 Welcome everybody. I'm Sam Luoma. I'm, as I mentioned in our first meeting, I'm chair of the National Academy of Science Committee on the future of water quality in Cordelain Lake. I'd like to welcome you to this second meeting in which we will be have two panel discussions. One about water quality and data analysis. And when about water quality models. Let me just reiterate for just a second that are the focus of our of this particular study is on understanding the data and the trends that might establish understanding that will allow us to understand better what the future might hold for Lake Cordelain. We will not be discussing discussing solutions in this phase of the study, presumably the base of understanding that we're developing with of course is necessary for any future discussion along those lines. And I'd like to also remind you that the agenda, the task is our specific task in the bios of the committee are on the committee website. So let's get started and we'll go to the moderators for the panel the first panel. My discussion of available water quality analysis is moderated by Bob Hirsch of the US Geological Survey for tired. Thanks Sam. Good morning everyone. We're going to get right into this session. Our speakers this morning will be first Craig Cooper of IDQ, Ben Dale Chess of the Cordelain tribe, and then third Lauren Zinser of the US Geological Survey. In each of their talks we're asking them to address what is the data collection program now or roughly over the last 20 years. And then what are some of the analyses and things that have been learned from the data collection program in terms of trends both spatial and temporal trends. And then finally some thoughts about some of the higher priorities of future monitoring efforts in the watershed. So our first speaker and that's Craig Cooper of the Idaho Department of Environmental Quality. Craig is a senior scientist with the department and is the lead, technical lead for a limnological studies of the Cordelain basin. Craig go ahead. Good morning and thank you for the opportunity to talk about the work we've done on Cordelain Lake. My name is Craig Cooper and I'm an onologist for DEQ here in Cordelain. Before I go off I'd like to begin by acknowledging my colleagues here without whom this data would set would not be possible. The lake management plan, Jamie Brunner, Glenn Pettit and Bob Witherow and also my colleagues in the water quality group Kristen Lowell and Craig Nelson who have been big helps in collecting water quality data in the Cordelain basin. We're on the stage with this bathymetric map of the lake that shows the four major regions we think about in terms of discussing the lake. The southern pool is shallower and warmer high productivity and predominantly influenced by the St. Joe River. As the St. Joe River water flows northward intersects with the Cordelain River we get the mixing zone that has complicated mixing between these two water masses. Then you get the central pool that is north-south and the lake is broader and deeper. And then the northern pool that comes from the northwest to southeast and is least influenced by the river and has important influences from the smaller tributaries in the eastern part of this pool. Our monitoring plan is designed to accommodate for these bathymetric and geographic differences. We collect core monitoring data at C1 tubs in the northern pool and C4 university in the central pool. We also collect profile data every year and emitting chemistry data at these orange data points. We have collected bay data at all of the open circles and the blue circles represents places the USGS sample of 1991-92. Through this extent possible our sampling locations coincide with the USGS sampling location to allow long-term trend analyses. For lake sampling we traditionally sample seven or nine times per year with two in on snow events in spring. Monthly from May to September again lake turnover and then when lake becomes isothermal typically after Thanksgiving. That's changed over time to reflect newer data needs so we now do regular monthly from March to September as well as turn over in winter taking up SON only measuring in January and February. When we do monitoring we get a second disk as well as SON profiles of light penetration as well as standard chemical physical measures. We get water quality samples for chemistry from the photozone and integrated sample. Discrete samples of 20 meters, 30 meters and 1 meter off the bottom or near bottom. We can change that for deeper sites and we've also begun getting separate integrated samples from the epillenium and the deep photo because in summertime from June to September the photo zone can extend beneath the epillenium. For our water quality parameters we get total and dissolved metals where dissolved is at which past their 0.45 micron filter. We also get total and dissolved measures of nitrogen and phosphorus. We've got chlorophyll A data as well as phytoplankton community structure for DEQ 2002. We've been monitoring at our core monitoring sites since 2007 and been collecting long-term SON profile monitoring at five additional sites. We've done short-term monitoring surveys at those sites since 2010, five phylogic sites and 22 bay sites. We've also done some special studies. We've looked at isotopes of water to track the movement of water masses. C-cell anoxia in the far northwestern corner of the lake with a small anoxid basin. We're going to primarily put activity rates at our core monitoring sites and the bentos with vegetation invertebrates. And then a pair of fight and recruitment study with the University of Idaho with Dr. Frank Wilhelm and a student at Randy Naughty. Elsewhere in the basin we've done a survey of the CDA River Chain Lakes. Worked with the tribe to do a profile study of the deep meander bins. We've done nutrient studies in both the St. Joe and St. Mary's River basin and the Coraline Lake tributaries. A short survey in 2009 and we're now doing a current more detailed study. We've looked at phosphorus data for the Coraline River banks and also in 2017 when EPA did their river flood study, worked with them to get phosphorus data for suspended sediments. We've also done studies for bank erosion the Coraline River and the St. Joe. With this data we've done a number of assessments and special studies. I'd like to highlight that we have annual summaries of lake conditions for the state waters in 2008 to 11. And then we did some trend analyses lake-wide with the tribe with data through 2014 and 2015. Most recently we've done a trend analysis for the state waters through 2018. For special studies we recently finished a large basin-wide phosphorus inventory using data up to 2013 because that is the most recent year for which we have a consistent set of data across the entire basin. We've also done studies on benthic invertebrates, aquatic vegetation, prime food activity via carbon-14 uptake, trend and phytoplankton community. Also did the pair fight in the recruitment state with the University of Idaho and we've also helped the University of Idaho do metal biology chemistry and lake sediments. Currently working on a report on the stabilized hook work we did in 2015 and beginning to do an assessment of the conceptual mixing model for the lake. So let's move on to some of our challenges. In terms of data collection, it is a challenge to get a good long-term data set. The lake is not always easy to sample. With respect to methods we're often at or below detection limits for nutrient chlorophyll A. We've been using different labs to try to bend the EQ and that has impacted phosphorus in the past. We have had different methods for chlorophyll A analysis in the lake where laboratory splits yield different results for the same water from different laboratories, different methods. We have three different chlorophyll A methods on the record so we have to evaluate our trends using current methods and their historical equivalent values. In doing that, we have to account potential biases from the historic analytical methods, seasonality and gaps in data record, and also potential bias from the focus on reinstall events from our historic sampling schemes. There are challenging data management, different agencies, different time periods giving track of all our data sets, and also the scope of the data versus our staff resources. We have a lot more data than staff time so there are studies and assessments we want to get done but haven't gotten done yet. Now let's dive into some data. I'll first talk about geography and seasonality and start with total phosphorus. This plot in the upper right shows total phosphorus for all our data from 2004 to 2018 on a seasonal progression at C4 University point in the central pool here in the red and Tubbs Hill in the northern pool here in the green. You'll note that phosphorus is higher in the spring in both sites declining down to some minimum values. It's also much higher at University Point in the central pool than it is at Tubbs Hill in the northern pool. If you look at chlorophyll A, it's a different pattern. For chlorophyll, chlorophyll is higher at Tubbs Hill in the northern pool than it is at University Point in the central pool, which is interesting. Higher phosphorus in the central pool, higher chlorophyll in the northern pool. Also, when we did our current 14th uptake rate for summer productivity, we did find that productivity rates are higher in the summertime in the central pool closer to the river than they are in the northern pool, even though chlorophyll A levels are comparable. Take a look now at nitrogen. Like phosphorus, nitrogen is higher in the spring dropping down to a certain minimum before rising again in the wintertime, though the sequence is a bit more pronounced. Nitrogen is also higher at C4 in the central pool than at C1 in the northern pool. Now, with respect to the nitrogen to phosphorus ratio, we see a distinct seasonality as well, where we have a very high in the key ratio during spring and spring runoff. We also see diatom blooms. Racial then drops precipitously in late spring to reach a minimum during the summertime when our community also shifts to favor and have more blue-green algae. The ratio that increases in the wintertime is nitrogen levels increase. What we see here is that we have a distinct seasonality in both the chemistry of the nitrogen to phosphorus ratio and in our phytoplantic community structure between diatoms and blue-greens. So, how do we assess our data? Well, we do two kinds of assessments. First, we ask, do we exceed the triggers on lake management plan? These would be a single annual value, be it a mean, be it a maximum, be it a minimum. And the means would be an average of multiple depths in sampling events. So, for example, for total phosphorus, we ask, does a geometric mean over the entire year for all data sets, yeah, for 30 meters, is it greater or less than the trigger value of 8 micrograms per liter? We also ask, is there a time trend over a time period? Is it calculated for each combination of depth, location, and parameter? So, for example, at Tubbs Hill, we have four depths, we have four different trends for edit that site. We use the cascic statistics because we do not have a normal distribution of data. And it goes to a seasonal cycle, high in the spring, low in the summer, high in the spring, low in the summer, with the peak in the spring not being consistent from year to year. We can also have different size data sets. So, for example, a long data set here since 04 is consistent. And this USGS data set back here in 1992 that's much shorter. Our stat analyses exclude samples less in reporting limit, attacking that problem. We do three kinds of calculations. We do a manhandled calculation to determine whether or not there's a trend and how significant it is. We use a teal-sin regression to the median to determine the magnitude of the trend. And for the case of comparing two disparate data sets, we use a manhunt in Wilcox calculation. Now, let's look at zinc. Zinc exceeds our targets on any average basis every year. And it's always higher at C4 in the central pool than the northern pool. Zinc is declining consistently across all sites with an average decline of about one microgram per liter per year. It declined far enough now so that in the summertime, zinc drops below the Idaho chronic criteria at both Tubbs Hill and University Point. Cagnum is broadly similar to zinc. It's declining at both sites in the northern lake, consistent across all depths and sites. Cagnum levels are lower relative to the chronic standard than our zinc. And the point now where we are generally below that standard can only exceed in the chronic criteria on a seasonal basis at some locations. And on an annual average basis, we are below our targets, so Cagnum's improving. Lead is a more nuanced trend than with zinc and cadmium. It's always higher in the central pool, closer to C4 than Tubbs Hill and northern pool. And we never exceed the criteria on an annual basis at Tubbs Hill. However, we do see historic exceedances for lead on an annualized basis at University Point, closer to the C4 river. Trends are mixed. They're either upward or no trend if pending on site and depth. For example, at Tubbs Hill and the Fodick Zone, there's no trend for lead over time. However, if we look at University Point at 30 meters in depth, there is an increasing trend in dissolved lead over time. Note here the logarithmic scale because you get a very large range in dissolved lead concentrations from spring to summer, with the largest ranges being closer to Corvine River at University Point. Note that at both locations, we do exceed our lead chronic criteria seasonally at all depth locations. Phosphorus. We are currently exceeding our phosphorus target on an annual average basis at both University Point and Tubbs Hill. And the phosphorus concentration is always higher closer to the river. We are trending upward with the rate of change being different at different sites and locations, but consistently upward at all locations with a range between 0.2 and 1.5 microgram per liter per year. Note that there is no numeric standard for total phosphorus in Idaho, so the target here that I'm showing you is the lake management plan trigger of an annual geometric mean of 8 micrograms per liter. Take a moment to talk about nitrogen. Now, nitrogen is not consistently higher or lower at either site, and there is no measurable long-term trend. Now, if you have no long-term trend of nitrogen and an increasing trend in total phosphorus, you're now getting a decreasing trend in nitrogen to phosphorus ratio. That means that as time progresses, we're getting a higher risk for harmful algae blooms and increasing risk of cyanotoxins. This is an emerging water quality concern. For chlorophyll A, we look at two different measures. Is the annual maximum value greater than 5 micrograms per liter? And is the annual geometric mean greater than or equal to 3 micrograms per liter? The plots I've given you here are based on the current method we used since 2014, and it's a historic equivalent of what that would have been if today's method had been used back then. We have rarely exceeded the target for maximum chlorophyll A, and here only at Tubbs Hill twice in our history. We've never exceeded it for the geometric mean chlorophyll A, and always chlorophyll A is higher at Tubbs Hill and Northern Pool than University Point in the Central Pool. Now, for chlorophyll A, we do not see a trend for the current method and its historic equivalent. However, there is a caveat to that, and that is historic method yielded higher chlorophyll A values than the current one does on sample splits. That means that using historic method would have had more exceedances and also had more pronounced trends. So in an earlier report, when we looked at trends through 2014-15, using the historic equivalent as a basis for trend calculations, we did see a potential increasing trend in chlorophyll A. Take them for this is that we do not see a discernible trend in chlorophyll A, but our methods are not very sensitive, and we cannot discount the potential for there to be a trend smaller than we can measure. Now, for hyperlimetic oxygen, the LMP assesses that as a minimum value measured one meter above the bottom. That should not drop below six micrograms per liter. We have really exceeded that target only twice and only at Tubbs Hill, the northern pool, where oxygen levels are always lower in the northern pool than in the central pool. For a trend, it varies from the porting period. We have not seen a trend for either location from 91 to 2018 or 2004-2018. However, in a prior report in 2015, we did see a potential declining trend in oxygen only at Tubbs Hill in the northern pool. So here with oxygen, the trend can vary depending upon the time period you select, and it can be different between different sites. The bottom line being, we do not see a trend in oxygen, but we also cannot discount the possibility for one to be present that's too small for our methods to discern. Let's put this all together and in doing so, I'm going to revisit the trend slide that Jamie shared on Wednesday. In here, my take home is that there is a very large step change in trends as you move north of the Coraline River. Cabin and zinc decreasing north of the river, very different trends south of the river. Lead and phosphorus increasing north of the river, very different trends south of the river. Chlorophyllae and oxygen hypolyminin, no-wheel change north of the river, different trends south of the river. And this is a very important distinction to keep in mind as we move forward and start developing management plans on how we address our phosphorus issues. Let's focus a bit now on phosphorus. We look more closely and look at the rates of change at the university point in the central pool versus the northern pool. There is an apparently very small difference in that phosphorus may be increasing faster in the northern pool than in the central pool. That's a very, very small difference with relatively large error bars and you need to be very careful in interpreting it this way. What you can be more sure of is that phosphorus is increasing at a rate of approximately 2-5% of its annual geometric mean or its annual median per year. A slow steady uptick that we need to slow down and reverse in order to protect the lake. Let's take a path forward. Overall, we've made progress. Zinc and cadmium are going down. That's a good thing. We've enclosed our water quality criteria. But they're emerging new challenges and new threats. Phosphorus is going up steadily. The lake is turning away from its legitimate status. That means we need to take additional actions now to protect the lake. This is a large basin and it will take time to do sufficient actions to keep the lake in its preferred state. We need to get sufficient nutrient control to keep the metals trapped in the sediments and protect water quality from emerging threats such as blue, green algae and invasive species. What is sufficient? What does that mean? One way to define this is what is a water quality risk envelope for a zero metals condition? If you can protect water quality when there's no metals, we also protect it when there are metals that inhibit productivity. What low targets do we have to hit to stay within that envelope, both from a total low perspective and a geographic perspective that accounts for different source areas? Factor in the challenges from development and climate change. And then how do we hit those targets? What are some proven strategies from lessons learned elsewhere? There's some innovative outside the box strategies we can use here that address our non point source loading problem. With that, I think if you're time retention and happy to take questions. Okay, thank you and came in right on time. So we have a few minutes for some questions. So if members of the committee or other panelists would like to raise questions just raise your hand use the raise hand feature in zoom and we'll call you as we see your hand come up. Michael Brett. Yeah, I have a couple questions. One is what's the water residence time with quarter lane is probably already been mentioned but I don't remember that. And this I'm sorry on that is the annual average is six months, though there is a very strong pronounced seasonality in that in the peak runoff it can be as short as 90 days, getting up to about 1100 days during the summer time. When we're in a stratified condition. Okay, and one more. I think it would be very useful to also report the oxygen values as a volume weighted hypolymnetic mean for the, you know, the minimum hyperlumnetic volume weighted value, as opposed to just one meter off the bottom. Yes, thank you we've done those calculations and I just didn't get today's talk for time reasons. Thank you. James Elzer. Thank you. I just wanted to ask what the detection limit for the total phosphorus and reactive phosphorus method that you're using for total phosphorus reporting limit is four micrograms per liter. Our detection varies from two to three with our current methods. It's very different under historic methods. It was a higher detection limit. Currently for orthophosphorus our detections and one microgram per liter was reporting limit of two micrograms per liter. They get as much lower than it was under short methods. Thank you. Okay, Bill Arnold. I actually have two questions that the first one is, do you monitor sulfate and sulfide in the water of the lake. And the second is, you have information about the composition and the mineralogy of the sediments and different lake compartments. Okay, we do monitor sulfate as we get that as part of our standard suite when we get nitrate and nitrite. For sulfide we don't measure it as a regular part of our monitoring because the lake is oxic around. However, we have gotten sulfide data for the anoxic base in the northern pool during our special study that we did there. And our mineralogy is not sample the sediments on a regular basis so internally we don't have that. The USGS did a study of mineralogy is quite extensive back I believe the 1990s. Thank you. Okay. Jeff Schradhol. Hi thank you. I was wondering if you've seen any trends in algal speciation. First of all, and could you just confirm for me whether I think you said you measure seven to nine times a year is that could you just tell me what what period of the year those those measurements cover. Okay, well first on the algae, we do have data. In fact, only 2007 and there are some one off studies are the map in our data that we did our analysis we did since 2007 we did see a trend in that there was a very large. Disturbance big step change we had in those two flood years in 0708 we had a fair amount of blue green algae coming in the spring, but since then it's been fairly stable with no long term trends is about 2010. We may not have caught any very small changes since 2010 because you look at the overall data set, the very large perturbation in 0708. And what was your other question I've lost track of it. I guess I think I heard you say you measure seven to nine times a year. I was just wondering whether what the what time of year that. Thank you. Historically, like manager plan we would collect two sampling events on during rain on snow events during February and eight from February to April, they would get samples that there weren't a rain on snow event. Then we went monthly from May to September, we pick up a sampling event and turn over during October early November, and then we would get a winter sampling event. Usually at the end of November or December when they're isothermal. There were times when we didn't get out and get samples from logistical purposes. More recently we've moved to a regular monthly sampling from March through September, rather than focus number on snow events, again and turn over, and again and winter. And most recently we've started getting son only data in January and February to get some more weather data. All right, one last question. The song you use is that providing continuous. I guess spatial measurements sort of measuring at a high frequency or is it at the street depths. We can get frequency spatial data, but we've been using it at the street depths to be consistent with the way they did it. We first started back in the 708. Okay, thank you. One last question, Sam Loma. That's that man jakers. Okay, Lynn, Lynn cats. Hold on shoot. There I am. Okay, can you hear me. Yes, yeah. Right. Okay, so I was sort of curious about the anoxia study and what you mentioned that you met measured some sulfate sulfide as well as sulfate I was wondering what other specification you were able to look at there. Can you give us some insight into that. Thank you. We weren't able to get speciation we only got sulfide with a field colorimeter. We also got iron two as part of that and our standard metal and biological sampling. We weren't able to do a really focused time study we tied on those analyses during our regular sampling runs. And then a few extra runs that focused on finer profiles. Does that cover your question, Lynn. Yeah, that helps. Thanks. Excuse me. Picture. What's the matter. Thanks everyone, which time to move on to our next speaker and just remind people that of course during the committee process there'll be many occasions I think we'll probably come back with questions to these speakers and others to getting into much more of the detail but this has been a great way to get begin to get a feel for things. Our next speaker is Dale chess, he's a limnologist with the quarter lane tribe he's been with the tribe and they're like management department since the year 2003 so it turned over to Dale. Thank you. Okay. So what I'm going to begin with is describing the tribe said data that's available to the committee, and then present a subset of water quality results from the data sets. Hey, I'm sorry for interrupting. So we're seeing your, your presenter view and not the slide view. If you're using two monitors if you go up to display settings at the top there. Yes, and then click that and click on swap the first one swap presenter view and slideshow. No, we're still stuck there. If you can read you the share but select the slideshow if you already have it in presenter mode. So if you stop your sharing and then reshare and the applications that are available you should see this the actual slideshow. Oh, excuse me, I messed that up let's see this try this. Is that better right now you're not sharing anything right here. Yeah, right now you're not sharing anything. Let me back out here. Excuse me for this this is. Okay what do I need to do. So in zoom click your, your green share button. Right now I don't have. Okay, there we go. Let's see here. Okay share. Right and then out of the applications available you should see your PowerPoint slideshow. Yes, yes I do double click that. Okay, now, let's see. Now I can start the slide show. Yeah. Okay, excuse me. How about that. There we go perfect also. Okay, sorry for that. Okay, so what I'd like to begin with is begin with the data sets that are available to the committee from the data we collected, and then present a subset of some of the results from those data sets. Okay, so in the southern half of the system. For a long term data sets we sampled the St. Joe River as deep me under Ben site. Sample chat collect, which is 11 meter site in chat collect lake. And then in the Southern pool Southern Plagic pool site C five, which is an 18 meter deep site. In 2019 we added the lower Coraline River, which has, which is at the USGS and Bemp site and that's right around here by the Coraline River by the D in the Coraline River label. Okay, so on the left here is the sampling periods just just a general condition of the lake at that time. January and February we can be heard the lake to be cold and clear. It could be cold and turbid that there usually is some ice cover. Some years there's rain on snow events during that time period, and then peaks in the hydrograph in March and April, generally hydrograph driven processes in the southern part of the lake. May and June we have mixing and the beginning of week thermal stratification in July through October initial summer stronger stratification and then weakening stratification in the fall in November and December. We have significant cooling and then mixing on the right here this table shows from that time period of our long term data set from 2007 through 2020. It shows the breakout of number of times or the breakout by month the number of times we sample. So as you can see, it's heavily during the summertime spring summer and then fall and in the winter time, we have fewer samples. One of the reasons for that is that like Craig said early on in the process we were we were we were kind of sampling more of the ranch snow events. Now we're beginning to sample or attempting to sample more in winter time but as you can see in this image the southern part of the system is froze. There's significant ice cover all the way up to the East Point central part of the lake. This is from 2017 late January 2017 and we had similar ice cover in 2019. Some years it'll only the ice cover will only extend from Conkling up into C five zone and it'll be kind of rotten ice is not not very good condition. There's no way you can actually move on the ice in this area of the lake. In the southern part people do ice fishing here in chat Colette and then the St. Joe River freezes almost every year even during mild winters will get some kind of ice cover. Okay, so now I'm going to show you a couple slides tables on on what we're collecting and where are at what depths. Every time we collect chemistry samples. We do profiles and our profiles are at one meter resolution at the deeper sites. If we have a site or when we sample sites that are less than 10 meters in depth. We use a point five meter increments. We're collecting the standard physical chemical variables temperature do pH specific conductance fluorescence and par. We also have a automated bully profiler system that we've deployed mostly in the summertime or from June through November at site C five. We've collected data there we've had a bully in the system in 2011 and 2015 at site C six we've had that profiler of bully in at site C six or I'm excuse me in the years 2014 and 2018. Those are collecting a temperature do pH and specific conductance. Also, in 2018, we began doing CTD profiles with just a small YSI little orange pill CTD at every site when we collected water, water chemistry samples. Just real quick, we also have three weather stations, one at East Point, one at shingle Bay point and then one at chat collect in the southern part of the system. Those are collecting data or logging data every five minutes. Okay, so we collect metals told recoverable and point four five micron filter from the photo zone composite, which is a it's a five it's five distinct grabs at equal distance in the photo zone so let's say the photo zone is nine meters deep. We would grab a sample at 1357 and nine meters, and then we combine those in a chair splitter and filter from there. We also sample one meter above the bottom. And beginning in 2017 we started to do an Epilemian composite because as Craig had mentioned previously, many times the photo zone will extend through the Epilemian and actually through the metal and in some cases into the hypolimia. So it kind of clouds that floating zone sample, the epilimetric sample of course collects that water that's being mixed in the upper water column. As Craig mentioned lead cadmium zinc arsenic iron manganese magnesium calcium. We do collect that there's a question of sulfate we do collect sulfate or analyze for sulfate also for nutrients total phosphorus orthophosphate told dissolve phosphorus total nitrogen ammonia nitrate and chlorophyll a and beginning in 2019. We started to collect the total organic carbon and dissolves organic carbon at these sites. I think one of the strengths of both these data sets of the cranks data set and ours is that we have phytoplankton composition taxonomy and counts every time or near every time we collect chemistry data. Also, one of the another strength is generally there have been mixing of labs at some point. I think IDQ has has has maybe used a couple different labs we've used shimikin creek laboratory which IDQ also uses. We've used that laboratory since the beginning. EPA Manchester laboratory has done all of our metal samples and one taxonomist that advanced eco solutions has done all of the phytoplankton work. Okay, now to some data. This is a chlorophyll a it at site C five that Southern Pelagic site. This time series shows no significant trend of given or using a mechanical test. The maximum is generally between three and four milligrams per liter and in many years that maximum is in late fall. We've had a maximum chlorophyll of at C five in December on to zinc. So this is a point four five micron filtered zinc at site C five. The there's two two figures here the top figure is the voting zone, the bottom or and the bottom figure is one meter above the bottom. The bottom is has a higher concentration shows a higher concentration of zinc and it's significantly higher in the summertime as compared to voting zone. One thing to notice is this this real dramatic seasonal effect below detection or below reporting limits of five milligrams per liter. Many years or most years in the spring and then increasing throughout the summer to some high levels. In fact, these levels here are these excuse me these concentrations here are actually higher than the northern than some of the northern cool samples you'll see during summertime. So the zinc concentration is actually higher at C five in that southern zone at times as compared to the northern pool. Another way to look at that is to just break out all the sample points and compare the bottom versus the floating zone from day of year standpoint on the X axis. This shows that seasonality. This is the lowest fit. And with the shaded area being 95% confidence servals. And once again, as I, as I said before, significantly higher concentrations later in the summer and that increases throughout the summer from these lower samples near detection limits actually in the early spring. So a couple of questions is why what's driving this is a hydrodynamics is it being resupplied from the the central pool from the north. Or is it or could it be excuse me enhanced bent pick flux from the low dissolved oxygen at the bottom at C five. Okay, in this slide we're comparing the St. Joe River hydrograph from 2011 here in the blue and 2015 in the orange. I picked these two years because they show how just how different the magnitude or the intensity of the hydrograph can be the high variability year in and year out from the St. Joe River and that directly affects site C five and the entire lake actually during that time period. We from the profile or dissolved oxygen data where the sensor was was collecting data at 16 to 17 meters. This shows the minimum dissolved oxygen concentration at the or near the bottom for those two years. As you can see, in 2011, there still is a saying there's a saying at site C five, a deal completion saying it's like C five every year regardless of hydrograph. But in 2011, there was later stratification thermal stratification development, and the water was much cooler later into the early summer and later stratification and the deal said isn't as prominent or as intense as in 2015. Which is the low, low flow year. It stratified early. And as you can see the DO, the pollution rate was quite significant down to 1.5 milligrams per liter on the 11th of October 2015. One thing I want to point out also are these spikes here in the hydrograph. Both years had rain on snow events, different intensity, but both significant. And this is, this is sometimes it's common. We've been through the last few years have been through a period of lower or I should say less intense small thoughts, but nothing like these types of rain on snow events from earlier in sampling. Okay, this slide busy and excuse me for making this busy slide. However, I just wanted to show or give the panel one slide that they can go back and look at for reference of some of the special studies and the data that's available from the special studies. We looked at low, the lower Cornelain River meander bends and the effect of anoxia on on the release of metals and nutrients in the system. We compared the inundated lower river deeper sections versus the free flowing catalog section because there's quite a difference in the amount of total lead, for instance, in the lower river compared to that upper lower part of free flowing segment. One of the keys that I think are important parts of this data set is that we have total metals we have the point four five fraction but we also have a point one micron filtered fraction. So I believe we have the ability to estimate the particulate the the colloidal and the approaching or the ionic form of those metals from this 2015 study. There's two reports for or there's one report for each one of these two studies. And let's see in 2019 we did the we collaborated by BQ the state and we did a dissolve oxygen synoptic at 25 meander bends in the lower river. Let's see for the lateral lakes we pretty much looked at the summertime limology of Thompson and Swan Lakes couple of different lakes. We talked about that later how those lakes differ. But we looked at metals, nutrients, doc and chlorophyll also in 2015 we analyzed for zooplankton metals burden, which I'll show you later. We have profiles in most of the lateral lakes throughout the years, usually during the summertime, but they extend they can extend from spring through early fall until it's difficult to get back into those lateral lakes because of like drawdown. We have metals in the macro fights from some of the lateral lakes. And once again in 2019 we did more of a little logical investigation or a little more intense investigation in Thompson Swan Lakes and looked at metals in the particulate organic matter. Also, we sampled or analyzed for TOC and DOC. In the lower St. Joe River, our low metals reference area. We have been a while lake and round lake where we collected data from 2011 through 2020 from June through October at those two sites in 2020. 2020 we have some we had some DOC and TOC at those sites and then another synoptic in 2020 of 12 meander ben sites in the lower St. Joe River. This is a map of the Coraline River. These dots here on the meander ben are the sample sites for the dissolved oxygen synoptics that we've done. Here's Swan Lake, Thompson Lake. This is the lower river site. It's the excuse me, it's the BEMP and EPA's USGS gauge site. Here's Harrison, the city of Harrison and Black Lake here. All of these we've done work on and then for reference here site C5 in that southern basin. They're all about two minutes. Okay. Okay, so I moved these pretty fast. These are the effect or this is the effect of anoxia on metals liberation in some of those meander ben sites in the Coraline River. One of the things to look at here is this thermal stratification. It doesn't look real significant, but it's enough stratification to drive this DO depletion in those meander bends. Excuse me. Once again in the lateral lakes, anoxic hypolymins with high concentrations of total metals and total phosphorus. Total phosphorus here. The red is the hypolymine. Okay, this iron and manganese part of the figure is in milligrams per liter. The rest is in micrograms per liter. So there is about 23 milligrams per liter of total iron in the hypolymine of Thompson Lake. This is what it looks like in the Churn splitter. This gray water here. Excuse me, this is in 2018 after turnover in Thompson Lake, what it looks like after turnover mixing. Okay, this is the metals in zooplankton metals burden in zooplankton in Thompson Lake. This is lead. This is cadmium Thompson versus swan. Now I'm going to move on to the dissolved oxygen synoptics in the lower river. So in 2019, 15 of 25 of the sites we sampled were anoxic in the lower Coraline River and in the St. Joe River in 2020, 10 of the 12 sites we sampled were anoxic in September. And I'll just leave it at that. These are my summary points in my presentation and you can look at those. I'll just, well, actually I'll have that keys. So the first one is high seasonal variability of zinc in the southern part of the system. In the lower Coraline River and St. Joe River systems, they have hypoxic and anoxic and the underbends during thermal stratification. In the latter lakes, even with the stew of metals contamination, the latter lakes are quite productive. And one general trend throughout the basin to think about is that the zinc to phosphorus ratio is decreasing in the lake and and basin wide. And I think that's one of those metrics we really need to look at closely. Okay. Thanks, Dale. So now we'll go to questions. Let me bring up the screen there. So please raise your hand. If you have a question. Let's see, Alejandro Flores. Thank you for that presentation. The, yeah, I have one question about the the Met stations that you the slide that you had on the Met stations. I noted that for two of them, there was a 2019 end date. And so I was wondering if that indicated that either the data is no longer being collected at that side or that's just sort of the end dates through which QA QC data is available. And I also noted that there's solar radiation indicated at those sites and I wonder if there's any net radiation data available at any of those sites. Okay, so for those, for those sites, the, the chat collect sites, so the, the, the further southern site is currently operating that site is collecting data. And, but for the shingle Bay Point site near site C five and the East Point site, those stations are not collecting data now. Basically what happened was that we haven't been able to really get to them and fun to get the new batteries and solar systems for them they pretty much run out of their, their, their cycle. We are going to get the stations up and running again we have new animometers, you know so they will be up they will be clicking data once again. Okay, Allison Colin. Thanks. Can you hear me. So I was just intrigued by something I know that USGS has done some work on wildfire and water quality and they are definitely picking up metals in water related to wildfires and we've had some really big seasons here in the northwest and certainly I'm further west of you all but I'm just wondering, are you seeing any of that sort of impact I know you're you know peeking with some of these metals in the late summer and that's like that's our fire season right the August September. I don't think there's enough of a signal against the signal of the waste that's already there but it's kind of intriguing and I'm just wondering if you see that or if you think that's related to any of the trending that you see. Well, I think it's really tied to the I mean part of part of that issue is that when we have when we tend to have, you know, high fires, or a lot of fires, the best during a time period when the hydrograph is is really low. It's really low summer, you know, low summer flows. And, and I think those those fires also there's there's a correlation between the fires and then snowpack. There's, you know, the there's real elevation gradient in this system, and I think that, you know, that snowpack those wet snowy winters, we may not see fires, the fire intensity that we would see in the drier seasons. 2015 had a lot of fires. Right, that's what I was looking at on your 2015. Yeah. Yeah, so you really barely see across the lake. But I don't think we're really picking up that that signal from those fires is because the hydrograph is so low. What I do think could potentially be happening in the southern part of the lake is, is those fires, the huge amount of smoke from those fires might actually be reducing our cyanobacterial blooms because it's adding a nitrogen to the water column. And it's actually, we believe it's shifting that end of P ratio in the late summer, when that would, you know, provide a lower end of P ratio for cyanobacterial type of blooms. Got it. Thanks. Okay, James Elser. Hey, Dale. I was interested to see the data on metal contents in zooplankton from the lateral lakes. I'm wondering if there's similar data from from Coeur d'Alene Lake or metal contents in zooplankton biomass and is anyone looking at metal contents and fish. So yes, there is. I think it was, we collected data in 2012 at three sites in Coeur d'Alene Lake. And there is some metals burden, zinc, and if I remember correctly, cadmium, I can definitely share that data with you. It's much, it's a much lower burden than what we find in the lateral lakes. Swan Lake is exceptionally high, very hot. Yes, there is some data from that from from the main lake. And your second question, excuse me. Yeah, are there similar data for fish, both in the lateral lakes and in Lake Coeur d'Alene? Yes, there is. There was a, there was an updated fish consumption advisory report that came out just last year. And that data, if I remember correctly, was collected in 2017 or or 18. And there's very current data. So there is, there is metals, metals in fish tissue results also. And oh, one more thing in the southern part of the system at C6, Round Lake and Benoit Lake, we just, the tribe just started to collect mercury samples. So we have some mercury data from 2020. Okay, we're done with the last couple of questions. Robert Anir. Dale, thanks for the presentation and thank you for all from the folks here at IBQ. It looks like you collected quite a bit of data from the lake itself. And it looks like you collected some data from the rivers. Has any attempts been made to draw any kind of relationship between the seasonal trends that you're seeing in the lake and what kind of loading might be coming or concentrations are coming out of the rivers? Yes, I've been doing that. That's what I've been working on the last year, just looking at that potential correlation between hydrograph intensity and loading, especially from the St. Joe River on site C5. Given the high variability, there is actually a relationship. It's weak. But for instance, if I look at loading intensity and loads from St. Joe River, there is a, there is an effect on chlorophyll, chlorophyll A if I believe, so there's also an effect on overall phytoplankton biol volume. But it is weak. Lynn Katch. So I wanted to actually follow up on that last question, too, about the loadings. Is that been looked at for metals coming into the system as well, or just nutrients? So yes, well, there has been loading. I'm not sure if we really synthesized or looked at the actual effects of the loading of metals, aside from the model of loading of metals in the system. There are other folks that can, I think, better answer that question. Maybe Lauren can answer that question better. We do know how much, for instance, we do know what amount of metals that enter the system are retaining the system and how much lead through the Spokane River. So we have estimates of that. There has been a lot of work done in the past. Good. And then, can I just follow up with one more time? Go ahead. So what's the extent of the TOC and DOC data? I know it was just in a couple years and it was in that, was it just in that special study? No, no, no. We started in 2019 collecting it in the Lower Carling River at site C5, at site C6, and in the lateral lakes. So there's only two years worth of that data, but there is a time series of TOC and DOC. Right. Thanks. Okay. One last quick question. Laura Ailers. No, my question is not quick. So I'll defer to the Q&A at the end of the panel. Okay. Great. All right. I think we're right about on time. The third and last speaker in this session is Lauren Zinzer of US Geological Survey. She's a hydrologist, has been working on the river inputs. And so it's, it's timely with those last few questions that we're relating the lake condition to the river. So Lauren, go ahead. Good morning. I think everybody can see and hear me. All right. So thanks for having me. Again, my name is Lauren Zinzer and I'm hydrologist with the US Geological Survey. I'll talk a bit about recent USGS data collection and trends in the Spokane River basin. And as you'll see, the most recent USGS data really focuses on the rivers in the system rather than the lakes. So that's in contrast to the presentations we've heard already today. All right. So the USGS has done a lot of work in the basin over the years. Briefly, there were multiple special studies completed in the 1990s and 2000s. This includes limnology studies by Woods, phosphorus, zinc, phytoplankton interactions by Cooabara, metals, geochemistry and bioavailability by Ballastrieri and various distributions by Fox. However, I'm not going to talk about this today, so I'd refer you to the bibliography if you want more information about those particular studies. So mostly what I'll focus on here is the long term data collection that USGS does and the most recent trend analyses that are based on these data collections. The USGS collects measures discharge and collects water quality samples throughout the basin. Sampling consistency was fairly variable prior to the late 1990s. The sampling program became unified under the EPA's Basin Environmental Monitoring Program in 2004. The explicit purpose of the BEMP is long term monitoring to evaluate remedy effectiveness associated with the Superfund site. So as you'll see then most of the data associated with this program are concentrated in the Coeur d'Alene River Basin, and they are mostly focused on metals, although there is some nutrient data as well. These monitoring data really underpin the long term data, the long term trend analyses that I'll discuss a little bit later. So here's an overview. The USGS has many, many gauging stations throughout the Spokane River Basin. I'm highlighting only a few here that I think are especially important and give a sense of the length of the records available. The oldest gauges are up on the North Fork of the Coeur d'Alene at Enneville up here, the Coeur d'Alene River at Cataldo here, and then the St. Joe River at, sorry, the St. Joe River at Colder, and those came online about 1911. In the late 1980s additional monitoring stations came online in the South Fork Coeur d'Alene River associated with the Superfund site. The most recent gauges that came online are those associated with the mouth of the Coeur d'Alene River and the mouth of the St. Joe River, and the outlet to the lake at the Spokane River, and that's because those sites are affected by backwater conditions and that makes measuring discharge a little bit tricky. So a little bit more on discharge data. The USGS gauging stations do not directly measure discharge. Instead, they generally measure stage or velocity. These parameters are related to discharge by periodic discharge measurements taken onsite by a technician and then these relationships are used to develop rating curves to correlate stage or velocity to discharge. Most of the gauges in the basin are stage gauges, but the backwater affected sites are index velocity gauges that use acoustic Doppler velocity meters or ADVMs. The USGS started using these in the early 2000s and ADVM gauges were installed shortly thereafter in this Coeur d'Alene River near Harrison, St. Joe River at Ramsdale, and the Spokane River at the lake outlet. Similar to discharge, this is by no means a comprehensive list of all the sites in the basin that have water quality data. Instead, I've highlighted some of the most important water quality sites, at least in my opinion. And in particular, these are the ones that I used for the trend analysis that I'll discuss later. Some of these sites have water quality data dating back all the way to 1971. But the year noted here is the year in which sampling became sufficiently regular that I was comfortable including an in data analysis or in trend analysis rather. The longest well sampled periods began around 1990 and are associated with characterizing the Superfund site and sites continue to be added where more definition was needed thereafter. The data water quality data and the discharge data are all available on our website and with some sure many of you are familiar with that. Samples are collected using standardized sample collection methods sample samples are isoconetic. That means that the concentration of sediment for example are constituent in the water is the same flowing into the sampling nozzle, as it is in the water flowing around the sampling nozzle so the effect of this effectively is that the sampler itself does not bias the sample. Samples are also with in depth integrated the right diagram shows this the sampler is lowered through the water column at the same rate and equally spaced intervals. This results in the sample collected being proportional to the discharge and each interval this is important because constituents are not necessarily evenly distributed through the water column. So this sampling method accurately represents the total mass of the constituent across the full river cross section. As you can see the bridge crane and sampling device the bridge crane lowers and raises the sampling device through an increment and then as advanced across the bridge to the next increment. The technician empties the sampling device into the churn splitter which is shown in the back here in the blue bin. As you can see from it fills the churn splitter is then taken into the mobile sampling lab, where whole water samples are are distributed into bottles in a homogenous way and then processing for filtered samples takes place in a chamber, which isolates the sample from contaminants. Analyze measured in the space and have varied over time but they currently include totaled and filtered metals, including arsenic cadmium copper iron lead manganese and zinc. There are a variety of totaled and filtered nutrients this includes total phosphorus dissolved phosphorus orthophosphate total nitrogen organic nitrogen nitrate plus nitrite and ammonia. Major cations measured are cat calcium and magnesium and that's that we can calculate hardness and suspended sediment concentration. So these long term discharge and water quality data are really the foundation for all the subsequent trend analysis the USGS has published multiple analyses over time, which have also clearly established the patterns of metal transport. Some of the speakers on Wednesday touched upon this but I want to give you a quick reminder of how metals move through the system. Most of the cadmium and zinc in the system is dissolved in the zinc trends are generally a pretty good proxy for the cadmium trends. Most of the lead in the system is particulate high flows transport the biggest loads of all constituents, the highest total lead and phosphorus concentrations also occur during high flows, and the highest dissolved zinc and cadmium concentrations generally occur during low flows. With metals transport fairly well understood in the basin the most recent trend analysis focused on trace metals and nutrients and covered water years 1990 through 2018. The main research question was fairly simple, how are concentrations and loads changing over time. The report covers multiple constituents but I'm only talking about dissolved lead total, or sorry dissolved zinc total lead and total phosphorus in this presentation. As I understand changes in concentrations and loads over time I used a statistical approach called weighted regressions on time discharge and season. WRTDS is a highly flexible regression approach that uses the relationships between concentration time discharge and season to estimate concentrations each day during the study period. These estimates can then be used to estimate flow normalized annual mean concentrations and annual total loads flow normalization in effect estimates what concentrations and loads would have been for a given year. If the hydrologic conditions have been average, as we know loading concentrations scale with discharge so this particular approach is best for trend detection, because it smooths out some of the year to year variability associated with higher low water years. I used WRTDS with Kelvin filtering to estimate annual mean concentrations and annual total loads. This approach provides the best estimate of actual annual conditions because this model is forced to respect the sampled concentrations on sample days. And finally I used a bootstrap model or bootstrap approach pardon me to model concentrations many times over in order to construct confidence intervals around the trends. The data are then used to describe the statistical likelihood of the trend direction. I should note here that all these statistical approach approaches were developed by our moderator here today Bob. So jumping right into the trends results I'll take a moment to orient you to the graphs because these graphs will show up again and again over the next couple slides. This shows dissolved concentration in micrograms per liter on the right hand side and dissolved zinc load in metric tons per year on the right hand side. The horizontal axis shows the water year, black dots are WRTDSK annual mean concentrations and annual total loads, green and blue lines are WRTDS flow normalized annual concentrations and annual total loads. I have just three key sites shown here. It's the South Fork Quarterlane River near Pinehurst at the top which of course represents the contribution from all of the South Fork Quarterlane River. The Quarterlane River near Harrison which represents inflow to the lake, Spokane River below the lake outlet which represents flow out of the lake. As you can see the decreasing trends are striking in both concentration and load in the South Fork Quarterlane River near Pinehurst. Decreasing trends are also strong and striking as you move downstream in the system through Quarterlane Lake and even in Spokane River below the lake. And although the absolute constant, although as you can see the absolute concentrations get lower as you move down through the system, at least at the Spokane River, and the flow is also very as well. Also the period of record changes and that's sort of an important thing to note these data records are not the same in length. Overall at these three sites dissolves and concentrations and loads decreased 35 to 65% over the period of record. So what level of statistical confidence do we have in these trends. Here I'm showing the results of the bootstrapped models represented in plain language. So if, for example, the trend was down in 85 or more models out of 100, then the trend was considered likely down and that's shown by that dark blue downward pointing arrow. So if the trends were down in 70 to 84 out of 100 models the trend was considered somewhat likely down and those are shown by the unfilled blue arrow down arrow. So here I'm showing the statistical confidence for all of the sites that I did trend analysis for not just the three. Concentration on the left hand side and load on the right hand side the trends over the entire period of record available for each given site across the top, and then the trend over the 2009 through 2018 period on the bottom. And so what you see here is that for dissolves and concentrations and loads decreases were statistically likely at the mining affected area over both periods of study, although the magnitude of the change was somewhat smaller in the most recent, recent decade. So here we have the same graphs but this time showing total lead concentrations and loads. As you can see concentrations and loads were strikingly down over the period of record in the south for quarterly near Pinehurst and somewhat down in the Spokane River. In contrast, lead loads were actually up a bit in the quarterly river near Harrison. So overall lead concentrations and loads decreased 25 to 75% over the period of record at these three sites, except for at Harrison where loads actually went up slightly by about 25%. So looking now at the statistical confidence and in the lead trends for all the sites across across the basin that were analyzed. Total lead concentration and load decreases were statistically likely for most mining affected sites during both periods studied. However, the total lead load in quarterly river near Harrison had a somewhat likely increase over the period of record and somewhat likely decreases and decreases were only somewhat likely in 2009 through 2018. So though the Harrison lead results are really quite different than the zig trends and the some of the lead trends at the other sites these these results are in line with what we expect giving metal sources transport and remediation in the basin. So just as a quick reminder, as I mentioned earlier, previous research has shown that most of the dissolve zinc in the system comes from the south for quarterly river and tributaries. Most of the remediation to date has also taken place in this part of the basin. In contrast, most of the total lead comes from the main stem quarterly river and relatively little remediation has taken place in this area so far. The metal trends that we're seeing, although they're somewhat different for zinc and lead, especially at Harrison are consistent with how metals move through the system and what we know about metals remediation in the system so far. This really stands in contrast to total phosphorus because the total phosphorus trends look quite different. So total phosphorus concentrations and loads actually went up in the south for quarterly river between 1992 about 2000, and then they leveled off and then actually go down slightly in the most recent decade. This is also true for loads in the south for quarterly river near Pinehurst. The shape of the trend is quite similar at Harrison, although the magnitude is somewhat different and the timing is somewhat different but again we see that concentrations and loads go up somewhat. They flatten off in the, in the 2000s and then they are actually declining slightly in the most recent year, although not shown the trends for the Northport quarterly river are fairly similar to those that are shown here for the quarterly river near Harrison. And the concentrations in the Spokane River below the Lake Outlet actually go down somewhat for total phosphorus concentration and loads are down a little bit but more or less down a little bit. The other thing that's really important to note here though is that there's a really big difference in record length and that hampers the comparison. So consistent to total phosphorus data go back to about 1990 for Pinehurst, but only back to 1999 for Harrison in 2003 for Spokane River. And so that makes comparisons between these data sets really really a little bit tricky. Again at all the sites across the entire basin, we see primarily here that the variables are the trends are variable spatially and temporally some sites have up trends, some sites have downtrends. Some sites have no clear trends which are shown by the gray dots, and some trends and some sites have insufficient data to model. So in order to try to try to, or again variable record lengths make the site to site comparison a little bit tricky for these constituents and especially can found the total phosphorus interpretation because those lengths vary so much. So, I looked at these data a little bit differently. For this reason it helps to look at these trends using standardized time intervals but the trade off here is that we're not looking at the period of the most dramatic increases which is the 1990s because there's really only one site for which we have data on that. So here the slope of the low trend is expressed as a percent per year on the vertical axis, the sites are shown across the bottom. 2002 to 2009 are shown in yellow 2009 to 2018 are in blue. The dot represents the median bars represent the 90% confidence intervals. So as you can see for the North Fork, or sorry, pardon me, the South Fork Correlate River near Pinehurst, the North Fork Correlate River and the Correlate River near Harrison you have similar patterns of it actually for Smilterville as well you have similar patterns of increasing in 2002 to 2009. And then you have decreases in 2009 to 2018 Smilterville is a little bit more ambiguous it's hard to say which way that is trending in the most recent time period. So the other two sites that had enough data to do this analysis Canyon Creek and South Fork Correlate at Elizabeth Park the trend direction is really ambiguous for both of those time periods. So suffice to say that there's a lot of variability in the sites and then the time periods of the trends and what does this mean. Well here honestly we're faced with the limits of a trend analysis trend analysis is really good at showing what happened, but it's much more limited than what it means. So for the metals we have a really solid conceptual model in a good understanding of the site remediation history and those bits of information that are external to the trend analysis are fully congruent with the trends we see so I'm a little bit more confident in describing what's happening. Unfortunately, we have much less phosphorus data and much less of an understanding of phosphorus loading transport and transformation in this particular system. For me, this really points to a key unresolved question which is what mechanism or mechanisms increase is is can possibly have increased phosphorus drastically in the late 1990s, increased phosphorus less so in the 2000s and then in fact to decreased phosphorus someone in the 2010s because that's really a little bit of an odd trend. So this summary real quick here, conclusions from this most recent trend analysis decreases and dissolves zinc and total lead concentrations and loads at most sites are large statistically likely inconsistent with conceptual models of metal transport and timing of remediation activities, somewhat likely increases in lead loads and the quarterly and river near Harrison are consistent with the conceptual models for lead transport and limited main stem quarterly and river remediation. So phosphorus trends are highly variable across the Spokane River both in space and in time, and are based on limited data and lack of clear conceptual model for sources and transport. So again, to me the key remaining question is really what is driving phosphorus trends in the Spokane River basin. And I think there should be plenty of time for questions. All right, we'll take questions. Thank you Lauren. Okay James Moberly. Thanks Lauren. I saw the data for phosphorus and you mentioned for lead zinc cadmium. Do you have also data for arsenic and and some of the other redox metals in the system. There is data for arsenic copper, I think those are probably two manganese iron but I did not do trend analysis on those just because you only have so much time for those constituents available. Okay, thanks. Sam Laoma. Nice presentation very nice. How does total zinc, have you have you analyzed trends in total zinc I mean that's comparable to total lead because of course suspended sediment concentrations are involved in the totals. So how does total zinc compared to dissolve zinc in terms of in terms of trends. Yeah, good question and so for for most the vast majority of the zinc and cadmium both present in the system are actually present in that filtered fraction that less than 0.45 micrograms. There is a little bit of a particulate component to zinc and cadmium both in the transport for the particulate component is more comparable to lead. Those are constituents that you see occurring most prominently during high flow events in particularly in the lower base and they tend to pop up at a little bit higher concentrations but overall because most of the signal for the zinc and the cadmium is dominated by the dissolved the overall trends track pretty closely trends. When you say most of it does that mean that constantly okay that that explains what if I could ask one additional question just a minor one, I must have missed it. This has to do with the value of absolute loads instead of trends but do you does the does the sampling concentrated all on first flush to get loads or is it kind of regular. How's the sampling. I probably missed that but anyway, no you didn't miss it I missed it. Thank you so thank you for bringing it up. We've tended to concentrate the sampling associated with the BAM for high flow loads because or high flow events because that is where most of the loads are. It's hard to get winter flooding events which can be really really significant the biggest biggest transport events and the biggest floods have been rain on snow events historically so it was a rain on snow event we always try to get those. We also try to get the peak of the hydrograph which on any given year is often the biggest loading event we also get a receiving limb of the hydrograph and then we get a base flow samples so over time our sampling and that's, I should say to that's that's for about the last 10 years we've we've sampled in that way the sampling strategy has varied over time we've had different programs with slightly different goals, but generally we've focused more on high flow events that on low flow events. Thank you. If I could just follow up with that so about how many samples might you get any year at some of your major sites. So currently we get four samples per year at the major sites over time that's probably varied between about two to eight samples per year depending on the specific program. Bill Arnold. Lauren, I like this data set a lot I was just curious, especially with regards to the changing process over time is, do you or does someone else have data on the changes in land use in these watersheds over the period where you've been collecting data. So I think honestly the person who's done the most thinking and the most data analysis on that is Craig Cooper who you heard from in the last or the last couple of presentations he did did a nutrient inventory analysis that was really quite extensive. And he looked at some of those land change and other things that could have potentially been impacting phosphorus loads with a little bit more detail than I was able to. You want to follow up on that. William. Bill. If there's time that'd be great. Go ahead. We did use satellite data to look at changes in land use, including changes in forest cover, and there are some significant changes in land use and some focus areas of the basin, but a broad large scale it's very comparable over the decades. And brings to the go on to that more later if you wish. Thank you. I can follow up somewhat along a similar line. Really to all the panelists and that's a question about. So there's a number of really small tributaries that that drain the areas close to the lake and I gather that some of them are areas that have seen a lot of population growth in recent years as well as a fair amount of agricultural activities. Does anybody really have long term water quality records on some of these smaller tributaries that are quite close to the lake. That is a huge data gap. And we're working on getting that now in the study started in 2018 for inventory we really had to resort to spare modeling which didn't show that type of distribution. That's a really big question that we're addressing. We also kind of tried to get it in the lake effects with our firefighting study. You can go that much with detail later as you wish. I can add to that we, yeah, we can supply some information on some of the nutrient work that we that we did in the early 2000s, several years, we did, I think there's four or five streams. On the tribal side that that have that we have data for. And were those, is there sufficient information to crowd to compute a load. At least for the years that were sampled. In other words, is there discharge data to go along with that water quality sampling data. Yes, there is. Yes, there is estimated daily numbers for those streams. Yeah. And on our current study, we're getting very detailed discharge, as well as phosphorus data. And I think we now this year have enough to start calculating loads for the 12 tributaries are working at right now. Okay. I see Laura has her hand up Laura Eilers. By the way, I think we should open up questions to all the panelists now before our break happens. I'm trying to kind of get my hands around the whole sampling enterprise. And it seems to me like what I heard was that IDQ is in the northern part of the lake, north of the, the confluence with the Coraline River. And that is certainly monitoring the southern part of the lake but also seems to be monitoring in the Coraline River which is not technically part of the reservation, correct. And also monitoring the St. Joe River and then the USGS is really strictly limited to the Coraline River and its tributaries is that, is that correct. The USGS also samples in the St. Joe River basin and the Spokane River and so really we're working on the major, the major systems into and out of the lake. But not in the lake itself. Not presently. I could Laura, historically, there's a good deal of USGS work in the lake and the lake sediments, but that's 30 or more years ago. Correct. Okay, thank you that's helpful I just for purposes of requesting data which I'm sure the committee will do. And make sure that we're asking all the right people, depending on what it is and then we just got Bob to eliminate some gaps which are perhaps data on the small tributaries coming into the lake I'm wondering if the free panelists could comment on what they've perceived to be data gaps that they would like to fill if they have more resources. From a DEQ perspective we're focusing on two data gaps. One is that tributaries information it's a really huge gap and it's a big effort to get that we're also there's a data gap in what the winter looks like on the lake in January and February. There's often we get out there in March or April we do see increasing chlorophyll a with depth showing there may have been a large bloom but we don't have data on that. So those are two major data gaps and that we're focusing on the most. So, yeah, I can add so I think one of the big data gaps we have is we were kind of heavy on on total loads total loading into the system in the lake. So I think a really good idea of how much of that total load in particulate form is moving through the lake and then or or ending up in sediments. So I think, you know, some sesson trap data would be really good to begin to parse out that particulate form and from a modeling perspective, we have, you know, we have these, we have this photo zone composite which is really kind of fuzzy. We need more discrete depth grabs for chlorophyll for nutrients for metals. And then that would help a lot with the modeling component of it which I'll talk about later. Um, I should also add that there's a gap on tying the river to the lake very good to get a more better data set that has more sampling frequency and covers things like conductivity at the Harrison site over the USGS and also some more data in that area where the coin ever comes into the lake. Lauren, did you want to add anything. I think from my perspective for for long term analyses more frequency is always nice. So if you can get it up to more times per year and if you especially as we start to all think about the low flow dynamics I think historically that's a little bit under represented in the USGS data. So I think those are two places that would be nice. I think the lower basin, the lower court lane or the main stem court lane river in general it would be nice to have better spatial coverage on that part of the river because it's a really complicated system. And I think it's quite possible that a lot of the phosphorus transformations and loadings are are tied to that part of the basin and we just don't have great special spatial or temporal coverage of that part of the system. Okay, I think we have time for one last question that's from Scott Fendorf. This is a general question, mostly towards Lauren. You mentioned a study from Lori Ballester on the poor what interstitial poor waters. Is anybody else monitoring that and that was back done in 92 the reports 98. But all the data seems to support that there's been thick fluxes coming out and my curiosity is, if we want to understand my take is that if we really want to understand the fluxes coming out we need to understand the diagenic processes in the sediments that are that are happening and we could follow up on specific but the redox active elements going from anywhere from iron sulfur to to the follow on what's that's doing to lead and cadmium and arsenic. So the question is, is it anybody tracking poor water data in the sediments. The short answer is no not since Lori did her work Ballester Ballester area did her work, though the EPA is doing a little bit of limited research into this or planning to do a little bit of limited research in this and some of the wetland areas in this coming year but basically it's been a really important but relatively understudied area as far as I understand and possibly Dale or Craig might have other insights into this but I don't know of other data sets that are specifically looking at water. Yeah, we haven't studied ourselves at DEQ but there was a recent years of Idaho study with us and core incubations and looked at fluxes in the poor waters I understand it. Yeah, I like oh I think also add. I think we need to we need to take a subset of what Horowitz did back in the 90s and and look at those and look at the sediment concentrations again because I think there is significant depth of flux especially with with zinc. And I think that that would begin to help us understand what those changes have been in the sediments. If I could just make this the last part just and it's more common than anything and looking at the profoundly decreasing trends in the metals that Lauren showed us in the rivers. One would think that the that a core of sediment from the lake would would show that history from extremely high deposition rates of the metals to to sediment that's much cleaner, still not clean but much cleaner. But is there any coring work that would describe sort of the history in out in the lake or the lower rivers. There hasn't been any sense the Horowitz studies in the 1990s when I set up to do that. It would be great to get that data. All right, well this has been an excellent presentation I think all of our speakers for crisp and on time presentations and we have a half hour break Laura Ailers did you want to or Sam did you have anything to say before we go to break. Laura, my schedule says a 15 minute break you got a half hour. I'm sorry. I'm sorry you're right 15. Okay, so let's see everybody back then at depending upon your time zone that'd be 1045 in the Kurtle Lane time zone. 940 or I'm sorry yeah 945 west coast and I won't translate the rest of the 15 minutes. Welcome everybody back. Welcome back everybody sorry. So on now to our move on to our second half of the panel discussion in this case the discussion of water quality models and this will be moderated by Jeff Slato. Okay. Thanks Sam. And good morning and good afternoon everybody. So in the water quality model panel discussion we have for presenters so without trying to take up any of their time let me introduce the first one. That'll be Craig Cooper from IDQ. Craig. Take a moment to talk about the lakes conceptual model and its key components. The first is that geography and bathymetry create four distinct physical and biogen chemical regions. These being the Southern Pool, the Coil and River Mixing Zone, the Central Pool, and the Northern Pool. Hydroclamid is no dominated and generates a highly variable hydrology and also responds to Enso cycles. River hydrology is the dominant physical and biogeochemical control in the lake. Other factors are also important such as diurnal wind fields, smaller tributaries, and winter precipitation as well as summer evaporation rates. The lake has a strong seasonality. We also know that metals inhibit lake productivity. Now from the sediment perspective an oxycypillenium trap set of metals under an iron oxide cap. That cap can break down if the overlying waters in the hypolyneum become hypoxic. That means we do not need to get to zero oxygen before metals come out of the sediments. We can maintain an oxycypillenium with sufficient nutrient control face a long-term challenge of how we maintain that sufficient nutrient control. Let's talk a moment now about hydrology and seasonality. We've previously talked about how the Coil and Enso rivers go through a strong seasonal hydrologic cycle as dominated by snow runoff. The combination of two rivers into the lake creates a very strong seasonality in the lake's hydraulic residence time. Now this box plot is based on AEM3D model predictions provided to DEQ by Dr. Michael Anderson, professor emeritus at UC Riverside. And a key feature of this is that during peak runoff months the average residence time is about 90 days to be shortest 30 days during high flow years. This means that the lake doesn't work like a conveyor belt, a continuous system. Rather it gets a big pulse that can fill the entire lake inside of three months and then it cooks the rest of the year and then pulses again. Kind of like a heartbeat pulse, rest, pulse, rest. We can also break the lake into five hydrologic seasons. Those being early spring with our shortest residence times, increasing through late spring to our longest residence times during summer, decreasing during fall turnover when we also have draw down for the post-fall stand, to winter time when we start to get our winter snows, again then reaching our fastest residence time again during spring runoff. Let's talk a little bit about the conceptual mixing model and atmospheric influences. Now the southern pool was primarily influenced by the St. Joe River water flowing northward. It then encounters water from the Coeur d'Alene River and doesn't really fully mix until it gets well into the central pool. Coeur d'Alene River water can also dive down and flow southwards to some extent. As we move the central pool, sediments rain out and the waters from these rivers more fully mix. As we get to the northern pool, there is a hydraulic pull from the Spokane River outlet and also a push from the smaller tributaries here on the eastern side of the lake, creating a different hydrodynamics in the northern pool that you get in the central pool. You also have a large influence from these tributaries in this part of the lake. Now the lake also has a diurnal wind cycle that is distinct throughout the year, which can create standing internal waves. We also have an important influence of precipitation, which falls predominantly as snow during the spring months and we get earlier runoff from the smaller tributaries. And this brings us to the lake's biogeochemical concepts, where low loading of nutrients in the runoff leads to a little bit of trophic surface waters, which leads to a lower carbon rain to the hypolymian and maintains an oxic state that protects the iron oxide cap and the sediments that keeps the metals trapped in there. You want to maintain that cap. And with this, that covers the core parts of the conceptual model, and I'll pass it on to Dale. Thanks. Thank you. Dale, are you ready to continue? Yes, I think so. I'm going to try to start this correctly this time. Can people see the slide? No. No, okay. Okay, how about now? No again. So, Dale, in Zoom, you have to click on your green share screen button. Yes, I'm not sure why it's not. Okay. Okay, how about now? Okay, finally. Okay, so what I want to talk about is the AEM3D model that we've applied to Corvina Lake, and just a little background. So AEM3D is an improved version of LCOM catam. Those improvements are now the model runs under multiple processors. The catam, the biology and chemistry submodel time step is now separated from the physics time step. And the hydrohub software that comes with the model is much improved, especially for visualization. What we've done is we've actually used a lot of R scripts. We've developed R scripts that take the raw .nc files and produce figures and metrics with those scripts, which the panel can definitely have. So initially, when I first started running the model, for a one-year simulation on Corvina Lake, it was taking about one core, taking about 137 hours to run. Now we're at six and a half hours, so we went from days to hours. We also have done a little bit of estimates of just on the right-hand side. This right-hand figure, the number of cores or number of threads, and the efficiency of the model. So we're trying to dial in just how efficient we can be in actually running the model, which has improved dramatically over time. So the data I'm going to show you here later in the talk is from this simulation. I'll move to this fairly fast. This is the 2014 calibration year. It starts in March and it ends in December. The grid for the lake is a 250 by 250-meter bathymetry grid. The upper 20 meters are at .5 meter increments, and the lower deeper part of the lake is at a one-meter increment. Time step of 240 seconds. The East Point Weather Station, with five-minute resolution, is the only weather station we've used for this, for these runs. The daily concentration is estimated from river loading estimates from the WRTDS, USGSWRTDS model, which Lauren spoke of earlier. We have initial conditions at C1, C4, C5, and C6. A static sediment model for phytoplankton groups. The organic metal cycling through the phytoplankton, and the Kuhl-Barras equations are in the CADEM component of this for zinc toxicity function for phytoplankton. For these runs, we have no zooplankton groups. However, we do have zooplankton data, and I have calibrated with zooplankton also. Standard boundary conditions, meteorology, river loading. The model requires inorganic forms of nutrients. We have POC and VOC and transition metals associated with that, with those loadings. So, for this talk, what I'm going to focus on are the variables of temperature, dissolved oxygen, chlorophyll A, and zinc. We're also working on iron, manganese, phosphate, nitrate, and ammonia, but we haven't calibrated yet. We haven't done much with those. My philosophy is don't overparameterize and take small bites, literature values, or our own measurements. I don't try to tweak the model too far beyond what I can find in the literature or what we've actually measured. We initially started with Kuobara's sediment flux estimates. That's Table 8 for SOD, and I think it's Table 9 for the metals and the nutrient flux from the sediments. That was from Kuobara et al. their lander estimates of sediment flux. So, like I said before, the model output produces net CDF files. We use the profiles component of that for this talk for C1, C4, and C5 specifically. As I said before, I didn't develop it. Ben Schofield of our staff, who is a guru at R, has developed these R scripts that take those raw NC files and produce metrics and our own trend series to compare observed versus modeled output. Just on the right-hand side, these figures just show some of the model sensitivity that I'm just trying to show that, yes, it is highly sensitive to changes in sediment oxygen demand parameters, and the zinc flux itself is very sensitive also to those changes in sediment oxygen demand, right to the results here. So, what this shows is the root mean square error of temperature predicted by the model on the y-axis versus the observed temperature on the x-axis. The colored circles are the different dates where we had observed versus modeled, and we have C1, C4, and C5 sites that we've done this analysis on. Just looking at the literature, these seem to be in the ballpark. C5 is kind of a troubled child because it mixes so much. It has so much wind energy that affects it at times at shallow, but overall, I think these are decent RMSEs for temperature. An example of temperature at depth. So, this is temperature in the hypolymine. Here at C1, 30 meters, modeled line versus the measured. C4 at 35 meters, once again, model line versus measured, and C5 at 17 meters, the modeled versus measured. I tried to expand the scale on the y-axis as far as I could to show the spread and show the dynamic. Here's the hypolymine temperatures. Once again, I'd like to get some perspective from the panel. Sometimes it's hard to find in the literature what are good results versus poor results for model predictability. Now, I'm going to move on to dissolved oxygen. Once again, C1, C4, and C5. This is in the south, central, and north basin. RMSE at 0.91. C4 tends to be the best for temperature in dissolved oxygen. Of course, it's the closest to the weather station also. Dissolved oxygen in the hypolymine at C1, again, 30 meters. You can see the bias, the offset here, but it does follow the general trend the model does. C4, 35 meters, tighter, and C5 at 17 meters, pretty tight. This is dissolved zinc, so calibration results for dissolved zinc. Of course, we have fewer observed versus measured comparisons because these are chemistries. The triangle is the bottom, or the hypolymine, and the circles are the uplymine. You can see in RMSE at C1, 7.56. Craig can maybe give an average later of what zinc is there, but it's probably around, I guess, 60, maybe something like that. Dissolved zinc predicted in the hypolymine at C1, C4, and C7. I'm moving kind of fast, but I want to get through this for you. Chlorophyll, low sample size, like I said before, we need to have more discrete grabs at the discrete depths to improve our measured chlorophyllate estimates. Very quickly, next steps is I'm going to focus on iron, manganese, phosphate, nitrate, and ammonia. I think we know we can improve the model because we've done temperature simulations and chemistry simulations at the 100 by 100 meter grid, which, of course, increases computation time, but that definitely improves the model. I'm looking to do a 50 by 50 meter grid and a mid-lake buoy with weather and thermistor DO chain would be an optimal boundary condition, I think, or a couple of those, one in the north, one in the south, potentially. We need to improve our synoptics, like our lake-wide synoptics. Like I said, once again, it gives us multiple grabs per site, gives us better spatial temporal measurements to compare for the model and help calibrate the model. With that, I will end. Okay, thank you. Maybe now would be a good time to stop and open it up to some questions. Robin here, I want you to go ahead. Thank you. Dale, thanks for the presentation. Thank you. So, I have a bunch of questions. So, Dale, could you speak a little bit about the water budget? How well about this calibrating? Okay, so this has been kind of a problem issue. I've actually had to go into the water budget and manually alter the outflow of the Spokane River for the water budget so it does fit. It is very tight, but it's a time-consuming process. I've tried to work on a dynamic boundary condition that adjusts the water to lake level to get a more precise water budget with that boundary condition. I haven't succeeded. I need some assistance with that, essentially. So... Follow the challenge. Yes. Have you used something like conductivity data or other like velocity data to sort of calibrate the hydrodynamics that we would like to talk about? No, I haven't. I haven't really got that far in that. We have done some tracers. We've released some tracers. That's one of the powerful components of this model is that you can release tracers and then model those tracers. So, that's kind of a next step from the standpoint of the temperature, especially with temperature, which we've done a fair amount of work with, actually. The last question for the moment is how is the model... I've not had a chance to dig into the reports on the model yet, but how is light penetration handled in the model? So, it does model the PAR. And so, it also has, of course, the fraction of different wavelengths of PAR versus the, I guess, the shortwave radiation. And it does... I think... I haven't used it yet, but it does model attenuation coefficients. I thought of one more, if I may. Simply, effective wind. I noticed you were talking about having a met station on the lake itself in a buoy. So, are you able to make adjustments to the meteorology data that you do have now thoughtfully to have it be more reflective of what's on the lake? Well, there is the potential for that. I haven't had the time to really delve into that. What I have done is I've tried to use the Schengel Bay, which is the weather station closest to C5. I've tried to use that data and I've tried to change the wind field between East Point and C5 to see if I can duplicate or replicate what's happening. That southern part of Corning Lake is highly dynamic with wind and there's wind fronts that are moving all around the lake. It's kind of in a little canyony area, so it's very difficult, but I have tried to change those wind zones and it really has an effect of the model. In fact, using East Point Weather Station gives us the best temperature, RMSE, and bias of all the weather stations. Let me actually, I'll let Priya ask her questions first. Great, thank you very much. Thank you. I have a couple, one of them is a very broad question. I was wondering, one of the speakers from the county on Wednesday talked about development along the lake shoreline and I was wondering if there's a kind of a map of how quickly that's going to happen and how that may change the dynamics of the lake. The second question was we were talking about sediment cores and that only they were taken I guess earlier than the 1990s, but have there been enough bathymetric surveys to get a sense of areas of deposition versus scouring within the lake? Well, I guess to answer your question on projections of development around the lake and the whole Pacific Northwest and you're always seeing homes go up at an explosive rate in the summertime and roads going in. So that's a concern of how that may affect both the particle deposition on the lake and near shore loading, but I don't have any future projection models of that. Does that answer your question on that, Priya? Yeah, thank you very much. Okay, and the bathymetry, we've got some, but do you know how good it is for your model? Well, the bathymetry itself is actually pretty high resolution. I guess maybe I don't understand your question, Priya, with regards to the are you talking about the hydrodynamics in the deeper basins? Just for influence, those types of things? I guess getting a sense of like in other studies I've seen bathymetric maps, a series of them used over years to kind of get a sense of where depositional areas within the system versus areas of erosion since we don't have extensive core data. Just wondering if that information is available. I don't believe that information is available. I've never seen that. Sorry, Jim, why don't you go ahead? Okay, hi, Dale. I just wanted to ask, so the model's running off of phosphate supply and driving the phytoplankton pool, but if a lot of phosphorus loading is coming in in particular form, how is the model going to accommodate that? As far as you understand, the model only uses phosphate loading. It doesn't use that particular form. As far as you understand, the particular form itself is part of the total phosphorus that's a derived variable in the model. Does that help? But a lot of that particular phosphorus might become bioavailable and supply phytoplankton production. Yeah, correct. From all the examples I've seen of the model used, it has only used or actually responded to phosphate loading. But there are components with the model that take that. There are mineralization components of the model, rates that can be changed. The model itself has a lot of knobs and dials, and I haven't turned a lot of those. I've refrained from turning a lot of those. I turned them up to 11. Thanks a lot. If I could just chime in there, Jim. Certainly earlier versions of the same model did have a complete I guess nutrient cycle for both phosphorus and for nitrogen. Because Dale intimated it's all in there, how it's currently set. I guess that's something for the tribe and others to look at in the future. Robert. Thank you. A quick question. Just the loading into the model from the river without including a component, a particular component and potentially a bed load component or is it just represented from the front side of it? There is no bed load component. What I've done is I've taken the the USGS WRTDS software and I've done the complete loading and then from that I've used the estimated daily concentrations to run the daily loads into the system. Yes. Thank you. James. Thanks guys. Once upon a time we talked about a more complicated model from the sediment to the water interface and one I guess do you think we have the information that we need from the permeability information from the sediment to the water interface to move forward with that and then also the biogeochemical information. I have done some work with the sediment diagenesis model of the candy that's associated with the model just enough to really get that candy sub-model running. The issue with that is for cadmium using cadmium I have to turn off the geochemistry model and the organic metals and toxicity functions to get the diagenesis sediment model up and running. I can't run both at the same time. I can't run zinc limitation and then run the sediment diagenesis component at the same time which is a real issue. Thanks. I'm going to jump in with a question now. One of the things I noticed in one of the stations there was a significant mismatch in the thermocline depth. I can't remember if the model or the measurements were higher. I was wondering what you're doing for long-wave radiation inputs because I think in earlier presentations you just have the standard metrological data. Yes, so for the long-wave I've taken there's the long-wave cloud cover. It's a scale from zero to one essentially so what I've done is I've taken the theoretical long-wave radiation model outputs for this area and then I've estimated from the short-wave radiation what that long-wave radiation should be. What the cloud cover should be for each day. I know I didn't explain that well but it is an estimate of that long-wave radiation it is not measured and it's fairly low resolution because it's only for a single day. So a cloudy day would be one and of course a sunny day would be closer to zero. No, that's just the opposite. It would be just the opposite, excuse me. I've been through that exercise so I know exactly what you're saying or trying to say. Thank you. Yeah and I guess maybe that feeds into my other question I noticed that there was there's a lot more variability shown in many of the measured parameters even though the model is getting the trend right it seems to be a monotonic decrease or increase which makes me think that there's some dynamism missing in the inputs and maybe that long-wave assumption is certainly one source of that. Did I hear you correctly that you're using daily averages for the inputs for everything else or is it a near instantaneous input? So do you mean for the weather station data in general? Well for weather station even for hydrologic inputs stream flows. So for the hydrologic inputs it is a daily discharge value for instance. So it's just that daily single discharge value per day the weather station data is on five-minute increments so the model runs on that five-minute increments for the actual river forcing it is a single daily value. And so the site that I think you're referring to is site C5 which is that shallow southern site it's highly affected by wind and there's multiple metalindians at times sometimes it's a shallow epilindian with one very long metalindian to the hypolindian to a very shallow hypolindian. I think there's a lot of wind energy that's really moving that metalindian around at C5. Okay. Well thank you and I guess in the interest of time we need to move on and the next presenter is Bob Steed. Good morning am I showing up here? Yes you are. I guess good morning to some speakers. I'm Bob Steed. I'm also getting a phone call at the same time here. I work for the court lane regional office and I've recently moved into a leadership role where I'm providing guidance for LMP section. Previously I worked in TMDLs and FERC relicensing and that type of stuff. I wanted to make the committee aware and the rest of the committee has been used over the last decade. There is a W-2 model that has been set up for the court lane system and it was really part of the relicensing for the post falls dam of Vista utilities had an alternative licensing process where they set up a committee and the committee was supported by Golder associates with W-2 modeling for the system. And again it really hasn't been used in the decade. It is a two-dimensional model with the ability to branch to take certain bays and incorporate that. And there has been some improvements on that but it does sediment diagenesis, particle transport and it has a eutrophication model. Again this was used for the relicensing. The model is in version 3.1 I believe they are up to 4.2 so it is kind of outdated on that. One of the nice features of it though is it was calibrated and validated and it does have the documentation of those calibration sessions and the output. Keep in mind that W-2 was really used as a tool to evaluate the potential changes in water quality that would result from Avista operations of that post-fall dam. So really the main scenarios that were run on that were with the dam present and with existing conditions and then if the dam was missing. And we used a lot of those outcomes to determine what impairments the dam was causing to the Coeur d'Alene lake system. The domain is pretty up the Coeur d'Alene river. And of course all of the inundated portion of the St. Joe river as well. The I guess I wanted to bring up that we do use W-2 modeling on the Spokane river for TMDLs. We've used that in the past as well as the Ponderay river system as well for temperature issues. I suppose this is just to demonstrate that we do have the hydrology and those components have been built into this model. And again this is just a picture of some of the calibration data. It has gone through those steps. You can see that it calibrates well with data that has good information on it. But when the information is kind of a shotgun it's not as well calibrated in those situations. So what I'm concerned with is I'm trying to work on what's the best use of our team for modeling for the lake management plan in Coeur d'Alene lake. And I really think that a progression for us is to start looking at what modeling runs, what goals do we have for modeling that we need to be prepared to address that modeling. There is some potential in using W2 because we do have some internal DEQ folks that are capable of running it. We also have contractors that are available for us as well with W2. Our history with the tribe, they've done a great job with AM3D. It is a complicated model run and we've fallen into the role with the tribe on this as if they're running it and we're just feeding them data for calibration and that type of situations. And if we need to do it ourselves or have it contracted, again I want the team to focus on coming up with what scenarios do we need to be run for modeling and certainly any advice that we get from the tribe would be well received. Some of the cons is that the update is required and we also have some concerns with the past predicted water quality conditions that they vary with a huge degree of accuracy and resolution. One of the that model was calibrated with the 90-91 data that you've seen and you can see we've got significant amount of data to better calibrate a model with and then one of the big problems that we ran into is the wind sheltering coefficient was insufficient. It had to be estimated and my understanding is that's one of the big knobs on the W2 model for calibration. Since then we have there is now data available to address the wind sheltering issue. I got a lot of the presentation from PSU and then there are two very thick volumes of the results and the calibration of the W2 model back in 2005. I can take any questions but my main purpose of this presentation is just to let committee members know that there is a dormant model that was developed and available. Thank you Bob. I see we have a question from Laura. I think it's probably more than one question. Just a quick question. I wondered if maybe Dale could provide his thoughts on the use of W3D. Do you feel like you're far enough along and you have more processes that you can consider with the AEM 3D model that you don't see any utility in developing W2. I'm just kind of curious since that. My perspective with W2 was this was from the advisory licensing. There wasn't a lot of calibration data. The model did not do well especially with some of the southern sites that we have modeled. We've also modeled the Lower Corling River and I run the model on Thompson and Swan Lakes. Most of that is just temperature calibration just kind of getting those set up to run. Overall I don't know that much about the W2 but if I remember correctly from the advisory licensing it really just did not do a very good job. Okay. Robert. Sure. So I actually have a little bit of background on this because back when I was at or in State University I actually did a peer review of that W2 model for Bob. Good to see you, Bob. But so the limitations with W2 is one is the two dimensional model and it doesn't really have a lot of the the metal is kind of chemistry. You can certainly put that into W2 but that would be a lot of work. And if the current model that Dale has already has that incorporated that might be the damage. Where I think W2 could be useful is the fact that it would run faster and if it can be shown to sort of dial in the hydrodynamic and dial in temperature things like that the more basic water quality that might be of utility to Dale and others who are doing the modeling to be able to sort of get those pieces right and understand the dynamic and the CSM the single site model before moving on to using the more three dimensional model but there are the limitations with the W2D model. Did you have another question Laura or is your hand just frozen? It's just frozen, sorry. Maybe I could follow up on Laura's question so running 3D models is a complex activity and one of the advantages of it over say a 2D model is that you can represent complex hydrodynamics and events that you alluded to Dale like the internal wave field things like that. Maybe how far along are you and your team on looking at those sorts of things whether they're in the measure data representing them in them with the model or is that just not being on the to do list yet? Yeah, we just haven't got there yet with that that takes so much time and energy and we've been collecting a lot of data we've been in the field a lot so we really have it and we're very small programs so we really haven't had a chance to do that I think maybe to get out there and do the CTD work get that higher resolution temperature data because right now we're really just relying mostly on the Hyderlab profile work so there's a vast amount of potential to do more work on this model I'm just an empirical limologist I'm not a modular I'm just using it as a tool and trying to understand it and it has helped us significantly with understanding the lake but there's a lot more that can be done with it of course Well you or somebody else earlier on alluded to I guess some some buoys that were out there collecting continuous data what was the what's the time frequency on those data? Okay, so yeah the profiling buoy that was out there it I had it set up in several ways actually I would have it taking profiles four times a day every six hours sometimes I had it working at taking profiles every three hours at generally one meter increments it kind of changes because of the way it profiles however there's a there's a lot of data available there that I really haven't had a chance to pour through and apply directly to to the model I was just thinking if there was say even higher frequency data at a point somewhere it would be possible to resolve if the internal wave field does exist and if it is significant and then whether the model could pick it up but anyway that was more a statement than a question I mean like I say there's a lot of room to there's a lot of data to work with and use I'm more of a food web person and not necessarily a physical modeler so I think given the model in the right hands with the data that there'd be vast improvements Okay, thank you Can I bring one last thing up on that? Sorry, you know the state of Idaho we have very much respect and appreciate the work that the tribe has done on the AEM3D model but it really initially started out that we'd be working on it together there's a really good reason why you can't work on it together because it takes one chief to be running that situation so we we're kind of locked out of modeling from the state's perspective on getting models getting model runs completed to meet the objectives of what we're asking for it and Dale needs three dales to do the amount of work that needs to be done on that front but we do need documented versions of the model so that we know which one we're working on we need calibration I've seen more calibration today than is documented yet I think that's the right model for most of our application but because of its complexity and because we don't really have our hands on the knobs on any of that kind of stuff nor do we have the resource to do that that's why we're looking to really focus our section on describing what our modeling goals are and developing the scenarios that we need simulated I think that's for the description Bob let's move on to our final presenter for this session and that's Kim Precipo from EPA Good morning afternoon, thank you I'm going to try to share my screen here does everybody see that Yes we can Okay so thank you I'm Kim Precipo I'm a remedial project manager at EPA So today I'm gonna take us back into the lower basin and I'm going to go about a thousand feet higher than where we've been talking this morning because I will try to provide a very brief summary on the fate and transport of the contaminated sediment in the lower basin and really just focusing on particulate lead as it relates to the lake. So I'll provide some key characteristics of the system and then Tyler Janssen will introduce our numerical model. So our work is performed under the 2002 Record of Decision or ROD which has provided a general understanding at the time and a path forward based on the information that we had and we really renewed our focus on the lower basin in 2008. And it was in part to address the recommendations made by the National Academy of Science Studies which included refining the conceptual site model, understanding issues with recontamination and developing a numerical and sediment transport model. So the enhanced CSM is an understanding of how the sediment transport in the basin works. The numerical model is an important tool that we've used to inform that. The work is documented in many technical memos which are available for review and I will not be able to begin to get into the details of our work today. So the Bunker Hill Superfund Complex is divided into the upper and the lower basin and EPA has generally addressed contamination starting in the upper tributaries in the lower in the South Fork and then moving down into the lower basin and you can see the confluence of the North and the South Fork of the Coeur d'Alene River here. So the area shown in red contains over 18,000 acres with about 30 distinct marshes, wetlands and lakes. There's a major flyway for migratory waterfowl and heavily used by people recreating in the basin. The lower Coeur d'Alene River has highly unusual and highly complex hydrodynamics with interconnected floodplains and channels along the route. These are two photos from a spring 2008 it was a major overbank flood event and it is these infrequent but large floods that mobilize contamination from the riverbed. So on average, we've estimated about 48,000 metric tons of contaminated sediment and 180 metric tons of particulate lead flow into the lake every year. And we estimate that 80% of the off-channel habitat is contaminated with lead concentrations that are acutely toxic to waterfowl. So this map shows the four primary USGS flow gauges and that these provide a record of the river discharge and the water surface elevation in and at the boundaries of the lower basin. So the Cotogo dredge pond, Rebecca mentioned that on Wednesday that is located about river mile 160. And this marks the location above which we have a steeper graded reach which transitions to the more flatter and more to the flatter, more meandering reach that extends to the river's mouth at Lake Coeur d'Alene near Harrison. So a key variable affecting hydrolysis was also discussed briefly on Wednesday is that it affects hydrolysis and sediment transport is water levels of Coeur d'Alene Lake which create a varying hydraulic backwater effect that extends as far up as river mile 160. So lower lake levels during the winter can result in higher shear stresses in the channel, higher erosion and higher sediment transport. And conversely, high lake levels can result in higher river and lateral lake levels which could increase the duration of an overbank flow. So when coupled with these other factors and as noted by other speakers, this variable discharge annually and this affects the erosion rates and the amount of sediment transport to the site. Our basin scale understanding is based on observed hydraulic suspended sediment data, multi beam bathymetry, numerous coring investigations and this numerical model which is used to fill in the spatial and temporal gaps. The main stem alone has more than 30 miles of contaminated sediment extending to over 16 feet thick in places. The riverbed is eroding over time. We estimate between one and four centimeters per year but unevenly and erosion is episodic. So during high flow events and during these high flow events, particulate lead is scoured from the bed and moves on downstream. The bathymetry work has helped to inform our investigations, map out units for the model and target areas for the cleanup. This shows a depositional and erosional features of a typical bend in the river. And our stratigraphic model for the riverbed shows a consistent chronological order of contaminated signature that reflects the history of mining at the site. There's a sharp interface between the native materials and the most contaminated silts from the earliest mining period. So this buildup of mineways continued through the 1950s and 60s but over the past decade, six decades, episodic erosion has cut down through these materials. So until it reaches native material, sediment lead concentrations are expected to increase as these more highly concentrated legacy deposits are exposed. I wanna talk briefly about the sediment and lead budget for the lower basin. And this is an accounting of the contaminated sediment entering the basin, what is stored in the bed and the banks, what is deposited outside the channel and the flood plains and what enters the lakes. So suspended sediment sampling and the related USGS monitoring program provide solid evidence that for a given discharge, sediment transport increases downstream. You can see from this chart here with the suspended sediment on the Y axis and discharge on the right, you can see that the range of SSC at Harrison is almost an order of magnitude higher than the suspended sediment SSC at Catoldo. And so these rating curves are the primary controls on the sediment fluxes that are computed for our sediment budget. So every budget requires sources and sinks. We estimate about 72,000 tons per year of the contaminated sediment is being transported through the basin. 44% is coming from upstream, 7% from bank erosion and 49% is scoured from the bed between Catoldo and Harrison. As for the sinks, there's much more uncertainty and variability around the percentage of contaminated sediment that is deposited on the flood plain versus what is transported to the lake. But on average, we figure about one third is deposited on the flood plain with two thirds flowing into the lake. Where sources of lead, almost three quarters of the lead is coming from the river bed between Catoldo and Harrison, whereas 14% is coming from upstream. That's predominantly the south fork, over 98%. An equal amount from the banks. So this is explained by the river gradually eroding through these legacy deposits and contaminated sediment that's stored in the bed. As for sinks, on average, 27% of the lead is deposited in the flood plain with the remaining going into the lake. So we've used our model to estimate how transport and volume of contaminated sediment will change over a 30-year period if the river were to naturally restore, so no remedial actions. And the model indicates that the volume of contaminated sediment could decrease. During these high flow events, we decreased by about 25% over this period. But due to these deeper legacy deposits, the lead concentrations within the sediment that is transported to the lake will probably increase until the river ultimately erodes down to native material. So I'm going to switch now and let Tyler talk just briefly about our numerical models. Yeah, thanks, Kim. So I'm gonna talk briefly about the development and use of the numerical models as part of the lower basin remediation program. The numerical model is one part of the overall enhanced conceptual site model that Kim just described. So as Kim mentioned earlier, the lower basin river bed is complex, variable, and dynamic. The hydraulics of this system are complicated by a flow leaving and re-entering the channel by a tie channels. And by variable backwater conditions in the lake itself. So the numerical models of the lower basin consist of a 1D model of hydrodynamics only and a 2D model of both hydrodynamics and sediment transport. Next. Numeric models of this system allow us to enhance and validate the conceptual site model to provide spatial and temporal resolution that are not available from observations, to predict future conditions, and also to predict the response of this system to remediation. These models are supported by a large quantity of observed data collected over more than 10 years in the basin that have been partially described by other speakers. Next. The 1D hydraulics model is built using HEC RAS. We use it for long-term simulations for answering questions related to hydraulics where these 1D approximations are sufficiently accurate and also for forecasting flood events to inform data gathering during those events. Next. The 2D hydraulics and sediment transport model is built using DHIs, mic 21C. The 2D model includes more accurate hydraulics than the 1D, but consequently takes much longer to run. So simulating one year takes about one day of computational time. The 2D model is used for evaluating remedial actions, enhancing and validating the conceptual site model, such as the sediment budget that Kim just described, and for understanding the interaction of these complex processes in the lower basin itself. Back to you, Kim. Okay, so just to wrap up a few takeaways. From this talk, riverbed erosion is a dominant source of lead contamination in the lower bed in the lower basin. Inflow from the South Fork and bank erosion are secondary sources. It is eroding through a layer cake of sediments that are deposited, that were deposited during this mining period. So we expect that lead concentrations of suspended sediment could increase over time. Transport occurs primarily during these high flow events, but is very affected by seasonal flow and by lake levels. So on average, a large fraction of the contaminated sediment and lead moving into the lower basin enters the flood plain, the rest enters Cootoline Lake. So our model has estimated that in any given year, the model rate of flood plain deposition could range from anywhere from 6% to 62% of the sediment that is flexed into the lake. So the model has been hugely informative for us. And I just wanna say, if we're going forward, we have a much better understanding of the system as a whole, and now we'll be using this ongoing observational data and the model to target specific source areas within the channel to compare these various technologies and look at what is most effective at reducing contaminant transport into the flood plains and to the lake. So thanks very much. Well, thank you, Kim and Tyler. I'm going to just try to limit the questions from the panelists to the one that's raised her now because we wanted to open it up to questions from the public. Robert, please go ahead. Thank you, I'll keep it short. This is a question maybe for Kim to start, maybe Tyler adds in, but you mentioned that 49% of the sediment load is coming from the bed of the river. Is that being all re-suspended or is some of that becoming bed load that goes down there? I think I heard you were asking if most of it's suspended or some of it's from bed load? Is that, can you just rephrase the variant? Yeah, so you mentioned in one of your slides, 49% of the contaminated sediment that's coming to the lake is coming from bed arom寬. So I'm curious if your modeling and your data indicates that that is suspended material or is it bed load? Tyler, why don't you, you might be able to make that distinction better. Yeah, so most of it is suspended. Certainly there is some bed load. A lot of the material in the bed is quite fine. So once it is eroded, it is suspended and it stays in the water column until it either goes to the flood plain or to the lake itself. Okay, thank you. So now I guess I'm going to ask Sam or Laura, how do we get questions in from the rest of the world? Right, well, we will move on now to questions from the audience. Eric, can you give people in the audience a little instruction as to how they can ask a question? So are you taking over now, Sam? Can you hear me? Oh boy. I can hear you. Yeah, we can hear you. Okay, yes, I'm taking over now, Jen. So those on the audience, I see some people have already started raising their hands. So if you start raising your hands, we'll kind of pull you over to the panelist side and you'll have the ability to unmute yourself and to turn on your microphone or turn on your webcam. So go ahead and raise your hand and we'll take care of it from there. And once you get over onto the panelist side, if you can raise your hand one more time and then Sam will see your hand is raised and he can start calling on people. Well, well, there we go. Okay, Bonnie Douglas. Oh, sorry, Sam. If you can say on the panelists tab, that's where the raised hands will be that you can call on. So right now you should see that Robert McFarlane has his hand raised. Yep, just got it. Okay, great. Thanks, Eric. Robert McFarlane, Bonnie, we'll get you later. Okay. Yeah, thank you. It looked from the diagram of the sediments that in the historical mining era, lead-laden sediments had been laid down and then less contaminated sediments over that. But now we're digging back through. Is there a reason why we're having net scouring and picking up of the lead in the water column now? Yeah, our understanding is that overall, the whole system is net erosional. So it is just based on the sediment budget. It has told us that the river is definitely net erosional. However, it's variable. There's places in the river where it's deposited and there's places where there's more erosion. Okay, it sounds like it's dynamic and maybe the sediments are moving downstream gradually. Would that be possible? Yes, the data indicates that. And with just the higher concentrations of suspended sediment concentrations in Harrison versus what's coming into Cataldo and just the increased amount of lead in the suspended sediment is that it is moving its way downstream. But based on these variable storms and also lake levels, in a given year, more might be deposited in the flood plain versus what ends up in the lake. Okay, thank you. Bonnie Douglas. Yes, I have two questions. One was, and Kim maybe, or maybe this is for Tyler, it was given as a statistic earlier that lead level was increasing in the Harrison area. That's an area where we have a beach that's used by children. And if this is true that we're getting down to scouring out higher lead concentrated deposits in the sediment, it's very concerning to me for recreation in that area. And the other thing is boat wakes and nothing's been mentioned about side erosion, but we have boats now that churn up a lot more wake and affect the erosion from the sides. And I wonder if not having boats come into the river, you know, if there's a way to help the situation. And yeah, thank you, Bonnie. We don't have a lot of data on the direct effect of the boat wakes, but it is certainly been a concern all along. And there is some impact. I think a number of things that could be impacting the effects on the sides of the river. So it's, but one thing we have looked at is it seems that the banks of the river appear to be less of a contributor in terms of then the river bed itself. And then in terms of the, I don't know if Tyler wants to add anything more in the Harrison, but we're measuring this is at the Harrison gauge. So in terms of the actual, we are looking at recreational sites throughout the basin and monitoring those using a number of ways to mitigate exposure to people recreating in the basin. And I just wanted to clarify, I came on the, what some of the projections are of as the erosion cuts down into these more concentrated sediments, is actually that the total sediment load over time decreases a little bit because we're starting to use up the available sediment. And same thing with the total lead, but it's the concentration of lead on sediment that increases over time because we're getting down to that very, that more highly concentrated sediment. So it's the, that concentration on sediment that's changing, that is increasing not so much the total lead that is going down the river. And I don't see any more questions from the audience. Eric, do you, are there some that I'm not seeing? Yeah, so we do have the numbered. So you should see numbers in front of their names all your participants. Yeah, so you have number three and number five. Oh, there we go. Okay. Sorry about that. Richard Meyer. Yes, I wonder if the lead is coming through the Coeur d'Alene River. Is there any way to either put a retainer on that, a restraining dam or some way to treat the river itself to keep that lead from hitting the main lake or see the bottom of the lake of the river? Is there some way to stabilize that? Yes, these are all things that we are evaluating. We are in the process now, and Maureen, I was probably on the line here who's the lead for the channel. We've got several different pilots that we're evaluating. And one of the focus areas, I didn't even have a chance to spend time on is up in the Dudley reach where we've identified as one of the potentially largest sources of particulate lead. So we're right now evaluating several different pilot projects and one of them includes various combinations of capping and dredging in the river. Excellent, thank you. Jim Duff. Jim Duff. Can you hear me now? Yes. Yes, question is, and this would be for Cam, I believe, why have the stream or the river segmentation dynamics changed? And that's the sense I get from a net depositional to now a net erosional regime. So during the mining period, which really extended up through 1968 or so, end of the 60s, there was a lot of, as Ed alluded to, there was a lot of transport and tailings and dumpings of tailings into the stream. It all moved its way down stream into the lower Coeur d'Alene River. There were several episodes where they had built plank dams and these plank dams released during some flood events were released additional tailings. So there was just a gradual buildup of mining material all through that period until mining eventually was ceased in about at the end of the 1960s. And at that point, and Tyler's better to talk about the dynamics of the river, but at that point, the river just naturally starts to re-equilibrate and starts to erode, like I say, it's net erosion. So over time, it starts to cut into the bed. So there are places we found that in the river where it does deposit and the other places where it's more erosive, but in the net it's continued to, it started to cut down starting after the end of the mining period. Yeah, thank you very much for that clarification. I appreciate it. No, Sandy Emerson, Sandy Emerson. Sandy, you hear me now? Yes. Yeah, thank you. I think there's a, you're getting all around my question and that is the toxic waste sink right at the mouth of the Coeur d'Alene River down toward Harrison by the Harrison Dockbetters Association in Springston. I've seen studies there that show 11,000 to 15,000 parts per million lead right there in the concentrated area. And that was actually historically used as kind of a place that they were dumping, intending to dump large amounts of mine waste. It's been discussed how to get rid of that over time rather than just letting it be capped because it's so huge and enormous. How does that factor into some of the things that we're talking about today? I can get my new button there. Those are the concentrations that have been seen. If you recall the slide that I showed you, some of the more concentrated mining material at depth that we've seen from our coring has been up in those concentrations of 20, 30,000 parts per million. And so depending on how much erosion has occurred and whether those legacy deposits are now at the surface, you can see these concentrations. And that is part of what our challenge is and what we're working on now in terms of identifying these sources. We generally want to work upstream to downstream and we know that there's some very high concentrated pockets up and again at the Dudley reach. But that's our goal is to incrementally start to remove or cap or remove them as sources to the lake and to the wetlands. Thank you. It's been said it was somewhere between 400 and 700 million tons just primarily in that particular location or on through that, is that accurate? Yeah, I know there's been some very large numbers. I'm trying to thank Tyler. Do you have the number that we've estimated for the bed itself? I don't have it in the top of my head, but it's- I don't have it on hand to tell. Yeah. But it is a large amount of contaminated sediment that is sitting in the 30 miles and down through. I'm not sure specifically about the location that you're talking about, but. Well, the concern was it would become remobilized as we've been talking about all throughout. So it's a lot to work with it. Thank you. Indeed. Adriana Hummer. Okay, can you hear me? Yes. Okay, thank you. And that previous question and answer partially addressed my question, but I was just curious about other remediation efforts. So we've talked a lot about all the data sets showing that the water is talking about water quality, but are there any other plans in hand right now to do further remediation aside from what was just discussed to improve the quality or are we still in the data collection and analysis phase? Well, I think Ed talked a lot about the, we have a lot about all of the remediation efforts that EPA has been conducting throughout the upper basin. And of course we have focused on the upper basin initially. It's again, it's more of this top-down approach. So in addition to all of the work that has been done up in the tributaries and the groundwater collection system that's been installed in the South Fork and a variety of work done at the mine and mill sites in the upper basin, we are starting to have some efforts down in the lower basin, but there was a definite need to really understand the system and make sure that if we did put something into place, we weren't going to recontaminate it again or just really understand that if we tackled the section of the river that it was gonna move the needle for us that we were really going to have an effect on the suspended sediment, contaminated sediment going into the blood planes and into the lake. So then in terms of the channel itself we are on the cusp of developing some pilot projects I would say in the next three years we'll have some designs in place to work on a section of the Dudley reach and we've also been working on cleaning up some of the wetlands we have the schlept wetland that was done earlier on and then we're currently working on what's known as Grace Meadow now to create more clean feeding habitats. So to remediate those impacted flood plain areas. Fred, I don't have a last name, somebody named Fred. Can you hear me? Oh yes, I can hear you, you can go now. I'm sorry, I'm a property owner on the lake and I own properties probably in four of the areas that you guys have modeled. I was first involved in the site back in the early 80s working for Office of Research and Development, EPA down at EMSL Las Vegas. Later I was director of the mine waste management studies at the University of Idaho where I received my master's and PhD and as part of the director, I put through about the 20 different master's students and PhD students working on the mine and the areas around there. And I did my master's down in the Bunker Hill Mine itself and the PhD I did was out on Smeltabill Flat. So I'm really familiar with the site and I still live in the area and I'm a downstream interest now in my later years. I enjoyed all of the discussions but I had kind of a big question was I missed the opening statements and I was curious what is the purpose and objectives of this group and what is your charge and who issued the charge to you guys to do this? I'm glad to clear all that up in the final statements. Let's finish up the questions here and then I'll summarize restating our charge and the sponsors. That's okay with you. Sure, sure. Now let's see, I think we have a question also from Jamie Sturges, if you can connect. Jamie, are you able to connect? Okay, here you go. Can you hear us? Yes. This is Jamie Sturges by telephone to Jamie Bruner to the internet and I don't have the ability to do audio right now and send because we're not located but I wanted to just, I'm so excited about the moving forward, the moderator, the panelists, the committee and expectations are high. I do have one question which I won't be able to hear the answer to unfortunately but I'm curious with the annual raising and lowering of the high pool and low pool, does that mitigate or aggravate sediment flux into the river in the Chain Lakes area? And I'll just wait for that answer to be able to connect to everybody. You want to take that Tyler? I think you have. It complicates it for sure. And I think Kim mentioned this at the beginning of hers. So during high pool, the sheer stress on the river is less, so there's less erosion. It lasts for longer and because the lake level is higher more water goes to the flood plain. So you have more water and more sediment going to the flood plain but you have less erosion on the channel. During low pool, these sheer stresses on the channel are higher. There's more erosion for a given flow rate but there's less connectivity to the flood plain. And so fortunately more of that sediment during the low pool events goes to the lake. So it's very event dependent. It depends on the dynamics, the flow rate and the length of that event. There are some short duration winter events when there's low pool that cause just as much scour and as much total sediment as long duration spring high pool events. And so it's hard to say that the change in pool helps or hurts the sediment flux to the flood plain or the lake but it certainly complicates and it's an event specific discussion. Thank you. Let's see. I'm waiting to see if there's any more. Do I have any more? Coming up Eric. I think there's one more that's coming over. Okay, thank you. Sorry for the pause here folks. There we go. There now. Let's see. I have the only number I see is Jamie. Let's see. It should be number nine. The name is DDSZ. Okay, would you wanna go ahead, sir or ma'am? Whichever it is. I don't see it on mine, but that's all right. Oh yeah, DDSZ. There we go. Thank you. So DDSZ, whoever that is. DDSZ. I guess we don't have anybody there that's able to connect. And so Eric, do we have any open mic? Anybody in the open mic list that wasn't down here? I don't think so. There we go. I've got a new one. Wait a minute. Oh no, did I get Sky Walden? No, that's fine. I'm just coming in over this way. You guys are talking a lot about future projects being capping, which I've seen up River, but there's also still signs by the creek that say don't touch the water. And I'm wondering when I've done independent research, I've seen like dredging and bioremediation as ways to clean up the existing lead is there any way that we could do something like that? And is there any way to repurpose the lead? Like for MRI doors for hospitals or like, are we just trying to cap it again? We're looking at a number of alternatives. Capping is one, dredging is one. We've looked at various options like putting in weirs and wind fences. There's a variety of options. Wind fences, there's a variety of ways you can tackle this and it would not probably be the same throughout the entire riverbed. They all have their pros and their cons. And we're basically gonna be starting kind of in a stepwise process, probably up at the Dudley reach and testing some of these technologies and it will probably be a combination. In terms of repurposing the lead, EPA has not really, just due to the volume and difficulties of this system, it is not something that is really panned out, not something that we would look at on a grand scale. So a lot of, if we do dredging, there needs to be a place on the site to place that material, which is why we have some well-managed repositories throughout the site. And we'd have to consider that as well for the lower basin. Thank you. Great. I think it's, we're a little, quite a bit over time actually, but that doesn't matter. We're very glad to hear all the questions from the audience and from the public, but I think it's probably time that we wrap up here. Let me, as I promised one of the earlier questioners, I will reiterate that we are specifically, our task is to specifically to focus on future water quality conditions in the lake. And we're collectively looking at available data. We're looking at trends. We're really interested in trends and we're interested in developing a base of understanding or at least discussing and putting together a base of understanding that ties together the things that we heard in these presentations today. It's from that base eventually that some of these more difficult questions hopefully will provide some help in addressing the question of what the future might hold and the other more complicated questions that follow what to do next. So that's what we see as our contribution. The sponsors of the study are the Department of Environmental Quality, Kootenai County, the Coeur d'Alene Tribe and U.S. Environmental Protection Agency, the National Academy's committee comes in at the request of the sponsors and with the charge defined by the sponsors. Our next meeting will be in May. Between now and May, the committee itself will start to drill down on some of these issues and start to put together our report. But let me emphasize that we are in the early information gathering phase. So we don't have much in the way answers right now but we are gonna seriously look at and address these issues. Let me make, let's see. I think that's, yeah, our meeting is in May and recordings of this meeting will be available next week on the National Academy's website for the meeting which I presume you all have access to or we can get to Laura if you need us. If there's anything else that you wanna add Laura, go ahead, otherwise I'll call the meeting to a close. And thank you all very much. Thanks panelists for the questions. Thanks presenters for all these excellent presentations. It's a great start. As Bob said, we're kind of starting, we're just beginning to get a feel for the system. So we appreciate the great start that you've helped us with. Laura, anything else to add? I'll just say that this meeting actually is not over for the committee members. They will be meeting next week in closed session. Those are internal deliberations but after that meeting we will be making information requests to the various study sponsors as well as others who may have submitted comments that we can respond to. So we look forward to everyone's continued participation. Please be looking for communications from myself or from Calar Rosenfeld. And if you need to ask us questions please just feel free to send either one of us emails and we will get back to you as soon as possible. Thanks everyone. That's great. And I should also add one last thing. We expect this process to expect to report in about a year and a half. I know if there's some of you that probably sounds like a long time but that's how much time these things take and the product in the end will provide a base for moving forward. I hope that's our goal. So thanks very much for your participation. Thanks for your questions and for the invitation to be here and we'll see you. We'll see the next public session in May. Thanks a lot.