

Temazcal Room: we had. Even before we went out in the field we had existing Lidar survey. Information allowed us to see how high is the berm, how wide is the berm?

Temazcal Room: Does it vary? Are there places where it’s higher than in other places.

Temazcal Room: what we.

Temazcal Room: So we looked specifically at places where

Temazcal Room: the top of the berm elevation

Temazcal Room: and the the

Temazcal Room: the adjoining low spot, whether that’s the toe of the berm, or, in fact, something even deeper than the toe of the berm, notably the the bottom of plumber slough.

Temazcal Room: Thus kind of being a change in elevation. We looked for places where that change of elevation was

Temazcal Room: largest

Temazcal Room: and closest. In other words, where do we have the biggest, most abrupt change from bottom to top.

Temazcal Room: That was a big factor, in fact, that ended up being the primary factor in how we chose these sections.

Temazcal Room: We were also on the lookout for indications of

Temazcal Room: might. There be places geographically where we’re finding

Temazcal Room: softer material than in other places? If we had seen such things that would have been a really important part of our selection. But we didn’t really see a a trend of softer geographies.

Temazcal Room: So what these ended up being was really based on.

Temazcal Room: shall we say? Abruptness of

Temazcal Room: elevation change from top to bottom?

Temazcal Room: And

Temazcal Room: well, there are 5

Temazcal Room: lines on this map. We actually

Temazcal Room: looked at 7 sections. And the reason I say that is because.

Temazcal Room: sections B and C cross all the way across plumber slough and include both the the flanking berm. So our models are set up to to evaluate

Temazcal Room: 7 sections. But

Temazcal Room: it was. It was the changing grade that would that ended up being the primary driver for us to

Temazcal Room: choose these places for our analysis. So so is there anywhere that’s worse than C.

Temazcal Room: Not not that we can tell.

Temazcal Room: not not from the evidence that we saw.

Temazcal Room: And you are right. C is is the more critical player as as we’ll talk about in a bit.

Temazcal Room: Yeah.

Temazcal Room: Michael, I have. another question that I was.

Temazcal Room: Since we’re talking about this now I’ll go ahead and jump in.

Temazcal Room: I hope.

Temazcal Room: and it’ll come back again a little bit later on, about 8 slides further ahead, I think, but the southwest corner there at the south side of the

Temazcal Room: Greek or channel whatever that is.

Temazcal Room: Cpts 8 and 9.

Temazcal Room: so 2 questions, I guess

Temazcal Room: part of it is related to

Temazcal Room: to the geometry. It looks like, since you have. You know, the southwest corner there is kind of west southwest, the creek. It looks like there might be. Yeah.

Temazcal Room: yeah. Aq. Cpt and 9 Ccp, 8 and 9. Okay, yeah, the 2 yellow ones I I had misspoke. By the way, folks that yeah, the yellow ones are the new ones. But anyway, it looks to me I’m I’m curious. Why, you cut off Bed Bay mud at 30 feet when it looks like those 2 have Bay mud at 32 and 36 feet. Oh, yeah, is one question. That sort of okay.

Temazcal Room: related to a few slides further down the road. But it also looks like this particular geometry might be a more critical one, because you have that that channel out in front of you. There, that

Temazcal Room: have you?

Temazcal Room: Have. You looked at the geometry

Temazcal Room: sort of going left from Cpt. 9, I guess.

Temazcal Room: Yeah. Are you describing how

Temazcal Room: like the slough is relative to the berm? When you when you say that. Is that what you’re but also, as you move, just sort of straight west, you get that wider water body. I’m not sure if that’s

Temazcal Room: Creek channel, or what? That is exactly. But those guys, you have a wider water body that

Temazcal Room: looks like it might be deeper channel. Okay? Less. Cpt. 9,

Temazcal Room: as it looks to me like bay mud bottom is about 36 feet rather than 30 feet, which make it

Temazcal Room: potentially, geotechnically more critical, but also, maybe geometrically more critical. Sure.

Temazcal Room: Okay. Well, I understand what you’re saying.

Temazcal Room: it is. It is possible. I I will admit it’s possible that there could be some places whose combination of factors is somewhat different, or even worse, than our selections. I think our selections are are pretty solid, that in this case and and I’m able to speak from having gone through the analyses. One thing, couple of things we found, and we’ll be looking at this soon when I, you know, should we look at all the slip services?

Temazcal Room: The slip services?

Temazcal Room: I I think it’s fair to say Andrew is gonna ping me if I say this wrong, but

Temazcal Room: that the slip surfaces that were critical for analysis didn’t go so deep that the the acknowledged fact that young bay mud does sometimes go below 30 feet. You’re absolutely right. There’s places 32, 34, 36 feet deep.

Temazcal Room: We haven’t seen that that

Temazcal Room: has translated to where the critical slip services end up. Being

Temazcal Room: so true though it is, I don’t know that it

Temazcal Room: affects the the conclusions we’re drawing.

Temazcal Room: Similarly, I I understand your observation about the the slough and the water bodies offshore from these locations.

Temazcal Room: I’m thinking.

Temazcal Room: And again, I’ll you know, as we go through, and Andrew might speak up on this when we’re kind of going through some things. But

Temazcal Room: I think that still may be far enough away from the berm that

Temazcal Room: that water body, even if it ends up, being really deep over here on the left.

Temazcal Room: I don’t know that that is, would end up affecting our results very much. That that’s my suspicion about how those might play out.

andrew barrett: Michael, that’s pretty much exactly what I was. Gonna say. At at Cbt. 9 and Cbt. 8. You do see that the young Bay mud is deeper than the 30 feet that we used as our average in our models.

andrew barrett: But one thing that we found is that the critical region, I guess you could call it in terms of stability in terms of strength is between 10 and 20 feet, where we saw a lot of failure services go through.

andrew barrett: So one of the things you’re gonna notice is that what.

Temazcal Room: I’m sorry, Andrew, do you mind turning on your camera when you’re talking?

Temazcal Room: Yeah.

andrew barrett: Oh.

andrew barrett: hello!

andrew barrett: And that was that was all I had to say. We we noted that the the critical area, the critical region

andrew barrett: of the strength parameters in the models was between 10 and 20 feet.

andrew barrett: So that deepening there around the the 30 to 36 range

andrew barrett: didn’t seem to have any effect on the the overall stability.

Temazcal Room: I have a few more questions about stability. Maybe we can wait until we get down to the stability section of the presentation. Okay? I mean, it’ll sort of follow on these. But I wanted to jump in and

Temazcal Room: about some

Temazcal Room: geometry here. Good. Yeah, that that makes sense. Okay. So I’ll keep moving up, moving forward. Alright.

Temazcal Room: But oh, yeah, let me clear in my mind

Temazcal Room: you had Lidar information to give you the the crest of the burns, if you will. Yeah.

Temazcal Room: So

Temazcal Room: the toe of the berms

Temazcal Room: did. You have also lighter information about that?

Temazcal Room: We did we? We did have Lidar information. But one thing I should mention

Temazcal Room: it’s in my notes is that part of our field engagement wasn’t just to do all these cpts and boardings, but we also did. We didn’t take a survey crew out there, but we checked manually all the dimensions out there in terms of berm width, and maybe even more notably berm height, just to do a ground check on what we had from the Lidar.

Temazcal Room: which was really helpful to us. Because the berms aren’t all that high as you’re as you’re standing there and kind of looking at them, and we needed to make sure we had that right in the cross sections we set up. So I guess what I’m saying is we had Lidar, but we also. Field checked it.

Temazcal Room: That that’s the issue that in my mind I I want to make sure that

Temazcal Room: you’re saying you’re

Temazcal Room: analyzing the steepest slopes.

Temazcal Room: Correct? Yeah.

Temazcal Room: that that is our intent. Yup. That’s right. Okay, that’s fine. I I want to

Temazcal Room: understand it better for myself. How the toe was, I mean, how did you measure it in terms of height or elevation, and and kind of the inclination to say, Hmm.

Temazcal Room: this is the steepest at this location. Yeah. And I should. I should probably clarify that a little further, because what we measured in the field was the observable

Temazcal Room: berm.

Temazcal Room: But

Temazcal Room: plumber slew particularly, being a really important factor in this whole evaluation for our selection of

Temazcal Room: steepness. We didn’t go into plumber, slew and measure that that was from the Lidar, for sure. That’s where we and and that kind of goes back to what I was kind of

Temazcal Room: describing in our selection. It turned out that our selection isn’t based on like

Temazcal Room: standing there and and seeing the burn be steep. It was based on recognizing that plumber slew out here or bay waters offshore.

Temazcal Room: Those are getting deep faster.

Temazcal Room: And so

Temazcal Room: that ended up to us being the the real critical definition of

Temazcal Room: what’s the most critical place. Where is it steepest? If if that makes sense? I I in other words, I’m I’m describing steepness, not just at the the immediate face of the of the berm as is visible. But all the way out to the nearest deep water.

Temazcal Room: Okay, continue forward. And we can obviously revisit these things as we go.

Temazcal Room: Yeah, berm cross sections developed for analyses. Let me start with just some very generic ones. I don’t know like I’d rather focus more on the the scaled ones we did. You’ve you may remember seeing these

Temazcal Room: before. I haven’t even changed these for this presentation, although in reality we have made some updates till we actually modeled.

Temazcal Room: But the general geometry of things

Temazcal Room: stays the same. Really. What I wanted to show everybody is our understanding of what the deal is with these berms.

Temazcal Room: They’re built out of densified fill upon young bay mud. That’s the real point I’m trying to make. Here you see the mixed sea salts on the left.

Temazcal Room: You see the berm crest, and I didn’t say the stirring

Temazcal Room: Jeremy’s earlier talk, but

Temazcal Room: I feel like the the fact that the surface of this, these densified fill berms and the and the cover with the

Temazcal Room: the surface and gravel. Sh! I’m not going to try to quantify that and what I’m saying. But surely that has some innate resistance to wave overtopping erosion.

Temazcal Room: Just want to make that side observation. But any case just wanted to show this, and also, as I scroll to the next

Temazcal Room: slide

Temazcal Room: the this keying activity that Cargill has been performing where

Temazcal Room: a trench, his dog and and compact and material placed back.

Temazcal Room: So that that’s the general concepts. I think this is all familiar. We’ve

Temazcal Room: gone through all this before.

Temazcal Room: What I wanted to do next was just run through

Temazcal Room: the 5 critical sections that we selected and modeled.

Temazcal Room: Those of you who are familiar ask real quick question. I think it’s be easy. The keying is to cut off seepage, or for stability or settlement, or what

Temazcal Room: I I think it’s primarily driven by cutting off seepage right primarily to reduce permeability

Temazcal Room: to reduce permeability. Sorry.

Temazcal Room: yeah. And we’ll comment in a few minutes about what might that imply for stability? And see? Bitch? Yeah.

Temazcal Room: have a question about the previous slide.

Temazcal Room: Is that slide? Is this slide intended

Temazcal Room: as schematic? Or, I mean. This has elevation on it, it has

Temazcal Room: exaggeration on it.

Temazcal Room: It is intended as a schematic.

Temazcal Room: it it definitely is intended as a schematic. I say that because we didn’t put this into our model.

Temazcal Room: We put what I’ll show next into our model. I mostly want. This is a schematic, and it’s true. This has

Temazcal Room: various elevations described on it. It’s a it can be a little confusing, I realize, because

Temazcal Room: we developed it with a different kind of

Temazcal Room: one data. And then we used aecoms findings. So

Temazcal Room: I I want this to be considered as a schematic. That’s why it’s intended. Thank you.

Temazcal Room: These. So this is the 1st of 5.

Temazcal Room: these aren’t schematic. I mean, these are literally what we put into our

Temazcal Room: slope stability model. Those of you who are familiar with this slope stability software recognize that

Temazcal Room: nowadays, when you build this model, you can very quickly run all sorts of different combinations of situations, all sorts of different water levels, you can vary the strengths of the soils. You can do a lot of these things. And the reason I say that is because.

Temazcal Room: what you are seeing in this slide set. And frankly, what you see in our report isn’t everything we run. We ran a lot of things because you can do it quick.

Temazcal Room: So, for example.

Temazcal Room: these all show a certain assumption of water levels.

Temazcal Room: But I think, as as you are all aware, you know, part of our work was to study the effects of different water levels. So these are just selected images. The real thing I wanted to show is just is the geometry

Temazcal Room: of the berm, and and you see

Temazcal Room: there’s the berm in the middle.

Temazcal Room: But as you go out to the left the outside of the pond, now you’re dropping out into the the offshore area to the north

Temazcal Room: of

Temazcal Room: of the pond at this particular location.

Temazcal Room: And the reason, I say that is because when I was talking a few minutes ago about you know how we define this, the top to the bottom at the closest proximity.

Temazcal Room: We’re kind of looking at. Where might this overall slope that I’m tracking with my cursor be most dramatic? And how might that be our critical second?

Temazcal Room: Anyway.

Temazcal Room: there’s location a

Temazcal Room: I’ll comment on the sub service in a minute here, because, you see all these colors, I just have a quick question, what are the units of the X and Y axes on these.

Temazcal Room: Those are in feet.

Temazcal Room: elevation and feet.

Temazcal Room: and

Temazcal Room: a arbitrarily selected horizontal location and feet.

Temazcal Room: Was, was there another

Temazcal Room: question.

Temazcal Room: okay, you know what? Let me let me hang on this one just a little further, because

Temazcal Room: there! There’s some colors that we use, that I will. I I

Temazcal Room: I want to explain.

Temazcal Room: we have young bay muds everywhere below the berm.

Temazcal Room: and then, as you get lower on the figures

Temazcal Room: there, there’s green bands for young bay muds.

Temazcal Room: and then all the way down to the bottom of the figure.

Temazcal Room: In in reality

Temazcal Room: Although, as I was saying a little bit ago, and and Andrew also said this.

Temazcal Room: the you know, the the young bay mud, reaching depths of 30 feet or 34 or 36, didn’t really affect our analysis. So once we found that out, these graphics were simplified.

Temazcal Room: But the point is, everything’s young bay mud with kind of down below. There’s an old bay mud floor.

Temazcal Room: and all the action that we’re talking about here happens, of course, in the young bay muds.

Temazcal Room: I also want to explain why we have this different color scheme protruding down below the berm.

Temazcal Room: where you see like green and pink.

Temazcal Room: If if you’re seeing the colors

Temazcal Room: that that’s the information we picked up and used from our analyses directly, and I’ll explain in a few minutes how we, you know, came up with these layers

Temazcal Room: versus the places to either side of the berm that are just kind of this consistent kind of dark blue.

Temazcal Room: The the dark blue on either side of the berm is where we applied kind of the worst case strength parameters. And the reason we looked at it this way is because we expect that the presence of the berm has

Temazcal Room: probably cause some strength gain that we’re observing, and we shouldn’t expect that that strength gain exists to either side of the berm.

Temazcal Room: We’re we’re really trying not to.

Temazcal Room: We’re just trying to stay appropriately conservative with our assumptions and not

Temazcal Room: not be overly optimistic about things. And that’s why the colors appear

Temazcal Room: the way that they do. There’s just a distinction. But below the berm versus not below the berm.

Temazcal Room: anyway.

Temazcal Room: Very similar storyline for these other locations.

Temazcal Room: There’s location B zoomed in.

Temazcal Room: Here’s Location C, where you can actually note that plumber slough is in the middle, and we got

Temazcal Room: we got some of the modeling on both sides of of the slew. But

Temazcal Room: the critical situation was here right in the middle. What you’re seeing there?

Temazcal Room: Location DA little smaller berm

Temazcal Room: and location E, and and again, these are zoomed in just to kind of show you folks how we developed these these models and kind of the scale of of the size of the berms themselves, because these are all the

Temazcal Room: to scale.

Temazcal Room: I I have a quick question.

Temazcal Room: So

Temazcal Room: I think the the purple line is the water level, and I think your purposely have the water level high on the pond side and low on the outboard side for stability analysis.

Temazcal Room: so on the pond side, it seems like it’s

Temazcal Room: not that far below the crest is that is, that the existing condition? Or is this a more conservative.

Temazcal Room: In other words, the the free board on the inside seems kinda

Temazcal Room: free. Board on the inside is not intended to be particularly

Temazcal Room: conservative.

Temazcal Room: But yeah, what you’re seeing in this case is about. What is that about 2 feet of of height

Temazcal Room: above ground surface, each of those? Okay, it’s 2 feet. Okay.

andrew barrett: This is one of the examples of the existing marshes to be seen from the edge of Pond 12. Cross. Section Ede. Prime is on Pond 12.

andrew barrett: There’s several 100 feet of soil.

andrew barrett: you know, that’s above the water line. This is at low tide.

andrew barrett: the pond

andrew barrett: water level. We were told by cargo that doesn’t change, which stays roughly around 9 depending using pumps. And if there’s rainfall, then they bring it back down. So in these models the the elevation is plus 9 nav. D. 88 for all of the ponds. Well, all of the models that show the pond water side, and then the elevation that’s changing is is the

andrew barrett: the water level

andrew barrett: on the bay side.

Temazcal Room: Thank you. Which side is upon, and which side is obey.

andrew barrett: In this case this is a low water condition. So

andrew barrett: if you’re looking at the screen, the left side is the pond.

andrew barrett: And and you’ll see. Generally speaking, the water level being higher on the pond side is is the condition where we would expect to see the lowest factors of safety.

andrew barrett: So you’ll see that a lot, generally speaking, in the models that are shown in this presentation

andrew barrett: are the low tide conditions.

Temazcal Room: Good thanks.

andrew barrett: So you’ll see that the pondsight is usually higher.

Temazcal Room: So

Temazcal Room: one of the things that’s a little bit frustrating with this is that there’s no strings

Temazcal Room: shown on these plots here. And so you’ve described what happens with the different shades of green and blue and

Temazcal Room: and pink

Temazcal Room: and even in your

Temazcal Room: port

Temazcal Room: I think 80% or more of the civility sections don’t have the strengths actually shown on them. There’s there’s a few that do.

Temazcal Room: If we look at one of them that does

Temazcal Room: it says that the pink

Temazcal Room: has a strength of 2 75, increasing by 15 psf. Per foot.

Temazcal Room: It also says that the

Temazcal Room: blue

Temazcal Room: which is adjacent to the pink well.

Temazcal Room: the dark blue, the

Temazcal Room: the thing to the left and right of the pink yeah, teal. It’s different on my screen than on your screen than up on the wall there, right. But what’s right and left of the pink

Temazcal Room: says that it’s 2, 75

Temazcal Room: increasing by 15 per foot. But if it’s 2, 75 at the top, and increases by foot by 15 per foot.

Temazcal Room: By the time the blue gets down to an elevation of the height of the top of the pink.

Temazcal Room: It’s going to be stronger than the pink.

Temazcal Room: I think that you have cpt data that goes right down the middle of the levee. Right? Yeah, and I think everything outside of the levee is inferred because you can’t drive rigs out over the that’s right.

Temazcal Room: And I think that the reason you have that

Temazcal Room: that trapezoid underneath

Temazcal Room: levee is because you’re assuming there’s some consolidation that happens from the weight of the levee. That’s right, right, which means that the blue on the sides of the pink should be weaker than the pink.

Temazcal Room: unconsolidating. You’re actually analyzing it. They’re stronger than

Temazcal Room: well, let’s if you give me a

Temazcal Room: seconds you’d have to look at page 5 0, 5. In your report

Temazcal Room: I have 5 0, 2,

Temazcal Room: which is another example. The same thing.

Temazcal Room: But yeah, hold on. Let me

Temazcal Room: zoom

Temazcal Room: share.

Temazcal Room: You are talking about this.

Temazcal Room: I think this table, the company ha happened to be looking at a different page. Yeah, same table. Okay, I think I think this is 5. This is, in fact, 5 on you’re saying

Temazcal Room: this lower row.

Temazcal Room: Well, actually, so I’m looking at.

Temazcal Room: I’m looking at Page.

Temazcal Room: You maybe, are you on?

Temazcal Room: I need to move my little sorry folks for the all the

Temazcal Room: flipping of pages.

Temazcal Room: This this is. Page 5, 0, 1.

Temazcal Room: Right here, right here.

Temazcal Room: Yeah. Okay, so 2, 75 and 15 and 2, 75 and 15 on both.

Temazcal Room: 2, 75 and 15. Yeah, you’re talking about you guys. See what I’m doing there when I draw these little

Temazcal Room: think, yeah, you’re talking about

Temazcal Room: this right here, right? And you’re comparing it to the I think the 275 is the strength at the top of the layer.

Temazcal Room: and I see by that 15

Temazcal Room: Psf. Per foot.

Temazcal Room: That’s right

Temazcal Room: below the top of the layer, and if you scroll down on this page, then

Temazcal Room: you can see where the the blue is higher. The top of blue is higher than the top of pink.

Temazcal Room: which means that the 2 set the the blue starts at 2 75 at the top.

Temazcal Room: and increase down so it will be

Temazcal Room: 10 feet

Temazcal Room: 10 feet.

Temazcal Room: So by the. So you’re suggesting that the arithmetic works out such that by the time you’re down at the depth of the pink.

Temazcal Room: You’ve actually got higher strengths on either side of the pink.

Temazcal Room: I understand what you’re saying.

Temazcal Room: I had a comment, for later on, again I would say, I would suggest

Temazcal Room: that you try putting these tables on every printout page.

Temazcal Room: It’s it’s a little bit of a nuisance when you’re setting it up. But yeah, once you get every run, it shows on every run. So like you’re saying, the software is awesome because you can do lots of runs.

Temazcal Room: Once a table set up, it follows you through on all the runs, and I I think that’s as simple as a

Temazcal Room: probably a button push to make it come out. Yeah, it’s a little bit of a nuisance to set it up sometimes to get it okay, scaled and formatted. And you have to move it left or right to get it out of the way of the

Temazcal Room: safety factor pronounced. But

Temazcal Room: sure, okay, that’s that. That makes sense that’s good.

Temazcal Room: But by putting it on every one, and you can just

Temazcal Room: I mean, we don’t have to

Temazcal Room: flip around. I wonder what you’ve used on this particular one, and one of the things that sort of alarms me now is the table you were looking at a second ago. Different page than this one has different numbers, which means that I assume that every single table I wonder how many different

Temazcal Room: variations there are. Sure, and I can’t follow that at all as a checker. Okay.

Temazcal Room: yeah. The other one.

andrew barrett: What he was looking at was.

Temazcal Room: Doing Andrew’s work won’t be able to tell what he’s doing, either yeah or Cole’s work. Whoever’s doing. Sure. Sure.

Temazcal Room: Go ahead, Andrew, you had a comment.

Temazcal Room: I think that was Andrew.

andrew barrett: Yeah, yeah, I was just gonna say, the table that

andrew barrett: the table that you were showing earlier. Michael was one of the checks that we ran using different parameters. That were found from the triaxial test data. So that’s why the values are different and that they are labeled on each page

andrew barrett: what? You know which system we’re using. So I know it’s not super intuitive and can’t be seen right now on the screen. But it it is there.

Temazcal Room: Yeah, no, I don’t mind. I don’t mind having different

Temazcal Room: cross sections having different numbers on them. That would be

Temazcal Room: probably expected.

Temazcal Room: But yeah, there’s most of the

Temazcal Room: profile cross slope stability profiles that are shown in the report don’t have the table shown at all, so I don’t know which table is applicable, for which one

Temazcal Room: I can assume that all the ones for B is the same as all the ones for B,

Temazcal Room: but

Temazcal Room: but just print it out, and then it’s there because I I know I’ve I’ve done thousands

Temazcal Room: thousands of runs over the years, and I know you. You tweak one. And it

Temazcal Room: right? How can you prove? How do I know for sure, when my Qc. Person is looking at it.

Temazcal Room: that that tweak got carried through on every other right. I don’t have a residual B analysis

Temazcal Room: that has the previous

Temazcal Room: unodated.

Temazcal Room: I I can appreciate that. I mean, it’s 1 thing for Cole and I to work with Andrew and know everything’s spread out, and what was done, in what order we have that advantage. But as a reader and someone coming into this I can appreciate how, if you’re missing that stuff, it is nearly impossible to piece together. Why not just do it

Temazcal Room: right.

Temazcal Room: That makes sense 2

Temazcal Room: to follow on on Jim’s point.

Temazcal Room: How would you distinguish

Temazcal Room: these strength parameters that

Temazcal Room: presumably

Temazcal Room: on the

Temazcal Room: left and right of the pink.

Temazcal Room: is the natural material right? And then the the

Temazcal Room: the key is this

Temazcal Room: engineered material.

Temazcal Room: presumably.

Temazcal Room: When you say the key engineered key correct

Temazcal Room: when you you, too, when you well, it’s a tiny little thing. It’s basically above well, but it’s shown in a way here that it implies that this trapezoid is the key.

Temazcal Room: Well, I that I don’t want to imply that cause. It’s not. But your point is that it could look that way right? And then it creates confusion with respect to all of these strength parameters that are being assigned particular layers.

Temazcal Room: Well, I certainly don’t want people to get the impression that’s intended to be the key, but I suppose it does kind of look like key. That’s right. If you look at a certain way, right? That’s another reason to.

Temazcal Room: With this table on every printout, because that table labels the pink as young bay mud.

Temazcal Room: Yeah. And so if you happen to look at one of the ones that has the table.

Temazcal Room: then you’re set.

Temazcal Room: but I think actually none of your presentation. But most of them don’t have the table. It is true there’s a whole bunch of them. And just if you had the table.

Temazcal Room: But it yeah, that that is not the key.

Temazcal Room: But I I understand your point. That is that the key?

Temazcal Room: Yeah, okay, that’s that’s good. I mean these these. Okay, I understand.

Temazcal Room: where am I? Here? Okay, so

Temazcal Room: alright. So we’ve been talking about the sections and the analyses.

Temazcal Room: I was next going to talk about how we came up with new strength parameters for these layers.

Temazcal Room: Do. I need to be worried about timing as I go through this or just keep. We got lots of time, I guess, right.

Temazcal Room: for now

Temazcal Room: we’re we’re

Temazcal Room: we’re on Slide 15 out of 45. So.

Temazcal Room: I am just showing this

Temazcal Room: graphic, because this is what you saw. Last year.

Temazcal Room: when we had 3 layers defined, we identified Berm Fill. We had young bay mud. There was comments on how we were showing the strengths of the young bay mud.

Temazcal Room: There was old bay mud, that was it. We’ve taken that a step further now, in 2,024. So let’s let’s go on to what we did here in 2,024.

Temazcal Room: So the previous

Temazcal Room: slides you where you’re shown with the the soil properties are those from

Temazcal Room: before you’ve done the the Cpts or this new round of they’re for the new. They’re they’re all new. Okay. Thank you. What I’m about to show here explains how we came up with those

Temazcal Room: you mean this, this page here.

Temazcal Room: Well.

Temazcal Room: this is this, let’s let’s let’s tackle that on in a couple of slides, because then, let’s

Temazcal Room: let’s look at how we did it. This definitely doesn’t match.

Temazcal Room: We. We have changed this.

Temazcal Room: and here’s how we did it.

Temazcal Room: This is a compilation of all the Cpts that were conducted.

Temazcal Room: If you can see all the colors

Temazcal Room: you’ll recognize. There’s a whole bunch of different colors, and that’s because we just assign a different color to every Cpt. So all 2 dozen of the Cpts get its own color, and we

Temazcal Room: plotted them all up to see what it told us. And

Temazcal Room: I mean, there’s a lot of scatter, but you also see some trends, and and it suggested to us that it would be more precise for us to subdivide

Temazcal Room: the young bay mud.

Temazcal Room: And and so that’s what we’ve done, and on the next slide.

Temazcal Room: We

Temazcal Room: you talking about here

Temazcal Room: like this?

Temazcal Room: Right?

Temazcal Room: Okay.

Temazcal Room: bye.

Temazcal Room: I’m sorry

Temazcal Room: I can lean in

Temazcal Room: sorry. You want me to start over again? No, no, I I mean I I’m getting it.

Temazcal Room: No, I well.

Temazcal Room: you’re talking about Cbt. 8 and 9. So, 8 and 9

Temazcal Room: you know, everything is consistent. It looks like Cpt. 8 to 9. Go down with bay mud down to 32 feet down to 36 feet, and it looks like really on that far west.

Temazcal Room: southwest, south, south, west, southwest Point.

Temazcal Room: It looks like that’s got deeper may but bay mud that stays with a nice smooth bay mud.

Temazcal Room: strength, profile.

Temazcal Room: and and I’m wondering whether that geometry might look critical also, and in any case, even if it doesn’t, I think that probably there needs to be some still stability done done

Temazcal Room: with that location that shows it going to 36 feet. Okay, I understand. It sounds like you, unless you can explain to me why it shouldn’t be that way. That’s how it looks to me.

Temazcal Room: And you’re. It sounds like you’re talking not only here about the depth

Temazcal Room: there of of the young Bay mud, but potentially also where it plots up on these graphs.

Temazcal Room: yeah, are you also? No, I think that’s like it’s going to plot just nicely that it’s, I assume, that’s going at about 15 psf. Per foot. Okay. So if you just extend the bay mud an extra 6 feet, you’d have that same profile going an extra.

Temazcal Room: Okay, an extra 6 feet. I understand? You’re really making the point. There’s been some stability cases at least.

Temazcal Room: I would expect that the circles are going to try and climb as deep as possible, climb downwards as deep as possible. It looks like some of your spill analyses. If you just scan through

Temazcal Room: the geotech report, some of them go down to 30 feet.

Temazcal Room: I think that those ones presumably bumped into something at 30 feet, and if you allow them, go to 36 feet and allow the Bay Ma to stay soft at 36 feet. I think they’ll extend a little bit deeper. They might go deeper, and typically if it if it bottoms out at a depth, and then you allow it to go a little bit deeper. The stability safety factor is going to go a little bit lower

Temazcal Room: it. Yeah, if it wants to bottom out and the bottom drops, it’ll probably keep chasing it down so that could that could be the case. If if you’re allowing the circle to go as deep as you want and it and it

Temazcal Room: finds a critical minimum safety factor. That’s higher than that. Then you say the

Temazcal Room: the depth doesn’t matter that much, but there were at least a few of the circles

Temazcal Room: in your report where the bottom is 30 feet, and I assume that that’s bottoming out, because there’s some constraint that it bumps into right there. Okay.

Temazcal Room: all of which is a an advocate you’re advocating that we might benefit by looking at what’s going on there in the

Temazcal Room: that western

Temazcal Room: edge where Cpts 8, 9 are. I think it’s only relevant to Cpt. 8 and 9. Nothing else goes deeper than 30 feet. A lot of it’s more like 24 feet.

Temazcal Room: Yeah. Okay. But

Temazcal Room: okay, that could be I. I hear you.

Temazcal Room: Okay. Well, let let me just give an explanation of what we did with this information.

Temazcal Room: We took. We broke it into the kind of subdivisions and the upper 5 feet. We looked at that. And for each of these subdivisions we did a probabilistic

Temazcal Room: plot of strength versus how often it occurs. And that’s what this

Temazcal Room: on the right is. It’s all the strengths plotted by the

Temazcal Room: frequency of occurring.

Temazcal Room: And it’s a pretty wide band. There’s a scatter

Temazcal Room: and what we did was in the next. In this case, and the next one, we chose

Temazcal Room: the 30 percentile level. In other words, we chose a strength that 30%, only only 30% of the day is below and the other 70% is above. We felt that was a reasonable way to

Temazcal Room: come up with an estimated strength.

Temazcal Room: Now for is particularly for wide ranges.

Temazcal Room: and and the same is true. 5 to 10 feet below ground service.

Temazcal Room: now 10 to 20 feet below ground service, a little different, in our opinion, because there’s more of a clustering of the strengths. It’s not as broad. It’s not as much of a bell curve. It’s more of a sharp curve.

Temazcal Room: and here we felt it was

Temazcal Room: reasonable to choose

Temazcal Room: the most typical strength. In other words, the

Temazcal Room: the top of the curve.

Temazcal Room: That wasn’t done to try to get a high strength. It just like that. Seems like that’s the dominant strength.

Temazcal Room: Alright! Let me jump in again.

Temazcal Room: so averaging works nicely when the data

Temazcal Room: is.

Temazcal Room: you know, if you’re if you have cpt variable data and you’re driving a pile through it. The pile is picking up a little bit of strength from 0 to 5. A little bit of strength from here, you know, and an average is an appropriate number.

Temazcal Room: but if you look at some of those colors, it looks like you’ve got straight down the far left edge of that all the way, and so some profiles.

Temazcal Room: some cpts at least, are all the way on the left edge there.

Temazcal Room: most of them. Maybe you nudge it up a few percent or so I don’t know. But really pretty darn close to that left edge is where some profiles are going to be.

Temazcal Room: Some profiles aren’t going to be averaged

Temazcal Room: over there. If you want to know whether the whole thing is going to slide or not, then you can say, Yeah, at least 50% of the sections are not going to slide because we’ve used 50% Median value here.

Temazcal Room: I don’t think we want 50% of the sections to be stable. I think we want all of them to be stable. And we’re looking for the worst.

Temazcal Room: not the not the average case, but aren’t by doing this. Aren’t we? Basically taken like down the middle of that? You’re right. I mean, almost all of them are clustered there on the left.

Temazcal Room: and there’s a bunch. There’s a bunch of stragglers off to the right. But

Temazcal Room: aren’t we choosing the most prominent

Temazcal Room: band

Temazcal Room: through this approach?

Temazcal Room: And that’s what we’re we’re we’re trying to rep. We’re trying to

Temazcal Room: capture the fact that there is a definitive.

Temazcal Room: a clustering of them on the left.

Temazcal Room: and and certainly aren’t looking to go past that it does seem like the appropriate strength is

Temazcal Room: right there in in the dentist part of the graph.

Temazcal Room: I think, for a stability analysis like this, where you have some cones that are far. If you have data on each cone that’s scattered

Temazcal Room: and the slope circle comes through all of those different layers, and you average it.

Temazcal Room: But I think if you got a single cone that’s

Temazcal Room: straight down the left edge, and you have actually.

Temazcal Room: But

Temazcal Room: it looks like you got 6 or 8

Temazcal Room: cones that are straight down the left edge.

Temazcal Room: and I don’t know how you can be really confident

Temazcal Room: that there’s not going to be some location out there where you have a slope circle that’s going to be able to find that weak spot.

Temazcal Room: and maybe it happens to be offset a hundred feet from where you did your cross section.

Temazcal Room: your cross section has to be representing

Temazcal Room: the safety factor of 100 feet away from where you did your section. And I think I mean, without having any geometry attached to the figure.

Temazcal Room: I think that you gotta

Temazcal Room: you gotta do something further left in your green 50 percentile.

Temazcal Room: Yeah.

Temazcal Room: Okay, I understand what you’re saying. I will. I will mention. Although it’s not in this slide deck. I’m not even frankly sure if it’s in our report.

Temazcal Room: because we can do these things so quickly and easily, we did look to see what happens if we

Temazcal Room: like, take the 30 percentile version of this

Temazcal Room: which is like 250 to 300 sheer strength.

Temazcal Room: And I’m I’m interested in other geotechs because I’m I’m

Temazcal Room: we’re a crowd here. But but I think that 30 percentile is

Temazcal Room: pretty optimistic for

Temazcal Room: this data with a slope stability analysis, what would you choose?

Temazcal Room: Like? 10% pretty close to the lower edge.

Temazcal Room: But just so, I make sure. I understand, like the blue one is at maybe 200 or so.

Temazcal Room: and the 50 percentile that you’ve chosen is more like 3, 50 or something like that. Yeah, so it’s not a geotech. But

Temazcal Room: I am an engineer, and I would think if you’re interested in the location where the blue one is, you want to be at about 200.

Temazcal Room: I’ll I’ll add some to that as well.

Temazcal Room: I mean anything that you’re looking at really, in this depth range that is beyond, say, about 500 Psf.

Temazcal Room: these are sandy layers that you are.

Temazcal Room: I mean all of those things. You’re not going to get a bay mud value. That is 2,000 Psr.

Temazcal Room: Those are sandy

Temazcal Room: layers within the Baymark.

Temazcal Room: Now, if if you are modeling this as Bay MoD,

Temazcal Room: then

Temazcal Room: I will agree with my friend Jim here that you are in a very tighter band, that the upper bound of that tighter band is more like

Temazcal Room: 400, the lower bound would be more like

Temazcal Room: 200, something like that, and that would represent

Temazcal Room: more appropriately

Temazcal Room: this young bay mud at these depth ranges that you are considering it

Temazcal Room: all those other points to me. Yes, they exist, and they are

Temazcal Room: what you measured, but they don’t represent

Temazcal Room: they mud in the context of what we are talking about.

Temazcal Room: Right? The so what we’re using right now is about 3.

Temazcal Room: So around 3 50 that the black line is about what reason?

Temazcal Room: And when you you’re saying.

Temazcal Room: what about? What if the Black Island were here? What if the black line were here.

Temazcal Room: I mean, that’s basically what we’re talking about, right is, where’s that line, either?

Temazcal Room: Strictly envelope the entire data set.

Temazcal Room: But I think he ought to be somewhere towards the left edge.

Temazcal Room: Yeah, I mean 2, 50 or something. I don’t know

Temazcal Room: more toward the left edge. I mean, I feel like we are kind of toward the left edge. But you’re saying

Temazcal Room: maybe we should be worse for the left edge right?

Temazcal Room: But put your 3, your 3 50. What’s your vertical Median number that you have? That’s 3

Temazcal Room: like 325, which would fall like, I don’t know. I’m just obviously eyeballing, but it’s about there.

Temazcal Room: Oh, man, hold on

Temazcal Room: so what this looks like is that

Temazcal Room: you know at least

Temazcal Room: 50% of your cross sections would be good

Temazcal Room: 50% are worse than what your analysis shows.

Temazcal Room: Statistics are awesome.

Temazcal Room: but I think they’re

Temazcal Room: have to be applied pretty cautiously

Temazcal Room: with it.

Temazcal Room: This type of

Temazcal Room: analysis.

Temazcal Room: I I agree with you there when we have, when we have.

Temazcal Room: I mean, if every single cpt was jumping back and forth all over the place.

Temazcal Room: you know that it maybe it’s different. But if you look at the Cpts themselves, a lot of them are pretty smooth.

Temazcal Room: yeah, a linear

Temazcal Room: linear tracks remain

Temazcal Room: points out that a lot of those things that are further off towards the right are probably

Temazcal Room: a sand.

Temazcal Room: thin sand lenses that

Temazcal Room: really appropriately or not even

Temazcal Room: clay, and shouldn’t be analyzed as a clay. But because A/C petite or coelec even

Temazcal Room: analyzes these, the thin layer factor doesn’t really

Temazcal Room: those are all outliers right? And and so the strengths are are

Temazcal Room: really not supposed to be averaged.

Temazcal Room: I mean, they’re not really part of the the su behavior of the material.

Temazcal Room: What what are we? So what do we take? We’re taking by taking the 50 percentile

Temazcal Room: we’re taking them. Are we doing a mode? Isn’t that a statistical mode like the

Temazcal Room: I should be okay. I don’t want to turn this into probability statistics discussion, but I do agree. The statist, the use of the statistics is very important. We do need to do that very thoughtfully. I understand what you’re saying.

Temazcal Room: The way we thought about that

Temazcal Room: principle was when we said, All right, we’re we’re presenting the 50% tile like I’m showing here.

Temazcal Room: We also recognized

Temazcal Room: what if we just stay consistent with what we’re doing, the other ones and use the 30 percentile.

Temazcal Room: And we did do those runs, and they don’t make that big of a difference necessarily. But

Temazcal Room: there’s an argument to be made for doing that, or even or even farther down. I think, for instance, I mean, I’m curious, I can’t tell, but that left edge there

Temazcal Room: looks pretty close to the same gray that’s at Cpt.

Temazcal Room: 9,

Temazcal Room: yeah, like goes to 36 feet.

Temazcal Room: And so

Temazcal Room: someplace that profile exists, and if if you want you can. You can get a little more detailed and look at specific C specific

Temazcal Room: profiles and say, You know, this one is averaged up and down it. But

Temazcal Room: but averaging.

Temazcal Room: you know, composited a whole bunch of locations is

Temazcal Room: well, it’s a it is a simplification. It’s it’s at at the least, it is a simplification

Temazcal Room: right to average a bunch of locations. And

Temazcal Room: and I understand the point that you know there are occasions when you want to bore 0 in on a specific

Temazcal Room: location. I think that

Temazcal Room: is part of where your comments are now, maybe that you’ve got you’ve got a band there, and maybe you look at some of your profiles, and they

Temazcal Room: cpts on both

Temazcal Room: there and on both sides are.

Temazcal Room: you know, towards the right edge of your dense band there, and maybe that

Temazcal Room: profile you use a slightly better.

Temazcal Room: you know. If you I mean ideally, you look at some sort of geomorphological background and say, Yeah, we think it makes sense. This one’s a little bit stronger. This one’s a little bit weaker. It may well be that Cpt. 9 is a little bit deeper, because it’s further out towards the bay, and everything is just and does tends to slope that way. And

Temazcal Room: yeah, and maybe because it’s out further towards the bay, maybe it happens to have been younger and less desiccation. And it all happened during the you know, post gold rush. I was actually expecting to see more of that, the bay muds there, and so it really is weaker than all the others which might be a few 100 years old.

Temazcal Room: I mean to be honest, we were kind of expecting to see more of that than we did. We think we might end up in a situation where there was a strong signal that

Temazcal Room: the Western Cpts are worse than the Eastern ones. I mean, that wouldn’t have shocked us if we’d seen it. Now, admittedly. Yeah, there are some Cpts that

Temazcal Room: are lower than others. You’re pointing out numbers 8, 9. Those are in the same place. So is that a geographic trend? Maybe it is, I mean.

Temazcal Room: but it’s not one that we’ve seen propagated throughout the rest of them. But

Temazcal Room: anyway, your point, your points are well taken about.

Temazcal Room: Might there be more critical places, both in going back earlier here.

Temazcal Room: based on, you know, topography.

Temazcal Room: And might there be more critical places based on

Temazcal Room: specific Cpt logs

Temazcal Room: understood.

Temazcal Room: There might be

Temazcal Room: cherry washta Nick would like to make a comment. He has his hand raised.

Temazcal Room: Nick.

Temazcal Room: Okay.

Temazcal Room: please.

Temazcal Room: Okay, so let me 1st put my geologist hat on

Temazcal Room: I was as I was looking at all of this I was

Temazcal Room: well, I have this microphone on, so I don’t worry.

Temazcal Room: Putting my geologist hat on as I was looking. All of this.

Temazcal Room: There surely are all channels underneath all of this that are sandy

Temazcal Room: and that’s as was suggested. That may explain some of those very high

Temazcal Room: or relatively high strengths that you see, and possible, even refusal

Temazcal Room: would have been nice to map those out, but you know, that requires going through a whole lot of very old Usgs coastal maps, and so on.

Temazcal Room: I’m not necessarily convinced that that would help. Now, when it comes to this kind of discussion of statistics. On on one hand, I don’t see this as a life safety situation, so necessarily taking the lowest strength is in my view, not

Temazcal Room: required.

Temazcal Room: however clustering it like this, while interesting, is not really helpful when one looks at a long linear structure.

Temazcal Room: And that’s what you have. You have a very long structure, and what I would have liked to have seen, and that

Temazcal Room: well, I I don’t know how this microphone works. So

Temazcal Room: you know, if I stick it in my mouth, then

Temazcal Room: maybe

Temazcal Room: anyway.

Temazcal Room: The the

Temazcal Room: because it is a long linear structure. I would like to have seen this parsed out

Temazcal Room: bisection.

Temazcal Room: As you’re looking at the different sections where you put your cross sections, I would have preferred to see this data presented for that particular section, because you actually have a pretty good coverage of of field data.

Temazcal Room: and that would allow you to do a better assessment whether you really have to go with the lowest strength, or whether, in fact, the local variability is such that some higher value is is

Temazcal Room: recommended rather than looking at all of the data in you know, in an aggregate. So I think that would be

Temazcal Room: my suggestion that that’s a much better way to approach it, I think.

Temazcal Room: seeing the scattering all of the data is is great. That’s that’s a beautiful plot. I love it, you know, if you if I present it for Young Bay mud, then you can probably plot all the data that we have for Young Bay mud from the Bay Area, and it will all nicely plot within this range. But

Temazcal Room: because it’s such a long linear structure, it would have been more

Temazcal Room: informative and probably useful for you to

Temazcal Room: look at the section where you

Temazcal Room: the nearby data from the section where you actually did the slope stability analysis based on your criteria, which I’m actually not taking exception with but looking at this discussion, and, as I said in my view.

Temazcal Room: it’s not necessary to take the absolutely lowest value, since this is not a life safety situation, but at the same time there may indeed be a section where all the data is in this lowest thing, which is what the Jim French suggested, that there may be a section where all of the data nicely plots, all on that low end, in which case

Temazcal Room: you have to use whatever you have.

Temazcal Room: So that that would be my comment on on this whole.

Temazcal Room: you know. Discussion. Thank you.

Temazcal Room: No, that that’s good. I mean, I I understand what you are all saying. I understand that and there’s no doubt there is, I’m sure, more that can be gleaned from this data. This is a lot of data. And and you guys all well know part of our job. And our judgment is to say, all right, we got all the say, what is the best amount of

Temazcal Room: processing and analysis we should devote to this data to answer the question

Temazcal Room: at hand. Now, as we get into the latter part of this presentation. I think we’re gonna see.

Temazcal Room: even with what we have done here. There’s some pretty clear answers becoming evident about

Temazcal Room: the situation and and I, I would imagine, if we

Temazcal Room: kind of chase down some of these additional levels of

Temazcal Room: detail behind these analyses and

Temazcal Room: maybe make less conservative assumptions.

Temazcal Room: There may be more of that. That is possible.

Temazcal Room: But but there’s no doubt there could be more analysis always done on this stuff.

Temazcal Room: Yeah, yeah, Bob’s got a question. Yeah, I just wanted to follow up on this. I I find this really interesting. Would you mind going back to that slide that showed the plan view, and it showed some of the adjacent marsh.

Temazcal Room: You know, one of the things I’ve done a lot of is

Temazcal Room: Wetland restoration, and these dikes subsided, Balens, and you can see where there’s the existing marsh which is green in the upper left.

Temazcal Room: You can see that there’s a

Temazcal Room: a whole bunch of channels.

Temazcal Room: and what we do find is when,

Temazcal Room: the water starts moving, or whatever the the old channels are often reoccupi. The old channels are often reoccupied.

Temazcal Room: Because they’re just more erodible. I’m not as familiar with the Mss. And

Temazcal Room: it’s sheer strength or or erosion resistance. But

Temazcal Room: The comment that Nick made, that there may be some sections that cross

Temazcal Room: old channels that aren’t otherwise apparent in the just the existing terrain. I think it’s a very good one.

Temazcal Room: and

Temazcal Room: One way to look at that would be to look at some old

Temazcal Room: tea, sheet maps or other maps which I think the South Bay Salt Ponds. People have that show where the the channels were.

Temazcal Room: especially the you know, the larger channels.

Temazcal Room: and then that might affect your your section

Temazcal Room: location selection.

Temazcal Room: Well, I will. I will say there’s no doubt there. There is evidence for lots of

Temazcal Room: channels, you know. There’s a lot. In other words, there. There’s evidence for lots of sand lenses all through here, and I I presume geologically, that that’s just a representation of the

Temazcal Room: ongoing meandering of them over, you know, millennia.

Temazcal Room: and but the the way it looks to us is they’re just kind of like all over the place. There’s this

Temazcal Room: a galaxy of little sand lenses, and I don’t even know if we could map them.

Temazcal Room: Well, yeah. And I just want to state that it may be their sand lenses in in traditional dykes applied to Balens, especially when they get

Temazcal Room: wet and they’re managed ponds. You often have

Temazcal Room: weaker material depositing in the old channels. It’s just

Temazcal Room: organic or other stuff that really erodes in this case. If it’s sand, maybe it’s less erosional. I don’t know.

Temazcal Room: But a geomorphic interpretation of the

Temazcal Room: subsurface might be might be helpful.

Temazcal Room: Okay? Is my only point. Thanks. Yeah.

Temazcal Room: Well, I mean one of the takeaways. I’m I get from this. I mean you. You are all making you’re you’re observing. You’re pointing out

Temazcal Room: the ways. We have simplified the analysis.

Temazcal Room: No doubt we have taken the State, and we have tried to find

Temazcal Room: you have to simplify to some degree right to do an analysis, there’s no way around it. So we’ve

Temazcal Room: we’ve said, all right. What’s the right amount of simplification to give us

Temazcal Room: to tell us what’s going on here

Temazcal Room: to a sufficient level of, you know, understanding to help everyone make decisions. And

Temazcal Room: and so your your points about some of the additional ways we can. Analysis are well taken, and and maybe that’s what we should do

Temazcal Room: to better understand the story. I must say I’m

Temazcal Room: really eager to hear your comments on the

Temazcal Room: the end of this presentation, because that’s I think we’re really the storyline is going to come through.

Temazcal Room: are we? Are we? Good?

Temazcal Room: Yeah, I think. So keep going. Yeah, please.

Temazcal Room: Okay, let me get. Let me catch this up to where I left us off.

Temazcal Room: Okay, th, this is what we ended up with. After all that statistical analysis and all that data. This is the new table we are now using where the young bay mud

Temazcal Room: is subdivided into

Temazcal Room: 4 layers.

Temazcal Room: Really the lowest of these, where it says, Ybm. 20 feet below ground service, and below, that’s really 20 to 30 feet, and Jim was making comments earlier about how

Temazcal Room: there are some places. It’s deeper than 30, that is true.

Temazcal Room: But in our models. It goes to 30, and then it’s underlain by old bay mud.

Temazcal Room: and these are the properties

Temazcal Room: we’ve used.

Temazcal Room: There’s been comments about how it would be helpful to kind of map this onto all the slide outputs. But that’s that’s the that’s the new

Temazcal Room: set of properties we’ve been using.

Temazcal Room: And

Temazcal Room: just to compare what we had last year to what we have now

Temazcal Room: this graph

Temazcal Room: compares them, and and the real difference

Temazcal Room: now versus last year

Temazcal Room: is that

Temazcal Room: we are now, seeing evidence that the young bay mud

Temazcal Room: stays

Temazcal Room: soft to a greater depth

Temazcal Room: than what we had expected from last year’s data. That’s the real

Temazcal Room: take away from what we did.

Temazcal Room: It’s not as good.

Temazcal Room: it’s softer, and it goes deeper.

Temazcal Room: And the e even on the simplified profiles. That’s what you see. Now, you know

Temazcal Room: all the other comments acknowledged

Temazcal Room: I mentioned. We also did triaxial strength testing in the laboratory

Temazcal Room: on undisturbed samples

Temazcal Room: which allowed us to develop a best fit

Temazcal Room: strength, envelope.

Temazcal Room: or effective stresses.

Temazcal Room: And as I’ll show you in a few minutes, we used that as another form of our analysis to see what it tells us

Temazcal Room: so. Those are the soil strengths we used, and we used, and we did it, and and put into the

Temazcal Room: put those into those cross sections I was showing you. And then we ran a whole bunch of stability analysis to figure out

Temazcal Room: what are the factors of safety at this site?

Temazcal Room: yeah.

Temazcal Room: So

Temazcal Room: before I get to that, though, let me let me go back to this concept of keying for a moment. That’s been an important subject

Temazcal Room: for our evaluation.

Temazcal Room: We, as I said, had explorations going through places that had been keyed, and we had explorations that went through places that had not been keyed.

Temazcal Room: And again, with that we plotted all of those strength points together.

Temazcal Room: this actually shows a comparison. If if you can pick it up between

Temazcal Room: places that were keyed, and dark dots and places that were not in light dots. And and really

Temazcal Room: the the bottom line that we found from our explorations is

Temazcal Room: minimal appearance of strength

Temazcal Room: gain

Temazcal Room: from King J. I’m just talking about strength gain. How much resistance did the cone pentromer experience?

Temazcal Room: A a little bit more, but almost not enough more to even put a number on it. That’s why I describe as minimal

Temazcal Room: change.

Temazcal Room: In other words, he doesn’t seem to have that big of an effect

Temazcal Room: on the strength

Temazcal Room: in the berm.

Temazcal Room: Yeah.

Temazcal Room: what kind of material are you using for the keying? You know, in one of the write-ups somewhere

Temazcal Room: read that. It was maybe your response to questions.

Temazcal Room: from staff.

Temazcal Room: It had some criteria that says

Temazcal Room: doesn’t have

Temazcal Room: deleterious material, or some some sort of generic kind of thing, but nothing about plasticity, nothing about grain, size, distribution. Right? Is this some bay mud that you’re back filling again with? Or I mean, it’s a bay mud, or is it import gravel? Right?

Temazcal Room: So ability. Obviously, it’s not gravel. But you guys have your set of criteria. No deleterious material. It is a little bit broad like like you say that that’s the kind of rule book you guys use. But we did go out. I think it was a couple of years ago when

Temazcal Room: surveyed all the it’s all imported material you have.

Temazcal Room: and we did a a reconnaissance of it. We took samples. We characterized it. It is not a young bay mud.

Temazcal Room: it is, it is silty. It’s largely a fine grained mix of silt with some sand. If I remember what

Temazcal Room: our results told us

Temazcal Room: so. It was still a. It was still a pretty fine material, but not

Temazcal Room: not to the degree like a bay. Mud would be plasticity.

Temazcal Room: I do not remember what the plasticity was.

Temazcal Room: I do not remember what the plasticity was. I do recall, though, that

Temazcal Room: in addition to the lack of deleterious material in it.

Temazcal Room: It looked like a material that if under the right moisture, conditions could be compacted.

Temazcal Room: and from what we understand from your team and what we’ve seen on our explorations. It appears to be a well compacted matrix of

Temazcal Room: sandy silt materials

Temazcal Room: placed into the trench. Not a big difference in strength from what was there before.

Temazcal Room: but in terms of the activity itself.

Temazcal Room: and the way in which you you for the cargo team specifically goes after places that might

Temazcal Room: have had some deleterious materials in them, and replaced it with a better, more consistent material.

Temazcal Room: It appears to us

Temazcal Room: that it’s going to have benefit of

Temazcal Room: the intention of making it more suitable against seepage, but not really with a

Temazcal Room: a

Temazcal Room: a change in strength.

Temazcal Room: So I’m curious. Just I’m in a

Temazcal Room: general observation is that

Temazcal Room: bill that’s compacted to 90% play. Phil

Temazcal Room: should typically have an unconfined, compressive strength

Temazcal Room: I would expect of at least

Temazcal Room: 6 to 706 to 800. Psf.

Temazcal Room: almost everything is

Temazcal Room: less than that. I guess. The top, the top several feet.

Temazcal Room: half of it’s like that.

Temazcal Room: What would you? What was your estimate? 60 packed it to? 95%. It should be

Temazcal Room: yep.

Temazcal Room: 1,500 pso.

Temazcal Room: Your your 1st estimate was like 6, 6 to 800 for like a 90% compaction, I know right?

Temazcal Room: Mediocre compaction. 90% ish sure

Temazcal Room: And

Temazcal Room: and you know, one of the photos, and I’m not sure if it was in the presentation or report, or someplace showed you guys with a sheep’s foot on the end of a

Temazcal Room: of an excavator which should put this stuff down at.

Temazcal Room: I mean, it’s Cape. If this, if the trench is solid enough, that should put it down at 95% without much difficulty.

Temazcal Room: So I’m curious. It look, it looks like

Temazcal Room: compaction is

Temazcal Room: below water, or

Temazcal Room: maybe maybe not 90, probably not 95%.

Temazcal Room: And it’s not a structural.

Temazcal Room: Then it should be off the charts with tip resistance, and it shouldn’t.

Temazcal Room: Shouldn’t give you a tip. Reason it shouldn’t give you an su out of it. It should give you a

Temazcal Room: friction angle

Temazcal Room: as a granular deposit if it’s granular yeah

Temazcal Room: are you observing relative to its

Temazcal Room: what? You’d interpret its ability to resist seepage as being

Temazcal Room: I mean, I I would I don’t. I don’t think this is a heavily like structural fill level compaction. I don’t think this is a necessarily

Temazcal Room: a 95% compact in drawing that

Temazcal Room: our findings bear that out in Bay mud. There is 0 chance that you’re going to get. I mean, if it’s surrounded by soft levee, and

Temazcal Room: that’d make it tough until the last couple of feet. Possibly. But it looks like to us. It’s a it’s probably more likely you’re down in May

Temazcal Room: 88% range. I would

Temazcal Room: might have guessed. Maybe

Temazcal Room: it looks like it’s a

Temazcal Room: compacted material.

Temazcal Room: not not not heavily compacted, but

Temazcal Room: but compacted and

Temazcal Room: better controlled, material wise. But the strengths are 4 to 600

Temazcal Room: Psf.

Temazcal Room: down below. 5 feet they are. That’s a, you know, pocket 10 of

Temazcal Room: or Tsf or something.

Temazcal Room: I mean isn’t most of the action here, though. Kind of in the down to 5 feet level

Temazcal Room: isn’t most of the seepage resistance, though, in the upper 5 feet, I mean, that’s where we see the biggest benefit here.

Temazcal Room: Well, that’s where we see the highest strength, I should say.

Temazcal Room: and probably the most compaction activity occurring.

Temazcal Room: I think once we get below 5, we’re starting to get into just pre-existing young bay muds.

Temazcal Room: I’m actually, frankly, not very concerned about the strength of the material. I’m just sort of

Temazcal Room: commenting on. It looks like

Temazcal Room: compaction is

Temazcal Room: mediocre.

Temazcal Room: Okay?

Temazcal Room: And maybe gotcha fine. Yeah.

Temazcal Room: right?

Temazcal Room: Well, I know. I mean, I know you’re

Temazcal Room: your intention is not to make a

Temazcal Room: structural fit, and I don’t think that’d be necessary anyway.

Temazcal Room: excuse me, Nick would like to speak.

Temazcal Room: can I? Just.

Temazcal Room: if I may just add my concern actually would be reactivity of whatever this fill is with salt water.

Temazcal Room: If the clay happens to be

Temazcal Room: what we normally want to use for impervious fill, which is high plasticity clay. Those shrink when exposed to salt water. So actually, they’re not the best material

Temazcal Room: to be used.

Temazcal Room: And so at some point, somebody looking at it to make sure that you’re basically not putting in material that eventually over a period of time is gonna shrink and cracks are gonna develop. And it’s gonna yeah, yeah, shrinkable in the sense that a high salt concentration will shrink to double layers. Yeah. And you know, it’s a fairly well known phenomenon.

Temazcal Room: but sometimes we kind of forget that that’s what happened. So I don’t. I don’t think that’s what they have out here, though you know it’s worth checking that it’s not happening. That’s all. Okay. Yeah, that’s fair. We we can have some commentary to that. I mean, based on what we saw, the fill on the ground and based on what we see it in its

Temazcal Room: placement in the keys. I I don’t think that’s what they have here. But yeah, I could. I could imagine a scenario where you brought a material that happened.

Temazcal Room: Yeah.

Temazcal Room: okay, I’m gonna point out that we’ve got about an hour

Temazcal Room: left of

Temazcal Room: meeting time here. If we’re trying to hit our 4 30

Temazcal Room: target of getting out of here.

Temazcal Room: Just just wanted to point that out. Okay, I am happy to move faster. Actually, some of this might go fast, because

Temazcal Room: this part about the seismic events has not changed. And so maybe I’ll just boil down. Say, as you remember.

Temazcal Room: we analyzed for a 50 year earthquake event and a 475 earthquake event and determined peak ground accelerations for both of those

Temazcal Room: partly based on the soil properties we saw at the site and partly based on the Usgs, derived compilation of all earthquakes and faults in the region.

Temazcal Room: so no change there.

Temazcal Room: and I don’t. I don’t think that was a

Temazcal Room: I know there’s some discussion last year about

Temazcal Room: is a 475 year. Earthquake

Temazcal Room: too big, bigger than it needs to be for this analysis. Would a 200 year earthquake make more sense

Temazcal Room: to that? I guess I’d say, maybe. But why not

Temazcal Room: see what happens with the bigger one?

Temazcal Room: alright! Let me let me go through the analyses, findings of of stability, because

Temazcal Room: th this is this is, I think, the thing I I’d like to hear input, on

Temazcal Room: Here’s the sections we analyzed.

Temazcal Room: You remember this.

Temazcal Room: and we analyze for Factor safety, as we know.

Temazcal Room: And let me just let me just skip to the

Temazcal Room: to the results. Under normal static conditions the factors of safety were quite high.

Temazcal Room: 2.8 9. In this case

Temazcal Room: these berms are sitting there stable.

Temazcal Room: Okay? I don’t think that’s a surprise to anybody. The question is, what happens in an earthquake?

Temazcal Room: And so I have a couple of slides presenting a 50 year earthquake.

Temazcal Room: In this. This example is at Section D, and you see a

Temazcal Room: all of these analyses basically go through the berm and out past the tow. They’re

Temazcal Room: slip services that involve

Temazcal Room: a potential for tow failures of the

Temazcal Room: of the berm. We analyzed a variety of these. These are always the the critical ones we came up with

Temazcal Room: in this section. The the berms factor. Safety is, is above the desired level of 1.1. So that’s good

Temazcal Room: in the next slide at section CC, it is below 1.1. Yeah.

Temazcal Room: So I’m curious.

Temazcal Room: what type of search constraints you’re doing.

Temazcal Room: How is this searching, is it? I mean, at some point in the draft.

Temazcal Room: Powerpoint. We had it said, No, sir, no surfaces are are circular, or all are non-circular, or something like that, and I think

Temazcal Room: I can’t remember what the note was there. All slide models shown are non circular.

Temazcal Room: That

Temazcal Room: slide got deleted from the final presentation, which which is fine

Temazcal Room: it looks like there are some circular circles. Oh, definitely, this looks

Temazcal Room: a

Temazcal Room: clearly non-circular looks like a not on typical type of non-circular surface. The

Temazcal Room: I think it was the next one that

Temazcal Room: is non circular, but it looks kind of like a sloppily drawn circle, or I mean, it looks like an awkwardly circle. I’m curious what? How this came up with that geometry for the circle.

Temazcal Room: And and in general.

Temazcal Room: you know, what is the

Temazcal Room: search algorithm that you’re using here? Are you limiting it? Is it circular? Are you limiting? The entry points? Exit points?

Temazcal Room: I don’t know. Slide 2 as well as I know. Slope W slope W. You can

Temazcal Room: print out the entry point

Temazcal Room: limits and the exit point limits, and the printout, if you’re allowing it to search to a certain depth maximum, if that’s what you’re doing.

Temazcal Room: Yeah. And I, you know, I

Temazcal Room: I think if you’re presenting this to

Temazcal Room: someone to review, it ought to have

Temazcal Room: some sort of explanation, preferably a graphic depiction on every

Temazcal Room: printout that says, this is what the slide constraints, the the slide surface constraints were.

Temazcal Room: Okay. Yeah. Cause I see, cause there are a lot of different ways to do it

Temazcal Room: right, because there are a lot of different ways to do it. Like you’re saying, which ones did we use. Right? Yeah, do we use this? Do we use that, you know? And my guess is that most of the time circular, I mean circular needs to be checked. I think

Temazcal Room: especially if you have soft clay, the most common expected case is going to be a deep circle that’s going to include most of the embankment and going to take it with it.

Temazcal Room: especially with seismic.

Temazcal Room: But

Temazcal Room: I’m I’m all in favor of

Temazcal Room: looking at other types of configurations also, because

Temazcal Room: other things

Temazcal Room: can happen. But but somehow, if if I’m checking this, I just need to know what the

Temazcal Room: what the search methodology is. And okay, I think the most helpful is is if you can give it graphically on the printout.

Temazcal Room: and then I just know every single time

Temazcal Room: what you do. I’d rather than a paragraph at the front than I go? Well.

Temazcal Room: okay. But was it.

Temazcal Room: does it? Does it allow it go to 36 feet this time, or is it trunking? Yeah.

Temazcal Room: okay.

Temazcal Room: we. I mean, at the risk of

Temazcal Room: sounding like, I’m oversimplifying things. We ran it a bunch of different ways, right? Circular, non circular wedges

Temazcal Room: some other, I mean. I I could probably ask Andrew to tell us for, like 15 min about all the things he did, and maybe that would be worthwhile. But at the very least, I think what I’m hearing is kind of like your comment on the

Temazcal Room: tabulation of the properties. It would be helpful as reviewers to understand.

Temazcal Room: Okay, for this output. That’s the style of

Temazcal Room: search that was done.

Temazcal Room: Because if we ran 5 different styles of churches of searches. Why not

Temazcal Room: tell you the 5 different ones, and label them each accordingly. Is that

Temazcal Room: that’s kind of what I’m taking away is that without that it’s just hard for you to understand sometimes what? Yeah.

Temazcal Room: the implication that we’re saying raffle here on the printout is the most useful, and it’s, you know, for your own internal. Qc, it’s most useful.

Temazcal Room: you know for the

Temazcal Room: people, that are doing the runs, you’re trying to keep track of all your burnouts. And yeah.

Temazcal Room: got to make sure that you’ve got it. And the printout Graphic just shows that you’ve got it

Temazcal Room: right exactly what it is.

Temazcal Room: It was a little easier when I was a young engineer doing this myself because I didn’t. I couldn’t do 100 runs a day. I did like 2 runs a day, so I didn’t have as many, but I understand, understand. Give. It would be helpful to understand.

Temazcal Room: And I think that I, you know.

Temazcal Room: referring back to some previous discussions. I think there’s

Temazcal Room: some questions about the blue strength profile being stronger than the pink strength, profile, right? Which I think is going to potentially change

Temazcal Room: many, most all of the

Temazcal Room: all of these results. But

Temazcal Room: okay, thank you, Jim. Nick.

Temazcal Room: Okay.

Temazcal Room: couple of questions. I don’t know if this is a typo or not, but

Temazcal Room: it for this OLE. Level or lower level, and one of these

Temazcal Room: I think

Temazcal Room: it is. It’s

Temazcal Room: it may be the next one.

Temazcal Room: Are you looking at the oh, yeah, it says.

Temazcal Room: this is.

Temazcal Room: I guess. PGA point 3 7. Is that it? I pull?

Temazcal Room: Yeah, is that a typo? Or it’s supposed to be point 3 4.

Temazcal Room: Not that. Oh, you’re talking about here? The yeah, the PGA that’s applied.

Temazcal Room: Yeah. Because in the previous slides it says, you know, the only level is point 3 4. Just curious. If

Temazcal Room: this was

Temazcal Room: so, I’m sorry. Hold on. Yeah. I want to go back. Yeah, right there point 3 4G, and your point is, why does this one show point 3 7 g, not that it’s a big difference. But but

Temazcal Room: I mean, yeah.

Temazcal Room: I.

Temazcal Room: And the other question is, are you applying a pseudo static of like? Let’s say in this case, point 3 7,

Temazcal Room: or are you reducing it for the slope. Stability analysis.

Temazcal Room: because that’s the PGA. That’s the peak value.

Temazcal Room: Andrew, correct me if I’m wrong. The these are pseudo static analyses.

Temazcal Room: So I believe we batcher the PGA accordingly, for a pseudostatic

Temazcal Room: enough, so.

andrew barrett: You didn’t apply any factoring for these. We started off with the analysis with a 2 thirds factor and then

andrew barrett: eventually move to the full PGA value

andrew barrett: conversations at our last meeting.

Temazcal Room: Andrew, do you? Do you remember the point? The reason for the point 3 7 here instead of a point 3 4?

Temazcal Room: Yeah, if you’re sleeping.

andrew barrett: As it is.

andrew barrett: I I think that I don’t know. I don’t think it would make much of a difference to be honest, but I I’m not sure if that’s just a

andrew barrett: in error.

Temazcal Room: Yeah. Okay.

Temazcal Room: In any event,

Temazcal Room: did that answer your question? Well.

Temazcal Room: not quite. Let me.

Temazcal Room: I’m curious. If this number is

Temazcal Room: 2 thirds. Is this mislabeled by any chance as being OLE.

Temazcal Room: It’s definitely not. Cle, it’s definitely not the larger one.

Temazcal Room: What? What is hold on a second?

Temazcal Room: Precisely.

Temazcal Room: then.

Temazcal Room: this point 3 7.

Temazcal Room: I

Temazcal Room: I don’t know what this is.

Temazcal Room: It’s a little higher point 3 4, right? What is it like? 2 thirds of point 5.

Temazcal Room: But it’s mislabeled as OLE.

Temazcal Room: You follow what I’m saying. Yeah, I I do.

Temazcal Room: I know that’s not what happened, but I understand why you’re asking that question.

Temazcal Room: Yeah, 2 thirds is more like point 33 and point 34. And this is point 3 37.

Temazcal Room: I’m just.

Temazcal Room: We’re trying to follow what what’s being done?

Temazcal Room: Well, and part part of the reason, I say, that’s because when we go to the next ones, you do see a higher one for the contingency level event, right?

Temazcal Room: In fact, since we’re talking about it

Temazcal Room: like, for example, when I go ahead a couple of slides, there’s a point 5. So that’s what you’d expect to see from the earlier statement of PGA. Right? The intention is for that to show the PGA

Temazcal Room: just what is the PGA that we derive from the

Temazcal Room: the earlier evaluation.

Temazcal Room: I understand. But what is your pseudo static

Temazcal Room: value that you’re putting for your slope? Stability

Temazcal Room: analysis, is it? Are you using full PGA, or are you reducing it by

Temazcal Room: some number?

Temazcal Room: I think we’re Andrew again. Correct me wrong. I think we’re using the full number.

andrew barrett: Using the.

Temazcal Room: The number we’re using.

Temazcal Room: Okay.

Temazcal Room: so why is the 1.3 7 instead of point 3? I’m I’m frankly not sure but the intention is to just

Temazcal Room: plug in the PGA. Okay, so that’s

Temazcal Room: bully. All right. Thank you.

Temazcal Room: Thank you, Rameen Nick.

Temazcal Room: but

Temazcal Room: so hopefully you can hear me now. I. I like this picture because

Temazcal Room: it becomes non circular, simply as a function of your layering that that’s a very normal thing that will happen.

Temazcal Room: If you have a gradually increasing strength with depth, then you get a completely different failure surface.

Temazcal Room: So, as you can see, it follows the layer that where you have a transition in strength. Okay? So you have actually predetermined the failure surface in here.

Temazcal Room: That that that is a problem.

Temazcal Room: Say say that you, predetermined by by your layering, you have predetermined where that thing will is going to flatten out.

Temazcal Room: See what I mean?

Temazcal Room: Well, I mean, I see how our layering dictates where? Well, that’s what I mean. So you predetermined by by where you put the layer boundary, you have actually determined where the bottom of this thing’s going to be. If you moved it lower down, it would move lower down. That’s what happens in these non, so non circle analysis, which I’ve done a lot.

Temazcal Room: But I have a question which really follows up

Temazcal Room: 1st of all.

Temazcal Room: Oh.

Temazcal Room: I don’t know how to put it.

Temazcal Room: Has anyone here actually checked slide against any other code, or even a hand calculation where it actually does all of this correctly.

Temazcal Room: I.

Temazcal Room: Many years ago I had experience with rock science, where they were very loose

Temazcal Room: with their

Temazcal Room: codes.

Temazcal Room: and I have not used them since.

Temazcal Room: For that reason I have not gone back, presumably over the years they’ve improved.

Temazcal Room: But I have not been impressed by a QR. Qa. Qc. Their own. What? What software were you carrying issues with? We were using slide and for for some other purposes, and things weren’t quite right. So we use other software. I’m simply asking, has anybody

Temazcal Room: my colleagues done any Qa. Qc. Normally, when you adopt the code. Of course you trust the

Temazcal Room: people who published it. Sure.

Temazcal Room: but

Temazcal Room: I generally run it against something that I know, just to make sure that it

Temazcal Room: gives me the results in any case. But looking at the seismic analysis you know, I think, what my colleagues were asking. You know, Magdi, Cnc. If you go back to it is those are the reduction coefficients that people take the

Temazcal Room: maximum acceleration, whatever you come up, and then you come up with a pseudostatic, coefficient, based on the thickness of the profile, and so on. And so I guess that’s the question, because, applying full point 5G. Of course

Temazcal Room: you can look at it. It’s conservative.

Temazcal Room: But, on the other hand, I don’t think it really gives the right response, and so puts you in a situation where you’re presenting point 7 5

Temazcal Room: factor of safety, which, in fact, may be real underestimation of what you have. So I would suggest. Take a look at how

Temazcal Room: you derive the seismic coefficient for this.

Temazcal Room: It’s not PGA.

Temazcal Room: If if anything, we’re overestimating the seismic forces, we’re absolutely, I think we’re being either corporately conservative or we’re being overly concerned. If if you’re applying, if you’re applying full PGA, then yes, you’re being very conservative, conservative on a

Temazcal Room: in a way that I don’t think anybody here would suggest that you should be.

Temazcal Room: Oh, why.

Temazcal Room: okay, thank you, Nick.

Temazcal Room: Jima, you had something.

Temazcal Room: Are you done, or you still have some more.

Temazcal Room: I I have one more part to discuss, which is the deformation analysis.

Temazcal Room: Oh.

Temazcal Room: okay. Why don’t you finish that? Okay, yeah. Let’s look, because I think we have these examples where the factor safety is less than 1.1.

Temazcal Room: Maybe we’re being overly conservative.

Temazcal Room: probably are. I mean, we want to purposely be conservative.

Temazcal Room: But we got these factors, maybe below 1.1, particularly in the 475 year earthquake.

Temazcal Room: Frankly, I like using that earthquake at all is pretty darn conservative, but it’s appropriate for us to look at it. But what does that mean? What is what is this telling us about the behavior of the berm in this

Temazcal Room: large earthquake. So

Temazcal Room: to understand that we performed a

Temazcal Room: displacement analysis, not not a

Temazcal Room: real fancy one.

Temazcal Room: We all know you could do that some very advanced ways. You could do full models. We didn’t do that. We

Temazcal Room: looked at. Oh, yeah, I’m sorry. Here’s the examples in yellow, where we have factors, safety less than 1.1.

Temazcal Room: They are in cross sections B and C,

Temazcal Room: and they are mostly in the large earthquake, and in one case in the smaller earthquake. But what do those tell us? So? Let me, let me tell you what we came up with there and then. I think we can, you know, talk about

Temazcal Room: things.

Temazcal Room: deformation analysis.

Temazcal Room: We used

Temazcal Room: an established

Temazcal Room: Co available code. Andrew can cite it. I’m not going to try to state the name of it at the moment, but I will tell you it is a

Temazcal Room: sliding block model.

Temazcal Room: but classic, you know, fairly simple model that

Temazcal Room: takes the weight of the berm. The frictional force of the base of the berm applies

Temazcal Room: the acceleration from the earthquake to it, and determines. How much is it going to move if the Thatcher safety is low, how much is the berm going to move? Is it going to completely move out of the way, or what is going to happen.

Temazcal Room: and we ran it for the worst case we had, which is a section CC. In a low tide.

Temazcal Room: and the answer we get from that is that it will move

Temazcal Room: along the slip plane 2 to 9 inches

Temazcal Room: with 5 inches, being the

Temazcal Room: the best estimate of movement.

Temazcal Room: That’s a result I wanted to make sure to put in front of everybody within the board and

Temazcal Room: get reactions to, because

Temazcal Room: when we see that answer come up.

Temazcal Room: Yeah. The factors of safety are sometimes.

Temazcal Room: you know, well, below 1.1, but

Temazcal Room: that is not an amount of deformation that is going to mean

Temazcal Room: a berm breach. I know ultimately, when you boil this all down. This, the whole purpose of this analysis we’re doing is are the berms gonna hold up.

Temazcal Room: And we’re our conclusion is even in these earthquake events.

Temazcal Room: Yeah, there will be some

Temazcal Room: deformation, but not enough to affect their ability to hold the mixed sea salts. And it seems like, isn’t that really the bottom line of all this analysis

Temazcal Room: is.

Temazcal Room: will they hold up

Temazcal Room: so right? And and so you’re talking about horizontal movement. I guess

Temazcal Room: the question is, is there vertical settlement as well? Yeah. So the way I would describe this movement is when I say along the slip service. I mean, it’s like

Temazcal Room: vertical atop and horizontal out at the toe. So it’s some of both.

Temazcal Room: is is what we would imagine.

andrew barrett: As an aside before that discussion keeps going. It’s the brain. Macedo method, 2,018, I believe, is the

andrew barrett: year that that paper was published I could look it up specifically. It’s the modified Newmark sliding block analysis that uses

andrew barrett: earthquake analysis from actual earthquakes. Thank you.

andrew barrett: Yep.

Temazcal Room: Good.

Temazcal Room: So we we would interpret it. That’s why we put this little picture of an example slip service on the slide that we’d interpret as moving

Temazcal Room: 2 to 9 inches along that surface.

Temazcal Room: and and we don’t see that as being something that affects the

Temazcal Room: robustness or

Temazcal Room: retaining ability of the of the berms.

Temazcal Room: So to us all this said that to us seems like that’s feels like that’s the ultimate conclusion. Did you ever

Temazcal Room: so? What method did you use for doing the deformation analysis?

Temazcal Room: what what Andrew just described is is a is a codified version of the sliding block

Temazcal Room: analysis. The Newmark sliding block analysis. But whose implementation of that.

Temazcal Room: Andrew, can you say that one more time.

andrew barrett: Brain Macedo Method.

Temazcal Room: Say it again.

Temazcal Room: Say that again, Andrew, I’m gonna pull up the statement in our

Temazcal Room: Brian macedo.

Temazcal Room: Yeah, yeah.

Temazcal Room: is that

Temazcal Room: meaningful?

Temazcal Room: Well, after what you said about rock science. Goodness.

Temazcal Room: Oh.

Temazcal Room: okay.

Temazcal Room: Brian, what about Brian Macedo?

Temazcal Room: No, I see.

Temazcal Room: you know. If we I will say I mean, if we were. We’ve been using slide 2 forever, I mean, and if

Temazcal Room: I have not yet been like Oh, my gosh! What is going on? If we had had a moment, even one moment. We’re like what is going on with this thing. I think we’d be digging in. Sounds like you did, but

Temazcal Room: I have not had that yet.

Temazcal Room: anyway, that that I I skipped over some slides in there. But

Temazcal Room: that’s that’s what we’ve come up with. I mean, this is our summary.

Temazcal Room: Our impression is, and and recognizing yes, for sure, we could

Temazcal Room: go into further analyses. Further data. We could do some more critical sections, certainly run some more ones like it.

Temazcal Room: Location 8, 9.

Temazcal Room: Probably. Maybe we find low factors of safety there, too.

Temazcal Room: wouldn’t shock me, I suppose. But

Temazcal Room: ultimately this deformation analysis seems to us like, that’s what’s really

Temazcal Room: going on.

Temazcal Room: And and I and I, I also recognize that earthquakes that have been experienced at this facility in the past are not 475 year events. We know that there have been earthquakes. There’s 1,989

Temazcal Room: that was not at that size, but

Temazcal Room: that is a data point, and there was no deformation in that earthquake. So that does give us, I think, some

Temazcal Room: confirmation that we’re using

Temazcal Room: appropriate values for this.

Temazcal Room: so I almost feel like that in some ways might end up being more important than delving further into what the factors safety are. Yes.

Temazcal Room: can you talk about the the low tide? Elevation that you selected, how you selected it? And if

Temazcal Room: power

Temazcal Room: sensitive, the deformation results are to that number. Yup

Temazcal Room: we selected 2 feet for our low tide. For most of these analyses not 0 feet. We. We recognize low tide goes below 2 every day.

Temazcal Room: But our 1st batch of analyses use 2 simply because we’re compounding probabilities. We’re talking about what happens during an earthquake, which is, you know, a 4 min event.

Temazcal Room: and the likelihood of the earthquake occurring during the

Temazcal Room: tiny part of the day when the low tide occurs, we said, Okay, let’s

Temazcal Room: 2. Seems like a more reasonable expectation of what might happen. So we ran a bunch of these with 2,

Temazcal Room: but also recognize that there’s interest

Temazcal Room: from from everybody and understand? Okay, you know, that’s great. But what about like a really low tide, which is really like more like 0? So we did a comparison. It made no effect whatsoever on the deformation. It made a very marginal effect on the factors of safety, but not even enough to

Temazcal Room: to round out to the numbers shown in our table. So whether or not it’s a 0 or a 2 foot low. Tide doesn’t really affect what we came up with, but those are the numbers that that we used in our analyses.

Temazcal Room: I have a question.

Temazcal Room: This relates to the previous

Temazcal Room: presentation that

Temazcal Room: run up goes up to elevation 11 or something like that. Okay, is that elevation that you’re kind of considering as being the the berm. Or are you using today’s elevation? We’re using today’s elevations.

Temazcal Room: We didn’t. We didn’t go in and make them 11.5.

Temazcal Room: In other words.

Temazcal Room: I don’t

Temazcal Room: really expect it would do much to change them to 11.5.

Temazcal Room: But we use the elevations that are current.

Temazcal Room: How much higher would 11 and a half be

Temazcal Room: from current television? A fraction of a foot

Temazcal Room: fraction of a foot. Okay.

Temazcal Room: thank you.

Temazcal Room: Dima. All right.

Temazcal Room: So thank you for your

Temazcal Room: presentation.

Temazcal Room: I don’t remember whether you had told us this

Temazcal Room: during your previous presentation or not. But I’m just curious about

Temazcal Room: the colored section

Temazcal Room: of the broom and the pink and the

Temazcal Room: I mean, how did you get the configuration of those

Temazcal Room: 3rd section.

Temazcal Room: Let me go back to the figure that shows one of those examples.

Temazcal Room: yeah. So the here’s a good one.

Temazcal Room: I wouldn’t say there was any science behind. How we exactly defined the trapezoid that you see other than we just wanted to have a trapezoid, we said, let’s just have a trapezoidal distinction between

Temazcal Room: what’s under the berm and what is not under the berm.

Temazcal Room: and the distinction. There, again, is

Temazcal Room: what we have used under the berm is strictly from our analysis of the Cpt data.

Temazcal Room: whereas what’s outside of that trapezoid

Temazcal Room: is a an attempt to estimate

Temazcal Room: what we would.

Temazcal Room: the the deeper material layer unaffected by the berm. It it is. It is an engineering judgment attempt to estimate that.

Temazcal Room: There has been a suggestion that might some of our values be, in fact.

Temazcal Room: making that

Temazcal Room: stronger than what’s under the berm

Temazcal Room: that could be. I I’m not sure what my answer that is at the moment, but that is, that’s that was our intention with the analysis. And that’s that’s what the trapezoid means. And that’s how we developed it. So it was strictly based on Strand, not on

Temazcal Room: some historical information on what

Temazcal Room: it’s. It’s all strength and just our interpretation that there would be an an area

Temazcal Room: of

Temazcal Room: soil

Temazcal Room: affected by the berm’s presence.

Temazcal Room: Okay.

Temazcal Room: thank you.

Temazcal Room: So from my perspective, you know, based on the presentation, the thing that I’m

Temazcal Room: really concerned about is

Temazcal Room: finding the critical section.

Temazcal Room: right? And I think the way you did it was based on

Temazcal Room: what the geometry is. Yeah, based on lighter data

Temazcal Room: and measurements that you took in the field.

Temazcal Room: I mean, I think what Nick said

Temazcal Room: is really the most important aspect of this.

Temazcal Room: because

Temazcal Room: if you don’t find the critical

Temazcal Room: section

Temazcal Room: right.

Temazcal Room: you you might not be representing what the risk really is, because it’s a long

Temazcal Room: linear structure. And so I would echo what Nick had previously said, which is.

Temazcal Room: you know, use the data close to

Temazcal Room: this section

Temazcal Room: that you have picked

Temazcal Room: rather than the average.

Temazcal Room: Right? I think. Now, yeah, that’s that’s going to be very important.

Temazcal Room: The other thing that right, I think you should also use in terms of

Temazcal Room: finding the critical section.

Temazcal Room: because you are picking geometry. And he said, if it’s narrower.

Temazcal Room: I mean, that’s likely to be

Temazcal Room: critical, because, you know, it’s narrower, like, the berm is narrower. Yeah.

Temazcal Room: But you could also use. Look at the strength.

Temazcal Room: Right? Yeah, you could go to sections and see in this area there’s a concentration

Temazcal Room: of soft material, even though the geometry

Temazcal Room: might be

Temazcal Room: logic, right?

Temazcal Room: So so you have to look at it

Temazcal Room: from that perspective

Temazcal Room: as well.

Temazcal Room: The other thing which caught my eye

Temazcal Room: really is the the weird shape

Temazcal Room: of the burn.

Temazcal Room: you know. I mean, I was kind of looking at the firm. I’m wondering what made them ship there.

Temazcal Room: The sheep.

Temazcal Room: the way it is.

Temazcal Room: You know the way that the way it’s shown in our model

Temazcal Room: or the way it really is.

Temazcal Room: Oh, in the photos. Yeah.

Temazcal Room: I’m kind of wondering

Temazcal Room: why would

Temazcal Room: they build a firm

Temazcal Room: and kind of shape it the way they did

Temazcal Room: what is, what is what is about the shape that is weird? Well, I’m I’m I’m just looking at.

Temazcal Room: Okay, you want to build a you want to build a firm right?

Temazcal Room: I mean, normally

Temazcal Room: right, you would expect that.

Temazcal Room: I mean, you want to make the things straight. You know there are these segments to it.

Temazcal Room: So I’m kind of wondering whether this was built in stages.

Temazcal Room: you know. Maybe there was a time ago, right? I don’t know whether you have any historical information. Was this all built? You know there was a plan.

Temazcal Room: and the plan was that sense should be shaped

Temazcal Room: the way it is.

Temazcal Room: So so you’re talking. You’re talking about the curves. Yeah, how it curves around and everything. Yeah, I don’t.

Temazcal Room: I don’t know why they built them the way they did. I mean, yeah.

Temazcal Room: yeah, yeah, because they’re 100 years ago is when when they built these. Yeah, because sometimes what happens is, maybe the initial plan was to build something small, and there was something small.

Temazcal Room: and he decided to expand it.

Temazcal Room: So you know, from

Temazcal Room: where the previous one ended. You know.

Temazcal Room: you want to hit the roadway so

Temazcal Room: it ends up being shaped like that.

Temazcal Room: But if that’s the case, I mean. What would happen is that you have

Temazcal Room: sections

Temazcal Room: of the berm

Temazcal Room: which are different by virtue

Temazcal Room: of age.

Temazcal Room: Right?

Temazcal Room: And so I mean, it kind of made me curious that

Temazcal Room: somehow.

Temazcal Room: you know, like that

Temazcal Room: bad section.

Temazcal Room: you know, close to them at all.

Temazcal Room: What was that for?

Temazcal Room: Because, I think

Temazcal Room: you know, looking at the shape

Temazcal Room: you know, it might drive you into saying.

Temazcal Room: you know, maybe this, then the site development history.

Temazcal Room: It’s also an important factor

Temazcal Room: in determining

Temazcal Room: what is the most critical section

Temazcal Room: you know. If yeah, I understand behind it, I mean, I can understand it

Temazcal Room: but it’s kind of.

Temazcal Room: you know.

Temazcal Room: pick my curiosity as to

Temazcal Room: well, it’s

Temazcal Room: it it.

Temazcal Room: you know. Why would anyone build the firm the way it is?

Temazcal Room: It’s it’s a little bit like our

Temazcal Room: I I will tell you. You know, when we were out there at all these places, looking and measuring this berm, if we had seen a stretch of berm that was distinctly different than another stretch of berm.

Temazcal Room: We would have said, Wait a minute.

Temazcal Room: maybe that needs to be analyzed separately, because that’s him. But we didn’t really see that I mean, it was pretty consistent throughout. I know the

Temazcal Room: the, the alignment of it’s kind of odd and changes a lot, but the berm itself didn’t change enough for us to see anything that would prompt us to

Temazcal Room: analyze that specifically. But we did. We did look for it, and it was a little bit like what we did with all the

Temazcal Room: Cpt logs again we’re like, are there places out here where the soil is worse or softer?

Temazcal Room: And we didn’t see that regionally. I I know there’s been discussion here, and i 1 of the takeaways from this discussion. I feel like is.

Temazcal Room: maybe we should analyze over at Cpt. 8 and 9. Maybe that’s a little batch of yeah. A situation that, you know, warrants its own analysis may maybe so, although I will say one advantage of having done all these analysis. I can offer a prediction of what we will find.

Temazcal Room: If we do that I will. I will bet

Temazcal Room: I’ll bet a Starbucks card

Temazcal Room: we will find a factor safety of like point 7,

Temazcal Room: and we’ll run a deformation analysis. It’ll be like 2 to 9 inches. I think that’s probably what we’re gonna learn. Yeah. And so we’re gonna have to reckon with. What do we all make of that, you know, is.

Temazcal Room: No, I mean I I am

Temazcal Room: okay with what you’ve done. I think you’ve made an effort.

Temazcal Room: You know you’ve done your due diligence.

Temazcal Room: and the only thing that I would suggest

Temazcal Room: be done is to kind of look more closely at the issue of

Temazcal Room: what is the critical section.

Temazcal Room: because ultimately the behavior of this, then, is going to be in 3 dimensions. Right?

Temazcal Room: Yeah.

Temazcal Room: you know, even if you have a weak section.

Temazcal Room: you know, when this thing is subjected to an earthquake is going to respond as a system rather than the

Temazcal Room: you know the section that you have true

Temazcal Room: 3 dimensional effects, you know, compete. Your due diligence is to kind of look at it

Temazcal Room: a little bit more in terms of

Temazcal Room: is there any either due to site, development, history.

Temazcal Room: or the strength of the material you’re encountering is there potentially a more critical section

Temazcal Room: than what you have looked at. So

Temazcal Room: you know, when we 1st got involved with Cargill on this question. We were prepared with Cargill team to look at 3 like, if this firm is going to breach, how big an area is gonna breach, and what are the 3 dimensional effects? We were all prepared to do that until our analysis suggested

Temazcal Room: it isn’t actually gonna breach. So once we found that we’re like, okay. Well.

Temazcal Room: suddenly, there isn’t such a need for that sort of 3 dimensional analysis. Now, we’re faced with this amount of deformation, and

Temazcal Room: there are surely 3 dimensional, you know, effects going on with that, too. But

Temazcal Room: given the magnitude and scale of it, it seems like we’re kind of getting our answer now, yeah, well, I mean, the 3 dimensional response is actually going to be better. It’ll probably make the numbers even less. Yeah, exactly.

Temazcal Room: you know. And you know, but I think that

Temazcal Room: the one piece is to

Temazcal Room: look at the sections, you know, in terms of strength, not there’s a geometry.

Temazcal Room: and see whether that would drive you

Temazcal Room: into looking at a particular section.

Temazcal Room: Yeah, okay, I understand.

Temazcal Room: Thank you. Gma.

Temazcal Room: See, Romaine, you got your hand up.

Temazcal Room: Yes, thank you.

Temazcal Room: I was wondering because I was looking your report, and it said that the yield acceleration is like point 1 9

Temazcal Room: I I’m curious what parameters you used in the beret and macedo

Temazcal Room: approach

Temazcal Room: to get the deformations you’re getting.

Temazcal Room: It looks a little low to me, but

Temazcal Room: in fairness the deformation does, or the yield. No, no, the yield. I’m I’m okay with the yield. I think the deformation numbers look a little low to me.

Temazcal Room: So

Temazcal Room: yeah, for that yield

Temazcal Room: and the materials that we have at at the site. So

Temazcal Room: yeah, 7, 5. Or I mean, even the 4 75 is

Temazcal Room: basically a big San Andreas

Temazcal Room: event. If you, or pay or 2, but 7 and a half or 8 doesn’t matter which one. But I’m curious

Temazcal Room: what parameters you used in your Bra Msato evaluation to come up with

Temazcal Room: deformations you came up with, okay.

Temazcal Room: okay,

Temazcal Room: I I get that and we can provide. We can provide that. I mean, we could kind of walk through with the team. Here we could provide a separate, follow up the kind of details, allow folks to kind of dive in and see it.

Temazcal Room: But yeah, I get I I understand your takeaway is like you were a little surprised. The numbers were what they were.

Temazcal Room: Okay.

Temazcal Room: Alright. We we can.

Temazcal Room: We can give more detail behind the inputs to the bray. Macedo.

Temazcal Room: Okay.

Temazcal Room: thank you, Michael.

Temazcal Room: Very good. Thank you.

Temazcal Room: Now we go to public comment before Ec. Further Ecrb discussion.

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Temazcal Room: That is the end of public comment.

Temazcal Room: Thank you.

Temazcal Room: So let’s

Temazcal Room: return to board discussion.

Temazcal Room: think there were a lot of questions today, and and

Temazcal Room: for the most part they’ve been answered, but it sounds like

Temazcal Room: there are some

Temazcal Room: additional pieces of information or analysis that

Temazcal Room: are going to be required. And I’m just

Temazcal Room: wondering.

Temazcal Room: you know, and or I think the question to the board right now is.

Temazcal Room: is there a path forward without a further

Temazcal Room: meeting?

Temazcal Room: Is there an information package or a calculation package

Temazcal Room: that Cargill can provide to us.

Temazcal Room: That satisfies everyone’s.

Temazcal Room: you know, comments. And I think

Temazcal Room: and so I put that that question to the board here.

Temazcal Room: I’d like to see some clarification of the

Temazcal Room: set up and run up analysis. And I could be more specific

Temazcal Room: if that’s helpful to the people.

Temazcal Room: and then I also had a question, for

Temazcal Room: I also had a a more general question to

Temazcal Room: I think to Janet, to the staff.

Temazcal Room: I don’t know when we should do that. But to answer your question, I think I’d like to see more on the way. Run up

Temazcal Room: still. Water analysis. Okay, yeah, thank you.

Temazcal Room: Thanks.

Temazcal Room: And Jen, I I assume you’ve been taking lots and lots of notes. And so the concerns of the Board of the questions.

Temazcal Room: Do you think that that can be.

Temazcal Room: you know, summarized and and turned into a request for Cargill to respond to, or

Temazcal Room: I mean, like cause, the thing, I I

Temazcal Room: what I don’t I mean I.

Temazcal Room: If we have to have another meeting, we have to have another meeting. But if the if the board is

Temazcal Room: satisfied that in general or not in general, that they are satisfied

Temazcal Room: that, you know conditions are being met, or the calculations and the analyses are

Temazcal Room: or proper.

Temazcal Room: with a few adjustments and clarifications.

Temazcal Room: You know I think we

Temazcal Room: I’m happy to go that way. But

Temazcal Room: you know again I’m asking the board here if

Temazcal Room: if there is something that is

Temazcal Room: troubling you enough to the point where.

Temazcal Room: you know you think we need to come back?

Temazcal Room: Well, I guess maybe a question could be, for the Board to think about is what kind of deformation

Temazcal Room: would be a deformation that would be a concern.

Temazcal Room: So, you know.

Temazcal Room: is is 9 inches a concern.

Temazcal Room: Is it something that they can address through inspections and maintenance

Temazcal Room: in this? In the worst case, scenario, and

Temazcal Room: and perhaps

Temazcal Room: you know, because they do

Temazcal Room: endeavor to have 2 feet of free board.

Temazcal Room: If their deformations don’t exceed 2 feet, then perhaps

Temazcal Room: The risk is very low that there could be a release

Temazcal Room: and so we could ask them, for

Temazcal Room: you know, it sounds like there’s a concern about how the

Temazcal Room: the bay muds outside of the zone, under the berms, were treated with their strength parameters, and also

Temazcal Room: that they may not have picked the most conservative

Temazcal Room: parts of the berm to model, and so maybe they could. They could run those and provide those results. And if the results were.

Temazcal Room: the deformations were within a certain range. Then then it would be fine.

Temazcal Room: Jen. In. In addition to those, there was the question of just the strength that was that was chosen.

Temazcal Room: You know, the 3 50 versus like 200,

Temazcal Room: I think I think that’s an important one.

Temazcal Room: And then there was also like a question of whether we’re using the full PGA or

Temazcal Room: something less than that.

Temazcal Room: Those 2 might be compensating changes that might get you back to the same answer. But I feel like all those things you said, and the 2 that, I added could be addressed in a you know, a, a written.

Temazcal Room: a response, sort of a thing

Temazcal Room: is, should they be applying a factor to the the peak, the PGA, instead of using the PGA in their analyses?

Temazcal Room: Well, they actually being conservative.

Temazcal Room: So

Temazcal Room: I mean, if they apply a factor, that deformation.

Temazcal Room: that factor of safety, is going to be higher. So yeah, Erin, on the safe side, is the way.

Temazcal Room: Okay.

Temazcal Room: frame.

Temazcal Room: Oh.

Temazcal Room: still.

Temazcal Room: yeah. But I think I think ultimately, is that defamation

Temazcal Room: is the factor of safety. The limit equilibrium analysis

Temazcal Room: is given as factor of safety which is low.

Temazcal Room: But the deformation analysis is saying, these are the kind of displacements

Temazcal Room: that we are getting.

Temazcal Room: and so it kind of

Temazcal Room: makes the limit. Equilibrium results, you know, less

Temazcal Room: significant.

Temazcal Room: Go ahead, Jim.

Temazcal Room: It looks to

Temazcal Room: hey, Kevin?

Temazcal Room: Oh, sorry, Nick.

Temazcal Room: Yeah, if if I may. I

Temazcal Room: on the

Temazcal Room: you know overall. This is a tremendous amount of work.

Temazcal Room: and in general it’s been quite carefully done. I think we’ve identified a couple of places. The the seismic deformation is interesting because brain macedo formulation is completely independent of the slide analysis.

Temazcal Room: It only you only use the geometry of whatever’s the potentially failing mass. The rest of it is independent, I think, in the seismic analysis, I I really do suggest that you actually look at proper, whether the slide code in itself

Temazcal Room: has a reduction formula in it for the pseudostatic, for the pseudostatic, which

Temazcal Room: would be nice. But whether you’re applying the right seismic coefficient.

Temazcal Room: that normally would be used in this kind of analysis, because if you did not, then this was an incredibly conservative

Temazcal Room: result, and the other one is, as Jen already mentioned. I I agree. If

Temazcal Room: you, I would suggest that you do look whether there is a more critical

Temazcal Room: area based on the shear strength, the actual shear strength, data that you have.

Temazcal Room: and if the deformation then following proper procedures, comes less than I would say, I agree 2 feet. Then we’re obviously in a reasonably good shape and and a memo to the effect, explaining what exactly the analysis were probably may suffice.

Temazcal Room: At least, that’s that’s my view. Thank you.

Temazcal Room: Okay, thank you, Nick.

Temazcal Room: I had a hard time hearing. What Nick was saying. Can you rephrase it?

Temazcal Room: Maybe broad or

Temazcal Room: presenter from from your commentary.

Temazcal Room: Well, you’re you’re advocating that. It would be wise to check an additional area as a critical section for stability.

Temazcal Room: That was one.

Temazcal Room: And the second

Temazcal Room: comment was that we should

Temazcal Room: either confirm or modify appropriately the pseudostatic

Temazcal Room: number in the model.

Temazcal Room: in in the slope, stability model in the slope stability model. And are we using the number that we should? Or could we really be using a smaller number? And that’s factored? And I mean, basically ask double check that you’re using the right numbers in your brain, macedo

Temazcal Room: analysis. And and the 3, rd that’s right. The 3rd one is the the numbers that went into the deformation analysis.

Temazcal Room: Thank you. Romine, I’m

Temazcal Room: I agree at the end of the day, if the deformation analyses, that

Temazcal Room: I guess this board feels

Temazcal Room: comfortable with the numbers, and you don’t get any breach or any overtopping. Obviously that that’s that’s the key.

Temazcal Room: But I like to

Temazcal Room: emphasize that

Temazcal Room: from your report. It says the yield is point 1 9, and even if you use two-thirds of the

Temazcal Room: lower level, you get like point 2 2. So you’re above it already. Now it’s important that well, all of those numbers are in the context of the strength parameters that you have used, which we have had questions about. So if if you use lower strength

Temazcal Room: parameters and you get

Temazcal Room: lower yield, you will get invariably larger deformations, and if those deformations are still within the limits that

Temazcal Room: there are no issues with breach and overtopping, etc.

Temazcal Room: Then those

Temazcal Room: will give at least me a lot more confidence that, hey? We are good. You have done a lot of good work, but

Temazcal Room: I think there are some loose ends that needs to be kind of

Temazcal Room: tidied up, so that

Temazcal Room: at least I can get a good sense that we are good good to go the way you are approaching it.

Temazcal Room: It’s, I think, one of the one of the points I I hear from. That is

Temazcal Room: not only your interest in understanding the parameters that went into the brain Macedo

Temazcal Room: displacement, analysis, but making sure that those parameters match up with

Temazcal Room: whatever modifications may be appropriate in the strengths.

Temazcal Room: Okay, you Jim.

Temazcal Room: I’ve

Temazcal Room: think this is probably everyone’s agreeing that something more needs to be resubmitted. There’s a question that remains outstanding whether the Ecrb wants to see that again.

Temazcal Room: and I’m somewhat up in the air about that somewhat undecided.

Temazcal Room: I I

Temazcal Room: heard some of what Nick said, and

Temazcal Room: Michael’s summary, and and remain. And so some. This is

Temazcal Room: a lot of it’s been said before, but I think

Temazcal Room: there’s several things that need to be resubmitted, one is, and I’m going to add a couple.

Temazcal Room: I think, over that

Temazcal Room: west, southwest corner.

Temazcal Room: Probably a need. A new section needs to be done there.

Temazcal Room: with bay mud going down to 36 feet.

Temazcal Room: I think probably the strengths need to be reevaluated and not use a median, and probably not even a 30 percentile.

Temazcal Room: but probably closer towards a lower bound less. You want to get section by section and cone by cone, and use specific sections with specific cones.

Temazcal Room: one of the things that’s hard to review and to know. I mean in terms of engineering criteria. I think the engineering criteria is that you need to do a robust search.

Temazcal Room: It’s going to be sure, to find the critical shape and depth

Temazcal Room: of of the stability surfaces.

Temazcal Room: and I think that we can’t know that from what’s been given

Temazcal Room: so far.

Temazcal Room: And you know, if if you were to provide something with

Temazcal Room: you know, entry and exit points

Temazcal Room: or bottom tangent depths that are allowed, or and so on.

Temazcal Room: Then that needs to be resubmitted to

Temazcal Room: Bcdc.

Temazcal Room: maybe Jen’s okay with looking at at that. Maybe Jen looks at it and says, Oh, this is over my head. I need the ecrb to look at it again.

Temazcal Room: It may be relatively straightforward, but it’s

Temazcal Room: but there’s there’s a lot of material that’s going to have to be looked at, not necessarily super complicated or difficult, I think. Yeah, I think

Temazcal Room: these instructions we’re giving are pretty straightforward. These requests we’re giving are pretty straightforward, and they’re they’re done, or they’re not done.

Temazcal Room: let’s see, I I think that there’s some problems with the

Temazcal Room: pink being weaker than the surrounding blue, and that should be revisited.

Temazcal Room: I understand that, you know, under, you know, in the trapezoid, where you have cones pushing through it and borings and lab data.

Temazcal Room: Probably your your results are pretty good.

Temazcal Room: but the way you put that outside, and where you start that from should not be weaker than the

Temazcal Room: should not be stronger than the

Temazcal Room: pink in particular.

Temazcal Room: Maybe there’s others

Temazcal Room: with their

Temazcal Room: and then and then the parameters with for Bray Macedo. I think that needs to be

Temazcal Room: explained what it’s there.

Temazcal Room: and it seems a little surprising, maybe, for

Temazcal Room: Rameen, who’s more familiar with brand Macedo.

Temazcal Room: that with a yield coefficient of 19, you get only 9 inches.

Temazcal Room: I mean I,

Temazcal Room: without knowing Brand

Temazcal Room: Macedo myself. You know, I got to think that point 19 yield coefficient should give you give you substantially more displacement than that

Temazcal Room: what’s too much displacement is an interesting question that in itself might

Temazcal Room: ask for a

Temazcal Room: ecrb review, because it’s there’s not a simple, easy answer.

Temazcal Room: 9 inches is probably, I mean, there’s 2 issues with with displacement. One is, you know. How low does it get? And when does it get overtopped? And does the hydraulic, you know. The overtopping frequency increases as soon as you get some

Temazcal Room: some seismic settlement, and so you have to jump back on it real quickly and build it back up as soon as you can, so you don’t have 10 years

Temazcal Room: of return interval to happen before you know, with the Lower Cross elevation.

Temazcal Room: The second thing that’s a little more tricky and more judgmenty, maybe, is

Temazcal Room: at some level, probably with bay mud 9 inches. You don’t get cracking, but at 2 feet you start to have to ask about. Are you getting cracking of the embankment materials itself, and do you

Temazcal Room: get up to? Not over topping? But you get seepage through these

Temazcal Room: cracks that you know, tension cracks that have developed and so on.

Temazcal Room: So at some point

Temazcal Room: that gets to be another more complicated issue

Temazcal Room: that I

Temazcal Room: that

Temazcal Room: It’s not worth speculating about all the different ramifications until we.

Temazcal Room: you know, find out what the the final numbers are for displacement.

Temazcal Room: I think those need to be resubmitted, and

Temazcal Room: much of that, at least, I think

Temazcal Room: I’d be okay if Jen feels comfortable with it.

Temazcal Room: I’d be okay with us looking at it.

Temazcal Room: I I am able to run submittals by less than a quorum of the board to assess if they’re satisfactory.

Temazcal Room: Okay, I think that’s

Temazcal Room: yeah.

Temazcal Room: Oh, well, Nick, you mean Chris has had her hand up. Okay.

Temazcal Room: I had. Well, one question for Jen. You mentioned that they were adding 2 feet of free board, and I don’t think I heard that they were adding free board. I think they were just going to the 11.5

Temazcal Room: when you mentioned earlier that maybe 9 inches of deformation was okay, since they were having adding free board.

Temazcal Room: Oh, add, if I said, adding, that was a miss.

Temazcal Room: a bad choice of words. They maintain 2 2 feet of free board in the ponds.

Temazcal Room: So that’s my understanding. And and maybe you know, cargo. You can comment that that the elevation of the water in the pond in the Mss. Ponds doesn’t get above 9 feet elevation.

Temazcal Room: and if they raised the berms. Then it would.

Temazcal Room: It would go up to 9.5 feet if they raised the berms to 11.5 feet.

Temazcal Room: Got it? That’s super helpful.

Temazcal Room: The other question I had or comment is, we talked about the locations of the marsh channels, and so

Temazcal Room: I looked up. I looked at them, and then I made my computer die, so I shouldn’t have been doing that but there are some great maps that show the mark marsh channels, and even on the 1993 aerial imagery, if you go through Google Earth, you can see some of the nice big ones.

Temazcal Room: And they’re not at the sections, and there is one that was to the right of Section C, so I think if they are going to do some analysis.

Temazcal Room: It would be good to look at the Marsh channel, so I can send you Jen, a link to what I was looking at, so you can share that out. Later.

Temazcal Room: And then my other question, is that I was also seeing and looking at the image imagery. The large borrow pits around the inside of the berms.

Temazcal Room: Cause when they were, you know, they excavated material from inside the ponds to build up the berms.

Temazcal Room: But it didn’t look like in any of the sections that they were analyzing. It included that deep borrow pit, and I am not a geotechnical engineer.

Temazcal Room: so I wasn’t sure if that configuration impacts any of the analysis. If we should be considering the fact that there is that deep borrow pit on the pond side of the berms.

Temazcal Room: So that’s it.

Temazcal Room: Thank you. Chris Gail.

Temazcal Room: Alright, yeah, we’ve

Temazcal Room: we’ve made several requests, some of which are

Temazcal Room: adding conservatism and a couple of which are potentially

Temazcal Room: reducing conservatism.

Temazcal Room: And this is actually a question more for my geotechnical colleagues.

Temazcal Room: and it has to do with the title Lag.

Temazcal Room: And right. Now they’ve done it with high tide and low tide. Obviously.

Temazcal Room: it looks like it’s

Temazcal Room: but a 30% difference in most cases on the

Temazcal Room: factors of safety.

Temazcal Room: And I’m I’m used to looking at this for bulkhead design. But

Temazcal Room: in a case like this.

Temazcal Room: do you have a sense of

Temazcal Room: how conservative or what is the likelihood of

Temazcal Room: you know.

Temazcal Room: considering the the low tide on the

Temazcal Room: what is it? The high tide on the

Temazcal Room: out inside, and the low tide on the outside right, which is obviously the most conservative.

Temazcal Room: Is that necessary?

Temazcal Room: They’ve given us results for both. Is that something where

Temazcal Room: we could reasonably

Temazcal Room: allow them to

Temazcal Room: as as they do. These additional analyses

Temazcal Room: do something either a Median Median tide.

Temazcal Room: or

Temazcal Room: consider

Temazcal Room: no, no title, no title, lag.

Temazcal Room: In the analysis. Why, I wanted the opinion of my

Temazcal Room: geotech colleagues on this one.

Temazcal Room: I think all of the critical

Temazcal Room: circles that you looked at were sliding waterward right rather than land. Yeah, they all were in. In that case low tide is going to always be

Temazcal Room: conservative.

Temazcal Room: but that’s again assuming

Temazcal Room: inside the berm.

Temazcal Room: The water table is high. Side is is that high tide right?

Temazcal Room: Which is a

Temazcal Room: which which assumes there’s a title lag.

Temazcal Room: And I’m asking, is that isn’t that what it is? Is that what causes it. I don’t think their title. I I don’t think their title. I think it’s just the static Waterloo.

andrew barrett: The the pond stays at plus 9 feet, nav. D. 88 at at all times. Essentially, besides, rainfall is my understanding. When the water is pumped out, then to make it back to be at 9. So inside the pond, at least in our models, and the way it was told to us by the car representatives on site.

andrew barrett: it stays at plus 9 all the time in the pond.

Temazcal Room: Oh, so that water level, the water level inside is not

Temazcal Room: driven by the tide. It’s driven by something that Cargill’s doing.

andrew barrett: These ponds are completely removed from being connected.

Temazcal Room: Okay.

andrew barrett: To the tidal effects of the bay. Yeah.

Temazcal Room: Okay. No. Title. Effects. Inside.

andrew barrett: Trying to keep them that way.

Temazcal Room: Okay? So then, so then the then the question would just be.

Temazcal Room: is it reasonable to

Temazcal Room: use a meet? Use a Median tide if you will.

Temazcal Room: or a mean tide.

Temazcal Room: instead of low or high, instead of low.

Temazcal Room: If we, if we, if we want to allow

Temazcal Room: something for reducing conservatism.

Temazcal Room: question for the question for my colleague.

Temazcal Room: and start with a low tide.

Temazcal Room: and if it becomes problematic and expensive, repairs are called for, or something like that, then fine it a little bit.

Temazcal Room: Yeah, just to comment on that. I think I heard that a was it a plus 2 tide was used

Temazcal Room: plus 2 plus 2 for low tide, and and that’s is that mean lower low water or Navd? Or are they about the same here? I can’t remember. It’s

Temazcal Room: project datum.

Temazcal Room: And Abd, 88.

Temazcal Room: Yeah. So I mean, a, a really low tide is like, minus 2 or something.

Temazcal Room: Yeah, yeah, yeah, just so it’s not. It’s not a

Temazcal Room: yeah. The mean lower, low water

Temazcal Room: is 0. Let’s say that’s close to NAVD.

Temazcal Room: In the South Bay. This the tide drops well below

Temazcal Room: mean lower, low water. That’s

Temazcal Room: so. If you wanted to be really conservative, you could add another 4 feet of height to your water difference

Temazcal Room: which I’m not suggesting, but I’m not sure. Was it quite as conservative as it may seem?

Temazcal Room: You think they’re not being too conservative by using. Well, I don’t know I it just as a coastal person. It made sense to me to assume a low tide on the outside

Temazcal Room: as a conservative measure. What water elevation were you using

Temazcal Room: 2

Temazcal Room: elevation, too? Yeah, in in the remember, this is in the seismic analysis I’m talking about. So that was part of our reasoning is like a seismic is a distinct, you know, momentary event. So

Temazcal Room: what’s the likelihood of that? Overlapping with an extreme low tide? We used to then we did it with 0 as well. It didn’t change much. We have not run it at minus 2. That would. That would definitely be a compounding of I’m not suggesting that you do. I just wanted to point out that the tide can be a lot lower.

Temazcal Room: I’d

Temazcal Room: it’s it’s a it’s it’s on the low end of the title cycle.

Temazcal Room: It’s not a low tide.

Temazcal Room: It’s just

Temazcal Room: it’s a dropping tide.

Temazcal Room: So

Temazcal Room: yeah, it’s below Msl, and and what they’re getting at is the joint probability. Right? Like, if you’re looking at a yeah, 475 year, I I think I think it’s okay.

Temazcal Room: Sure, okay,

Temazcal Room: okay, Nick, you had you had your hand up earlier.

Temazcal Room: Well, Mr. Chairman, actually, I was going to make a motion, but I’ll let go ahead before.

Temazcal Room: I have my hand up.

Temazcal Room: Yes, but Bob has his hand up as well.

Temazcal Room: I’m I’m I’m going to talk coastal stuff, so I’ll let if it’s geotech. I think you need to go ahead.

Temazcal Room: I’m not suggesting that

Temazcal Room: different levels of earthquake shaking should be used, but these are not the largest levels either. So there is some inherent. If there is some conservatism somewhere else. We’re not

Temazcal Room: looking at the largest level of shaking either, so that I’m I’m not suggesting that you should. But just put it in context as well.

Temazcal Room: Dima.

Temazcal Room: continuing the geotax.

Temazcal Room: Okay, Michael, I don’t remember whether you mentioned he said anything about cpage.

Temazcal Room: Oh, I I actually I all I said about seepage was when I was talking about our

Temazcal Room: conclusions regarding the effects of keying in the berm.

Temazcal Room: where we really didn’t see any appreciable strength increase in the berm.

Temazcal Room: but because of our

Temazcal Room: observations of the keyed material in place, it’s apparent level of compaction, which which is not a huge amount of compaction we discussed, but

Temazcal Room: but there is compaction that has occurred that we see, and our observations of the material used.

Temazcal Room: that it’s our conclusion that

Temazcal Room: that should improve seepage

Temazcal Room: just based on that alone, you may minimize seepage.

Temazcal Room: Yeah, minimize seepage, minimize seepage. Yeah.

Temazcal Room: alright.

Temazcal Room: that that’s our conclusion based on what we see.

Temazcal Room: Okay? And then.

Temazcal Room: from the perspective of the overtopping presentation.

Temazcal Room: I think you alluded to

Temazcal Room: the material being used to top the broom.

Temazcal Room: Yeah, I should minimize scarring.

Temazcal Room: I think it should be pretty resistant to scouring.

Temazcal Room: Yeah, if you had waves hitting it, for, you know, days upon days, of course, but

Temazcal Room: for a short

Temazcal Room: wave over topping event. I think that with that compacted material

Temazcal Room: and the gravel servicing, I think that’s going to resist scour pretty well.

Temazcal Room: Well, I mean, I think maybe.

Temazcal Room: Now, what happened where?

Temazcal Room: I’ve

Temazcal Room: perhaps not. I think maybe that should be something that you should

Temazcal Room: formalize as a recommendation to address the issue of of our observations about its apparent resistance to a wave over tapping scour.

Temazcal Room: Yeah.

Temazcal Room: do that?

Temazcal Room: Thank you, Jima. Bob.

Temazcal Room: Yes. So from the coastal side. I’d be interested in seeing

Temazcal Room: selected profiles of the one or more transects

Temazcal Room: showing the static and dynamic water levels and other parameters used.

Temazcal Room: That would be for Jeremy. I don’t know if he’s still on the phone

Temazcal Room: and then I’d also like to see those values tabulated. Some representative

Temazcal Room: portion of all the wave run up, runs

Temazcal Room: tabulated, so I can see what the wave heights, water depths.

Temazcal Room: dynamic water, level, etc, are.

Temazcal Room: or a representative number of the calculations.

Temazcal Room: I I don’t think that’s that hard to do. It’s it is something that Fema did for their flood studies and in their intermediate data submittals. And I think the software probably allows you to do that.

Temazcal Room: But separate from that.

Temazcal Room: I wanted to say that I think

Temazcal Room: Chris and I,

Temazcal Room: Chris May and I could

Temazcal Room: look over what you get on that topic and work with you, Jen, or one of us.

Temazcal Room: If if we didn’t want to bring it back. So I I don’t know that.

Temazcal Room: That might. That might make it easier.

Temazcal Room: But I had an overall question, and I’m sorry I’m not if I’m supposed to be up to speed on this. But my concern with this

Temazcal Room: situation

Temazcal Room: is that

Temazcal Room: the material

Temazcal Room: is

Temazcal Room: has salt levels and certain types of salt levels that could adversely affect wildlife

Temazcal Room: if released into the bay.

Temazcal Room: That’s what I, my concern, has been

Temazcal Room: more than a life safety.

Temazcal Room: and I thought I heard somebody say that that’s not really a concern, because the material the

Temazcal Room: Mss.

Temazcal Room: Just

Temazcal Room: dissolves immediately or something, and I’m not sure I understand that

Temazcal Room: is. Is, am I

Temazcal Room: wrong to be concerned or wrong to not understand that it dissolves

Temazcal Room: right away?

Temazcal Room: Listen to that while we’re here. It depends on the concentration.

Temazcal Room: So it it depends on how much is is, you know. It’s a it’s a concentrated salt, right? So.

Temazcal Room: But the, but the concentrations themselves are are quite high because it’s crystallized, and some of it might be

Temazcal Room: more soluble than others, but certainly.

Temazcal Room: if it was a hundred parts per 1,000, which I think is

Temazcal Room: lower than it is, and it was liquid, and that was released. I think that could probably kill fish, couldn’t it.

Temazcal Room: I mean, I I just trying to understand how serious this is if we have a release which is an important consideration in terms of what the criteria are.

Temazcal Room: and I don’t know the exact levels. But if you put a bowl of this and dissolve the mix sea salts in it, and then put the fish in it. Yeah, the fish wouldn’t

Temazcal Room: wouldn’t be good, but that’s a big difference than a little bit getting out into the ocean and diluting.

Temazcal Room: I do remember working on the Napa Salt Ponds. Of course that was way a long time ago, and I think everyone’s learned a lot more since then, but we had a pond with up to maybe 100 parts per 1,000 pond 3,

Temazcal Room: and there was quite a bit of concern about diluting that before it was released.

Temazcal Room: That was one of our major challenges, and we got through that in 2,005.

Temazcal Room: But Newark slew has a number of

Temazcal Room: protected species in it.

Temazcal Room: So I I have to admit that I haven’t analyzed this or read everything about that. But what I’ve seen is not really satisfied me.

Temazcal Room: In terms of my concern, and we don’t have a biologist on here. So I’m I’m wondering what the implications are. If the implications are serious, then this could be a risk level that is higher

Temazcal Room: than we think.

Temazcal Room: which case, if it was a new project, it might have to be designed to a higher standard than what we’re talking about.

Temazcal Room: So, on the other hand, I think

Temazcal Room: it needs to be managed. Cargo has a lot of experience.

Temazcal Room: you know. They they should be able to maintain. This is in everybody’s interest.

Temazcal Room: But I’m

Temazcal Room: a little unclear on how serious the situation is.

Temazcal Room: and I don’t know is that generally, just because I didn’t read everything, or is there?

Temazcal Room: No, just I mean to recap a little bit in the very 1st meeting of the ecrb Ecrb asked Cargill to present information on the risk of

Temazcal Room: the mixed sea salts on the ecology and human health.

Temazcal Room: and

Temazcal Room: instead of providing that information, Cargill said that instead they would model the most conservative scenarios.

Temazcal Room: And so that’s that’s where we’re at

Temazcal Room: the most conservative levy failure or defamation scenarios or release scenarios.

Temazcal Room: But there’s been no modeling of the okay.

Temazcal Room: So I I just think that’s an important context. And

Temazcal Room: for me, anyway, if somebody’s worked around the bay a lot on restoration projects and around Newark Slough in particular, and

Temazcal Room: sufficient wildlife, reserve, etc.

Temazcal Room: So I just think that’s something

Temazcal Room: to think about, and why I would like to

Temazcal Room: review the wave, run up information again.

Temazcal Room: even though I don’t doubt the Cargill’s judgment that some wave overtopping probably has no significance.

Temazcal Room: And so I appreciate that viewpoint quite a bit. Actually.

Temazcal Room: sure, if I could just add the reason we didn’t do the you know environmental assessment, because.

Temazcal Room: you know, the studies indicated that we went to have, we would not have a breach, or we would not have mixed. See salt

Temazcal Room: going out into the pond, which is why.

Temazcal Room: you know, that’s why we didn’t proceed with doing an environmental

Temazcal Room: assessment. You didn’t think that, you know there’s no breach. It’s not going to be in a

Temazcal Room: any ecological impact.

Temazcal Room: That’s kind of the reason why we didn’t. Do you know, further environmental. So so I think in that case, I just want to be more sure that we understand what the wave run up and overtopping potential are, and

Temazcal Room: how that feeds into the geotech, and how the

Temazcal Room: would apply to our judgment regarding whether or not

Temazcal Room: the analysis indicates that this somewhat ambiguous failure, scenario of

Temazcal Room: possibly some levee erosion or possible breaching and release that’s undefined is likely not to be exceeded.

Temazcal Room: So that’s kind of where I am. I want to be more careful.

Temazcal Room: so I would like to see the wave run up

Temazcal Room: information.

Temazcal Room: And I would like the geotech to be comfortable with the situations, too. Recognizing

Temazcal Room: that impacting ecology is a big deal.

Temazcal Room: Thanks.

Temazcal Room: Okay.

Temazcal Room: Think that’s that’s it. Now,

Temazcal Room: so it sounds like.

Temazcal Room: everybody is okay with

Temazcal Room: additional information and clarification from Cargill.

Temazcal Room: that we’re okay, recommending approval of the permit

Temazcal Room: ending

Temazcal Room: the middle of clarifications and information

Temazcal Room: to the satisfaction. Yeah, right? And and so

Temazcal Room: I think we would, Jen, you’d have to pick

Temazcal Room: 4 of us who are, you know, so we don’t have a quorum issue.

Temazcal Room: But you know I would suggest

Temazcal Room: Bob and

Temazcal Room: Jim

Temazcal Room: remain, and

Temazcal Room: probably

Temazcal Room: Nick

Temazcal Room: to, or maybe, or maybe, if somebody’s not interested, I I would be

Temazcal Room: a good person to help.

Temazcal Room: But one of 4 of those 5 names

Temazcal Room: would be

Temazcal Room: reviewers of the information and pending that set, you know, pending our satisfaction to that, then we would recommend

Temazcal Room: approval

Temazcal Room: of a permit.

Temazcal Room: Can I? Have a little discussion? Chris did. Were you interested? Or

Temazcal Room: so it’s 5 for the quorum. So it’s like one coastal, and which is probably enough. But it could be Chris or I. But if there’s room it might be good at both of us. Okay, 4.

Temazcal Room: See yourself.

Temazcal Room: That’s all right.

Temazcal Room: But for the coastal part.

Temazcal Room: anyway, I can go either way with it. I just wanted to give Chris an opportunity to

Temazcal Room: to weigh in. See how interested she is. And no, I’m I’m happy to review the coastal part.

Temazcal Room: Yeah.

Temazcal Room: but I don’t think I think the geotech issues are

Temazcal Room: our significance. I don’t think they could have both of us if we only have 4 got it.

Temazcal Room: So either one whatever. Yeah.

Temazcal Room: okay. So do I have a motion?

Temazcal Room: Second.

Temazcal Room: all in favor.

Temazcal Room: or do we? Do you need to do a

Temazcal Room: a roll call, or can we just do a voice? Vote? Jen.

Temazcal Room: let’s do a roll call just

Temazcal Room: to be thorough.

Temazcal Room: we are going to have a roll call vote now on the motion which is

Temazcal Room: to

Temazcal Room: request additional information based on our discussion today.

Temazcal Room: and if it seems like it satisfies

Temazcal Room: our our concerns. Then the Ecrb will find that the safety issues have been addressed by cargo.

Temazcal Room: Okay

Temazcal Room: Roddy washedatch here. Aye.

Temazcal Room: Jim, French

Temazcal Room: Bob Italia. Yes.

Temazcal Room: Jima Kasali.

Temazcal Room: Chris May.

Temazcal Room: Yes.

Temazcal Room: Rameen Golisarki. Yes.

Temazcal Room: Nick Sitar. Yes.

Temazcal Room: Gail Johnson. Yes.

Temazcal Room: and Patrick Ryan. Yes.

Temazcal Room: right. Yeses have it.

Temazcal Room: I have another. So we will.

Temazcal Room: Jen, I assume you’re going to put together minutes and the

Temazcal Room: the request for information. Additional information and clarification will go to Cargill right? And

Temazcal Room: copied to

Temazcal Room: the ecrb.

Temazcal Room: Yeah. So what I’ll do is I’ll draft a letter summarizing the information request.

Temazcal Room: I’ll probably run a draft of it by

Temazcal Room: couple of people on the ecrb, maybe the chair, the chair and vice chair.

Temazcal Room: and then

Temazcal Room: and then send it off.

Temazcal Room: We will all to Cargill. Try to do that in

Temazcal Room: in a week.

Temazcal Room: And then this meeting, which is being recorded, will also be posted.

Temazcal Room: On our website at the meeting. Notice?

Temazcal Room: Right?

Temazcal Room: Okay.

Temazcal Room: okay.

Temazcal Room: okay, thanks.

Temazcal Room: Okay. There. A motion to adjourn.

Temazcal Room: Second, okay, all those in favor.

Temazcal Room: Aye.

Temazcal Room: okay, thank you.

Temazcal Room: Thank you. Cargill. Thank you.

ZOOM TRANSCRIPT

Jenn Hyman, BCDC: muted. Can everybody mute?

Jenn Hyman, BCDC: the script that we have? It’s fine fine!

Jenn Hyman, BCDC: Oh, I know. Sorry! That’s me.

Temazcal Room: We can go ahead and start right. Rod

Temazcal Room: the microphones.

Temazcal Room: Okay. Good afternoon. Welcome to this hybrid in person and online Ecrb meeting.

Temazcal Room: My name is Rod Iwashta. I am the chair of the Ecrb, and I have a few announcements.

Temazcal Room: Our 1st order of business is to call the roll board. Members, please

Temazcal Room: unmute yourselves to respond and then mute yourselves again after responding. Jen, please call the roll

Temazcal Room: okay, and actually make sure to

Temazcal Room: microphones for

Temazcal Room: general observation is that

Temazcal Room: bill that’s compacted to 90% play. Phil

Temazcal Room: should typically have an unconfined, compressive strength

Temazcal Room: I would expect of at least

Temazcal Room: 6 to 706 to 800. Psf.

Temazcal Room: almost everything is

Temazcal Room: less than that. I guess. The top, the top several feet.

Temazcal Room: half of it’s like that.

Temazcal Room: What would you? What was your estimate? 60 packed it to? 95%. It should be

Temazcal Room: yep.

Temazcal Room: 1,500 pso.

Temazcal Room: Your your 1st estimate was like 6, 6 to 800 for like a 90% compaction, I know right?

Temazcal Room: Mediocre compaction. 90% ish sure

Temazcal Room: And

Temazcal Room: and you know, one of the photos, and I’m not sure if it was in the presentation or report, or someplace showed you guys with a sheep’s foot on the end of a

Temazcal Room: of an excavator which should put this stuff down at.

Temazcal Room: I mean, it’s Cape. If this, if the trench is solid enough, that should put it down at 95% without much difficulty.

Temazcal Room: So I’m curious. It look, it looks like

Temazcal Room: compaction is

Temazcal Room: below water, or

Temazcal Room: maybe maybe not 90, probably not 95%.

Temazcal Room: And it’s not a structural.

Temazcal Room: Then it should be off the charts with tip resistance, and it shouldn’t.

Temazcal Room: Shouldn’t give you a tip. Reason it shouldn’t give you an su out of it. It should give you a

Temazcal Room: friction angle

Temazcal Room: as a granular deposit if it’s granular yeah

Temazcal Room: are you observing relative to its

Temazcal Room: what? You’d interpret its ability to resist seepage as being

Temazcal Room: I mean, I I would I don’t. I don’t think this is a heavily like structural fill level compaction. I don’t think this is a necessarily

Temazcal Room: a 95% compact in drawing that

Temazcal Room: our findings bear that out in Bay mud. There is 0 chance that you’re going to get. I mean, if it’s surrounded by soft levee, and

Temazcal Room: that’d make it tough until the last couple of feet. Possibly. But it looks like to us. It’s a it’s probably more likely you’re down in May

Temazcal Room: 88% range. I would

Temazcal Room: might have guessed. Maybe

Temazcal Room: it looks like it’s a

Temazcal Room: compacted material.

Temazcal Room: not not not heavily compacted, but

Temazcal Room: but compacted and

Temazcal Room: better controlled, material wise. But the strengths are 4 to 600

Temazcal Room: Psf.

Temazcal Room: down below. 5 feet they are. That’s a, you know, pocket 10 of

Temazcal Room: or Tsf or something.

Temazcal Room: I mean isn’t most of the action here, though. Kind of in the down to 5 feet level

Temazcal Room: isn’t most of the seepage resistance, though, in the upper 5 feet, I mean, that’s where we see the biggest benefit here.

Temazcal Room: Well, that’s where we see the highest strength, I should say.

Temazcal Room: and probably the most compaction activity occurring.

Temazcal Room: I think once we get below 5, we’re starting to get into just pre-existing young bay muds.

Temazcal Room: I’m actually, frankly, not very concerned about the strength of the material. I’m just sort of

Temazcal Room: commenting on. It looks like

Temazcal Room: compaction is

Temazcal Room: mediocre.

Temazcal Room: Okay?

Temazcal Room: And maybe gotcha fine. Yeah.

Temazcal Room: right?

Temazcal Room: Well, I know. I mean, I know you’re

Temazcal Room: your intention is not to make a

Temazcal Room: structural fit, and I don’t think that’d be necessary anyway.

Temazcal Room: excuse me, Nick would like to speak.

Temazcal Room: can I? Just.

Temazcal Room: if I may just add my concern actually would be reactivity of whatever this fill is with salt water.

Temazcal Room: If the clay happens to be

Temazcal Room: what we normally want to use for impervious fill, which is high plasticity clay. Those shrink when exposed to salt water. So actually, they’re not the best material

Temazcal Room: to be used.

Temazcal Room: And so at some point, somebody looking at it to make sure that you’re basically not putting in material that eventually over a period of time is gonna shrink and cracks are gonna develop. And it’s gonna yeah, yeah, shrinkable in the sense that a high salt concentration will shrink to double layers. Yeah. And you know, it’s a fairly well known phenomenon.

Temazcal Room: but sometimes we kind of forget that that’s what happened. So I don’t. I don’t think that’s what they have out here, though you know it’s worth checking that it’s not happening. That’s all. Okay. Yeah, that’s fair. We we can have some commentary to that. I mean, based on what we saw, the fill on the ground and based on what we see it in its

Temazcal Room: placement in the keys. I I don’t think that’s what they have here. But yeah, I could. I could imagine a scenario where you brought a material that happened.

Temazcal Room: Yeah.

Temazcal Room: okay, I’m gonna point out that we’ve got about an hour

Temazcal Room: left of

Temazcal Room: meeting time here. If we’re trying to hit our 4 30

Temazcal Room: target of getting out of here.

Temazcal Room: Just just wanted to point that out. Okay, I am happy to move faster. Actually, some of this might go fast, because

Temazcal Room: this part about the seismic events has not changed. And so maybe I’ll just boil down. Say, as you remember.

Temazcal Room: we analyzed for a 50 year earthquake event and a 475 earthquake event and determined peak ground accelerations for both of those

Temazcal Room: partly based on the soil properties we saw at the site and partly based on the Usgs, derived compilation of all earthquakes and faults in the region.

Temazcal Room: so no change there.

Temazcal Room: and I don’t. I don’t think that was a

Temazcal Room: I know there’s some discussion last year about

Temazcal Room: is a 475 year. Earthquake

Temazcal Room: too big, bigger than it needs to be for this analysis. Would a 200 year earthquake make more sense

Temazcal Room: to that? I guess I’d say, maybe. But why not

Temazcal Room: see what happens with the bigger one?

Temazcal Room: alright! Let me let me go through the analyses, findings of of stability, because

Temazcal Room: th this is this is, I think, the thing I I’d like to hear input, on

Temazcal Room: Here’s the sections we analyzed.

Temazcal Room: You remember this.

Temazcal Room: and we analyze for Factor safety, as we know.

Temazcal Room: And let me just let me just skip to the

Temazcal Room: to the results. Under normal static conditions the factors of safety were quite high.

Temazcal Room: 2.8 9. In this case

Temazcal Room: these berms are sitting there stable.

Temazcal Room: Okay? I don’t think that’s a surprise to anybody. The question is, what happens in an earthquake?

Temazcal Room: And so I have a couple of slides presenting a 50 year earthquake.

Temazcal Room: In this. This example is at Section D, and you see a

Temazcal Room: all of these analyses basically go through the berm and out past the tow. They’re

Temazcal Room: slip services that involve

Temazcal Room: a potential for tow failures of the

Temazcal Room: of the berm. We analyzed a variety of these. These are always the the critical ones we came up with

Temazcal Room: in this section. The the berms factor. Safety is, is above the desired level of 1.1. So that’s good

Temazcal Room: in the next slide at section CC, it is below 1.1. Yeah.

Temazcal Room: So I’m curious.

Temazcal Room: what type of search constraints you’re doing.

Temazcal Room: How is this searching, is it? I mean, at some point in the draft.

Temazcal Room: Powerpoint. We had it said, No, sir, no surfaces are are circular, or all are non-circular, or something like that, and I think

Temazcal Room: I can’t remember what the note was there. All slide models shown are non circular.

Temazcal Room: That

Temazcal Room: slide got deleted from the final presentation, which which is fine

Temazcal Room: it looks like there are some circular circles. Oh, definitely, this looks

Temazcal Room: a

Temazcal Room: clearly non-circular looks like a not on typical type of non-circular surface. The

Temazcal Room: I think it was the next one that

Temazcal Room: is non circular, but it looks kind of like a sloppily drawn circle, or I mean, it looks like an awkwardly circle. I’m curious what? How this came up with that geometry for the circle.

Temazcal Room: And and in general.

Temazcal Room: you know, what is the

Temazcal Room: search algorithm that you’re using here? Are you limiting it? Is it circular? Are you limiting? The entry points? Exit points?

Temazcal Room: I don’t know. Slide 2 as well as I know. Slope W slope W. You can

Temazcal Room: print out the entry point

Temazcal Room: limits and the exit point limits, and the printout, if you’re allowing it to search to a certain depth maximum, if that’s what you’re doing.

Temazcal Room: Yeah. And I, you know, I

Temazcal Room: I think if you’re presenting this to

Temazcal Room: someone to review, it ought to have

Temazcal Room: some sort of explanation, preferably a graphic depiction on every

Temazcal Room: printout that says, this is what the slide constraints, the the slide surface constraints were.

Temazcal Room: Okay. Yeah. Cause I see, cause there are a lot of different ways to do it

Temazcal Room: right, because there are a lot of different ways to do it. Like you’re saying, which ones did we use. Right? Yeah, do we use this? Do we use that, you know? And my guess is that most of the time circular, I mean circular needs to be checked. I think

Temazcal Room: especially if you have soft clay, the most common expected case is going to be a deep circle that’s going to include most of the embankment and going to take it with it.

Temazcal Room: especially with seismic.

Temazcal Room: But

Temazcal Room: I’m I’m all in favor of

Temazcal Room: looking at other types of configurations also, because

Temazcal Room: other things

Temazcal Room: can happen. But but somehow, if if I’m checking this, I just need to know what the

Temazcal Room: what the search methodology is. And okay, I think the most helpful is is if you can give it graphically on the printout.

Temazcal Room: and then I just know every single time

Temazcal Room: what you do. I’d rather than a paragraph at the front than I go? Well.

Temazcal Room: okay. But was it.

Temazcal Room: does it? Does it allow it go to 36 feet this time, or is it trunking? Yeah.

Temazcal Room: okay.

Temazcal Room: we. I mean, at the risk of

Temazcal Room: sounding like, I’m oversimplifying things. We ran it a bunch of different ways, right? Circular, non circular wedges

Temazcal Room: some other, I mean. I I could probably ask Andrew to tell us for, like 15 min about all the things he did, and maybe that would be worthwhile. But at the very least, I think what I’m hearing is kind of like your comment on the

Temazcal Room: tabulation of the properties. It would be helpful as reviewers to understand.

Temazcal Room: Okay, for this output. That’s the style of

Temazcal Room: search that was done.

Temazcal Room: Because if we ran 5 different styles of churches of searches. Why not

Temazcal Room: tell you the 5 different ones, and label them each accordingly. Is that

Temazcal Room: that’s kind of what I’m taking away is that without that it’s just hard for you to understand sometimes what? Yeah.

Temazcal Room: the implication that we’re saying raffle here on the printout is the most useful, and it’s, you know, for your own internal. Qc, it’s most useful.

Temazcal Room: you know for the

Temazcal Room: people, that are doing the runs, you’re trying to keep track of all your burnouts. And yeah.

Temazcal Room: got to make sure that you’ve got it. And the printout Graphic just shows that you’ve got it

Temazcal Room: right exactly what it is.

Temazcal Room: It was a little easier when I was a young engineer doing this myself because I didn’t. I couldn’t do 100 runs a day. I did like 2 runs a day, so I didn’t have as many, but I understand, understand. Give. It would be helpful to understand.

Temazcal Room: And I think that I, you know.

Temazcal Room: referring back to some previous discussions. I think there’s

Temazcal Room: some questions about the blue strength profile being stronger than the pink strength, profile, right? Which I think is going to potentially change

Temazcal Room: many, most all of the

Temazcal Room: all of these results. But

Temazcal Room: okay, thank you, Jim. Nick.

Temazcal Room: Okay.

Temazcal Room: couple of questions. I don’t know if this is a typo or not, but

Temazcal Room: it for this OLE. Level or lower level, and one of these

Temazcal Room: I think

Temazcal Room: it is. It’s

Temazcal Room: it may be the next one.

Temazcal Room: Are you looking at the oh, yeah, it says.

Temazcal Room: this is.

Temazcal Room: I guess. PGA point 3 7. Is that it? I pull?

Temazcal Room: Yeah, is that a typo? Or it’s supposed to be point 3 4.

Temazcal Room: Not that. Oh, you’re talking about here? The yeah, the PGA that’s applied.

Temazcal Room: Yeah. Because in the previous slides it says, you know, the only level is point 3 4. Just curious. If

Temazcal Room: this was

Temazcal Room: so, I’m sorry. Hold on. Yeah. I want to go back. Yeah, right there point 3 4G, and your point is, why does this one show point 3 7 g, not that it’s a big difference. But but

Temazcal Room: I mean, yeah.

Temazcal Room: I.

Temazcal Room: And the other question is, are you applying a pseudo static of like? Let’s say in this case, point 3 7,

Temazcal Room: or are you reducing it for the slope. Stability analysis.

Temazcal Room: because that’s the PGA. That’s the peak value.

Temazcal Room: Andrew, correct me if I’m wrong. The these are pseudo static analyses.

Temazcal Room: So I believe we batcher the PGA accordingly, for a pseudostatic

Temazcal Room: enough, so.

andrew barrett: You didn’t apply any factoring for these. We started off with the analysis with a 2 thirds factor and then

andrew barrett: eventually move to the full PGA value

andrew barrett: conversations at our last meeting.

Temazcal Room: Andrew, do you? Do you remember the point? The reason for the point 3 7 here instead of a point 3 4?

Temazcal Room: Yeah, if you’re sleeping.

andrew barrett: As it is.

andrew barrett: I I think that I don’t know. I don’t think it would make much of a difference to be honest, but I I’m not sure if that’s just a

andrew barrett: in error.

Temazcal Room: Yeah. Okay.

Temazcal Room: In any event,

Temazcal Room: did that answer your question? Well.

Temazcal Room: not quite. Let me.

Temazcal Room: I’m curious. If this number is

Temazcal Room: 2 thirds. Is this mislabeled by any chance as being OLE.

Temazcal Room: It’s definitely not. Cle, it’s definitely not the larger one.

Temazcal Room: What? What is hold on a second?

Temazcal Room: Precisely.

Temazcal Room: then.

Temazcal Room: this point 3 7.

Temazcal Room: I

Temazcal Room: I don’t know what this is.

Temazcal Room: It’s a little higher point 3 4, right? What is it like? 2 thirds of point 5.

Temazcal Room: But it’s mislabeled as OLE.

Temazcal Room: You follow what I’m saying. Yeah, I I do.

Temazcal Room: I know that’s not what happened, but I understand why you’re asking that question.

Temazcal Room: Yeah, 2 thirds is more like point 33 and point 34. And this is point 3 37.

Temazcal Room: I’m just.

Temazcal Room: We’re trying to follow what what’s being done?

Temazcal Room: Well, and part part of the reason, I say, that’s because when we go to the next ones, you do see a higher one for the contingency level event, right?

Temazcal Room: In fact, since we’re talking about it

Temazcal Room: like, for example, when I go ahead a couple of slides, there’s a point 5. So that’s what you’d expect to see from the earlier statement of PGA. Right? The intention is for that to show the PGA

Temazcal Room: just what is the PGA that we derive from the

Temazcal Room: the earlier evaluation.

Temazcal Room: I understand. But what is your pseudo static

Temazcal Room: value that you’re putting for your slope? Stability

Temazcal Room: analysis, is it? Are you using full PGA, or are you reducing it by

Temazcal Room: some number?

Temazcal Room: I think we’re Andrew again. Correct me wrong. I think we’re using the full number.

andrew barrett: Using the.

Temazcal Room: The number we’re using.

Temazcal Room: Okay.

Temazcal Room: so why is the 1.3 7 instead of point 3? I’m I’m frankly not sure but the intention is to just

Temazcal Room: plug in the PGA. Okay, so that’s

Temazcal Room: bully. All right. Thank you.

Temazcal Room: Thank you, Rameen Nick.

Temazcal Room: but

Temazcal Room: so hopefully you can hear me now. I. I like this picture because

Temazcal Room: it becomes non circular, simply as a function of your layering that that’s a very normal thing that will happen.

Temazcal Room: If you have a gradually increasing strength with depth, then you get a completely different failure surface.

Temazcal Room: So, as you can see, it follows the layer that where you have a transition in strength. Okay? So you have actually predetermined the failure surface in here.

Temazcal Room: That that that is a problem.

Temazcal Room: Say say that you, predetermined by by your layering, you have predetermined where that thing will is going to flatten out.

Temazcal Room: See what I mean?

Temazcal Room: Well, I mean, I see how our layering dictates where? Well, that’s what I mean. So you predetermined by by where you put the layer boundary, you have actually determined where the bottom of this thing’s going to be. If you moved it lower down, it would move lower down. That’s what happens in these non, so non circle analysis, which I’ve done a lot.

Temazcal Room: But I have a question which really follows up

Temazcal Room: 1st of all.

Temazcal Room: Oh.

Temazcal Room: I don’t know how to put it.

Temazcal Room: Has anyone here actually checked slide against any other code, or even a hand calculation where it actually does all of this correctly.

Temazcal Room: I.

Temazcal Room: Many years ago I had experience with rock science, where they were very loose

Temazcal Room: with their

Temazcal Room: codes.

Temazcal Room: and I have not used them since.

Temazcal Room: For that reason I have not gone back, presumably over the years they’ve improved.

Temazcal Room: But I have not been impressed by a QR. Qa. Qc. Their own. What? What software were you carrying issues with? We were using slide and for for some other purposes, and things weren’t quite right. So we use other software. I’m simply asking, has anybody

Temazcal Room: my colleagues done any Qa. Qc. Normally, when you adopt the code. Of course you trust the

Temazcal Room: people who published it. Sure.

Temazcal Room: but

Temazcal Room: I generally run it against something that I know, just to make sure that it

Temazcal Room: gives me the results in any case. But looking at the seismic analysis you know, I think, what my colleagues were asking. You know, Magdi, Cnc. If you go back to it is those are the reduction coefficients that people take the

Temazcal Room: maximum acceleration, whatever you come up, and then you come up with a pseudostatic, coefficient, based on the thickness of the profile, and so on. And so I guess that’s the question, because, applying full point 5G. Of course

Temazcal Room: you can look at it. It’s conservative.

Temazcal Room: But, on the other hand, I don’t think it really gives the right response, and so puts you in a situation where you’re presenting point 7 5

Temazcal Room: factor of safety, which, in fact, may be real underestimation of what you have. So I would suggest. Take a look at how

Temazcal Room: you derive the seismic coefficient for this.

Temazcal Room: It’s not PGA.

Temazcal Room: If if anything, we’re overestimating the seismic forces, we’re absolutely, I think we’re being either corporately conservative or we’re being overly concerned. If if you’re applying, if you’re applying full PGA, then yes, you’re being very conservative, conservative on a

Temazcal Room: in a way that I don’t think anybody here would suggest that you should be.

Temazcal Room: Oh, why.

Temazcal Room: okay, thank you, Nick.

Temazcal Room: Jima, you had something.

Temazcal Room: Are you done, or you still have some more.

Temazcal Room: I I have one more part to discuss, which is the deformation analysis.

Temazcal Room: Oh.

Temazcal Room: okay. Why don’t you finish that? Okay, yeah. Let’s look, because I think we have these examples where the factor safety is less than 1.1.

Temazcal Room: Maybe we’re being overly conservative.

Temazcal Room: probably are. I mean, we want to purposely be conservative.

Temazcal Room: But we got these factors, maybe below 1.1, particularly in the 475 year earthquake.

Temazcal Room: Frankly, I like using that earthquake at all is pretty darn conservative, but it’s appropriate for us to look at it. But what does that mean? What is what is this telling us about the behavior of the berm in this

Temazcal Room: large earthquake. So

Temazcal Room: to understand that we performed a

Temazcal Room: displacement analysis, not not a

Temazcal Room: real fancy one.

Temazcal Room: We all know you could do that some very advanced ways. You could do full models. We didn’t do that. We

Temazcal Room: looked at. Oh, yeah, I’m sorry. Here’s the examples in yellow, where we have factors, safety less than 1.1.

Temazcal Room: They are in cross sections B and C,

Temazcal Room: and they are mostly in the large earthquake, and in one case in the smaller earthquake. But what do those tell us? So? Let me, let me tell you what we came up with there and then. I think we can, you know, talk about

Temazcal Room: things.

Temazcal Room: deformation analysis.

Temazcal Room: We used

Temazcal Room: an established

Temazcal Room: Co available code. Andrew can cite it. I’m not going to try to state the name of it at the moment, but I will tell you it is a

Temazcal Room: sliding block model.

Temazcal Room: but classic, you know, fairly simple model that

Temazcal Room: takes the weight of the berm. The frictional force of the base of the berm applies

Temazcal Room: the acceleration from the earthquake to it, and determines. How much is it going to move if the Thatcher safety is low, how much is the berm going to move? Is it going to completely move out of the way, or what is going to happen.

Temazcal Room: and we ran it for the worst case we had, which is a section CC. In a low tide.

Temazcal Room: and the answer we get from that is that it will move

Temazcal Room: along the slip plane 2 to 9 inches

Temazcal Room: with 5 inches, being the

Temazcal Room: the best estimate of movement.

Temazcal Room: That’s a result I wanted to make sure to put in front of everybody within the board and

Temazcal Room: get reactions to, because

Temazcal Room: when we see that answer come up.

Temazcal Room: Yeah. The factors of safety are sometimes.

Temazcal Room: you know, well, below 1.1, but

Temazcal Room: that is not an amount of deformation that is going to mean

Temazcal Room: a berm breach. I know ultimately, when you boil this all down. This, the whole purpose of this analysis we’re doing is are the berms gonna hold up.

Temazcal Room: And we’re our conclusion is even in these earthquake events.

Temazcal Room: Yeah, there will be some

Temazcal Room: deformation, but not enough to affect their ability to hold the mixed sea salts. And it seems like, isn’t that really the bottom line of all this analysis

Temazcal Room: is.

Temazcal Room: will they hold up

Temazcal Room: so right? And and so you’re talking about horizontal movement. I guess

Temazcal Room: the question is, is there vertical settlement as well? Yeah. So the way I would describe this movement is when I say along the slip service. I mean, it’s like

Temazcal Room: vertical atop and horizontal out at the toe. So it’s some of both.

Temazcal Room: is is what we would imagine.

andrew barrett: As an aside before that discussion keeps going. It’s the brain. Macedo method, 2,018, I believe, is the

andrew barrett: year that that paper was published I could look it up specifically. It’s the modified Newmark sliding block analysis that uses

andrew barrett: earthquake analysis from actual earthquakes. Thank you.

andrew barrett: Yep.

Temazcal Room: Good.

Temazcal Room: So we we would interpret it. That’s why we put this little picture of an example slip service on the slide that we’d interpret as moving

Temazcal Room: 2 to 9 inches along that surface.

Temazcal Room: and and we don’t see that as being something that affects the

Temazcal Room: robustness or

Temazcal Room: retaining ability of the of the berms.

Temazcal Room: So to us all this said that to us seems like that’s feels like that’s the ultimate conclusion. Did you ever

Temazcal Room: so? What method did you use for doing the deformation analysis?

Temazcal Room: what what Andrew just described is is a is a codified version of the sliding block

Temazcal Room: analysis. The Newmark sliding block analysis. But whose implementation of that.

Temazcal Room: Andrew, can you say that one more time.

andrew barrett: Brain Macedo Method.

Temazcal Room: Say it again.

Temazcal Room: Say that again, Andrew, I’m gonna pull up the statement in our

Temazcal Room: Brian macedo.

Temazcal Room: Yeah, yeah.

Temazcal Room: is that

Temazcal Room: meaningful?

Temazcal Room: Well, after what you said about rock science. Goodness.

Temazcal Room: Oh.

Temazcal Room: okay.

Temazcal Room: Brian, what about Brian Macedo?

Temazcal Room: No, I see.

Temazcal Room: you know. If we I will say I mean, if we were. We’ve been using slide 2 forever, I mean, and if

Temazcal Room: I have not yet been like Oh, my gosh! What is going on? If we had had a moment, even one moment. We’re like what is going on with this thing. I think we’d be digging in. Sounds like you did, but

Temazcal Room: I have not had that yet.

Temazcal Room: anyway, that that I I skipped over some slides in there. But

Temazcal Room: that’s that’s what we’ve come up with. I mean, this is our summary.

Temazcal Room: Our impression is, and and recognizing yes, for sure, we could

Temazcal Room: go into further analyses. Further data. We could do some more critical sections, certainly run some more ones like it.

Temazcal Room: Location 8, 9.

Temazcal Room: Probably. Maybe we find low factors of safety there, too.

Temazcal Room: wouldn’t shock me, I suppose. But

Temazcal Room: ultimately this deformation analysis seems to us like, that’s what’s really

Temazcal Room: going on.

Temazcal Room: And and I and I, I also recognize that earthquakes that have been experienced at this facility in the past are not 475 year events. We know that there have been earthquakes. There’s 1,989

Temazcal Room: that was not at that size, but

Temazcal Room: that is a data point, and there was no deformation in that earthquake. So that does give us, I think, some

Temazcal Room: confirmation that we’re using

Temazcal Room: appropriate values for this.

Temazcal Room: so I almost feel like that in some ways might end up being more important than delving further into what the factors safety are. Yes.

Temazcal Room: can you talk about the the low tide? Elevation that you selected, how you selected it? And if

Temazcal Room: power

Temazcal Room: sensitive, the deformation results are to that number. Yup

Temazcal Room: we selected 2 feet for our low tide. For most of these analyses not 0 feet. We. We recognize low tide goes below 2 every day.

Temazcal Room: But our 1st batch of analyses use 2 simply because we’re compounding probabilities. We’re talking about what happens during an earthquake, which is, you know, a 4 min event.

Temazcal Room: and the likelihood of the earthquake occurring during the

Temazcal Room: tiny part of the day when the low tide occurs, we said, Okay, let’s

Temazcal Room: 2. Seems like a more reasonable expectation of what might happen. So we ran a bunch of these with 2,

Temazcal Room: but also recognize that there’s interest

Temazcal Room: from from everybody and understand? Okay, you know, that’s great. But what about like a really low tide, which is really like more like 0? So we did a comparison. It made no effect whatsoever on the deformation. It made a very marginal effect on the factors of safety, but not even enough to

Temazcal Room: to round out to the numbers shown in our table. So whether or not it’s a 0 or a 2 foot low. Tide doesn’t really affect what we came up with, but those are the numbers that that we used in our analyses.

Temazcal Room: I have a question.

Temazcal Room: This relates to the previous

Temazcal Room: presentation that

Temazcal Room: run up goes up to elevation 11 or something like that. Okay, is that elevation that you’re kind of considering as being the the berm. Or are you using today’s elevation? We’re using today’s elevations.

Temazcal Room: We didn’t. We didn’t go in and make them 11.5.

Temazcal Room: In other words.

Temazcal Room: I don’t

Temazcal Room: really expect it would do much to change them to 11.5.

Temazcal Room: But we use the elevations that are current.

Temazcal Room: How much higher would 11 and a half be

Temazcal Room: from current television? A fraction of a foot

Temazcal Room: fraction of a foot. Okay.

Temazcal Room: thank you.

Temazcal Room: Dima. All right.

Temazcal Room: So thank you for your

Temazcal Room: presentation.

Temazcal Room: I don’t remember whether you had told us this

Temazcal Room: during your previous presentation or not. But I’m just curious about

Temazcal Room: the colored section

Temazcal Room: of the broom and the pink and the

Temazcal Room: I mean, how did you get the configuration of those

Temazcal Room: 3rd section.

Temazcal Room: Let me go back to the figure that shows one of those examples.

Temazcal Room: yeah. So the here’s a good one.

Temazcal Room: I wouldn’t say there was any science behind. How we exactly defined the trapezoid that you see other than we just wanted to have a trapezoid, we said, let’s just have a trapezoidal distinction between

Temazcal Room: what’s under the berm and what is not under the berm.

Temazcal Room: and the distinction. There, again, is

Temazcal Room: what we have used under the berm is strictly from our analysis of the Cpt data.

Temazcal Room: whereas what’s outside of that trapezoid

Temazcal Room: is a an attempt to estimate

Temazcal Room: what we would.

Temazcal Room: the the deeper material layer unaffected by the berm. It it is. It is an engineering judgment attempt to estimate that.

Temazcal Room: There has been a suggestion that might some of our values be, in fact.

Temazcal Room: making that

Temazcal Room: stronger than what’s under the berm

Temazcal Room: that could be. I I’m not sure what my answer that is at the moment, but that is, that’s that was our intention with the analysis. And that’s that’s what the trapezoid means. And that’s how we developed it. So it was strictly based on Strand, not on

Temazcal Room: some historical information on what

Temazcal Room: it’s. It’s all strength and just our interpretation that there would be an an area

Temazcal Room: of

Temazcal Room: soil

Temazcal Room: affected by the berm’s presence.

Temazcal Room: Okay.

Temazcal Room: thank you.

Temazcal Room: So from my perspective, you know, based on the presentation, the thing that I’m

Temazcal Room: really concerned about is

Temazcal Room: finding the critical section.

Temazcal Room: right? And I think the way you did it was based on

Temazcal Room: what the geometry is. Yeah, based on lighter data

Temazcal Room: and measurements that you took in the field.

Temazcal Room: I mean, I think what Nick said

Temazcal Room: is really the most important aspect of this.

Temazcal Room: because

Temazcal Room: if you don’t find the critical

Temazcal Room: section

Temazcal Room: right.

Temazcal Room: you you might not be representing what the risk really is, because it’s a long

Temazcal Room: linear structure. And so I would echo what Nick had previously said, which is.

Temazcal Room: you know, use the data close to

Temazcal Room: this section

Temazcal Room: that you have picked

Temazcal Room: rather than the average.

Temazcal Room: Right? I think. Now, yeah, that’s that’s going to be very important.

Temazcal Room: The other thing that right, I think you should also use in terms of

Temazcal Room: finding the critical section.

Temazcal Room: because you are picking geometry. And he said, if it’s narrower.

Temazcal Room: I mean, that’s likely to be

Temazcal Room: critical, because, you know, it’s narrower, like, the berm is narrower. Yeah.

Temazcal Room: But you could also use. Look at the strength.

Temazcal Room: Right? Yeah, you could go to sections and see in this area there’s a concentration

Temazcal Room: of soft material, even though the geometry

Temazcal Room: might be

Temazcal Room: logic, right?

Temazcal Room: So so you have to look at it

Temazcal Room: from that perspective

Temazcal Room: as well.

Temazcal Room: The other thing which caught my eye

Temazcal Room: really is the the weird shape

Temazcal Room: of the burn.

Temazcal Room: you know. I mean, I was kind of looking at the firm. I’m wondering what made them ship there.

Temazcal Room: The sheep.

Temazcal Room: the way it is.

Temazcal Room: You know the way that the way it’s shown in our model

Temazcal Room: or the way it really is.

Temazcal Room: Oh, in the photos. Yeah.

Temazcal Room: I’m kind of wondering

Temazcal Room: why would

Temazcal Room: they build a firm

Temazcal Room: and kind of shape it the way they did

Temazcal Room: what is, what is what is about the shape that is weird? Well, I’m I’m I’m just looking at.

Temazcal Room: Okay, you want to build a you want to build a firm right?

Temazcal Room: I mean, normally

Temazcal Room: right, you would expect that.

Temazcal Room: I mean, you want to make the things straight. You know there are these segments to it.

Temazcal Room: So I’m kind of wondering whether this was built in stages.

Temazcal Room: you know. Maybe there was a time ago, right? I don’t know whether you have any historical information. Was this all built? You know there was a plan.

Temazcal Room: and the plan was that sense should be shaped

Temazcal Room: the way it is.

Temazcal Room: So so you’re talking. You’re talking about the curves. Yeah, how it curves around and everything. Yeah, I don’t.

Temazcal Room: I don’t know why they built them the way they did. I mean, yeah.

Temazcal Room: yeah, yeah, because they’re 100 years ago is when when they built these. Yeah, because sometimes what happens is, maybe the initial plan was to build something small, and there was something small.

Temazcal Room: and he decided to expand it.

Temazcal Room: So you know, from

Temazcal Room: where the previous one ended. You know.

Temazcal Room: you want to hit the roadway so

Temazcal Room: it ends up being shaped like that.

Temazcal Room: But if that’s the case, I mean. What would happen is that you have

Temazcal Room: sections

Temazcal Room: of the berm

Temazcal Room: which are different by virtue

Temazcal Room: of age.

Temazcal Room: Right?

Temazcal Room: And so I mean, it kind of made me curious that

Temazcal Room: somehow.

Temazcal Room: you know, like that

Temazcal Room: bad section.

Temazcal Room: you know, close to them at all.

Temazcal Room: What was that for?

Temazcal Room: Because, I think

Temazcal Room: you know, looking at the shape

Temazcal Room: you know, it might drive you into saying.

Temazcal Room: you know, maybe this, then the site development history.

Temazcal Room: It’s also an important factor

Temazcal Room: in determining

Temazcal Room: what is the most critical section

Temazcal Room: you know. If yeah, I understand behind it, I mean, I can understand it

Temazcal Room: but it’s kind of.

Temazcal Room: you know.

Temazcal Room: pick my curiosity as to

Temazcal Room: well, it’s

Temazcal Room: it it.

Temazcal Room: you know. Why would anyone build the firm the way it is?

Temazcal Room: It’s it’s a little bit like our

Temazcal Room: I I will tell you. You know, when we were out there at all these places, looking and measuring this berm, if we had seen a stretch of berm that was distinctly different than another stretch of berm.

Temazcal Room: We would have said, Wait a minute.

Temazcal Room: maybe that needs to be analyzed separately, because that’s him. But we didn’t really see that I mean, it was pretty consistent throughout. I know the

Temazcal Room: the, the alignment of it’s kind of odd and changes a lot, but the berm itself didn’t change enough for us to see anything that would prompt us to

Temazcal Room: analyze that specifically. But we did. We did look for it, and it was a little bit like what we did with all the

Temazcal Room: Cpt logs again we’re like, are there places out here where the soil is worse or softer?

Temazcal Room: And we didn’t see that regionally. I I know there’s been discussion here, and i 1 of the takeaways from this discussion. I feel like is.

Temazcal Room: maybe we should analyze over at Cpt. 8 and 9. Maybe that’s a little batch of yeah. A situation that, you know, warrants its own analysis may maybe so, although I will say one advantage of having done all these analysis. I can offer a prediction of what we will find.

Temazcal Room: If we do that I will. I will bet

Temazcal Room: I’ll bet a Starbucks card

Temazcal Room: we will find a factor safety of like point 7,

Temazcal Room: and we’ll run a deformation analysis. It’ll be like 2 to 9 inches. I think that’s probably what we’re gonna learn. Yeah. And so we’re gonna have to reckon with. What do we all make of that, you know, is.

Temazcal Room: No, I mean I I am

Temazcal Room: okay with what you’ve done. I think you’ve made an effort.

Temazcal Room: You know you’ve done your due diligence.

Temazcal Room: and the only thing that I would suggest

Temazcal Room: be done is to kind of look more closely at the issue of

Temazcal Room: what is the critical section.

Temazcal Room: because ultimately the behavior of this, then, is going to be in 3 dimensions. Right?

Temazcal Room: Yeah.

Temazcal Room: you know, even if you have a weak section.

Temazcal Room: you know, when this thing is subjected to an earthquake is going to respond as a system rather than the

Temazcal Room: you know the section that you have true

Temazcal Room: 3 dimensional effects, you know, compete. Your due diligence is to kind of look at it

Temazcal Room: a little bit more in terms of

Temazcal Room: is there any either due to site, development, history.

Temazcal Room: or the strength of the material you’re encountering is there potentially a more critical section

Temazcal Room: than what you have looked at. So

Temazcal Room: you know, when we 1st got involved with Cargill on this question. We were prepared with Cargill team to look at 3 like, if this firm is going to breach, how big an area is gonna breach, and what are the 3 dimensional effects? We were all prepared to do that until our analysis suggested

Temazcal Room: it isn’t actually gonna breach. So once we found that we’re like, okay. Well.

Temazcal Room: suddenly, there isn’t such a need for that sort of 3 dimensional analysis. Now, we’re faced with this amount of deformation, and

Temazcal Room: there are surely 3 dimensional, you know, effects going on with that, too. But

Temazcal Room: given the magnitude and scale of it, it seems like we’re kind of getting our answer now, yeah, well, I mean, the 3 dimensional response is actually going to be better. It’ll probably make the numbers even less. Yeah, exactly.

Temazcal Room: you know. And you know, but I think that

Temazcal Room: the one piece is to

Temazcal Room: look at the sections, you know, in terms of strength, not there’s a geometry.

Temazcal Room: and see whether that would drive you

Temazcal Room: into looking at a particular section.

Temazcal Room: Yeah, okay, I understand.

Temazcal Room: Thank you. Gma.

Temazcal Room: See, Romaine, you got your hand up.

Temazcal Room: Yes, thank you.

Temazcal Room: I was wondering because I was looking your report, and it said that the yield acceleration is like point 1 9

Temazcal Room: I I’m curious what parameters you used in the beret and macedo

Temazcal Room: approach

Temazcal Room: to get the deformations you’re getting.

Temazcal Room: It looks a little low to me, but

Temazcal Room: in fairness the deformation does, or the yield. No, no, the yield. I’m I’m okay with the yield. I think the deformation numbers look a little low to me.

Temazcal Room: So

Temazcal Room: yeah, for that yield

Temazcal Room: and the materials that we have at at the site. So

Temazcal Room: yeah, 7, 5. Or I mean, even the 4 75 is

Temazcal Room: basically a big San Andreas

Temazcal Room: event. If you, or pay or 2, but 7 and a half or 8 doesn’t matter which one. But I’m curious

Temazcal Room: what parameters you used in your Bra Msato evaluation to come up with

Temazcal Room: deformations you came up with, okay.

Temazcal Room: okay,

Temazcal Room: I I get that and we can provide. We can provide that. I mean, we could kind of walk through with the team. Here we could provide a separate, follow up the kind of details, allow folks to kind of dive in and see it.

Temazcal Room: But yeah, I get I I understand your takeaway is like you were a little surprised. The numbers were what they were.

Temazcal Room: Okay.

Temazcal Room: Alright. We we can.

Temazcal Room: We can give more detail behind the inputs to the bray. Macedo.

Temazcal Room: Okay.

Temazcal Room: thank you, Michael.

Temazcal Room: Very good. Thank you.

Temazcal Room: Now we go to public comment before Ec. Further Ecrb discussion.

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Temazcal Room: Margie, are there any hands raised?

Temazcal Room: I do not see any.

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Temazcal Room: That is the end of public comment.

Temazcal Room: Thank you.

Temazcal Room: So let’s

Temazcal Room: return to board discussion.

Temazcal Room: think there were a lot of questions today, and and

Temazcal Room: for the most part they’ve been answered, but it sounds like

Temazcal Room: there are some

Temazcal Room: additional pieces of information or analysis that

Temazcal Room: are going to be required. And I’m just

Temazcal Room: wondering.

Temazcal Room: you know, and or I think the question to the board right now is.

Temazcal Room: is there a path forward without a further

Temazcal Room: meeting?

Temazcal Room: Is there an information package or a calculation package

Temazcal Room: that Cargill can provide to us.

Temazcal Room: That satisfies everyone’s.

Temazcal Room: you know, comments. And I think

Temazcal Room: and so I put that that question to the board here.

Temazcal Room: I’d like to see some clarification of the

Temazcal Room: set up and run up analysis. And I could be more specific

Temazcal Room: if that’s helpful to the people.

Temazcal Room: and then I also had a question, for

Temazcal Room: I also had a a more general question to

Temazcal Room: I think to Janet, to the staff.

Temazcal Room: I don’t know when we should do that. But to answer your question, I think I’d like to see more on the way. Run up

Temazcal Room: still. Water analysis. Okay, yeah, thank you.

Temazcal Room: Thanks.

Temazcal Room: And Jen, I I assume you’ve been taking lots and lots of notes. And so the concerns of the Board of the questions.

Temazcal Room: Do you think that that can be.

Temazcal Room: you know, summarized and and turned into a request for Cargill to respond to, or

Temazcal Room: I mean, like cause, the thing, I I

Temazcal Room: what I don’t I mean I.

Temazcal Room: If we have to have another meeting, we have to have another meeting. But if the if the board is

Temazcal Room: satisfied that in general or not in general, that they are satisfied

Temazcal Room: that, you know conditions are being met, or the calculations and the analyses are

Temazcal Room: or proper.

Temazcal Room: with a few adjustments and clarifications.

Temazcal Room: You know I think we

Temazcal Room: I’m happy to go that way. But

Temazcal Room: you know again I’m asking the board here if

Temazcal Room: if there is something that is

Temazcal Room: troubling you enough to the point where.

Temazcal Room: you know you think we need to come back?

Temazcal Room: Well, I guess maybe a question could be, for the Board to think about is what kind of deformation

Temazcal Room: would be a deformation that would be a concern.

Temazcal Room: So, you know.

Temazcal Room: is is 9 inches a concern.

Temazcal Room: Is it something that they can address through inspections and maintenance

Temazcal Room: in this? In the worst case, scenario, and

Temazcal Room: and perhaps

Temazcal Room: you know, because they do

Temazcal Room: endeavor to have 2 feet of free board.

Temazcal Room: If their deformations don’t exceed 2 feet, then perhaps

Temazcal Room: The risk is very low that there could be a release

Temazcal Room: and so we could ask them, for

Temazcal Room: you know, it sounds like there’s a concern about how the

Temazcal Room: the bay muds outside of the zone, under the berms, were treated with their strength parameters, and also

Temazcal Room: that they may not have picked the most conservative

Temazcal Room: parts of the berm to model, and so maybe they could. They could run those and provide those results. And if the results were.

Temazcal Room: the deformations were within a certain range. Then then it would be fine.

Temazcal Room: Jen. In. In addition to those, there was the question of just the strength that was that was chosen.

Temazcal Room: You know, the 3 50 versus like 200,

Temazcal Room: I think I think that’s an important one.

Temazcal Room: And then there was also like a question of whether we’re using the full PGA or

Temazcal Room: something less than that.

Temazcal Room: Those 2 might be compensating changes that might get you back to the same answer. But I feel like all those things you said, and the 2 that, I added could be addressed in a you know, a, a written.

Temazcal Room: a response, sort of a thing

Temazcal Room: is, should they be applying a factor to the the peak, the PGA, instead of using the PGA in their analyses?

Temazcal Room: Well, they actually being conservative.

Temazcal Room: So

Temazcal Room: I mean, if they apply a factor, that deformation.

Temazcal Room: that factor of safety, is going to be higher. So yeah, Erin, on the safe side, is the way.

Temazcal Room: Okay.

Temazcal Room: frame.

Temazcal Room: Oh.

Temazcal Room: still.

Temazcal Room: yeah. But I think I think ultimately, is that defamation

Temazcal Room: is the factor of safety. The limit equilibrium analysis

Temazcal Room: is given as factor of safety which is low.

Temazcal Room: But the deformation analysis is saying, these are the kind of displacements

Temazcal Room: that we are getting.

Temazcal Room: and so it kind of

Temazcal Room: makes the limit. Equilibrium results, you know, less

Temazcal Room: significant.

Temazcal Room: Go ahead, Jim.

Temazcal Room: It looks to

Temazcal Room: hey, Kevin?

Temazcal Room: Oh, sorry, Nick.

Temazcal Room: Yeah, if if I may. I

Temazcal Room: on the

Temazcal Room: you know overall. This is a tremendous amount of work.

Temazcal Room: and in general it’s been quite carefully done. I think we’ve identified a couple of places. The the seismic deformation is interesting because brain macedo formulation is completely independent of the slide analysis.

Temazcal Room: It only you only use the geometry of whatever’s the potentially failing mass. The rest of it is independent, I think, in the seismic analysis, I I really do suggest that you actually look at proper, whether the slide code in itself

Temazcal Room: has a reduction formula in it for the pseudostatic, for the pseudostatic, which

Temazcal Room: would be nice. But whether you’re applying the right seismic coefficient.

Temazcal Room: that normally would be used in this kind of analysis, because if you did not, then this was an incredibly conservative

Temazcal Room: result, and the other one is, as Jen already mentioned. I I agree. If

Temazcal Room: you, I would suggest that you do look whether there is a more critical

Temazcal Room: area based on the shear strength, the actual shear strength, data that you have.

Temazcal Room: and if the deformation then following proper procedures, comes less than I would say, I agree 2 feet. Then we’re obviously in a reasonably good shape and and a memo to the effect, explaining what exactly the analysis were probably may suffice.

Temazcal Room: At least, that’s that’s my view. Thank you.

Temazcal Room: Okay, thank you, Nick.

Temazcal Room: I had a hard time hearing. What Nick was saying. Can you rephrase it?

Temazcal Room: Maybe broad or

Temazcal Room: presenter from from your commentary.

Temazcal Room: Well, you’re you’re advocating that. It would be wise to check an additional area as a critical section for stability.

Temazcal Room: That was one.

Temazcal Room: And the second

Temazcal Room: comment was that we should

Temazcal Room: either confirm or modify appropriately the pseudostatic

Temazcal Room: number in the model.

Temazcal Room: in in the slope, stability model in the slope stability model. And are we using the number that we should? Or could we really be using a smaller number? And that’s factored? And I mean, basically ask double check that you’re using the right numbers in your brain, macedo

Temazcal Room: analysis. And and the 3, rd that’s right. The 3rd one is the the numbers that went into the deformation analysis.

Temazcal Room: Thank you. Romine, I’m

Temazcal Room: I agree at the end of the day, if the deformation analyses, that

Temazcal Room: I guess this board feels

Temazcal Room: comfortable with the numbers, and you don’t get any breach or any overtopping. Obviously that that’s that’s the key.

Temazcal Room: But I like to

Temazcal Room: emphasize that

Temazcal Room: from your report. It says the yield is point 1 9, and even if you use two-thirds of the

Temazcal Room: lower level, you get like point 2 2. So you’re above it already. Now it’s important that well, all of those numbers are in the context of the strength parameters that you have used, which we have had questions about. So if if you use lower strength

Temazcal Room: parameters and you get

Temazcal Room: lower yield, you will get invariably larger deformations, and if those deformations are still within the limits that

Temazcal Room: there are no issues with breach and overtopping, etc.

Temazcal Room: Then those

Temazcal Room: will give at least me a lot more confidence that, hey? We are good. You have done a lot of good work, but

Temazcal Room: I think there are some loose ends that needs to be kind of

Temazcal Room: tidied up, so that

Temazcal Room: at least I can get a good sense that we are good good to go the way you are approaching it.

Temazcal Room: It’s, I think, one of the one of the points I I hear from. That is

Temazcal Room: not only your interest in understanding the parameters that went into the brain Macedo

Temazcal Room: displacement, analysis, but making sure that those parameters match up with

Temazcal Room: whatever modifications may be appropriate in the strengths.

Temazcal Room: Okay, you Jim.

Temazcal Room: I’ve

Temazcal Room: think this is probably everyone’s agreeing that something more needs to be resubmitted. There’s a question that remains outstanding whether the Ecrb wants to see that again.

Temazcal Room: and I’m somewhat up in the air about that somewhat undecided.

Temazcal Room: I I

Temazcal Room: heard some of what Nick said, and

Temazcal Room: Michael’s summary, and and remain. And so some. This is

Temazcal Room: a lot of it’s been said before, but I think

Temazcal Room: there’s several things that need to be resubmitted, one is, and I’m going to add a couple.

Temazcal Room: I think, over that

Temazcal Room: west, southwest corner.

Temazcal Room: Probably a need. A new section needs to be done there.

Temazcal Room: with bay mud going down to 36 feet.

Temazcal Room: I think probably the strengths need to be reevaluated and not use a median, and probably not even a 30 percentile.

Temazcal Room: but probably closer towards a lower bound less. You want to get section by section and cone by cone, and use specific sections with specific cones.

Temazcal Room: one of the things that’s hard to review and to know. I mean in terms of engineering criteria. I think the engineering criteria is that you need to do a robust search.

Temazcal Room: It’s going to be sure, to find the critical shape and depth

Temazcal Room: of of the stability surfaces.

Temazcal Room: and I think that we can’t know that from what’s been given

Temazcal Room: so far.

Temazcal Room: And you know, if if you were to provide something with

Temazcal Room: you know, entry and exit points

Temazcal Room: or bottom tangent depths that are allowed, or and so on.

Temazcal Room: Then that needs to be resubmitted to

Temazcal Room: Bcdc.

Temazcal Room: maybe Jen’s okay with looking at at that. Maybe Jen looks at it and says, Oh, this is over my head. I need the ecrb to look at it again.

Temazcal Room: It may be relatively straightforward, but it’s

Temazcal Room: but there’s there’s a lot of material that’s going to have to be looked at, not necessarily super complicated or difficult, I think. Yeah, I think

Temazcal Room: these instructions we’re giving are pretty straightforward. These requests we’re giving are pretty straightforward, and they’re they’re done, or they’re not done.

Temazcal Room: let’s see, I I think that there’s some problems with the

Temazcal Room: pink being weaker than the surrounding blue, and that should be revisited.

Temazcal Room: I understand that, you know, under, you know, in the trapezoid, where you have cones pushing through it and borings and lab data.

Temazcal Room: Probably your your results are pretty good.

Temazcal Room: but the way you put that outside, and where you start that from should not be weaker than the

Temazcal Room: should not be stronger than the

Temazcal Room: pink in particular.

Temazcal Room: Maybe there’s others

Temazcal Room: with their

Temazcal Room: and then and then the parameters with for Bray Macedo. I think that needs to be

Temazcal Room: explained what it’s there.

Temazcal Room: and it seems a little surprising, maybe, for

Temazcal Room: Rameen, who’s more familiar with brand Macedo.

Temazcal Room: that with a yield coefficient of 19, you get only 9 inches.

Temazcal Room: I mean I,

Temazcal Room: without knowing Brand

Temazcal Room: Macedo myself. You know, I got to think that point 19 yield coefficient should give you give you substantially more displacement than that

Temazcal Room: what’s too much displacement is an interesting question that in itself might

Temazcal Room: ask for a

Temazcal Room: ecrb review, because it’s there’s not a simple, easy answer.

Temazcal Room: 9 inches is probably, I mean, there’s 2 issues with with displacement. One is, you know. How low does it get? And when does it get overtopped? And does the hydraulic, you know. The overtopping frequency increases as soon as you get some

Temazcal Room: some seismic settlement, and so you have to jump back on it real quickly and build it back up as soon as you can, so you don’t have 10 years

Temazcal Room: of return interval to happen before you know, with the Lower Cross elevation.

Temazcal Room: The second thing that’s a little more tricky and more judgmenty, maybe, is

Temazcal Room: at some level, probably with bay mud 9 inches. You don’t get cracking, but at 2 feet you start to have to ask about. Are you getting cracking of the embankment materials itself, and do you

Temazcal Room: get up to? Not over topping? But you get seepage through these

Temazcal Room: cracks that you know, tension cracks that have developed and so on.

Temazcal Room: So at some point

Temazcal Room: that gets to be another more complicated issue

Temazcal Room: that I

Temazcal Room: that

Temazcal Room: It’s not worth speculating about all the different ramifications until we.

Temazcal Room: you know, find out what the the final numbers are for displacement.

Temazcal Room: I think those need to be resubmitted, and

Temazcal Room: much of that, at least, I think

Temazcal Room: I’d be okay if Jen feels comfortable with it.

Temazcal Room: I’d be okay with us looking at it.

Temazcal Room: I I am able to run submittals by less than a quorum of the board to assess if they’re satisfactory.

Temazcal Room: Okay, I think that’s

Temazcal Room: yeah.

Temazcal Room: Oh, well, Nick, you mean Chris has had her hand up. Okay.

Temazcal Room: I had. Well, one question for Jen. You mentioned that they were adding 2 feet of free board, and I don’t think I heard that they were adding free board. I think they were just going to the 11.5

Temazcal Room: when you mentioned earlier that maybe 9 inches of deformation was okay, since they were having adding free board.

Temazcal Room: Oh, add, if I said, adding, that was a miss.

Temazcal Room: a bad choice of words. They maintain 2 2 feet of free board in the ponds.

Temazcal Room: So that’s my understanding. And and maybe you know, cargo. You can comment that that the elevation of the water in the pond in the Mss. Ponds doesn’t get above 9 feet elevation.

Temazcal Room: and if they raised the berms. Then it would.

Temazcal Room: It would go up to 9.5 feet if they raised the berms to 11.5 feet.

Temazcal Room: Got it? That’s super helpful.

Temazcal Room: The other question I had or comment is, we talked about the locations of the marsh channels, and so

Temazcal Room: I looked up. I looked at them, and then I made my computer die, so I shouldn’t have been doing that but there are some great maps that show the mark marsh channels, and even on the 1993 aerial imagery, if you go through Google Earth, you can see some of the nice big ones.

Temazcal Room: And they’re not at the sections, and there is one that was to the right of Section C, so I think if they are going to do some analysis.

Temazcal Room: It would be good to look at the Marsh channel, so I can send you Jen, a link to what I was looking at, so you can share that out. Later.

Temazcal Room: And then my other question, is that I was also seeing and looking at the image imagery. The large borrow pits around the inside of the berms.

Temazcal Room: Cause when they were, you know, they excavated material from inside the ponds to build up the berms.

Temazcal Room: But it didn’t look like in any of the sections that they were analyzing. It included that deep borrow pit, and I am not a geotechnical engineer.

Temazcal Room: so I wasn’t sure if that configuration impacts any of the analysis. If we should be considering the fact that there is that deep borrow pit on the pond side of the berms.

Temazcal Room: So that’s it.

Temazcal Room: Thank you. Chris Gail.

Temazcal Room: Alright, yeah, we’ve

Temazcal Room: we’ve made several requests, some of which are

Temazcal Room: adding conservatism and a couple of which are potentially

Temazcal Room: reducing conservatism.

Temazcal Room: And this is actually a question more for my geotechnical colleagues.

Temazcal Room: and it has to do with the title Lag.

Temazcal Room: And right. Now they’ve done it with high tide and low tide. Obviously.

Temazcal Room: it looks like it’s

Temazcal Room: but a 30% difference in most cases on the

Temazcal Room: factors of safety.

Temazcal Room: And I’m I’m used to looking at this for bulkhead design. But

Temazcal Room: in a case like this.

Temazcal Room: do you have a sense of

Temazcal Room: how conservative or what is the likelihood of

Temazcal Room: you know.

Temazcal Room: considering the the low tide on the

Temazcal Room: what is it? The high tide on the

Temazcal Room: out inside, and the low tide on the outside right, which is obviously the most conservative.

Temazcal Room: Is that necessary?

Temazcal Room: They’ve given us results for both. Is that something where

Temazcal Room: we could reasonably

Temazcal Room: allow them to

Temazcal Room: as as they do. These additional analyses

Temazcal Room: do something either a Median Median tide.

Temazcal Room: or

Temazcal Room: consider

Temazcal Room: no, no title, no title, lag.

Temazcal Room: In the analysis. Why, I wanted the opinion of my

Temazcal Room: geotech colleagues on this one.

Temazcal Room: I think all of the critical

Temazcal Room: circles that you looked at were sliding waterward right rather than land. Yeah, they all were in. In that case low tide is going to always be

Temazcal Room: conservative.

Temazcal Room: but that’s again assuming

Temazcal Room: inside the berm.

Temazcal Room: The water table is high. Side is is that high tide right?

Temazcal Room: Which is a

Temazcal Room: which which assumes there’s a title lag.

Temazcal Room: And I’m asking, is that isn’t that what it is? Is that what causes it. I don’t think their title. I I don’t think their title. I think it’s just the static Waterloo.

andrew barrett: The the pond stays at plus 9 feet, nav. D. 88 at at all times. Essentially, besides, rainfall is my understanding. When the water is pumped out, then to make it back to be at 9. So inside the pond, at least in our models, and the way it was told to us by the car representatives on site.

andrew barrett: it stays at plus 9 all the time in the pond.

Temazcal Room: Oh, so that water level, the water level inside is not

Temazcal Room: driven by the tide. It’s driven by something that Cargill’s doing.

andrew barrett: These ponds are completely removed from being connected.

Temazcal Room: Okay.

andrew barrett: To the tidal effects of the bay. Yeah.

Temazcal Room: Okay. No. Title. Effects. Inside.

andrew barrett: Trying to keep them that way.

Temazcal Room: Okay? So then, so then the then the question would just be.

Temazcal Room: is it reasonable to

Temazcal Room: use a meet? Use a Median tide if you will.

Temazcal Room: or a mean tide.

Temazcal Room: instead of low or high, instead of low.

Temazcal Room: If we, if we, if we want to allow

Temazcal Room: something for reducing conservatism.

Temazcal Room: question for the question for my colleague.

Temazcal Room: and start with a low tide.

Temazcal Room: and if it becomes problematic and expensive, repairs are called for, or something like that, then fine it a little bit.

Temazcal Room: Yeah, just to comment on that. I think I heard that a was it a plus 2 tide was used

Temazcal Room: plus 2 plus 2 for low tide, and and that’s is that mean lower low water or Navd? Or are they about the same here? I can’t remember. It’s

Temazcal Room: project datum.

Temazcal Room: And Abd, 88.

Temazcal Room: Yeah. So I mean, a, a really low tide is like, minus 2 or something.

Temazcal Room: Yeah, yeah, yeah, just so it’s not. It’s not a

Temazcal Room: yeah. The mean lower, low water

Temazcal Room: is 0. Let’s say that’s close to NAVD.

Temazcal Room: In the South Bay. This the tide drops well below

Temazcal Room: mean lower, low water. That’s

Temazcal Room: so. If you wanted to be really conservative, you could add another 4 feet of height to your water difference

Temazcal Room: which I’m not suggesting, but I’m not sure. Was it quite as conservative as it may seem?

Temazcal Room: You think they’re not being too conservative by using. Well, I don’t know I it just as a coastal person. It made sense to me to assume a low tide on the outside

Temazcal Room: as a conservative measure. What water elevation were you using

Temazcal Room: 2

Temazcal Room: elevation, too? Yeah, in in the remember, this is in the seismic analysis I’m talking about. So that was part of our reasoning is like a seismic is a distinct, you know, momentary event. So

Temazcal Room: what’s the likelihood of that? Overlapping with an extreme low tide? We used to then we did it with 0 as well. It didn’t change much. We have not run it at minus 2. That would. That would definitely be a compounding of I’m not suggesting that you do. I just wanted to point out that the tide can be a lot lower.

Temazcal Room: I’d

Temazcal Room: it’s it’s a it’s it’s on the low end of the title cycle.

Temazcal Room: It’s not a low tide.

Temazcal Room: It’s just

Temazcal Room: it’s a dropping tide.

Temazcal Room: So

Temazcal Room: yeah, it’s below Msl, and and what they’re getting at is the joint probability. Right? Like, if you’re looking at a yeah, 475 year, I I think I think it’s okay.

Temazcal Room: Sure, okay,

Temazcal Room: okay, Nick, you had you had your hand up earlier.

Temazcal Room: Well, Mr. Chairman, actually, I was going to make a motion, but I’ll let go ahead before.

Temazcal Room: I have my hand up.

Temazcal Room: Yes, but Bob has his hand up as well.

Temazcal Room: I’m I’m I’m going to talk coastal stuff, so I’ll let if it’s geotech. I think you need to go ahead.

Temazcal Room: I’m not suggesting that

Temazcal Room: different levels of earthquake shaking should be used, but these are not the largest levels either. So there is some inherent. If there is some conservatism somewhere else. We’re not

Temazcal Room: looking at the largest level of shaking either, so that I’m I’m not suggesting that you should. But just put it in context as well.

Temazcal Room: Dima.

Temazcal Room: continuing the geotax.

Temazcal Room: Okay, Michael, I don’t remember whether you mentioned he said anything about cpage.

Temazcal Room: Oh, I I actually I all I said about seepage was when I was talking about our

Temazcal Room: conclusions regarding the effects of keying in the berm.

Temazcal Room: where we really didn’t see any appreciable strength increase in the berm.

Temazcal Room: but because of our

Temazcal Room: observations of the keyed material in place, it’s apparent level of compaction, which which is not a huge amount of compaction we discussed, but

Temazcal Room: but there is compaction that has occurred that we see, and our observations of the material used.

Temazcal Room: that it’s our conclusion that

Temazcal Room: that should improve seepage

Temazcal Room: just based on that alone, you may minimize seepage.

Temazcal Room: Yeah, minimize seepage, minimize seepage. Yeah.

Temazcal Room: alright.

Temazcal Room: that that’s our conclusion based on what we see.

Temazcal Room: Okay? And then.

Temazcal Room: from the perspective of the overtopping presentation.

Temazcal Room: I think you alluded to

Temazcal Room: the material being used to top the broom.

Temazcal Room: Yeah, I should minimize scarring.

Temazcal Room: I think it should be pretty resistant to scouring.

Temazcal Room: Yeah, if you had waves hitting it, for, you know, days upon days, of course, but

Temazcal Room: for a short

Temazcal Room: wave over topping event. I think that with that compacted material

Temazcal Room: and the gravel servicing, I think that’s going to resist scour pretty well.

Temazcal Room: Well, I mean, I think maybe.

Temazcal Room: Now, what happened where?

Temazcal Room: I’ve

Temazcal Room: perhaps not. I think maybe that should be something that you should

Temazcal Room: formalize as a recommendation to address the issue of of our observations about its apparent resistance to a wave over tapping scour.

Temazcal Room: Yeah.

Temazcal Room: do that?

Temazcal Room: Thank you, Jima. Bob.

Temazcal Room: Yes. So from the coastal side. I’d be interested in seeing

Temazcal Room: selected profiles of the one or more transects

Temazcal Room: showing the static and dynamic water levels and other parameters used.

Temazcal Room: That would be for Jeremy. I don’t know if he’s still on the phone

Temazcal Room: and then I’d also like to see those values tabulated. Some representative

Temazcal Room: portion of all the wave run up, runs

Temazcal Room: tabulated, so I can see what the wave heights, water depths.

Temazcal Room: dynamic water, level, etc, are.

Temazcal Room: or a representative number of the calculations.

Temazcal Room: I I don’t think that’s that hard to do. It’s it is something that Fema did for their flood studies and in their intermediate data submittals. And I think the software probably allows you to do that.

Temazcal Room: But separate from that.

Temazcal Room: I wanted to say that I think

Temazcal Room: Chris and I,

Temazcal Room: Chris May and I could

Temazcal Room: look over what you get on that topic and work with you, Jen, or one of us.

Temazcal Room: If if we didn’t want to bring it back. So I I don’t know that.

Temazcal Room: That might. That might make it easier.

Temazcal Room: But I had an overall question, and I’m sorry I’m not if I’m supposed to be up to speed on this. But my concern with this

Temazcal Room: situation

Temazcal Room: is that

Temazcal Room: the material

Temazcal Room: is

Temazcal Room: has salt levels and certain types of salt levels that could adversely affect wildlife

Temazcal Room: if released into the bay.

Temazcal Room: That’s what I, my concern, has been

Temazcal Room: more than a life safety.

Temazcal Room: and I thought I heard somebody say that that’s not really a concern, because the material the

Temazcal Room: Mss.

Temazcal Room: Just

Temazcal Room: dissolves immediately or something, and I’m not sure I understand that

Temazcal Room: is. Is, am I

Temazcal Room: wrong to be concerned or wrong to not understand that it dissolves

Temazcal Room: right away?

Temazcal Room: Listen to that while we’re here. It depends on the concentration.

Temazcal Room: So it it depends on how much is is, you know. It’s a it’s a concentrated salt, right? So.

Temazcal Room: But the, but the concentrations themselves are are quite high because it’s crystallized, and some of it might be

Temazcal Room: more soluble than others, but certainly.

Temazcal Room: if it was a hundred parts per 1,000, which I think is

Temazcal Room: lower than it is, and it was liquid, and that was released. I think that could probably kill fish, couldn’t it.

Temazcal Room: I mean, I I just trying to understand how serious this is if we have a release which is an important consideration in terms of what the criteria are.

Temazcal Room: and I don’t know the exact levels. But if you put a bowl of this and dissolve the mix sea salts in it, and then put the fish in it. Yeah, the fish wouldn’t

Temazcal Room: wouldn’t be good, but that’s a big difference than a little bit getting out into the ocean and diluting.

Temazcal Room: I do remember working on the Napa Salt Ponds. Of course that was way a long time ago, and I think everyone’s learned a lot more since then, but we had a pond with up to maybe 100 parts per 1,000 pond 3,

Temazcal Room: and there was quite a bit of concern about diluting that before it was released.

Temazcal Room: That was one of our major challenges, and we got through that in 2,005.

Temazcal Room: But Newark slew has a number of

Temazcal Room: protected species in it.

Temazcal Room: So I I have to admit that I haven’t analyzed this or read everything about that. But what I’ve seen is not really satisfied me.

Temazcal Room: In terms of my concern, and we don’t have a biologist on here. So I’m I’m wondering what the implications are. If the implications are serious, then this could be a risk level that is higher

Temazcal Room: than we think.

Temazcal Room: which case, if it was a new project, it might have to be designed to a higher standard than what we’re talking about.

Temazcal Room: So, on the other hand, I think

Temazcal Room: it needs to be managed. Cargo has a lot of experience.

Temazcal Room: you know. They they should be able to maintain. This is in everybody’s interest.

Temazcal Room: But I’m

Temazcal Room: a little unclear on how serious the situation is.

Temazcal Room: and I don’t know is that generally, just because I didn’t read everything, or is there?

Temazcal Room: No, just I mean to recap a little bit in the very 1st meeting of the ecrb Ecrb asked Cargill to present information on the risk of

Temazcal Room: the mixed sea salts on the ecology and human health.

Temazcal Room: and

Temazcal Room: instead of providing that information, Cargill said that instead they would model the most conservative scenarios.

Temazcal Room: And so that’s that’s where we’re at

Temazcal Room: the most conservative levy failure or defamation scenarios or release scenarios.

Temazcal Room: But there’s been no modeling of the okay.

Temazcal Room: So I I just think that’s an important context. And

Temazcal Room: for me, anyway, if somebody’s worked around the bay a lot on restoration projects and around Newark Slough in particular, and

Temazcal Room: sufficient wildlife, reserve, etc.

Temazcal Room: So I just think that’s something

Temazcal Room: to think about, and why I would like to

Temazcal Room: review the wave, run up information again.

Temazcal Room: even though I don’t doubt the Cargill’s judgment that some wave overtopping probably has no significance.

Temazcal Room: And so I appreciate that viewpoint quite a bit. Actually.

Temazcal Room: sure, if I could just add the reason we didn’t do the you know environmental assessment, because.

Temazcal Room: you know, the studies indicated that we went to have, we would not have a breach, or we would not have mixed. See salt

Temazcal Room: going out into the pond, which is why.

Temazcal Room: you know, that’s why we didn’t proceed with doing an environmental

Temazcal Room: assessment. You didn’t think that, you know there’s no breach. It’s not going to be in a

Temazcal Room: any ecological impact.

Temazcal Room: That’s kind of the reason why we didn’t. Do you know, further environmental. So so I think in that case, I just want to be more sure that we understand what the wave run up and overtopping potential are, and

Temazcal Room: how that feeds into the geotech, and how the

Temazcal Room: would apply to our judgment regarding whether or not

Temazcal Room: the analysis indicates that this somewhat ambiguous failure, scenario of

Temazcal Room: possibly some levee erosion or possible breaching and release that’s undefined is likely not to be exceeded.

Temazcal Room: So that’s kind of where I am. I want to be more careful.

Temazcal Room: so I would like to see the wave run up

Temazcal Room: information.

Temazcal Room: And I would like the geotech to be comfortable with the situations, too. Recognizing

Temazcal Room: that impacting ecology is a big deal.

Temazcal Room: Thanks.

Temazcal Room: Okay.

Temazcal Room: Think that’s that’s it. Now,

Temazcal Room: so it sounds like.

Temazcal Room: everybody is okay with

Temazcal Room: additional information and clarification from Cargill.

Temazcal Room: that we’re okay, recommending approval of the permit

Temazcal Room: ending

Temazcal Room: the middle of clarifications and information

Temazcal Room: to the satisfaction. Yeah, right? And and so

Temazcal Room: I think we would, Jen, you’d have to pick

Temazcal Room: 4 of us who are, you know, so we don’t have a quorum issue.

Temazcal Room: But you know I would suggest

Temazcal Room: Bob and

Temazcal Room: Jim

Temazcal Room: remain, and

Temazcal Room: probably

Temazcal Room: Nick

Temazcal Room: to, or maybe, or maybe, if somebody’s not interested, I I would be

Temazcal Room: a good person to help.

Temazcal Room: But one of 4 of those 5 names

Temazcal Room: would be

Temazcal Room: reviewers of the information and pending that set, you know, pending our satisfaction to that, then we would recommend

Temazcal Room: approval

Temazcal Room: of a permit.

Temazcal Room: Can I? Have a little discussion? Chris did. Were you interested? Or

Temazcal Room: so it’s 5 for the quorum. So it’s like one coastal, and which is probably enough. But it could be Chris or I. But if there’s room it might be good at both of us. Okay, 4.

Temazcal Room: See yourself.

Temazcal Room: That’s all right.

Temazcal Room: But for the coastal part.

Temazcal Room: anyway, I can go either way with it. I just wanted to give Chris an opportunity to

Temazcal Room: to weigh in. See how interested she is. And no, I’m I’m happy to review the coastal part.

Temazcal Room: Yeah.

Temazcal Room: but I don’t think I think the geotech issues are

Temazcal Room: our significance. I don’t think they could have both of us if we only have 4 got it.

Temazcal Room: So either one whatever. Yeah.

Temazcal Room: okay. So do I have a motion?

Temazcal Room: Second.

Temazcal Room: all in favor.

Temazcal Room: or do we? Do you need to do a

Temazcal Room: a roll call, or can we just do a voice? Vote? Jen.

Temazcal Room: let’s do a roll call just

Temazcal Room: to be thorough.

Temazcal Room: we are going to have a roll call vote now on the motion which is

Temazcal Room: to

Temazcal Room: request additional information based on our discussion today.

Temazcal Room: and if it seems like it satisfies

Temazcal Room: our our concerns. Then the Ecrb will find that the safety issues have been addressed by cargo.

Temazcal Room: Okay

Temazcal Room: Roddy washedatch here. Aye.

Temazcal Room: Jim, French

Temazcal Room: Bob Italia. Yes.

Temazcal Room: Jima Kasali.

Temazcal Room: Chris May.

Temazcal Room: Yes.

Temazcal Room: Rameen Golisarki. Yes.

Temazcal Room: Nick Sitar. Yes.

Temazcal Room: Gail Johnson. Yes.

Temazcal Room: and Patrick Ryan. Yes.

Temazcal Room: right. Yeses have it.

Temazcal Room: I have another. So we will.

Temazcal Room: Jen, I assume you’re going to put together minutes and the

Temazcal Room: the request for information. Additional information and clarification will go to Cargill right? And

Temazcal Room: copied to

Temazcal Room: the ecrb.

Temazcal Room: Yeah. So what I’ll do is I’ll draft a letter summarizing the information request.

Temazcal Room: I’ll probably run a draft of it by

Temazcal Room: couple of people on the ecrb, maybe the chair, the chair and vice chair.

Temazcal Room: and then

Temazcal Room: and then send it off.

Temazcal Room: We will all to Cargill. Try to do that in

Temazcal Room: in a week.

Temazcal Room: And then this meeting, which is being recorded, will also be posted.

Temazcal Room: On our website at the meeting. Notice?

Temazcal Room: Right?

Temazcal Room: Okay.

Temazcal Room: okay.

Temazcal Room: okay, thanks.

Temazcal Room: Okay. There. A motion to adjourn.

Temazcal Room: Second, okay, all those in favor.

Temazcal Room: Aye.

Temazcal Room: okay, thank you.

Temazcal Room: Thank you. Cargill. Thank you.

Temazcal Room: for speaking and pushing the buttons to turn it on and off.

Temazcal Room: rod you want to share here.

Temazcal Room: Jim French vice chair. Sure.

Temazcal Room: Bob Natalia.

Temazcal Room: Here.

Temazcal Room: Jima Kasali.

Temazcal Room: Yeah.

Temazcal Room: Chris may

Temazcal Room: here

Temazcal Room: Rameen Gosarky.

Temazcal Room: Here.

Temazcal Room: Nick Sitar.

Temazcal Room: Present.

Temazcal Room: Gail Johnson. Hello.

Temazcal Room: Patrick Ryan.

Temazcal Room: Here.

Temazcal Room: Cherry Washta. We have a forum of at least 5 present.

Temazcal Room: Okay, thank you. Jen. We have a quorum present. So we are duly constituted to conduct business.

Temazcal Room: we may have some alternate board members who may be participating as members of the public.

Temazcal Room: Names I see listed are Thalia, Travaceru, Philip Trevetti.

Temazcal Room: Justin Van Diever, and Bill Tremaine and I now call the meeting to order.

Temazcal Room: I wanna

Temazcal Room: Carrie Washer Robert Batali would like to speak. He has his hand raised.

Temazcal Room: I’m sorry I didn’t know how I had my hand raised. I was trying to figure out how to get myself on the

Temazcal Room: video on Zoom, oh, yeah. Okay.

Temazcal Room: okay, okay. Thank you.

Temazcal Room: Okay. I want to start with some instructions, and how we can best participate

Temazcal Room: in this meeting, so that it runs as smoothly as possible.

Temazcal Room: First, st everyone, when you are not involved in the active discussion. Please make sure

Temazcal Room: you have your microphones or phones muted to avoid background noise

Temazcal Room: for board members. If you have a camera, please make sure that it is on during the meeting. So everyone online can see you.

Temazcal Room: Every now and then I may refer to the meeting host Margie, who is working behind the scenes

Temazcal Room: to ensure that the technology moves the meeting forward smoothly and consistently.

Temazcal Room: And

Temazcal Room: please be patient with us if it’s needed.

Temazcal Room: Ex parte communications

Temazcal Room: as set forth in the Bcdc’s regulations. A member of the Ecrb.

Temazcal Room: Shall not have any oral or written communication regarding a proposed

Temazcal Room: project or other matter that has been noticed

Temazcal Room: to be considered at an Ecrb meeting with a project proponent permit applicant, prospective applicant

Temazcal Room: or member of the public, except on the record during an Ecrb meeting

Temazcal Room: Board members, in case you have inadvertently forgotten to provide

Temazcal Room: the staff with a notice on any written or oral ex parte communications.

Temazcal Room: I invite you to report on any such communications at this point by raising your hand and unmuting yourself.

Temazcal Room: Okay, I don’t see any.

Temazcal Room: for the record. No hands have been raised.

Temazcal Room: And

Temazcal Room: Jen, are you going to talk about the timing of this, the room and and all of that? Okay.

Temazcal Room: then let’s have a staff update

Temazcal Room: from senior engineer and board. Secretary, Jen Hyman.

Temazcal Room: Thank you, Cherry Washta.

Temazcal Room: I would like to provide an update on upcoming meetings

Temazcal Room: on September 25, th the Ecrb will have a second meeting with the Representatives from the San Francisco International Airport on their shoreline protection project.

Temazcal Room: On October 23, rd the Ecrb will review and discuss the updated regional shoreline adaptation plan or Rsap guidelines.

Temazcal Room: At the end of that meeting, Bcdc. Council, Michael Ng. Will give a legal training to Ecr Ecrb members on regulations and policies of the Ecrb

Temazcal Room: and board members. I would like to

Temazcal Room: let everyone know and app permit applicants today that we building management asked us to vacate the room at 5 o’clock sharp, because, that’s the end of their workday, and we’re getting their assistance in running this meeting, and they have to leave so hopefully, we can try to, if possible, wind the meeting up by around 4 30 today.

Temazcal Room: yeah, if need be. If we have to go beyond 5 o’clock, then we’ll

Temazcal Room: probably all just log into zoom without any of the screens or anything.

Temazcal Room: if if need be.

Temazcal Room: Those are all my announcements, Cherry Rashta.

Temazcal Room: Okay, thank you, Jan.

Temazcal Room: Before we move on to the presentation. Are there any announcements from board members.

Temazcal Room: Okay? Seeing none. Let’s let’s move on

Temazcal Room: to agenda. Item, 3

Temazcal Room: Cargills, solar sea salt system, maintenance and operations project firm stability.

Temazcal Room: So the main agenda item related to the permit application for Cargill Cargills.

Temazcal Room: solar sea salt maintenance or system, maintenance and operations. Our discussion will focus on the stability of the berms surrounding the mixed sea. Salt or Mss. Ponds.

Temazcal Room: p. 12, p. 2, 12, and p. 2, 13.

Temazcal Room: Mixed tea salts are also referred to as Bittern

Temazcal Room: Jen, the Board Secretary and Senior engineer for Bcdc. Has a slide presentation for us

Temazcal Room: with an introduction and a bit of background

Temazcal Room: since is. This is this is the 3rd meeting on this topic

Temazcal Room: during the presentation. It is fine for board members to ask clarifying questions.

Temazcal Room: I would like to ask board members and presenters to please turn on your cameras for any discussion

Temazcal Room: during or after the presentation.

Temazcal Room: and I will now turn it over to Jen to begin her presentation.

Temazcal Room: I’m just going to give some brief introductory slides on the Project

Temazcal Room: and the Permit history and the history of the Ecrb meetings for this project.

Temazcal Room: Cargill salts, current maintenance and operation activities are regulated by Vcdc. By a 10 year permit

Temazcal Room: that was issued by Bcdc. In 1,995.

Temazcal Room: This permit has been extended numerous times.

Temazcal Room: Cargill has applied to renew the 10 year Permit and staff plan to present the new permit to the Commission. In December of this year

Temazcal Room: Bcdc. Has prepared a draft environmental assessment

Temazcal Room: to comply with Ceqa assessing the potential impacts from Cargill’s maintenance and operational activities.

Temazcal Room: The draft Ea is currently out for the 30 day public comment period right now.

Temazcal Room: and that comment period will be ending on September 21, st

Temazcal Room: the Ea can be accessed at the Bcd Bcdc. Website.

Temazcal Room: The link is provided in the slide. But there’s also a link on Bcdc’s homepage.

Temazcal Room: The Engineering Criteria Review Board’s review

Temazcal Room: has been.

Temazcal Room: and today we’ll focus on the stability and safety of the earth and berm surrounding ponds. P. 212 and p. 213. At Cargill’s Newark plant number 2.

Temazcal Room: These ponds store mixed sea salts, which

Temazcal Room: we you will hear the acronym Mss. For these mixed sea salts

Temazcal Room: due to its high salinity, and the fact that its Ionic balance differs from bay water.

Temazcal Room: Mss.

Temazcal Room: Could contribute to potential environmental impacts if overtopping scour and erosion caused a release of brine to the bay.

Temazcal Room: Important to note, however, that once Mss. Is diluted with seawater.

Temazcal Room: it no longer exhibits toxicity.

Temazcal Room: The static and seismic stability of the berms is also a concern.

Temazcal Room: The Ecrb’s engineering review today has prompted some draft permit conditions, and Bcdc. Is in the process of drafting

Temazcal Room: the updated permit. Right now.

Temazcal Room: these are some examples.

Temazcal Room: Argill will be raising the berms around the Mss. Ponds to an elevation of 11.5 feet.

Temazcal Room: nabbed 88 by the end of the 10 year permit period.

Temazcal Room: Cargill has also proposed to raise the external berm at Pond, p. 212 to 11.5 feet at a slightly earlier date. Because that’s the berm

Temazcal Room: of all the of the of the 2 ponds that is facing the bay.

Temazcal Room: They’re proposing to do that earlier by 2029

Temazcal Room: cargo will track and report potential seepage from the Mss. Ponds annually.

Temazcal Room: The permit

Temazcal Room: will present the Ecrb’s concluding assessment of the Mss. Burn safety to the Commission.

Temazcal Room: The other

Temazcal Room: function that Ep, the Ecrb’s input has had on the permit is Cargill’s technical reports that were requested by the Ecrb have informed portions of the environmental assessment.

Temazcal Room: This map shows a location of the Mss. Ponds, p. 2, 12 and p. 2, 13,

Temazcal Room: close to Newark.

Temazcal Room: and along the shores of San Francisco’s South Bay, south of the Dumbarton Bridge.

Temazcal Room: The Ecrb meetings on the topic of stability of the mixed sea. Salt Pond berms

Temazcal Room: were previously held, first, st on November 16, th 2022,

Temazcal Room: and a second meeting was held on August 30, th 2023.

Temazcal Room: The remaining issues to discuss today are as follows.

Temazcal Room: updated sea level rise, risk assessment focusing on wave run up and wave induced firm erosion

Temazcal Room: results from the geotechnical investigation of the berms

Temazcal Room: using Cone penetrometer testing.

Temazcal Room: also known as Cpt.

Temazcal Room: that was performed just this summer.

Temazcal Room: Updated stability analyses for the Mss. Berms based on the new geotechnical data.

Temazcal Room: including

Temazcal Room: post slope and non-circular failure surfaces.

Temazcal Room: seismic and funny scenario

Temazcal Room: firm keying and layering scenarios.

Temazcal Room: firm displacement and settlement, analysis

Temazcal Room: a consideration of settlement

Temazcal Room: of the Nss. Palm berms

Temazcal Room: and questions regarding seepage of the Mss. Out through the berms.

Temazcal Room: Those were all the results

Temazcal Room: that all the comments that the Ecrb had made

Temazcal Room: on the issues at the last meeting.

Temazcal Room: So

Temazcal Room: I’ve put together these questions for the Board to consider for this 3rd meeting.

Temazcal Room: Number one is Cargill’s plan to maintain the berms to a crest elevation of 11.5 feet.

Temazcal Room: plus inspections and maintenance adequate to address the risk posed by sea level rise and and waves

Temazcal Room: did the field investigation adequately characterize the subsurface. Geology and geotechnical parameters

Temazcal Room: are the scenarios and criteria in the static and seismic berm stability analysis adequate for assessing the risk of berm failure at the Mss. Ponds

Temazcal Room: do the updated static and seismic stability calculations for the berms adequately characterize and model the berm stability.

Temazcal Room: including any berm raising

Temazcal Room: possible subsidence and sea level rise predicted for 2030, and 2040

Temazcal Room: for the stability analyses that indicate areas where the berms do not meet. The 1.1 factor of safety are the risks adequately addressed?

Temazcal Room: Does the presentation on Mss. Seepage and Berm coring adequately address the concerns and comments from the Ecrb?

Temazcal Room: Do the do the results of the updated berm stability, modeling, utilize adequately conservative assumptions and meet adequate levels of safety, so that an ecological and human health risk analysis is not needed.

Temazcal Room: This was a statement made by Cargill in the second Ecrb meeting.

Temazcal Room: responding to the Ecrb’s request in the 1st meeting to provide a risk assessment.

Temazcal Room: And lastly, does the Board have any other concerns regarding burn stability that have not been addressed.

Temazcal Room: and that’s the end of my

Temazcal Room: presentation.

Temazcal Room: Okay, thank you, Jen.

Temazcal Room: Now Jeremy Mull, of Aecom will make a presentation on behalf of Cargill.

Jeremy Mull (AECOM): Hey, everybody! Can you hear me? Okay.

Temazcal Room: Yes.

Jeremy Mull (AECOM): Okay, great.

Jeremy Mull (AECOM): I’m gonna share my screen.

Jeremy Mull (AECOM): And someone confirm that they’re they can see a Powerpoint presentation up on the screen.

Temazcal Room: Yes.

Jeremy Mull (AECOM): Okay, great, thank you.

Jeremy Mull (AECOM): My name is Jeremy Mull. I’m a coastal engineer with acom. Thank you. Everybody for attending and listening. Today I’m going to give a brief presentation on the

Jeremy Mull (AECOM): The wave run up

Jeremy Mull (AECOM): and overtopping analysis that we perform for Cargill.

Jeremy Mull (AECOM): I’ll note that Justin Vannever was the coastal engineering lead for this project. But because he’s part of the the ecrb that I’m presenting.

Temazcal Room: Excuse me, Jeremy, can you? Do you mind turning on your camera.

Jeremy Mull (AECOM): Not at all.

Temazcal Room: Thank you.

Jeremy Mull (AECOM): Can you guys see me now?

Jeremy Mull (AECOM): Yes, okay, thanks.

Jeremy Mull (AECOM): Okay. So just a a quick background on the project. I know some of this was outlined by Jen and her presentation.

Jeremy Mull (AECOM): In 2,020 and 2,021, Cargill prepared a sea level rise assessment

Jeremy Mull (AECOM): to support his long-term operations and the Bcdc. 10 year operations and maintenance permit renewal.

Jeremy Mull (AECOM): This assessment included a mapping of the shoreline and the England berms, including some assets of the site.

Jeremy Mull (AECOM): An evaluation of sea level rise impacts for the year 2,100

Jeremy Mull (AECOM): the identification of vulnerable berm segments. That could be

Jeremy Mull (AECOM): vulnerable to us, overtopping from storm surge.

Jeremy Mull (AECOM): vulnerability and risk assessment, for you know, some of the assets on Cargill side, including operations and and the environment.

Jeremy Mull (AECOM): And then a conceptual phase, sea level rise, adaptation, approach.

Jeremy Mull (AECOM): That included adaptation considerations.

Jeremy Mull (AECOM): Then, in December 2022 Bcdc. Requested that Cardio evaluate. The impacts of wave run up and overtopping, including future sea level, rise on the bayfront berms. So those are the berms between the ponds and shoreline of San Francisco Bay, and this was based on requests from the Ecrb.

Jeremy Mull (AECOM): In August 2023, Cargill presented preliminary wave run up methods and findings to Dcrb.

Jeremy Mull (AECOM): worth noting that the the methodology and the results largely haven’t changed since this presentation.

Jeremy Mull (AECOM): And then in 2023, through 2024 we run up an overtopping analysis. Memo was prepared and then submitted

Jeremy Mull (AECOM): to the the Bcdc

Jeremy Mull (AECOM): So these slides are just going to be a high, level overview of the project. It’s my understanding that

Jeremy Mull (AECOM): the presentation that was done previously had a pretty detailed overview of the

Jeremy Mull (AECOM): the methods and findings, and then those are also included in a lot of detail in in the technical memo

Jeremy Mull (AECOM): so prior sea level rise assessments, those focus on impacts of of high tides and combined the storm surge and more of a overtopping from the still water level of the berms.

Jeremy Mull (AECOM): This assessment evaluated the potential for way run up and overtopping on those bayfront berms. For existing conditions, and then future conditions with sea level rise under a no action scenario. And what that means is the analysis assumed that the berms would not be elevated from their their current elevations.

Jeremy Mull (AECOM): we developed 2 kind of metrics to evaluate the impacts of waves.

Jeremy Mull (AECOM): The 1st included the duration of the berm toe exceedance

Jeremy Mull (AECOM): by the total water level with a wave height greater than one foot, and we calculated the average hours per year that this might occur. So this was kind of a proxy for the amount of time that the waves

Jeremy Mull (AECOM): excuse me that the berms would be exposed to significant wave energy in a year we then looked at the frequency of berm crest overtopping and we evaluated this, based on the return period,

Jeremy Mull (AECOM): for different storm events.

Jeremy Mull (AECOM): So these results are helping Cargill identify and prioritize maintenance

Jeremy Mull (AECOM): for the burn segments that may experience, increased exposure

Jeremy Mull (AECOM): to wave impacts due to sea level rise. It also can help inform the development of a long term adaptation management plan for these Burns.

Jeremy Mull (AECOM): Okay, so just a quick overview of the technical approach. This, the approach is detailed or presented more detailed report.

Jeremy Mull (AECOM): This slide just conceptually shows each of the steps in the technical analysis.

Jeremy Mull (AECOM): starting with step, one on the top left, and then all finishing up

Jeremy Mull (AECOM): with the

Jeremy Mull (AECOM): the firm.

Jeremy Mull (AECOM): sorry I have something on the screen, the firm exposure metrics on the bottom. Right? So,

Jeremy Mull (AECOM): starting in step one, we applied a 1-dimensional transact based analysis.

Jeremy Mull (AECOM): Where transects are spaced.

Jeremy Mull (AECOM): perpendicular

Jeremy Mull (AECOM): perpendicularly to the the berm, we place transacts

Jeremy Mull (AECOM): based on segments of berm with different

Jeremy Mull (AECOM): exposures to wave energy.

Jeremy Mull (AECOM): Then all of our empirical equations to calculate over top and run up and overtopping were applied in in one dimension.

Jeremy Mull (AECOM): In step 2. We extracted

Jeremy Mull (AECOM): cross shore profiles from topographic and bathymetric data, and then identified the key features of the berms that were used in our our engineering calculations.

Jeremy Mull (AECOM): In step 3. We assigned representative transects to each berm segment. So the berms

Jeremy Mull (AECOM): we’re divided into short segments.

Jeremy Mull (AECOM): and the results of the analysis were then compared to the elevations of each burn segment.

Jeremy Mull (AECOM): So each berm segment came with a representative transect.

Jeremy Mull (AECOM): As it’s described in the report, we rely primarily on

Jeremy Mull (AECOM): a a multi decatal wave and water level model that was used in a fema coastal flood. Study of San Francisco Bay.

Jeremy Mull (AECOM): Model was built by dhi and had waves and water levels, I believe, every 15 min for over 50 years.

Jeremy Mull (AECOM): So each transect was paired with a model output station.

Jeremy Mull (AECOM): We then calculated

Jeremy Mull (AECOM): the total water level at each of those time steps

Jeremy Mull (AECOM): for the entire hindcast and use statistical extreme value analysis

Jeremy Mull (AECOM): to come up with the conditions for storms for different return periods.

Jeremy Mull (AECOM): Finally, with the results of the total water levels at each transect, we map those spatially onto the the berm segments with different different elevations and presented those results as

Jeremy Mull (AECOM): as results. Maps.

Jeremy Mull (AECOM): Okay, so just a quick like overview of what the total water level is this is just a conceptual slide and hopefully helps orient Orient people to the total water level because it drives a lot of flooding in San Francisco Bay, so the total water level consists of several different components.

Jeremy Mull (AECOM): It includes the astronomical tide sometimes referred to as predicted tide, which ranges about 6 to 8 feet in the bay

Jeremy Mull (AECOM): and includes storm surge, which is composed of

Jeremy Mull (AECOM): yeah atmospheric pressure events, winds, atmospheric pressure effects, wind setup, and El Nino effects. It ranges on the order of like one to 3 feet in the bay.

Jeremy Mull (AECOM): It also includes wave components like wave setup and wave wave run up.

Jeremy Mull (AECOM): and those range about 2 to 5 feet.

Jeremy Mull (AECOM): and then you add that all up and you get the total water level. Extreme total water, total water level events on the Bay range from about 10 to 15 feet

Jeremy Mull (AECOM): any vd, 88, depending on the storm conditions you’re looking at. And each, you know.

Jeremy Mull (AECOM): areas exposure to wave energy and things like that.

Jeremy Mull (AECOM): In the cartoon on the bottom. You can see how all these components add up. You see the tide.

Jeremy Mull (AECOM): How time and storm surge add up to the still water level, and then, if a segment of the berm is exposed to wind waves, those waves usually propagate up.

Jeremy Mull (AECOM): propagate through the marsh, and then

Jeremy Mull (AECOM): break

Jeremy Mull (AECOM): near, or at the Bernto, and the uprush

Jeremy Mull (AECOM): of water can come up the outward side of the berm, and then potentially over top levee

Jeremy Mull (AECOM): so we did incorporate future sea level rise, and that would be that was incorporated into the still water level in which we

Jeremy Mull (AECOM): Then we ran all of our total water level calculations.

Jeremy Mull (AECOM): Okay, so just an overview of some of the results. These figures are all

Jeremy Mull (AECOM): presented in the report.

Jeremy Mull (AECOM): and

Jeremy Mull (AECOM): we’re focused on Pond 12 today. Which is shown in the upper left of all the figures. It’s highlighted in the 1st figure.

Jeremy Mull (AECOM): The 1st figure is the baseline conditions, which are

Jeremy Mull (AECOM): approximately from the year 2,010, and then the results.

Jeremy Mull (AECOM): The different figures show the results for 6 inches, 12 inches and 36 inches of sea level rise.

Jeremy Mull (AECOM): We are using the sea level rise estimates from the Ocean Ocean Protection Council report.

Jeremy Mull (AECOM): From 2,024 you can see the timing of those different amounts of sea level rise in the bottom right there. This table.

Jeremy Mull (AECOM): so

Jeremy Mull (AECOM): just as an example for 12 inches of sea level rise that could occur as early as the year 2,050. If you’re looking at the intermediate high scenario, it’s likely by 2,055, if you’re using the intermediate scenario.

Jeremy Mull (AECOM): So these the slides show the results for the berm toe exceedance. Remember, this is the average number of hours per year that the total water level

Jeremy Mull (AECOM): would exceed the burnt tow with a wave height

Jeremy Mull (AECOM): of at least one foot.

Jeremy Mull (AECOM): So it’s kind of a measure of how often the outboard the bayfront firm is being impacted by waves.

Jeremy Mull (AECOM): Up in the upper left. You have the baseline conditions, and you can see all. Jeremy.

Jeremy Mull (AECOM): Yeah, go ahead.

Temazcal Room: Can I ask? This is Bob Battaglio. Hi, Jeremy.

Jeremy Mull (AECOM): Hey! Bob!

Temazcal Room: I’d like to ask a question.

Temazcal Room: so

Temazcal Room: I was a little surprised by this slide, because if I understand it correctly.

Temazcal Room: Under existing conditions the toe of the berm, which is the base

Temazcal Room: on the bay side.

Temazcal Room: is exceeded by the total water level.

Temazcal Room: Less than 1 HA year is, am I interpreting this correctly?

Jeremy Mull (AECOM): Mostly. So remember it’s 1

Jeremy Mull (AECOM): hour per year, combined with a wave height greater than one foot.

Temazcal Room: Okay?

Temazcal Room: So the toe of the berm is in places is fronted by Marsh, which is around me. High water, I mean higher high water.

Temazcal Room: so just the still water level alone should exceed the tow

Temazcal Room: of the lev of the levy like 8% of the time, or something like that is that

Temazcal Room: just just because of the tide, not including non tidal residuals. So

Temazcal Room: it just seems like this is.

Temazcal Room: there should be waves

Temazcal Room: during some of those 8% of the time. So

Temazcal Room: it seems like the total water level would be

Temazcal Room: higher. So I have a concern about that. I don’t know if you wanna

Temazcal Room: address that now or.

Jeremy Mull (AECOM): Yeah, I mean, I I guess I can just speak conceptually to that. It’s it’s it’s a good question. And I think

Jeremy Mull (AECOM): you have to.

Jeremy Mull (AECOM): I imagine it’s through a combination of

Jeremy Mull (AECOM): high tides combined with

Jeremy Mull (AECOM): exposure. So waves approaching at the right angle to attack. You know the burn you kind of think about like

Jeremy Mull (AECOM): every firm has a little bit different. Exposure in this firm.

Jeremy Mull (AECOM): you know, is really only vulnerable to ways that are

Jeremy Mull (AECOM): coming in, you know, a bit from maybe the South Southwest here. So it would be those times when you have a combination, the high tide. So the

Jeremy Mull (AECOM): sorry advance the slide, so the

Jeremy Mull (AECOM): the tide, like you said, is coming up above the berm toe, but then that also has to coincide with a wind event, where the wind’s approaching from the right direction to to generate those waves.

Temazcal Room: Yeah, so it sounds like the way you’re filtering it. The waves are not above one foot

Temazcal Room: when the tide is above the marsh in her high water

Temazcal Room: more than 1 HA year, if I understand that correctly. And again, that just seems

Temazcal Room: less than I would expect.

Temazcal Room: So I you know I just have a concern there. Can I? Ask you another question?

Temazcal Room: How was the wind setup computed? Was it

Temazcal Room: extracted at the offshore wave location.

Temazcal Room: or was it

Temazcal Room: recomputed, based on the profile

Temazcal Room: towards shore, towards the tow.

Jeremy Mull (AECOM): Are you asking about the wave set.

Temazcal Room: By the wind. The wind set up.

Jeremy Mull (AECOM): Okay. Sorry.

Temazcal Room: Start with. The wind setup.

Jeremy Mull (AECOM): Yeah, it’s good question.

Jeremy Mull (AECOM): I would have to go

Jeremy Mull (AECOM): back into the

Jeremy Mull (AECOM): dhi methodology for the model. What?

Jeremy Mull (AECOM): I? So we didn’t

Jeremy Mull (AECOM): adjust

Jeremy Mull (AECOM): the still water levels at all. We took them straight from the model output.

Jeremy Mull (AECOM): They ran my

Jeremy Mull (AECOM): my 21

Jeremy Mull (AECOM): about the the water level wave conditions.

Jeremy Mull (AECOM): And so we extracted those from, you know, each each output station in the transects I would have to

Jeremy Mull (AECOM): not familiar enough with to say offhand exactly how they handled when set up in the model.

Temazcal Room: Yeah, no, that’s okay. I I just I’ll make a point here that

Temazcal Room: The wind setup increases with

Temazcal Room: proximity to the shore, because the wind blows the water on shore, and as it gets shallower the return flow

Temazcal Room: is suppressed. So you get a setup.

Temazcal Room: So the wind setup profile is not horizontal, it should actually increase as you get closer to the levee

Temazcal Room: and your offshore way of reference point is not

Temazcal Room: close to the total levee, so I think the water depth would be higher.

Temazcal Room: Then, perhaps, is being modeled, which, of course.

Temazcal Room: allows larger waves to propagate

Temazcal Room: landward to reach the toe.

Temazcal Room: which may also be contributing to this very low

Temazcal Room: wave total water level exceedance at the toe of the berm. I think I’ve made my point, but I had. That’s that’s 1 of the concerns I have. And we can discuss more.

Temazcal Room: In the discussion.

Temazcal Room: Is is that okay?

Temazcal Room: Okay? Thanks. Jeremy.

Jeremy Mull (AECOM): Sure.

Jeremy Mull (AECOM): so let’s see, we this slide. We’re looking at the berm tail exceedance.

Jeremy Mull (AECOM): and that’s the average number of hours per year, where the total water level is exceeding the berm tail with a wave height greater than one foot.

Jeremy Mull (AECOM): So under baseline conditions, you can see in the upper left. The levee is completely colored and green, and that’s

Jeremy Mull (AECOM): for

Jeremy Mull (AECOM): entire berm. Sorry.

Jeremy Mull (AECOM): And so that’s less than 1 h per year. The legends, the color legends here.

Jeremy Mull (AECOM): to interpret the different colors. You look at

Jeremy Mull (AECOM): the 6 inch sea level Rise scenario, which is what we’re considering to be the the 10 year sea level rise amount

Jeremy Mull (AECOM): the berm is still mostly green with some yellow, so that would bump the segment of berm up into the one to $12 per year.

Jeremy Mull (AECOM): That it’s been impacted by these waves, and then you can look at the results for the higher sea level rise scenarios of 12 inches and 36 inches sea level rise.

Jeremy Mull (AECOM): The next thing we looked at was the frequency of crest overtopping by waves.

Jeremy Mull (AECOM): And we looked at the approximate return period. Total water levels.

Jeremy Mull (AECOM): That would result

Jeremy Mull (AECOM): in in overtopping. So these would be

Jeremy Mull (AECOM): from events as frequent as 2 years. So a total water level with 2 year term period

Jeremy Mull (AECOM): through 1050, and then on up to

Jeremy Mull (AECOM): 100 years.

Jeremy Mull (AECOM): I’m

Jeremy Mull (AECOM): and same as before. Baseline conditions are shown here in the

Jeremy Mull (AECOM): upper left, and then

Jeremy Mull (AECOM): on 36 inches of sea level rise. Most extreme scenario shown here on the bottom right? So for baseline conditions. You can see here. Most of the the berm is shaded in orange, which

Jeremy Mull (AECOM): indicates that it’s vulnerable to

Jeremy Mull (AECOM): overtopping from a storm with a roughly 10 to 50 year return period. There is a small segment in red which is more vulnerable to the light red, so that’s vulnerable to

Jeremy Mull (AECOM): to 10 year. Total water level with 6 inches of sea level rise. More of the berm here is colored in red meaning. It’s more vulnerable. Obviously, to to storms

Jeremy Mull (AECOM): with lower return periods. So it happened more frequently.

Temazcal Room: Hey, hey, Jeremy? This is Bobby again. Sorry.

Jeremy Mull (AECOM): Yeah.

Temazcal Room: Ha! The dynamic water level, or the wave set up, you know, like the wind setup is

Temazcal Room: sloping upwards towards shore.

Temazcal Room: A lot of the same physics.

Temazcal Room: The wave setup? Was it

Temazcal Room: associated with

Temazcal Room: the wave height at the toe of the levee, or with the wave, the largest wave breaking farther offshore.

Jeremy Mull (AECOM): That’s a great question. And

Jeremy Mull (AECOM): it really I I guess it depends on the wave condition. So I’ll kind of walk you through what we did.

Jeremy Mull (AECOM): We generally follow the the engineering guidance, and that the Fema

Jeremy Mull (AECOM): Pacific Islands. So

Jeremy Mull (AECOM): guidelines for the west coast, and so for

Jeremy Mull (AECOM): the 1st step in the run up calculation. We use the

Jeremy Mull (AECOM): the Bim equation, the direct integration method equation to calculate both

Jeremy Mull (AECOM): wave setup

Jeremy Mull (AECOM): and we run up

Jeremy Mull (AECOM): and then we looked at the

Jeremy Mull (AECOM): the dynamic water level so that would be

Jeremy Mull (AECOM): the still water level plus static wave set up, and the dynamic wave set up.

Jeremy Mull (AECOM): and then, if that exceeded the berm toe, we switched to

Jeremy Mull (AECOM): the tar equation, which is a wave wave wrap equation for steep

Jeremy Mull (AECOM): coastal barriers.

Jeremy Mull (AECOM): And then we did a check. So we use the the near shore wave height

Jeremy Mull (AECOM): shoaled to the depth of the toe. If that exceeded

Jeremy Mull (AECOM): the depth limited wave height we would use the depth limited wave height, until, if it did it, we would use that wave height to calculate

Jeremy Mull (AECOM): way round up with tall.

Temazcal Room: Yeah. So I I think that all sounds good. I’m I’m familiar with that methodology. It makes.

Jeremy Mull (AECOM): Yeah.

Temazcal Room: So I mean, I think the question is, where was the what wave was used? At? What pansec location offshore

Temazcal Room: to calculate the way it’s set up.

Temazcal Room: The dynamic water level.

Jeremy Mull (AECOM): Sorry. So you’re are you asking what wave I was used in tall, or what? What wave height.

Temazcal Room: I know.

Jeremy Mull (AECOM): Extracted from the the model to start the calculations.

Temazcal Room: No, I think I understand that the wave height for the run up calculation using the paw equation

Temazcal Room: was the maximum expected.

Temazcal Room: That’s limited or otherwise wave height at the toe of the levee.

Temazcal Room: But the question is.

Temazcal Room: what wave height was used to compute

Temazcal Room: the way it’s set up.

Temazcal Room: which may be a wave that’s bigger farther offshore.

Jeremy Mull (AECOM): Yeah, I I think I get what you’re saying. So we use the near shore wave. I extracted from the the dhi model.

Temazcal Room: Okay.

Jeremy Mull (AECOM): Yeah, so it wouldn’t be an offshore wave. And people are being a nearshore wave.

Temazcal Room: So it’s the offshore. It’s at the extraction point.

Jeremy Mull (AECOM): Right.

Temazcal Room: Okay.

Jeremy Mull (AECOM): Yeah.

Temazcal Room: Thank you.

Jeremy Mull (AECOM): Sure.

Temazcal Room: Maybe. Can I? Ask one question as well, Jeremy?

Temazcal Room: I don’t know if it’s you, but we’re using. You’re using overtopping

Temazcal Room: as kind of the measurement metric for

Temazcal Room: for the hazard. And can you maybe just explain what

Temazcal Room: that that

Temazcal Room: what that does to the the bittern? And

Temazcal Room: ultimately, I think we’re concerned about release

Temazcal Room: of the bittern from into the bay, right? And so

Temazcal Room: is there like a sequence of that happens.

Temazcal Room: That you know that that causes you to use the overtopping as

Temazcal Room: the

Temazcal Room: the measurement of the risk.

Jeremy Mull (AECOM): So I I think what you’re asking is like, what’s the impact of wave over topping to the the the contents of the Mss. Fund.

Temazcal Room: Yes, what I mean. I assume that’s the hazard that we’re that we’re all concerned about, right.

Jeremy Mull (AECOM): Right. So we so we considered.

Jeremy Mull (AECOM): I I guess. We looked at Wave, overtopping as really

Jeremy Mull (AECOM): the

Jeremy Mull (AECOM): the the risk from like a flooding standpoint. And as I guess, really, for just a like a

Jeremy Mull (AECOM): a metric on how vulnerable upon

Jeremy Mull (AECOM): would be to

Jeremy Mull (AECOM): storm conditions and then future sea level rise. We didn’t do any

Jeremy Mull (AECOM): detailed analysis on, like what the actual impacts of the overtopping would be.

Temazcal Room: Yeah, so my name is Matt Pitcher. I’m the operations guy for Cargill. So the overtopping can scour the top of the berms so it wouldn’t be. One wave wouldn’t do anything right. And one wave going into the pond is just a drop, right, you know. I mean. So there! There’s plenty of free board in the pond, so it would take many waves

Temazcal Room: scouring the top to erode the top of the berm, so that then the level in the pond was higher than whatever got scoured, so that that would be the risk.

Temazcal Room: Okay, thank you. And and then it’s just the release of the bittern into the bay, and I’m understanding that

Temazcal Room: the dilution it dilutes. But there is still

Temazcal Room: is there like a time, hazard, or or a hazard in

Temazcal Room: a short period of time, as the the matrix is released.

Temazcal Room: Yeah. So the the hazard would be. Yes, the bitterin getting out of the pond and getting onto the vegetation, or coming in contact with a aquatic species out there, or or whatever but it dilutes.

Temazcal Room: you know, with all the water out there, so it dilutes quickly. But it it all depends on how much of a release. It is right.

Temazcal Room: The the majority of the Mss. Pond is a solid

Temazcal Room: salt

Temazcal Room: or different types of salts, but there is a liquid component in it, too. That’s in inside the matrix. And so that’s really what you’d be worried about is that liquid component because it would take a lot to dissolve the salt and then get

Temazcal Room: that high of a concentration.

Temazcal Room: Thank you.

Temazcal Room: Yeah. I’d I’d like to follow up on that discussion. I I understand what you were saying that.

Temazcal Room: The ponds are very big, and so if there’s a couple of waves that come over, it really doesn’t provide that much

Temazcal Room: water volume, and it doesn’t necessarily raise the water level that much, yet

Temazcal Room: I think I understand that the plan is to continue to

Temazcal Room: increase the the amount of what is it? Mss.

Temazcal Room: Whatever in these ponds, so that the water level is going to go up over time. Right? Correct. We are still using the the ponds for the Mss. To to store the Mss. So so the water level is going to go up over time, and then with sea level, the amount of wave overtopping is going to increase over time. And so

Temazcal Room: I think what Rod’s question is, you know, how does all this translate to the

Temazcal Room: threshold? Criterion for

Temazcal Room: the ponds not overflowing, or

Temazcal Room: you know, it’s hard for us to have a feel for that. It doesn’t seem like that was analyzed. Yeah, there’s a there’s. There’s

Temazcal Room: feet of free board, you know, a couple of feet at least at the minimum inside the pond, so it would take a large amount, and your accumulation per year is

Temazcal Room: less than a half inch.

Temazcal Room: Okay, yeah. So I think it sounds like it’s apparent to you. I guess it’s just not apparent to us. But I appreciate. Thank you for the answer. I I understand.

Temazcal Room: Yeah, this is Chris.

Temazcal Room: My understanding is the purpose of what Jeremy is presenting is less

Temazcal Room: accumulation of bay water in the Mss. Ponds. But looking at the risk to these berms of being

Temazcal Room: eroded or made less stable by the wave overtopping, so it’s the risk of damage to these

Temazcal Room: which would then allow for a larger release.

Temazcal Room: So that’s why we’re looking at like the wave impacts. And the overtopping is that going to damage

Temazcal Room: these burns and cause a larger release.

Temazcal Room: Is that is that right?

Temazcal Room: Yes, that’s correct.

Temazcal Room: Yeah, yeah. I mean, yeah, to to get a large release of it. You would need a lot of scouring

Temazcal Room: which would take

Temazcal Room: it would take a lot of waves, and all those waves would have to happen at a high tide

Temazcal Room: with surge to to get there, because you’ve got you’ve got a large amount. It’s hard to see in the picture, but there’s a large amount of marsh in front of here, so the marsh, the only time the marsh gets covered would be like a king tide.

Temazcal Room: so it would have to happen during a king tide. All the other high tides, you know, or the majority of the high tides during a year don’t even cover the marsh.

Temazcal Room: so you’d have your waves would break up before they ever got through the mark.

Temazcal Room: Okay, yeah, I mean I. And then I understand that you’re looking at

Temazcal Room: into the future with different rates of sea level rise right? So that the risk increases as you move forward in time.

Temazcal Room: Correct? Yes.

Temazcal Room: Okay. Sorry for the interruption. Please please continue.

Jeremy Mull (AECOM): No, no problem at all.

Jeremy Mull (AECOM): I let’s see. I think that I had covered the results for the the baseline conditions. Here, and then the 6 inch sea Level Rise scenario which we’re considering that the sea Level Rise scenario for the next 10 years.

Jeremy Mull (AECOM): And see that

Jeremy Mull (AECOM): roughly. I mean, there’s there’s different spots. But roughly, we’re switching from

Jeremy Mull (AECOM): overtopping, occurring from a

Jeremy Mull (AECOM): 10 to 50 year.

Jeremy Mull (AECOM): return period total water level. Then to one with a

Jeremy Mull (AECOM): the term period of 2

Jeremy Mull (AECOM): to 10 years.

Jeremy Mull (AECOM): so this slide has a little bit of the same information. But it’s just kind of more of a focus on on

Jeremy Mull (AECOM): or a summary of the results, I guess, for point 12. So we’re obviously focused on. Here’s 1 12. Here’s the the bayfront. Berm and

Jeremy Mull (AECOM): So if you’re reading the report, you’re curious what transects were used for this section. We looked at transacts. 2122. Well, 21 through 24, and they’re shown here in the snapshot

Jeremy Mull (AECOM): on the right.

Jeremy Mull (AECOM): The existing Bay front crest elevations for this firm range generally from 11 to 12 feet. Any vd, 88. See that in the picture and also in the report, there’s a

Jeremy Mull (AECOM): color index here shows that the different elevations you’ve got some high spots, some low spots.

Jeremy Mull (AECOM): The majority of the pond. 12 burn crops are above the 100 year. Still water elevation, which is roughly around 11 feet

Jeremy Mull (AECOM): and DVD 88

Jeremy Mull (AECOM): and just a summary set for baseline conditions. Wave overtopping.

Jeremy Mull (AECOM): Generally occurs for a 10 year storm and greater

Jeremy Mull (AECOM): and as a reference, the 100 year

Jeremy Mull (AECOM): total water level is 11 to

Jeremy Mull (AECOM): 13 feet. Any vd, 88

Jeremy Mull (AECOM): just as a note, we’ve been referring to storms in terms of return period.

Jeremy Mull (AECOM): The 10 year storm is actually a 10, a storm with a 10%

Jeremy Mull (AECOM): annual chance of occurrence. And so

Jeremy Mull (AECOM): on average, we would expect it to occur once

Jeremy Mull (AECOM): every 10 years.

Jeremy Mull (AECOM): so for future conditions, that’s 6 inches of sea level rise, wave overtopping roughly occurs, and for a 5 year storm. So it’s more frequent.

Jeremy Mull (AECOM): That has about a 20% annual chance of occurrence, and under your total water level is

Jeremy Mull (AECOM): 12 to 13 feet. Any Bd 88. With that amount of sea level rise.

Temazcal Room: Hey, Jeremy? Sorry to interrupt again. This is Bob again.

Temazcal Room: So you’re saying that the the levee crest elevations are somewhere around the 100 year. Still water level SW. EL.

Temazcal Room: Of about 11 feet in Avd.

Temazcal Room: So that means there’s really no free board.

Temazcal Room: Essentially

Temazcal Room: so with sea level rise.

Temazcal Room: Wouldn’t it be possible that

Temazcal Room: at that 100 year water level water would

Temazcal Room: spilled over the levee.

Jeremy Mull (AECOM): Yeah, so that right now.

Jeremy Mull (AECOM): the the bird crests are above the 100 year. Still water level elevation, the majority of them. It’s around 11 feet. So nothing.

Jeremy Mull (AECOM): If if there was no raising of the firms, yes, there would be

Jeremy Mull (AECOM): potentially subject to to flooding

Jeremy Mull (AECOM): but a hundred years still water level.

Jeremy Mull (AECOM): So what happens.

Temazcal Room: Okay? And then my other comment is, it seems that the total water level 100 year listed there of 11 to 13 feet

Temazcal Room: doesn’t seem to be

Temazcal Room: that much higher than the 100. You’re still water level of 11 feet, and I understand that the bigger winds and waves don’t happen necessarily during the 100, you’re still water level. But still.

Temazcal Room: or even so

Temazcal Room: again, the total water levels seem a little low to me.

Temazcal Room: And I don’t know if that’s because of the wind setup computation or other computation. But

Temazcal Room: And furthermore, usually you would like to have free board unless

Temazcal Room: there’s no consequence to, I guess, the overtopping in terms of

Temazcal Room: the internal water levels or the levee erosion, etc. So I know.

Temazcal Room: So

Temazcal Room: I think that’s still a concern that I have, both in terms of the total water level, seeming a little low to me.

Temazcal Room: and also the implications of the apparent overtopping that will will occur.

Jeremy Mull (AECOM): Yeah, I I think, it’s a it’s a good comment. And you know it. It could potentially be due to yeah, the exposure like we talked about different orientation of the

Jeremy Mull (AECOM): that

Jeremy Mull (AECOM): you know, segments of berm. And then how much

Jeremy Mull (AECOM): Windfash they’re exposed to. And then the frequency that you actually get big wind events time with those high still water levels that

Jeremy Mull (AECOM): we’re actually able to generate waves.

Temazcal Room: Thank you.

Temazcal Room: Rod, can I ask a question? Too?

Temazcal Room: Sure. Yeah, Jeremy, this is Gail Johnson

Temazcal Room: actually had a similar question to Rod about the

Temazcal Room: what are the actual

Temazcal Room: hazards associated with the overtopping?

Temazcal Room: And Chris mentioned about erosion?

Temazcal Room: maybe this is a question for Cargill. We saw photographs from Jen’s staff. Report of

Temazcal Room: that. You trench in the center of the berm

Temazcal Room: and put some kind of a slurry mix.

Temazcal Room: And and you’ve created kind of a

Temazcal Room: interior wall, if you will.

Temazcal Room: Yeah. So it we’re just putting dirt in there. So it’s it’s just. It’s nothing, nothing that. No, it’s not. It’s not hardens it, so to speak. No, okay, no.

Temazcal Room: And but we are compacting it. And his

Temazcal Room: oh, sorry and historically, when you have had

Temazcal Room: overtopping in the past.

Temazcal Room: is it? Has it been in the form of

Temazcal Room: massive breaches or over extensive lengths? Or what what is it? What’s what’s the his history of

Temazcal Room: of damage that’s occurred.

Temazcal Room: Yeah, from from single, from single storms. Assuming you can do repairs.

Temazcal Room: It’s been very minor. I I mean you can. You can tell where some water has gone over, you know, but it’s not. I mean, we haven’t even lost.

Temazcal Room: I wouldn’t even see an inch

Temazcal Room: of material off the top of it.

Temazcal Room: Just you can. You can just sort of see where the where the waves came over.

Temazcal Room: Okay. Yeah. Cause I was, I was having a hard time envisioning

Temazcal Room: what would cause them.

Temazcal Room: Ms. Has to

Temazcal Room: come out of the levee. Because just water going in

Temazcal Room: isn’t the hazard. As far as I can see, that’s what that’s why, I was a little confused.

Temazcal Room: Thanks.

Temazcal Room: My name is Don Brown. I’m the land resources manager for Cargill. So

Temazcal Room: they asked me to cover this slide.

Temazcal Room: What we’re going to do with this information that we received. It really allows us to.

Temazcal Room: you know, identify those specific areas for inspection and maintenance.

Temazcal Room: and that allows us to

Temazcal Room: work our maintenance plan to prioritize, you know, working on those.

Temazcal Room: perhaps more vulnerable segments of of those firms.

Temazcal Room: And and this is in addition to what we already do with regard to you know, we’re we’re out there.

Temazcal Room: you know. Matt’s team is out there inspecting the berms all the time, especially after storms identifying any area that may need some additional maintenance

Temazcal Room: and inspection.

Temazcal Room: And again, this the the study here was under what Jeremy explained as a

Temazcal Room: no action scenario.

Temazcal Room: Well, we’re we’re planning on increasing the height of those berms. So we’ll increase it to 11.5.

Temazcal Room: Nabbed

Temazcal Room: 88 by 2034.

Temazcal Room: We’ve worked with BC. Bcdc staff on on how we’re going to do that.

Temazcal Room: We are going to prioritize the pond. 12 firms.

Temazcal Room: We’ll have that

Temazcal Room: up to that 11.5 by the end of 2029, and, in fact, we’ve already started working on it. Matt’s team is out there already

Temazcal Room: is is increased

Temazcal Room: small segments of those berms

Temazcal Room: already to that that height. So

Temazcal Room: and and we’ll continue to.

Temazcal Room: you know, evaluate any impact that overtopping might have as far as scouring or having any impact to to the berms.

Temazcal Room: So and anything that might anything that might impact firm stability.

Temazcal Room: You know, we’ll be closely monitoring.

Temazcal Room: And and then during the next 10 year period, we’ll have a longer term

Temazcal Room: adaptation plan. How do we? How do we make sure that those those berms around those mixed sea salt palms

Temazcal Room: remained

Temazcal Room: stable and and safely

Temazcal Room: hold that that Mss.

Temazcal Room: Can I ask? Can I ask a question. Oh.

Temazcal Room: oh, you go ahead.

Temazcal Room: So we should see a 5, 6 inches of sea level rise by 2,034. So it seems like you would be building a system that would be

Temazcal Room: too short by 2,034, since we’re supposed to have, it’s highly likely that we would have 11 inches of sea level rise by 2,050

Temazcal Room: so it would seem like it would be more prudent to build now for a 2050 condition instead of building. Now

Temazcal Room: for a condition that you’re going to start exceeding already by 2,034 with that 100 year. Fill water

Temazcal Room: something we’re going to look at in the next 10 year. Permit period the issue would be, you start getting too high. You might have to build horizontally out in order to support the height.

Temazcal Room: So one thing that we’ll be looking at the next 10 years is

Temazcal Room: is really that long term adaptation plan. This is just a commitment we want to do to stay ahead of sea level rise. But

Temazcal Room: we will. That will be part of a long term plan that we look at. How do you actually.

Temazcal Room: make sure that those berms, you know, withstand again, even higher sea level rise?

Temazcal Room: I think you would need to start implementing your long term plan by 2,029. So I, yeah, that that just concerns me. I guess. Yeah, I I had a follow up. I had a similar question. So how was the 11.5 elevation

Temazcal Room: that you’re going to raise the levies to?

Temazcal Room: How was that selected?

Temazcal Room: I was 11.5.

Temazcal Room: It was just based on sea level rise projections, on what

Temazcal Room: you know, as far as the vulnerability of having wave overtopping

Temazcal Room: so that that was based on, I guess.

Temazcal Room: a projection from the existing condition which you consider to be

Temazcal Room: okay.

Temazcal Room: And then

Temazcal Room: a certain amount of sea level rise like half a foot or something like that.

Temazcal Room: I’m sorry. So it sounds like you’re using the existing condition, plus

Temazcal Room: something like half a foot of sea level rise. Is that? Or how?

Temazcal Room: Yep. Yeah. So that

Temazcal Room: I think that’s what we’re struggling with a little bit. What are the criteria for? The initial

Temazcal Room: levee crest elevation rise.

Temazcal Room: and

Temazcal Room: it sounds like it might actually be limited by geotechnical factors rather than

Temazcal Room: something that was developed, based on the hydraulics, the hydraulic exposure. You mentioned the concern that if you raised it higher than that now, which is what Chris was suggesting.

Temazcal Room: That that might be problematic, necessarily problematic. But it’s something that we’re just not permitted to do in our our current maintenance. So it’s that’s why we want to spend the you know.

Temazcal Room: during that 10 year permit period

Temazcal Room: term. And you know, if we want to, if we need to build it even higher or raise them even higher, how would you go about doing that because you know that we can raise it to 11.5 under. You know, that’s part of our existing maintenance that we

Temazcal Room: that we do every year. Thank you. Appreciate it. Thank you.

Jeremy Mull (AECOM): That is all that we have for this live presentation, unless there’s any more questions.

Temazcal Room: Okay, thank you, Jeremy.

Temazcal Room: Are there any

Temazcal Room: further comments from the board?

Temazcal Room: Oh, Jen, yes.

Temazcal Room: I have a comment question. Do these analyses depend? Did they take into account the dampening

Temazcal Room: effect from the tidal marshes that are there.

Temazcal Room: so that if the tidal marshes, for example, either eroded or were not able to create, to keep up with sea level rise. Would that change the outcome of the modeling.

Jeremy Mull (AECOM): So the answer to your 1st question is, no, that

Jeremy Mull (AECOM): on

Jeremy Mull (AECOM): the analysis did not.

Jeremy Mull (AECOM): did not account for the dampening of of the marsh, except for the

Jeremy Mull (AECOM): You know the elevation of the marsh, so that

Jeremy Mull (AECOM): the way we

Jeremy Mull (AECOM): calculated way to set up and run up is purely.

Jeremy Mull (AECOM): purely based on

Jeremy Mull (AECOM): I guess, depth and and elevations only. So it considered. Like the you know, the the flooded depth of the the toe of the berm

Jeremy Mull (AECOM): which is impacted by the marsh elevations. But it didn’t account for

Jeremy Mull (AECOM): any any kind of like future

Jeremy Mull (AECOM): changes to the marsh.

Jeremy Mull (AECOM): like the marsh, potentially rising to keep pace with sea level, rise.

Jeremy Mull (AECOM): A marsh actually potentially dampening the waves a little bit to drag and friction

Jeremy Mull (AECOM): stuff like that.

Temazcal Room: This is this is Chris again.

Temazcal Room: When I look at figure one of your wave analysis. Memo. It looks like you are accounting, at least in that figure for the dampening

Temazcal Room: of the wave height. Under existing conditions. That’s what the figure shows. But I think then, when you’re adding the 6 inches of sea level rise or

Temazcal Room: higher. In your analysis, I’m assuming you’re just keeping that marsh plain edits

Temazcal Room: existing condition. So, not accounting for the rise that it could have.

Jeremy Mull (AECOM): Yeah, that’s a good point. So that we’re accounting for the dampening that might occur. Due to shallow water of the marsh. So as the waves come in. You know they could potentially break

Jeremy Mull (AECOM): you know, and the the shallow water and you get death limited waves at the tail of the firm.

Jeremy Mull (AECOM): and the marsh elevation is not changed for the with future sea level rise, so it stays the same, and we add sea level rise into the calculations.

Jeremy Mull (AECOM): But there’s no dampening like to the marsh.

Jeremy Mull (AECOM): or from the marsh grass.

Jeremy Mull (AECOM): right like providing friction and stuff like that

Jeremy Mull (AECOM): that make any sense, Chris.

Temazcal Room: Yeah. Got it? Thank you.

Temazcal Room: Okay. Thank you, Chris. Any any other questions from the board?

Temazcal Room: Okay.

Temazcal Room: thank you, Jeremy. You

Temazcal Room: see next page of the script.

Temazcal Room: Now Michael Whalen, of Anchor Qea will make a presentation

Temazcal Room: on behalf of Cargill.

Temazcal Room: Hello!

Temazcal Room: Yes.

Temazcal Room: Well, hello! My name is Michael Whalen. I am with the firm anchor. Qea. I’m a principal geotechnical engineer. I will be leading this

Temazcal Room: presentation.

Temazcal Room: should I

Temazcal Room: log in and do it from my screen, or is there a more? What would be the most practical way to go through the

Temazcal Room: okay? I haven’t actually

Temazcal Room: logged in. So let let me let me do that.

Temazcal Room: and I’m I’m joined on the virtually by my colleagues, Andrew Barrett and Cole bales.

Temazcal Room: I’m a i’m Andrew performed a lot of the analyses under my direction.

Temazcal Room: and Cole and I have been

Temazcal Room: the folks to review it and put it all together.

Temazcal Room: So let me

Temazcal Room: let me get get myself logged in to this.

Temazcal Room: Yeah, I got. I got that.

Temazcal Room: I have 45 slides. I do, and I will. I do want to be conscious of time. And I know folks may have comments as I go.

Temazcal Room: Okay.

Temazcal Room: yep, okay. I’m I’m getting. I’m getting in there.

Temazcal Room: Oh, yeah.

Temazcal Room: just

Temazcal Room: okay.

Temazcal Room: And there’s me.

Temazcal Room: okay?

Temazcal Room: Oh, join as panelists. Right?

Temazcal Room: Okay.

Temazcal Room: there’s me. Okay.

Temazcal Room: And then if I share my screen.

Temazcal Room: we

Temazcal Room: we’ll be good

Temazcal Room: share screen.

Temazcal Room: Mike, yeah, let us know when you’re ready, Michael. But I think we want to wait for the board members to okay to show up. Sure.

Temazcal Room: Yep, okay, I I will. That’s I’m all set. And I will.

Temazcal Room: I will hold up.

Temazcal Room: Okay, Michael. I think we’re we’re back now. So

Temazcal Room: okay.

Temazcal Room: very good.

Temazcal Room: Okay, thanks again. Yeah. Michael Whalen, principal geotechnical engineer, anchor. Qea. I. I spoke in the in our last 2 engagements on this topic.

Temazcal Room: and I will go through our updated analysis of

Temazcal Room: static and seismic stability for the for the Pond, p. 2, 12 and p. 2, 13. Firms.

Temazcal Room: And I will start

Temazcal Room: with a short recap of what you heard from us last summertime.

Temazcal Room: where we had obtained all the available information on the sub service conditions that existed at the time performed by other parties.

Temazcal Room: Several borings 24, and, to be exact, were had been done. We had access to that information.

Temazcal Room: I’m including 2 deeper ones to 80 feet.

Temazcal Room: We had quite a few cone penetration tests or cpts to use

Temazcal Room: many of them with hydraulic profiling tools.

Temazcal Room: although those tended to go to depths of like around 20 feet. So there were some limitations on how deep into the subservice we could obtain information, but we used what we had.

Temazcal Room: and developed a model

Temazcal Room: of the subsurface and performed stability analyses for the berm for the berms.

Temazcal Room: And you’ll remember our technical memo. We discussed it. Our conclusions at the time was that the berms showed an adequate level of

Temazcal Room: stability, factors of safety under static and seismic conditions.

Temazcal Room: and we did the analysis for 2 distinct earthquake

Temazcal Room: magnitudes a 50 year earthquake and a 475 year earthquake

Temazcal Room: and

Temazcal Room: We discussed it, and one of the takeaways from our engagement with the Board was that you’re at. You were recommending that

Temazcal Room: a a

Temazcal Room: further series of field investigations be performed

Temazcal Room: specific to this type of analysis.

Temazcal Room: focusing on Cpts, getting to greater depths, etc.

Temazcal Room: And so that’s what we put together. And you saw our work plan

Temazcal Room: right at the end of the year last year.

Temazcal Room: and, as was mentioned early in this conversation in this meeting.

Temazcal Room: we performed that work plan. The investigations described in that work plan

Temazcal Room: late this spring. We got out there as soon as we could, and we we had to wait through difficult weather and rain conditions, but we got out there and did the work. We’re finished by May 3, rd

Temazcal Room: and again consistent with the work plan that we prepared. We did

Temazcal Room: 24 Cpts

Temazcal Room: to as much as 100 feet below below ground surface. Oftentimes, though, they didn’t actually get that far.

Temazcal Room: they got to 64 to 65 feet, and then kind of refusal, but significantly deeper than what we had before.

Temazcal Room: 2 of them were seismic cones, which is, which is a useful way to get an understanding of

Temazcal Room: some of the seismic properties that came into our analysis, as you’ll see in a in a few minutes.

Temazcal Room: We did one deeper boring to help us understand seismic properties. In the subsurface

Temazcal Room: we obtained a handful of undisturbed samples by pushing Shelby tubes.

Temazcal Room: and used those as well as

Temazcal Room: the samples we obtained

Temazcal Room: from the deep boring to perform a series of laboratory tests

Temazcal Room: strength test for the triaxial equipment. You’ll see that comes into play in some of this presentation, and some various index properties of the subsurface, elasticity, grain, size, moisture, content. So all in all, we’re able to successfully execute the program that was described in our

Temazcal Room: in our work plan.

Temazcal Room: And this is a map

Temazcal Room: of

Temazcal Room: the 2 ponds in question.

Temazcal Room: and I could zoom in if folks, and maybe as we go through this, there may be opportunities to zoom in and take a look closer. But there’s a number of things that are depicted on this map.

Temazcal Room: You see, a whole string of little circles, and that is, showing both

Temazcal Room: the preceding existing explorations that we had used for last year’s analysis

Temazcal Room: as well as

Temazcal Room: in the, in the darker color. I I realize that

Temazcal Room: they’re a little small here, but

Temazcal Room: the new ones that we did.

Temazcal Room: and I guess the the takeaway I wanted to show all of you is that we

Temazcal Room: we got information all along these these berms

Temazcal Room: around these ponds. On the bayward side, and between ponds 12 and 13 on both sides of plumber slough. So

Temazcal Room: we were able to get to all these places and get our information. Another thing that appears on this map in our report is

Temazcal Room: the fact that as we discussed a few minutes ago in the in the preceding presentation.

Temazcal Room: Cargill has performed the keying process where the the trench is excavated and then imported, fill, controlled fill is put back in a in a compacted fashion.

Temazcal Room: and

Temazcal Room: This map includes the areas that were

Temazcal Room: keyed over the last 5 years, and our series of explorations included going right through some of the keyed areas and also going through places that had not been

Temazcal Room: need. So we’re able to, you know. Look and compare. And I’ll I’ll talk about that in a

Temazcal Room: in a few minutes. What what did we learn from that?

Temazcal Room: Can I ask a question before you change the slide?

Temazcal Room: when you get further in the presentation section CC is, gonna be kind of right on the line. It looks like

Temazcal Room: and so my question is, can you tell us a little bit more about how you selected these critical sections. Yeah. And how do you know there isn’t 1 that’s worse.

Temazcal Room: And just from a very simplistic perspective, it looks like down to the right of CC. The berm gets narrower.

Temazcal Room: which would seem to indicate, you know, more vulnerable. So can you tell us a little bit about that. Sure? Yeah, thanks that I really should. As a matter of fact, because you do see the 5 sections that we selected on these maps

Temazcal Room: the what we used to select these 5 sections was,

Temazcal Room: a combination of things

Temazcal Room: we had. Even before we went out in the field we had existing Lidar survey. Information allowed us to see how high is the berm, how wide is the berm?

Temazcal Room: Does it vary? Are there places where it’s higher than in other places.

Temazcal Room: what we.

Temazcal Room: So we looked specifically at places where

Temazcal Room: the top of the berm elevation

Temazcal Room: and the the

Temazcal Room: the adjoining low spot, whether that’s the toe of the berm, or, in fact, something even deeper than the toe of the berm, notably the the bottom of plumber slough.

Temazcal Room: Thus kind of being a change in elevation. We looked for places where that change of elevation was

Temazcal Room: largest

Temazcal Room: and closest. In other words, where do we have the biggest, most abrupt change from bottom to top.

Temazcal Room: That was a big factor, in fact, that ended up being the primary factor in how we chose these sections.

Temazcal Room: We were also on the lookout for indications of

Temazcal Room: might. There be places geographically where we’re finding

Temazcal Room: softer material than in other places? If we had seen such things that would have been a really important part of our selection. But we didn’t really see a a trend of softer geographies.

Temazcal Room: So what these ended up being was really based on.

Temazcal Room: shall we say? Abruptness of

Temazcal Room: elevation change from top to bottom?

Temazcal Room: And

Temazcal Room: well, there are 5

Temazcal Room: lines on this map. We actually

Temazcal Room: looked at 7 sections. And the reason I say that is because.

Temazcal Room: sections B and C cross all the way across plumber slough and include both the the flanking berm. So our models are set up to to evaluate

Temazcal Room: 7 sections. But

Temazcal Room: it was. It was the changing grade that would that ended up being the primary driver for us to

Temazcal Room: choose these places for our analysis. So so is there anywhere that’s worse than C.

Temazcal Room: Not not that we can tell.

Temazcal Room: not not from the evidence that we saw.

Temazcal Room: And you are right. C is is the more critical player as as we’ll talk about in a bit.

Temazcal Room: Yeah.

Temazcal Room: Michael, I have. another question that I was.

Temazcal Room: Since we’re talking about this now I’ll go ahead and jump in.

Temazcal Room: I hope.

Temazcal Room: and it’ll come back again a little bit later on, about 8 slides further ahead, I think, but the southwest corner there at the south side of the

Temazcal Room: Greek or channel whatever that is.

Temazcal Room: Cpts 8 and 9.

Temazcal Room: so 2 questions, I guess

Temazcal Room: part of it is related to

Temazcal Room: to the geometry. It looks like, since you have. You know, the southwest corner there is kind of west southwest, the creek. It looks like there might be. Yeah.

Temazcal Room: yeah. Aq. Cpt and 9 Ccp, 8 and 9. Okay, yeah, the 2 yellow ones I I had misspoke. By the way, folks that yeah, the yellow ones are the new ones. But anyway, it looks to me I’m I’m curious. Why, you cut off Bed Bay mud at 30 feet when it looks like those 2 have Bay mud at 32 and 36 feet. Oh, yeah, is one question. That sort of okay.

Temazcal Room: related to a few slides further down the road. But it also looks like this particular geometry might be a more critical one, because you have that that channel out in front of you. There, that

Temazcal Room: have you?

Temazcal Room: Have. You looked at the geometry

Temazcal Room: sort of going left from Cpt. 9, I guess.

Temazcal Room: Yeah. Are you describing how

Temazcal Room: like the slough is relative to the berm? When you when you say that. Is that what you’re but also, as you move, just sort of straight west, you get that wider water body. I’m not sure if that’s

Temazcal Room: Creek channel, or what? That is exactly. But those guys, you have a wider water body that

Temazcal Room: looks like it might be deeper channel. Okay? Less. Cpt. 9,

Temazcal Room: as it looks to me like bay mud bottom is about 36 feet rather than 30 feet, which make it

Temazcal Room: potentially, geotechnically more critical, but also, maybe geometrically more critical. Sure.

Temazcal Room: Okay. Well, I understand what you’re saying.

Temazcal Room: it is. It is possible. I I will admit it’s possible that there could be some places whose combination of factors is somewhat different, or even worse, than our selections. I think our selections are are pretty solid, that in this case and and I’m able to speak from having gone through the analyses. One thing, couple of things we found, and we’ll be looking at this soon when I, you know, should we look at all the slip services?

Temazcal Room: The slip services?

Temazcal Room: I I think it’s fair to say Andrew is gonna ping me if I say this wrong, but

Temazcal Room: that the slip surfaces that were critical for analysis didn’t go so deep that the the acknowledged fact that young bay mud does sometimes go below 30 feet. You’re absolutely right. There’s places 32, 34, 36 feet deep.

Temazcal Room: We haven’t seen that that

Temazcal Room: has translated to where the critical slip services end up. Being

Temazcal Room: so true though it is, I don’t know that it

Temazcal Room: affects the the conclusions we’re drawing.

Temazcal Room: Similarly, I I understand your observation about the the slough and the water bodies offshore from these locations.

Temazcal Room: I’m thinking.

Temazcal Room: And again, I’ll you know, as we go through, and Andrew might speak up on this when we’re kind of going through some things. But

Temazcal Room: I think that still may be far enough away from the berm that

Temazcal Room: that water body, even if it ends up, being really deep over here on the left.

Temazcal Room: I don’t know that that is, would end up affecting our results very much. That that’s my suspicion about how those might play out.

andrew barrett: Michael, that’s pretty much exactly what I was. Gonna say. At at Cbt. 9 and Cbt. 8. You do see that the young Bay mud is deeper than the 30 feet that we used as our average in our models.

andrew barrett: But one thing that we found is that the critical region, I guess you could call it in terms of stability in terms of strength is between 10 and 20 feet, where we saw a lot of failure services go through.

andrew barrett: So one of the things you’re gonna notice is that what.

Temazcal Room: I’m sorry, Andrew, do you mind turning on your camera when you’re talking?

Temazcal Room: Yeah.

andrew barrett: Oh.

andrew barrett: hello!

andrew barrett: And that was that was all I had to say. We we noted that the the critical area, the critical region

andrew barrett: of the strength parameters in the models was between 10 and 20 feet.

andrew barrett: So that deepening there around the the 30 to 36 range

andrew barrett: didn’t seem to have any effect on the the overall stability.

Temazcal Room: I have a few more questions about stability. Maybe we can wait until we get down to the stability section of the presentation. Okay? I mean, it’ll sort of follow on these. But I wanted to jump in and

Temazcal Room: about some

Temazcal Room: geometry here. Good. Yeah, that that makes sense. Okay. So I’ll keep moving up, moving forward. Alright.

Temazcal Room: But oh, yeah, let me clear in my mind

Temazcal Room: you had Lidar information to give you the the crest of the burns, if you will. Yeah.

Temazcal Room: So

Temazcal Room: the toe of the berms

Temazcal Room: did. You have also lighter information about that?

Temazcal Room: We did we? We did have Lidar information. But one thing I should mention

Temazcal Room: it’s in my notes is that part of our field engagement wasn’t just to do all these cpts and boardings, but we also did. We didn’t take a survey crew out there, but we checked manually all the dimensions out there in terms of berm width, and maybe even more notably berm height, just to do a ground check on what we had from the Lidar.

Temazcal Room: which was really helpful to us. Because the berms aren’t all that high as you’re as you’re standing there and kind of looking at them, and we needed to make sure we had that right in the cross sections we set up. So I guess what I’m saying is we had Lidar, but we also. Field checked it.

Temazcal Room: That that’s the issue that in my mind I I want to make sure that

Temazcal Room: you’re saying you’re

Temazcal Room: analyzing the steepest slopes.

Temazcal Room: Correct? Yeah.

Temazcal Room: that that is our intent. Yup. That’s right. Okay, that’s fine. I I want to

Temazcal Room: understand it better for myself. How the toe was, I mean, how did you measure it in terms of height or elevation, and and kind of the inclination to say, Hmm.

Temazcal Room: this is the steepest at this location. Yeah. And I should. I should probably clarify that a little further, because what we measured in the field was the observable

Temazcal Room: berm.

Temazcal Room: But

Temazcal Room: plumber slew particularly, being a really important factor in this whole evaluation for our selection of

Temazcal Room: steepness. We didn’t go into plumber, slew and measure that that was from the Lidar, for sure. That’s where we and and that kind of goes back to what I was kind of

Temazcal Room: describing in our selection. It turned out that our selection isn’t based on like

Temazcal Room: standing there and and seeing the burn be steep. It was based on recognizing that plumber slew out here or bay waters offshore.

Temazcal Room: Those are getting deep faster.

Temazcal Room: And so

Temazcal Room: that ended up to us being the the real critical definition of

Temazcal Room: what’s the most critical place. Where is it steepest? If if that makes sense? I I in other words, I’m I’m describing steepness, not just at the the immediate face of the of the berm as is visible. But all the way out to the nearest deep water.

Temazcal Room: Okay, continue forward. And we can obviously revisit these things as we go.

Temazcal Room: Yeah, berm cross sections developed for analyses. Let me start with just some very generic ones. I don’t know like I’d rather focus more on the the scaled ones we did. You’ve you may remember seeing these

Temazcal Room: before. I haven’t even changed these for this presentation, although in reality we have made some updates till we actually modeled.

Temazcal Room: But the general geometry of things

Temazcal Room: stays the same. Really. What I wanted to show everybody is our understanding of what the deal is with these berms.

Temazcal Room: They’re built out of densified fill upon young bay mud. That’s the real point I’m trying to make. Here you see the mixed sea salts on the left.

Temazcal Room: You see the berm crest, and I didn’t say the stirring

Temazcal Room: Jeremy’s earlier talk, but

Temazcal Room: I feel like the the fact that the surface of this, these densified fill berms and the and the cover with the

Temazcal Room: the surface and gravel. Sh! I’m not going to try to quantify that and what I’m saying. But surely that has some innate resistance to wave overtopping erosion.

Temazcal Room: Just want to make that side observation. But any case just wanted to show this, and also, as I scroll to the next

Temazcal Room: slide

Temazcal Room: the this keying activity that Cargill has been performing where

Temazcal Room: a trench, his dog and and compact and material placed back.

Temazcal Room: So that that’s the general concepts. I think this is all familiar. We’ve

Temazcal Room: gone through all this before.

Temazcal Room: What I wanted to do next was just run through

Temazcal Room: the 5 critical sections that we selected and modeled.

Temazcal Room: Those of you who are familiar ask real quick question. I think it’s be easy. The keying is to cut off seepage, or for stability or settlement, or what

Temazcal Room: I I think it’s primarily driven by cutting off seepage right primarily to reduce permeability

Temazcal Room: to reduce permeability. Sorry.

Temazcal Room: yeah. And we’ll comment in a few minutes about what might that imply for stability? And see? Bitch? Yeah.

Temazcal Room: have a question about the previous slide.

Temazcal Room: Is that slide? Is this slide intended

Temazcal Room: as schematic? Or, I mean. This has elevation on it, it has

Temazcal Room: exaggeration on it.

Temazcal Room: It is intended as a schematic.

Temazcal Room: it it definitely is intended as a schematic. I say that because we didn’t put this into our model.

Temazcal Room: We put what I’ll show next into our model. I mostly want. This is a schematic, and it’s true. This has

Temazcal Room: various elevations described on it. It’s a it can be a little confusing, I realize, because

Temazcal Room: we developed it with a different kind of

Temazcal Room: one data. And then we used aecoms findings. So

Temazcal Room: I I want this to be considered as a schematic. That’s why it’s intended. Thank you.

Temazcal Room: These. So this is the 1st of 5.

Temazcal Room: these aren’t schematic. I mean, these are literally what we put into our

Temazcal Room: slope stability model. Those of you who are familiar with this slope stability software recognize that

Temazcal Room: nowadays, when you build this model, you can very quickly run all sorts of different combinations of situations, all sorts of different water levels, you can vary the strengths of the soils. You can do a lot of these things. And the reason I say that is because.

Temazcal Room: what you are seeing in this slide set. And frankly, what you see in our report isn’t everything we run. We ran a lot of things because you can do it quick.

Temazcal Room: So, for example.

Temazcal Room: these all show a certain assumption of water levels.

Temazcal Room: But I think, as as you are all aware, you know, part of our work was to study the effects of different water levels. So these are just selected images. The real thing I wanted to show is just is the geometry

Temazcal Room: of the berm, and and you see

Temazcal Room: there’s the berm in the middle.

Temazcal Room: But as you go out to the left the outside of the pond, now you’re dropping out into the the offshore area to the north

Temazcal Room: of

Temazcal Room: of the pond at this particular location.

Temazcal Room: And the reason, I say that is because when I was talking a few minutes ago about you know how we define this, the top to the bottom at the closest proximity.

Temazcal Room: We’re kind of looking at. Where might this overall slope that I’m tracking with my cursor be most dramatic? And how might that be our critical second?

Temazcal Room: Anyway.

Temazcal Room: there’s location a

Temazcal Room: I’ll comment on the sub service in a minute here, because, you see all these colors, I just have a quick question, what are the units of the X and Y axes on these.

Temazcal Room: Those are in feet.

Temazcal Room: elevation and feet.

Temazcal Room: and

Temazcal Room: a arbitrarily selected horizontal location and feet.

Temazcal Room: Was, was there another

Temazcal Room: question.

Temazcal Room: okay, you know what? Let me let me hang on this one just a little further, because

Temazcal Room: there! There’s some colors that we use, that I will. I I

Temazcal Room: I want to explain.

Temazcal Room: we have young bay muds everywhere below the berm.

Temazcal Room: and then, as you get lower on the figures

Temazcal Room: there, there’s green bands for young bay muds.

Temazcal Room: and then all the way down to the bottom of the figure.

Temazcal Room: In in reality

Temazcal Room: Although, as I was saying a little bit ago, and and Andrew also said this.

Temazcal Room: the you know, the the young bay mud, reaching depths of 30 feet or 34 or 36, didn’t really affect our analysis. So once we found that out, these graphics were simplified.

Temazcal Room: But the point is, everything’s young bay mud with kind of down below. There’s an old bay mud floor.

Temazcal Room: and all the action that we’re talking about here happens, of course, in the young bay muds.

Temazcal Room: I also want to explain why we have this different color scheme protruding down below the berm.

Temazcal Room: where you see like green and pink.

Temazcal Room: If if you’re seeing the colors

Temazcal Room: that that’s the information we picked up and used from our analyses directly, and I’ll explain in a few minutes how we, you know, came up with these layers

Temazcal Room: versus the places to either side of the berm that are just kind of this consistent kind of dark blue.

Temazcal Room: The the dark blue on either side of the berm is where we applied kind of the worst case strength parameters. And the reason we looked at it this way is because we expect that the presence of the berm has

Temazcal Room: probably cause some strength gain that we’re observing, and we shouldn’t expect that that strength gain exists to either side of the berm.

Temazcal Room: We’re we’re really trying not to.

Temazcal Room: We’re just trying to stay appropriately conservative with our assumptions and not

Temazcal Room: not be overly optimistic about things. And that’s why the colors appear

Temazcal Room: the way that they do. There’s just a distinction. But below the berm versus not below the berm.

Temazcal Room: anyway.

Temazcal Room: Very similar storyline for these other locations.

Temazcal Room: There’s location B zoomed in.

Temazcal Room: Here’s Location C, where you can actually note that plumber slough is in the middle, and we got

Temazcal Room: we got some of the modeling on both sides of of the slew. But

Temazcal Room: the critical situation was here right in the middle. What you’re seeing there?

Temazcal Room: Location DA little smaller berm

Temazcal Room: and location E, and and again, these are zoomed in just to kind of show you folks how we developed these these models and kind of the scale of of the size of the berms themselves, because these are all the

Temazcal Room: to scale.

Temazcal Room: I I have a quick question.

Temazcal Room: So

Temazcal Room: I think the the purple line is the water level, and I think your purposely have the water level high on the pond side and low on the outboard side for stability analysis.

Temazcal Room: so on the pond side, it seems like it’s

Temazcal Room: not that far below the crest is that is, that the existing condition? Or is this a more conservative.

Temazcal Room: In other words, the the free board on the inside seems kinda

Temazcal Room: free. Board on the inside is not intended to be particularly

Temazcal Room: conservative.

Temazcal Room: But yeah, what you’re seeing in this case is about. What is that about 2 feet of of height

Temazcal Room: above ground surface, each of those? Okay, it’s 2 feet. Okay.

andrew barrett: This is one of the examples of the existing marshes to be seen from the edge of Pond 12. Cross. Section Ede. Prime is on Pond 12.

andrew barrett: There’s several 100 feet of soil.

andrew barrett: you know, that’s above the water line. This is at low tide.

andrew barrett: the pond

andrew barrett: water level. We were told by cargo that doesn’t change, which stays roughly around 9 depending using pumps. And if there’s rainfall, then they bring it back down. So in these models the the elevation is plus 9 nav. D. 88 for all of the ponds. Well, all of the models that show the pond water side, and then the elevation that’s changing is is the

andrew barrett: the water level

andrew barrett: on the bay side.

Temazcal Room: Thank you. Which side is upon, and which side is obey.

andrew barrett: In this case this is a low water condition. So

andrew barrett: if you’re looking at the screen, the left side is the pond.

andrew barrett: And and you’ll see. Generally speaking, the water level being higher on the pond side is is the condition where we would expect to see the lowest factors of safety.

andrew barrett: So you’ll see that a lot, generally speaking, in the models that are shown in this presentation

andrew barrett: are the low tide conditions.

Temazcal Room: Good thanks.

andrew barrett: So you’ll see that the pondsight is usually higher.

Temazcal Room: So

Temazcal Room: one of the things that’s a little bit frustrating with this is that there’s no strings

Temazcal Room: shown on these plots here. And so you’ve described what happens with the different shades of green and blue and

Temazcal Room: and pink

Temazcal Room: and even in your

Temazcal Room: port

Temazcal Room: I think 80% or more of the civility sections don’t have the strengths actually shown on them. There’s there’s a few that do.

Temazcal Room: If we look at one of them that does

Temazcal Room: it says that the pink

Temazcal Room: has a strength of 2 75, increasing by 15 psf. Per foot.

Temazcal Room: It also says that the

Temazcal Room: blue

Temazcal Room: which is adjacent to the pink well.

Temazcal Room: the dark blue, the

Temazcal Room: the thing to the left and right of the pink yeah, teal. It’s different on my screen than on your screen than up on the wall there, right. But what’s right and left of the pink

Temazcal Room: says that it’s 2, 75

Temazcal Room: increasing by 15 per foot. But if it’s 2, 75 at the top, and increases by foot by 15 per foot.

Temazcal Room: By the time the blue gets down to an elevation of the height of the top of the pink.

Temazcal Room: It’s going to be stronger than the pink.

Temazcal Room: I think that you have cpt data that goes right down the middle of the levee. Right? Yeah, and I think everything outside of the levee is inferred because you can’t drive rigs out over the that’s right.

Temazcal Room: And I think that the reason you have that

Temazcal Room: that trapezoid underneath

Temazcal Room: levee is because you’re assuming there’s some consolidation that happens from the weight of the levee. That’s right, right, which means that the blue on the sides of the pink should be weaker than the pink.

Temazcal Room: unconsolidating. You’re actually analyzing it. They’re stronger than

Temazcal Room: well, let’s if you give me a

Temazcal Room: seconds you’d have to look at page 5 0, 5. In your report

Temazcal Room: I have 5 0, 2,

Temazcal Room: which is another example. The same thing.

Temazcal Room: But yeah, hold on. Let me

Temazcal Room: zoom

Temazcal Room: share.

Temazcal Room: You are talking about this.

Temazcal Room: I think this table, the company ha happened to be looking at a different page. Yeah, same table. Okay, I think I think this is 5. This is, in fact, 5 on you’re saying

Temazcal Room: this lower row.

Temazcal Room: Well, actually, so I’m looking at.

Temazcal Room: I’m looking at Page.

Temazcal Room: You maybe, are you on?

Temazcal Room: I need to move my little sorry folks for the all the

Temazcal Room: flipping of pages.

Temazcal Room: This this is. Page 5, 0, 1.

Temazcal Room: Right here, right here.

Temazcal Room: Yeah. Okay, so 2, 75 and 15 and 2, 75 and 15 on both.

Temazcal Room: 2, 75 and 15. Yeah, you’re talking about you guys. See what I’m doing there when I draw these little

Temazcal Room: think, yeah, you’re talking about

Temazcal Room: this right here, right? And you’re comparing it to the I think the 275 is the strength at the top of the layer.

Temazcal Room: and I see by that 15

Temazcal Room: Psf. Per foot.

Temazcal Room: That’s right

Temazcal Room: below the top of the layer, and if you scroll down on this page, then

Temazcal Room: you can see where the the blue is higher. The top of blue is higher than the top of pink.

Temazcal Room: which means that the 2 set the the blue starts at 2 75 at the top.

Temazcal Room: and increase down so it will be

Temazcal Room: 10 feet

Temazcal Room: 10 feet.

Temazcal Room: So by the. So you’re suggesting that the arithmetic works out such that by the time you’re down at the depth of the pink.

Temazcal Room: You’ve actually got higher strengths on either side of the pink.

Temazcal Room: I understand what you’re saying.

Temazcal Room: I had a comment, for later on, again I would say, I would suggest

Temazcal Room: that you try putting these tables on every printout page.

Temazcal Room: It’s it’s a little bit of a nuisance when you’re setting it up. But yeah, once you get every run, it shows on every run. So like you’re saying, the software is awesome because you can do lots of runs.

Temazcal Room: Once a table set up, it follows you through on all the runs, and I I think that’s as simple as a

Temazcal Room: probably a button push to make it come out. Yeah, it’s a little bit of a nuisance to set it up sometimes to get it okay, scaled and formatted. And you have to move it left or right to get it out of the way of the

Temazcal Room: safety factor pronounced. But

Temazcal Room: sure, okay, that’s that. That makes sense that’s good.

Temazcal Room: But by putting it on every one, and you can just

Temazcal Room: I mean, we don’t have to

Temazcal Room: flip around. I wonder what you’ve used on this particular one, and one of the things that sort of alarms me now is the table you were looking at a second ago. Different page than this one has different numbers, which means that I assume that every single table I wonder how many different

Temazcal Room: variations there are. Sure, and I can’t follow that at all as a checker. Okay.

Temazcal Room: yeah. The other one.

andrew barrett: What he was looking at was.

Temazcal Room: Doing Andrew’s work won’t be able to tell what he’s doing, either yeah or Cole’s work. Whoever’s doing. Sure. Sure.

Temazcal Room: Go ahead, Andrew, you had a comment.

Temazcal Room: I think that was Andrew.

andrew barrett: Yeah, yeah, I was just gonna say, the table that

andrew barrett: the table that you were showing earlier. Michael was one of the checks that we ran using different parameters. That were found from the triaxial test data. So that’s why the values are different and that they are labeled on each page

andrew barrett: what? You know which system we’re using. So I know it’s not super intuitive and can’t be seen right now on the screen. But it it is there.

Temazcal Room: Yeah, no, I don’t mind. I don’t mind having different

Temazcal Room: cross sections having different numbers on them. That would be

Temazcal Room: probably expected.

Temazcal Room: But yeah, there’s most of the

Temazcal Room: profile cross slope stability profiles that are shown in the report don’t have the table shown at all, so I don’t know which table is applicable, for which one

Temazcal Room: I can assume that all the ones for B is the same as all the ones for B,

Temazcal Room: but

Temazcal Room: but just print it out, and then it’s there because I I know I’ve I’ve done thousands

Temazcal Room: thousands of runs over the years, and I know you. You tweak one. And it

Temazcal Room: right? How can you prove? How do I know for sure, when my Qc. Person is looking at it.

Temazcal Room: that that tweak got carried through on every other right. I don’t have a residual B analysis

Temazcal Room: that has the previous

Temazcal Room: unodated.

Temazcal Room: I I can appreciate that. I mean, it’s 1 thing for Cole and I to work with Andrew and know everything’s spread out, and what was done, in what order we have that advantage. But as a reader and someone coming into this I can appreciate how, if you’re missing that stuff, it is nearly impossible to piece together. Why not just do it

Temazcal Room: right.

Temazcal Room: That makes sense 2

Temazcal Room: to follow on on Jim’s point.

Temazcal Room: How would you distinguish

Temazcal Room: these strength parameters that

Temazcal Room: presumably

Temazcal Room: on the

Temazcal Room: left and right of the pink.

Temazcal Room: is the natural material right? And then the the

Temazcal Room: the key is this

Temazcal Room: engineered material.

Temazcal Room: presumably.

Temazcal Room: When you say the key engineered key correct

Temazcal Room: when you you, too, when you well, it’s a tiny little thing. It’s basically above well, but it’s shown in a way here that it implies that this trapezoid is the key.

Temazcal Room: Well, I that I don’t want to imply that cause. It’s not. But your point is that it could look that way right? And then it creates confusion with respect to all of these strength parameters that are being assigned particular layers.

Temazcal Room: Well, I certainly don’t want people to get the impression that’s intended to be the key, but I suppose it does kind of look like key. That’s right. If you look at a certain way, right? That’s another reason to.

Temazcal Room: With this table on every printout, because that table labels the pink as young bay mud.

Temazcal Room: Yeah. And so if you happen to look at one of the ones that has the table.

Temazcal Room: then you’re set.

Temazcal Room: but I think actually none of your presentation. But most of them don’t have the table. It is true there’s a whole bunch of them. And just if you had the table.

Temazcal Room: But it yeah, that that is not the key.

Temazcal Room: But I I understand your point. That is that the key?

Temazcal Room: Yeah, okay, that’s that’s good. I mean these these. Okay, I understand.

Temazcal Room: where am I? Here? Okay, so

Temazcal Room: alright. So we’ve been talking about the sections and the analyses.

Temazcal Room: I was next going to talk about how we came up with new strength parameters for these layers.

Temazcal Room: Do. I need to be worried about timing as I go through this or just keep. We got lots of time, I guess, right.

Temazcal Room: for now

Temazcal Room: we’re we’re

Temazcal Room: we’re on Slide 15 out of 45. So.

Temazcal Room: I am just showing this

Temazcal Room: graphic, because this is what you saw. Last year.

Temazcal Room: when we had 3 layers defined, we identified Berm Fill. We had young bay mud. There was comments on how we were showing the strengths of the young bay mud.

Temazcal Room: There was old bay mud, that was it. We’ve taken that a step further now, in 2,024. So let’s let’s go on to what we did here in 2,024.

Temazcal Room: So the previous

Temazcal Room: slides you where you’re shown with the the soil properties are those from

Temazcal Room: before you’ve done the the Cpts or this new round of they’re for the new. They’re they’re all new. Okay. Thank you. What I’m about to show here explains how we came up with those

Temazcal Room: you mean this, this page here.

Temazcal Room: Well.

Temazcal Room: this is this, let’s let’s let’s tackle that on in a couple of slides, because then, let’s

Temazcal Room: let’s look at how we did it. This definitely doesn’t match.

Temazcal Room: We. We have changed this.

Temazcal Room: and here’s how we did it.

Temazcal Room: This is a compilation of all the Cpts that were conducted.

Temazcal Room: If you can see all the colors

Temazcal Room: you’ll recognize. There’s a whole bunch of different colors, and that’s because we just assign a different color to every Cpt. So all 2 dozen of the Cpts get its own color, and we

Temazcal Room: plotted them all up to see what it told us. And

Temazcal Room: I mean, there’s a lot of scatter, but you also see some trends, and and it suggested to us that it would be more precise for us to subdivide

Temazcal Room: the young bay mud.

Temazcal Room: And and so that’s what we’ve done, and on the next slide.

Temazcal Room: We

Temazcal Room: you talking about here

Temazcal Room: like this?

Temazcal Room: Right?

Temazcal Room: Okay.

Temazcal Room: bye.

Temazcal Room: I’m sorry

Temazcal Room: I can lean in

Temazcal Room: sorry. You want me to start over again? No, no, I I mean I I’m getting it.

Temazcal Room: No, I well.

Temazcal Room: you’re talking about Cbt. 8 and 9. So, 8 and 9

Temazcal Room: you know, everything is consistent. It looks like Cpt. 8 to 9. Go down with bay mud down to 32 feet down to 36 feet, and it looks like really on that far west.

Temazcal Room: southwest, south, south, west, southwest Point.

Temazcal Room: It looks like that’s got deeper may but bay mud that stays with a nice smooth bay mud.

Temazcal Room: strength, profile.

Temazcal Room: and and I’m wondering whether that geometry might look critical also, and in any case, even if it doesn’t, I think that probably there needs to be some still stability done done

Temazcal Room: with that location that shows it going to 36 feet. Okay, I understand. It sounds like you, unless you can explain to me why it shouldn’t be that way. That’s how it looks to me.

Temazcal Room: And you’re. It sounds like you’re talking not only here about the depth

Temazcal Room: there of of the young Bay mud, but potentially also where it plots up on these graphs.

Temazcal Room: yeah, are you also? No, I think that’s like it’s going to plot just nicely that it’s, I assume, that’s going at about 15 psf. Per foot. Okay. So if you just extend the bay mud an extra 6 feet, you’d have that same profile going an extra.

Temazcal Room: Okay, an extra 6 feet. I understand? You’re really making the point. There’s been some stability cases at least.

Temazcal Room: I would expect that the circles are going to try and climb as deep as possible, climb downwards as deep as possible. It looks like some of your spill analyses. If you just scan through

Temazcal Room: the geotech report, some of them go down to 30 feet.

Temazcal Room: I think that those ones presumably bumped into something at 30 feet, and if you allow them, go to 36 feet and allow the Bay Ma to stay soft at 36 feet. I think they’ll extend a little bit deeper. They might go deeper, and typically if it if it bottoms out at a depth, and then you allow it to go a little bit deeper. The stability safety factor is going to go a little bit lower

Temazcal Room: it. Yeah, if it wants to bottom out and the bottom drops, it’ll probably keep chasing it down so that could that could be the case. If if you’re allowing the circle to go as deep as you want and it and it

Temazcal Room: finds a critical minimum safety factor. That’s higher than that. Then you say the

Temazcal Room: the depth doesn’t matter that much, but there were at least a few of the circles

Temazcal Room: in your report where the bottom is 30 feet, and I assume that that’s bottoming out, because there’s some constraint that it bumps into right there. Okay.

Temazcal Room: all of which is a an advocate you’re advocating that we might benefit by looking at what’s going on there in the

Temazcal Room: that western

Temazcal Room: edge where Cpts 8, 9 are. I think it’s only relevant to Cpt. 8 and 9. Nothing else goes deeper than 30 feet. A lot of it’s more like 24 feet.

Temazcal Room: Yeah. Okay. But

Temazcal Room: okay, that could be I. I hear you.

Temazcal Room: Okay. Well, let let me just give an explanation of what we did with this information.

Temazcal Room: We took. We broke it into the kind of subdivisions and the upper 5 feet. We looked at that. And for each of these subdivisions we did a probabilistic

Temazcal Room: plot of strength versus how often it occurs. And that’s what this

Temazcal Room: on the right is. It’s all the strengths plotted by the

Temazcal Room: frequency of occurring.

Temazcal Room: And it’s a pretty wide band. There’s a scatter

Temazcal Room: and what we did was in the next. In this case, and the next one, we chose

Temazcal Room: the 30 percentile level. In other words, we chose a strength that 30%, only only 30% of the day is below and the other 70% is above. We felt that was a reasonable way to

Temazcal Room: come up with an estimated strength.

Temazcal Room: Now for is particularly for wide ranges.

Temazcal Room: and and the same is true. 5 to 10 feet below ground service.

Temazcal Room: now 10 to 20 feet below ground service, a little different, in our opinion, because there’s more of a clustering of the strengths. It’s not as broad. It’s not as much of a bell curve. It’s more of a sharp curve.

Temazcal Room: and here we felt it was

Temazcal Room: reasonable to choose

Temazcal Room: the most typical strength. In other words, the

Temazcal Room: the top of the curve.

Temazcal Room: That wasn’t done to try to get a high strength. It just like that. Seems like that’s the dominant strength.

Temazcal Room: Alright! Let me jump in again.

Temazcal Room: so averaging works nicely when the data

Temazcal Room: is.

Temazcal Room: you know, if you’re if you have cpt variable data and you’re driving a pile through it. The pile is picking up a little bit of strength from 0 to 5. A little bit of strength from here, you know, and an average is an appropriate number.

Temazcal Room: but if you look at some of those colors, it looks like you’ve got straight down the far left edge of that all the way, and so some profiles.

Temazcal Room: some cpts at least, are all the way on the left edge there.

Temazcal Room: most of them. Maybe you nudge it up a few percent or so I don’t know. But really pretty darn close to that left edge is where some profiles are going to be.

Temazcal Room: Some profiles aren’t going to be averaged

Temazcal Room: over there. If you want to know whether the whole thing is going to slide or not, then you can say, Yeah, at least 50% of the sections are not going to slide because we’ve used 50% Median value here.

Temazcal Room: I don’t think we want 50% of the sections to be stable. I think we want all of them to be stable. And we’re looking for the worst.

Temazcal Room: not the not the average case, but aren’t by doing this. Aren’t we? Basically taken like down the middle of that? You’re right. I mean, almost all of them are clustered there on the left.

Temazcal Room: and there’s a bunch. There’s a bunch of stragglers off to the right. But

Temazcal Room: aren’t we choosing the most prominent

Temazcal Room: band

Temazcal Room: through this approach?

Temazcal Room: And that’s what we’re we’re we’re trying to rep. We’re trying to

Temazcal Room: capture the fact that there is a definitive.

Temazcal Room: a clustering of them on the left.

Temazcal Room: and and certainly aren’t looking to go past that it does seem like the appropriate strength is

Temazcal Room: right there in in the dentist part of the graph.

Temazcal Room: I think, for a stability analysis like this, where you have some cones that are far. If you have data on each cone that’s scattered

Temazcal Room: and the slope circle comes through all of those different layers, and you average it.

Temazcal Room: But I think if you got a single cone that’s

Temazcal Room: straight down the left edge, and you have actually.

Temazcal Room: But

Temazcal Room: it looks like you got 6 or 8

Temazcal Room: cones that are straight down the left edge.

Temazcal Room: and I don’t know how you can be really confident

Temazcal Room: that there’s not going to be some location out there where you have a slope circle that’s going to be able to find that weak spot.

Temazcal Room: and maybe it happens to be offset a hundred feet from where you did your cross section.

Temazcal Room: your cross section has to be representing

Temazcal Room: the safety factor of 100 feet away from where you did your section. And I think I mean, without having any geometry attached to the figure.

Temazcal Room: I think that you gotta

Temazcal Room: you gotta do something further left in your green 50 percentile.

Temazcal Room: Yeah.

Temazcal Room: Okay, I understand what you’re saying. I will. I will mention. Although it’s not in this slide deck. I’m not even frankly sure if it’s in our report.

Temazcal Room: because we can do these things so quickly and easily, we did look to see what happens if we

Temazcal Room: like, take the 30 percentile version of this

Temazcal Room: which is like 250 to 300 sheer strength.

Temazcal Room: And I’m I’m interested in other geotechs because I’m I’m

Temazcal Room: we’re a crowd here. But but I think that 30 percentile is

Temazcal Room: pretty optimistic for

Temazcal Room: this data with a slope stability analysis, what would you choose?

Temazcal Room: Like? 10% pretty close to the lower edge.

Temazcal Room: But just so, I make sure. I understand, like the blue one is at maybe 200 or so.

Temazcal Room: and the 50 percentile that you’ve chosen is more like 3, 50 or something like that. Yeah, so it’s not a geotech. But

Temazcal Room: I am an engineer, and I would think if you’re interested in the location where the blue one is, you want to be at about 200.

Temazcal Room: I’ll I’ll add some to that as well.

Temazcal Room: I mean anything that you’re looking at really, in this depth range that is beyond, say, about 500 Psf.

Temazcal Room: these are sandy layers that you are.

Temazcal Room: I mean all of those things. You’re not going to get a bay mud value. That is 2,000 Psr.

Temazcal Room: Those are sandy

Temazcal Room: layers within the Baymark.

Temazcal Room: Now, if if you are modeling this as Bay MoD,

Temazcal Room: then

Temazcal Room: I will agree with my friend Jim here that you are in a very tighter band, that the upper bound of that tighter band is more like

Temazcal Room: 400, the lower bound would be more like

Temazcal Room: 200, something like that, and that would represent

Temazcal Room: more appropriately

Temazcal Room: this young bay mud at these depth ranges that you are considering it

Temazcal Room: all those other points to me. Yes, they exist, and they are

Temazcal Room: what you measured, but they don’t represent

Temazcal Room: they mud in the context of what we are talking about.

Temazcal Room: Right? The so what we’re using right now is about 3.

Temazcal Room: So around 3 50 that the black line is about what reason?

Temazcal Room: And when you you’re saying.

Temazcal Room: what about? What if the Black Island were here? What if the black line were here.

Temazcal Room: I mean, that’s basically what we’re talking about, right is, where’s that line, either?

Temazcal Room: Strictly envelope the entire data set.

Temazcal Room: But I think he ought to be somewhere towards the left edge.

Temazcal Room: Yeah, I mean 2, 50 or something. I don’t know

Temazcal Room: more toward the left edge. I mean, I feel like we are kind of toward the left edge. But you’re saying

Temazcal Room: maybe we should be worse for the left edge right?

Temazcal Room: But put your 3, your 3 50. What’s your vertical Median number that you have? That’s 3

Temazcal Room: like 325, which would fall like, I don’t know. I’m just obviously eyeballing, but it’s about there.

Temazcal Room: Oh, man, hold on

Temazcal Room: so what this looks like is that

Temazcal Room: you know at least

Temazcal Room: 50% of your cross sections would be good

Temazcal Room: 50% are worse than what your analysis shows.

Temazcal Room: Statistics are awesome.

Temazcal Room: but I think they’re

Temazcal Room: have to be applied pretty cautiously

Temazcal Room: with it.

Temazcal Room: This type of

Temazcal Room: analysis.

Temazcal Room: I I agree with you there when we have, when we have.

Temazcal Room: I mean, if every single cpt was jumping back and forth all over the place.

Temazcal Room: you know that it maybe it’s different. But if you look at the Cpts themselves, a lot of them are pretty smooth.

Temazcal Room: yeah, a linear

Temazcal Room: linear tracks remain

Temazcal Room: points out that a lot of those things that are further off towards the right are probably

Temazcal Room: a sand.

Temazcal Room: thin sand lenses that

Temazcal Room: really appropriately or not even

Temazcal Room: clay, and shouldn’t be analyzed as a clay. But because A/C petite or coelec even

Temazcal Room: analyzes these, the thin layer factor doesn’t really

Temazcal Room: those are all outliers right? And and so the strengths are are

Temazcal Room: really not supposed to be averaged.

Temazcal Room: I mean, they’re not really part of the the su behavior of the material.

Temazcal Room: What what are we? So what do we take? We’re taking by taking the 50 percentile

Temazcal Room: we’re taking them. Are we doing a mode? Isn’t that a statistical mode like the

Temazcal Room: I should be okay. I don’t want to turn this into probability statistics discussion, but I do agree. The statist, the use of the statistics is very important. We do need to do that very thoughtfully. I understand what you’re saying.

Temazcal Room: The way we thought about that

Temazcal Room: principle was when we said, All right, we’re we’re presenting the 50% tile like I’m showing here.

Temazcal Room: We also recognized

Temazcal Room: what if we just stay consistent with what we’re doing, the other ones and use the 30 percentile.

Temazcal Room: And we did do those runs, and they don’t make that big of a difference necessarily. But

Temazcal Room: there’s an argument to be made for doing that, or even or even farther down. I think, for instance, I mean, I’m curious, I can’t tell, but that left edge there

Temazcal Room: looks pretty close to the same gray that’s at Cpt.

Temazcal Room: 9,

Temazcal Room: yeah, like goes to 36 feet.

Temazcal Room: And so

Temazcal Room: someplace that profile exists, and if if you want you can. You can get a little more detailed and look at specific C specific

Temazcal Room: profiles and say, You know, this one is averaged up and down it. But

Temazcal Room: but averaging.

Temazcal Room: you know, composited a whole bunch of locations is

Temazcal Room: well, it’s a it is a simplification. It’s it’s at at the least, it is a simplification

Temazcal Room: right to average a bunch of locations. And

Temazcal Room: and I understand the point that you know there are occasions when you want to bore 0 in on a specific

Temazcal Room: location. I think that

Temazcal Room: is part of where your comments are now, maybe that you’ve got you’ve got a band there, and maybe you look at some of your profiles, and they

Temazcal Room: cpts on both

Temazcal Room: there and on both sides are.

Temazcal Room: you know, towards the right edge of your dense band there, and maybe that

Temazcal Room: profile you use a slightly better.

Temazcal Room: you know. If you I mean ideally, you look at some sort of geomorphological background and say, Yeah, we think it makes sense. This one’s a little bit stronger. This one’s a little bit weaker. It may well be that Cpt. 9 is a little bit deeper, because it’s further out towards the bay, and everything is just and does tends to slope that way. And

Temazcal Room: yeah, and maybe because it’s out further towards the bay, maybe it happens to have been younger and less desiccation. And it all happened during the you know, post gold rush. I was actually expecting to see more of that, the bay muds there, and so it really is weaker than all the others which might be a few 100 years old.

Temazcal Room: I mean to be honest, we were kind of expecting to see more of that than we did. We think we might end up in a situation where there was a strong signal that

Temazcal Room: the Western Cpts are worse than the Eastern ones. I mean, that wouldn’t have shocked us if we’d seen it. Now, admittedly. Yeah, there are some Cpts that

Temazcal Room: are lower than others. You’re pointing out numbers 8, 9. Those are in the same place. So is that a geographic trend? Maybe it is, I mean.

Temazcal Room: but it’s not one that we’ve seen propagated throughout the rest of them. But

Temazcal Room: anyway, your point, your points are well taken about.

Temazcal Room: Might there be more critical places, both in going back earlier here.

Temazcal Room: based on, you know, topography.

Temazcal Room: And might there be more critical places based on

Temazcal Room: specific Cpt logs

Temazcal Room: understood.

Temazcal Room: There might be

Temazcal Room: cherry washta Nick would like to make a comment. He has his hand raised.

Temazcal Room: Nick.

Temazcal Room: Okay.

Temazcal Room: please.

Temazcal Room: Okay, so let me 1st put my geologist hat on

Temazcal Room: I was as I was looking at all of this I was

Temazcal Room: well, I have this microphone on, so I don’t worry.

Temazcal Room: Putting my geologist hat on as I was looking. All of this.

Temazcal Room: There surely are all channels underneath all of this that are sandy

Temazcal Room: and that’s as was suggested. That may explain some of those very high

Temazcal Room: or relatively high strengths that you see, and possible, even refusal

Temazcal Room: would have been nice to map those out, but you know, that requires going through a whole lot of very old Usgs coastal maps, and so on.

Temazcal Room: I’m not necessarily convinced that that would help. Now, when it comes to this kind of discussion of statistics. On on one hand, I don’t see this as a life safety situation, so necessarily taking the lowest strength is in my view, not

Temazcal Room: required.

Temazcal Room: however clustering it like this, while interesting, is not really helpful when one looks at a long linear structure.

Temazcal Room: And that’s what you have. You have a very long structure, and what I would have liked to have seen, and that

Temazcal Room: well, I I don’t know how this microphone works. So

Temazcal Room: you know, if I stick it in my mouth, then

Temazcal Room: maybe

Temazcal Room: anyway.

Temazcal Room: The the

Temazcal Room: because it is a long linear structure. I would like to have seen this parsed out

Temazcal Room: bisection.

Temazcal Room: As you’re looking at the different sections where you put your cross sections, I would have preferred to see this data presented for that particular section, because you actually have a pretty good coverage of of field data.

Temazcal Room: and that would allow you to do a better assessment whether you really have to go with the lowest strength, or whether, in fact, the local variability is such that some higher value is is

Temazcal Room: recommended rather than looking at all of the data in you know, in an aggregate. So I think that would be

Temazcal Room: my suggestion that that’s a much better way to approach it, I think.

Temazcal Room: seeing the scattering all of the data is is great. That’s that’s a beautiful plot. I love it, you know, if you if I present it for Young Bay mud, then you can probably plot all the data that we have for Young Bay mud from the Bay Area, and it will all nicely plot within this range. But

Temazcal Room: because it’s such a long linear structure, it would have been more

Temazcal Room: informative and probably useful for you to

Temazcal Room: look at the section where you

Temazcal Room: the nearby data from the section where you actually did the slope stability analysis based on your criteria, which I’m actually not taking exception with but looking at this discussion, and, as I said in my view.

Temazcal Room: it’s not necessary to take the absolutely lowest value, since this is not a life safety situation, but at the same time there may indeed be a section where all the data is in this lowest thing, which is what the Jim French suggested, that there may be a section where all of the data nicely plots, all on that low end, in which case

Temazcal Room: you have to use whatever you have.

Temazcal Room: So that that would be my comment on on this whole.

Temazcal Room: you know. Discussion. Thank you.

Temazcal Room: No, that that’s good. I mean, I I understand what you are all saying. I understand that and there’s no doubt there is, I’m sure, more that can be gleaned from this data. This is a lot of data. And and you guys all well know part of our job. And our judgment is to say, all right, we got all the say, what is the best amount of

Temazcal Room: processing and analysis we should devote to this data to answer the question

Temazcal Room: at hand. Now, as we get into the latter part of this presentation. I think we’re gonna see.

Temazcal Room: even with what we have done here. There’s some pretty clear answers becoming evident about

Temazcal Room: the situation and and I, I would imagine, if we

Temazcal Room: kind of chase down some of these additional levels of

Temazcal Room: detail behind these analyses and

Temazcal Room: maybe make less conservative assumptions.

Temazcal Room: There may be more of that. That is possible.

Temazcal Room: But but there’s no doubt there could be more analysis always done on this stuff.

Temazcal Room: Yeah, yeah, Bob’s got a question. Yeah, I just wanted to follow up on this. I I find this really interesting. Would you mind going back to that slide that showed the plan view, and it showed some of the adjacent marsh.

Temazcal Room: You know, one of the things I’ve done a lot of is

Temazcal Room: Wetland restoration, and these dikes subsided, Balens, and you can see where there’s the existing marsh which is green in the upper left.

Temazcal Room: You can see that there’s a

Temazcal Room: a whole bunch of channels.

Temazcal Room: and what we do find is when,

Temazcal Room: the water starts moving, or whatever the the old channels are often reoccupi. The old channels are often reoccupied.

Temazcal Room: Because they’re just more erodible. I’m not as familiar with the Mss. And

Temazcal Room: it’s sheer strength or or erosion resistance. But

Temazcal Room: The comment that Nick made, that there may be some sections that cross

Temazcal Room: old channels that aren’t otherwise apparent in the just the existing terrain. I think it’s a very good one.

Temazcal Room: and

Temazcal Room: One way to look at that would be to look at some old

Temazcal Room: tea, sheet maps or other maps which I think the South Bay Salt Ponds. People have that show where the the channels were.

Temazcal Room: especially the you know, the larger channels.

Temazcal Room: and then that might affect your your section

Temazcal Room: location selection.

Temazcal Room: Well, I will. I will say there’s no doubt there. There is evidence for lots of

Temazcal Room: channels, you know. There’s a lot. In other words, there. There’s evidence for lots of sand lenses all through here, and I I presume geologically, that that’s just a representation of the

Temazcal Room: ongoing meandering of them over, you know, millennia.

Temazcal Room: and but the the way it looks to us is they’re just kind of like all over the place. There’s this

Temazcal Room: a galaxy of little sand lenses, and I don’t even know if we could map them.

Temazcal Room: Well, yeah. And I just want to state that it may be their sand lenses in in traditional dykes applied to Balens, especially when they get

Temazcal Room: wet and they’re managed ponds. You often have

Temazcal Room: weaker material depositing in the old channels. It’s just

Temazcal Room: organic or other stuff that really erodes in this case. If it’s sand, maybe it’s less erosional. I don’t know.

Temazcal Room: But a geomorphic interpretation of the

Temazcal Room: subsurface might be might be helpful.

Temazcal Room: Okay? Is my only point. Thanks. Yeah.

Temazcal Room: Well, I mean one of the takeaways. I’m I get from this. I mean you. You are all making you’re you’re observing. You’re pointing out

Temazcal Room: the ways. We have simplified the analysis.

Temazcal Room: No doubt we have taken the State, and we have tried to find

Temazcal Room: you have to simplify to some degree right to do an analysis, there’s no way around it. So we’ve

Temazcal Room: we’ve said, all right. What’s the right amount of simplification to give us

Temazcal Room: to tell us what’s going on here

Temazcal Room: to a sufficient level of, you know, understanding to help everyone make decisions. And

Temazcal Room: and so your your points about some of the additional ways we can. Analysis are well taken, and and maybe that’s what we should do

Temazcal Room: to better understand the story. I must say I’m

Temazcal Room: really eager to hear your comments on the

Temazcal Room: the end of this presentation, because that’s I think we’re really the storyline is going to come through.

Temazcal Room: are we? Are we? Good?

Temazcal Room: Yeah, I think. So keep going. Yeah, please.

Temazcal Room: Okay, let me get. Let me catch this up to where I left us off.

Temazcal Room: Okay, th, this is what we ended up with. After all that statistical analysis and all that data. This is the new table we are now using where the young bay mud

Temazcal Room: is subdivided into

Temazcal Room: 4 layers.

Temazcal Room: Really the lowest of these, where it says, Ybm. 20 feet below ground service, and below, that’s really 20 to 30 feet, and Jim was making comments earlier about how

Temazcal Room: there are some places. It’s deeper than 30, that is true.

Temazcal Room: But in our models. It goes to 30, and then it’s underlain by old bay mud.

Temazcal Room: and these are the properties

Temazcal Room: we’ve used.

Temazcal Room: There’s been comments about how it would be helpful to kind of map this onto all the slide outputs. But that’s that’s the that’s the new

Temazcal Room: set of properties we’ve been using.

Temazcal Room: And

Temazcal Room: just to compare what we had last year to what we have now

Temazcal Room: this graph

Temazcal Room: compares them, and and the real difference

Temazcal Room: now versus last year

Temazcal Room: is that

Temazcal Room: we are now, seeing evidence that the young bay mud

Temazcal Room: stays

Temazcal Room: soft to a greater depth

Temazcal Room: than what we had expected from last year’s data. That’s the real

Temazcal Room: take away from what we did.

Temazcal Room: It’s not as good.

Temazcal Room: it’s softer, and it goes deeper.

Temazcal Room: And the e even on the simplified profiles. That’s what you see. Now, you know

Temazcal Room: all the other comments acknowledged

Temazcal Room: I mentioned. We also did triaxial strength testing in the laboratory

Temazcal Room: on undisturbed samples

Temazcal Room: which allowed us to develop a best fit

Temazcal Room: strength, envelope.

Temazcal Room: or effective stresses.

Temazcal Room: And as I’ll show you in a few minutes, we used that as another form of our analysis to see what it tells us

Temazcal Room: so. Those are the soil strengths we used, and we used, and we did it, and and put into the

Temazcal Room: put those into those cross sections I was showing you. And then we ran a whole bunch of stability analysis to figure out

Temazcal Room: what are the factors of safety at this site?

Temazcal Room: yeah.

Temazcal Room: So

Temazcal Room: before I get to that, though, let me let me go back to this concept of keying for a moment. That’s been an important subject

Temazcal Room: for our evaluation.

Temazcal Room: We, as I said, had explorations going through places that had been keyed, and we had explorations that went through places that had not been keyed.

Temazcal Room: And again, with that we plotted all of those strength points together.

Temazcal Room: this actually shows a comparison. If if you can pick it up between

Temazcal Room: places that were keyed, and dark dots and places that were not in light dots. And and really

Temazcal Room: the the bottom line that we found from our explorations is

Temazcal Room: minimal appearance of strength

Temazcal Room: gain

Temazcal Room: from King J. I’m just talking about strength gain. How much resistance did the cone pentromer experience?

Temazcal Room: A a little bit more, but almost not enough more to even put a number on it. That’s why I describe as minimal

Temazcal Room: change.

Temazcal Room: In other words, he doesn’t seem to have that big of an effect

Temazcal Room: on the strength

Temazcal Room: in the berm.

Temazcal Room: Yeah.

Temazcal Room: what kind of material are you using for the keying? You know, in one of the write-ups somewhere

Temazcal Room: read that. It was maybe your response to questions.

Temazcal Room: from staff.

Temazcal Room: It had some criteria that says

Temazcal Room: doesn’t have

Temazcal Room: deleterious material, or some some sort of generic kind of thing, but nothing about plasticity, nothing about grain, size, distribution. Right? Is this some bay mud that you’re back filling again with? Or I mean, it’s a bay mud, or is it import gravel? Right?

Temazcal Room: So ability. Obviously, it’s not gravel. But you guys have your set of criteria. No deleterious material. It is a little bit broad like like you say that that’s the kind of rule book you guys use. But we did go out. I think it was a couple of years ago when

Temazcal Room: surveyed all the it’s all imported material you have.

Temazcal Room: and we did a a reconnaissance of it. We took samples. We characterized it. It is not a young bay mud.

Temazcal Room: it is, it is silty. It’s largely a fine grained mix of silt with some sand. If I remember what

Temazcal Room: our results told us

Temazcal Room: so. It was still a. It was still a pretty fine material, but not

Temazcal Room: not to the degree like a bay. Mud would be plasticity.

Temazcal Room: I do not remember what the plasticity was.

Temazcal Room: I do not remember what the plasticity was. I do recall, though, that

Temazcal Room: in addition to the lack of deleterious material in it.

Temazcal Room: It looked like a material that if under the right moisture, conditions could be compacted.

Temazcal Room: and from what we understand from your team and what we’ve seen on our explorations. It appears to be a well compacted matrix of

Temazcal Room: sandy silt materials

Temazcal Room: placed into the trench. Not a big difference in strength from what was there before.

Temazcal Room: but in terms of the activity itself.

Temazcal Room: and the way in which you you for the cargo team specifically goes after places that might

Temazcal Room: have had some deleterious materials in them, and replaced it with a better, more consistent material.

Temazcal Room: It appears to us

Temazcal Room: that it’s going to have benefit of

Temazcal Room: the intention of making it more suitable against seepage, but not really with a

Temazcal Room: a

Temazcal Room: a change in strength.

Temazcal Room: So I’m curious. Just I’m in a