1 1 DIVISION OF ADMINISTRATIVE HEARINGS DEPARTMENT OF ADMINISTRATION, STATE OF FLORIDA 2 3 SUGAR CANE GROWERS COOPERATIVE OF FLORIDA; ROTH FARMS, INC.; 4 and WEDGWORTH FARMS, INC., 5 and DOAH CASE NOS. 92-3038 92-3039 6 FLORIDA SUGAR CANE LEAGUE, INC.; 92-3040 UNITED STATES SUGAR CORPORATION; 92-6796 7 and NEW HOPE SOUTH, INC., 92-6797 92-6799 8 and 92-6800 9 FLORIDA FRUIT AND VEGETABLE VOLUME I (Pages 1 - 204) ASSOCIATION, LEWIS POPE FARMS, 10 W.E. SCHLECHTER & SONS, INC., and HUNDLEY FARMS, INC., 11 Petitioners, 12 v. 13 SOUTH FLORIDA WATER MANAGEMENT 14 DISTRICT, 15 Respondent, 16 and 17 MICCOSUKEE TRIBE OF INDIANS, THE UNITED STATES OF AMERICA, 18 et al., 19 Intervenors. _____________________________________ 20 Deposition of CURTIS D. POLLMAN, Ph.D. 21 Taken before Lynn Marie Durscher, Registered 22 Professional Reporter and Notary Public in and for the State of Florida at Large, pursuant to notice of taking 23 deposition filed by the Respondents in the above cause. 24 Monday, February 14, 1994 15 Southeast First Avenue 25 Gainesville, Florida 3260l 9:00 a.m. - 5:00 p.m. 2 1 APPEARANCES: 2 On behalf of the Petitioners Sugar Cane Growers Cooperative, Roth Farms, Inc., and Wedgworth Farms, 3 Inc.: Hopping, Boyd, Green & Sams 4 123 South Calhoun Street Post Office Box 6526 5 Tallahassee, Florida 32314-6526 BY: WILLIAM HARRIS GREEN, ESQUIRE 6 On behalf of the Respondent SFWMD: 7 Popham, Haik, Schnobrich & Kaufman, Ltd. 4000 International Place 8 100 Southeast Second Street Miami, Florida 33131 9 BY: PAUL L. NETTLETON, ESQUIRE 10 On behalf of the Intervenor, United States of America: 11 United States Department of Justice General Litigation Section 12 Environment and Natural Resources Division Washington, D.C. 20530 13 BY: MICHAEL W. REED, ASSISTANT CHIEF 14 ALSO PRESENT: 15 RONALD D. JONES, Ph.D. 16 17 18 19 20 21 22 23 24 25 3 1 - - - 2 I N D E X 3 - - - 4 5 WITNESS: DIRECT CROSS REDIRECT RECROSS 6 Curtis D. Pollman, Ph.D. 7 BY MR. NETTLETON: 4 8 9 10 11 12 13 14 15 - - - 16 E X H I B I T S 17 - - - 18 19 (NO EXHIBITS MARKED VOLUME I) 20 21 22 23 24 25 4 1 P-R-O-C-E-E-D-I-N-G-S 2 - - - 3 Thereupon, 4 CURTIS D. POLLMAN, Ph.D., 5 being by the undersigned Notary Public first duly sworn, was 6 examined and testified as follows: 7 THE WITNESS: I do. 8 DIRECT (Curtis Pollman, Ph.D.) 9 BY MR. NETTLETON: 10 Q. Would you state your name for the record. 11 A. My name is Curtis D. Pollman, P-o-l-l-m-a-n. 12 Q. Dr. Pollman, we're here on the continuation of 13 your deposition from approximately a year ago, I believe 14 February 16th and 17th of 1993. At that time we'd gone over 15 some of the stuff you had done in this case, as well as some 16 preliminary opinions and things that you might testify about 17 at the final hearing. 18 What I'd like to do now to get us off and running, 19 if we could, is to ask you if you could tell me as 20 specifically or generally as you think appropriate the 21 opinions or categories of opinions that you have been asked 22 to present at the final hearing in this matter. 23 MR. GREEN: If I could interject, Mr. Nettleton, I 24 assume -- I believe we stipulated the first time around 25 that objections are reserved except to the form of the 5 1 question. 2 MR. NETTLETON: That's right. 3 MR. GREEN: And we would still operate under that, 4 and I object to the form of that because you're asking for a 5 narrative response and I'd ask you to be more specific, if 6 you could. 7 Q. Well, I don't know that a narrative response is 8 objectionable, but can you tell me what opinions or what 9 opinions have you been asked to present at the final hearing 10 in this matter? 11 A. The areas that I've been asked to testify to 12 relate to several. The first would be on issues that relate 13 to the Loxahatchee National Wildlife Refuge particularly 14 regarding the quality of data that are being used to -- that 15 were originally used to set the criteria limits, and in 16 addition, the relevance of that data as it pertains to, say, 17 a cause-and-effect relationship that might be perceived 18 between, say, inflow concentrations going into the marsh and 19 interior marsh concentrations. 20 Second area that I would be asked to testify to 21 relates to sediment accumulation rates. In other words, a 22 key variable in this proceeding is the phosphorus settling 23 velocity that's being used to size the STAs. I have some 24 opinions as to the efficacy of the approach that has been 25 taken by Dr. Walker to arrive at that settling velocity and 6 1 I would be expected to provide some testimony in that area. 2 I believe there is one other area, but at the 3 moment it escapes me. 4 Q. Would the other area concern the mercury sampling 5 that's going on? 6 A. I envision that I would be asked to provide some 7 testimony in that area insofar as what was conducted and 8 perhaps what those results are. 9 Q. Is that the other area you were thinking of, or is 10 there still another one? 11 A. No. I think there's a fourth area. 12 Q. Have you seen your witness designation or 13 disclosure of subject matter of your expected testimony? 14 A. Yes, I have. 15 Q. If I showed that to you, would that help refresh 16 your recollection on this other area? 17 A. I'm sure it would. 18 Q. Let me hand you a copy of what the Cooperative has 19 filed as your designated area of testimony. 20 MR. GREEN: Just for the record, Paul, what's the 21 date of the document? 22 Q. That's the one that was faxed in last week, I 23 believe. 24 MR. GREEN: Okay. Thank you. 25 A. Yeah. Basically, what I have before me here in 7 1 terms of the subject matter of expected testimony recaptures 2 or reiterates what I have just stated. The only difference 3 is that what I have before me breaks the Loxahatchee work 4 into really two different components, and I sort of lumped 5 it all into one area. 6 Q. Which components did it break it into? I'm 7 sorry. 8 A. Okay. 9 Q. That would be the quality of the data that -- 10 A. Yes. As far as addressing the issues in the 11 Loxahatchee are concerned, there are two basic issues of 12 concern; first of all, is that the data itself are of rather 13 poor quality and that we have concerns, then, about using 14 data of poor quality to establish criteria limits. 15 The second area that also relates to Loxahatchee 16 concerns that we believe that there should be a 17 cause-and-effect relationship or a link, some sort of a 18 physical link between loads coming in through the S-5 and 19 S-6 structures and the stations that are being used to 20 monitor compliance as part of the criteria. 21 Q. Okay. Any other areas you intend to testify on at 22 final hearing than what you've mentioned? 23 A. Well, I've got to admit that I have some confusion 24 as to actually what my role in the hearing is going to be 25 since -- 8 1 Q. Well, I -- I'm sorry. 2 A. -- as you may or may not be aware, I have been 3 conflicted out of the -- out of the hearing as a witness 4 for the co-op. 5 MR. NETTLETON: I was unaware that you had been 6 conflicted out, but -- I wasn't at the hearing Friday, but 7 we can talk about that later. 8 Does that affect this deposition at all, Mr. 9 Green? 10 MR. GREEN: Well, the topic came up at the case 11 management conference last Friday, Mr. Nettleton, and I 12 believe that all the representatives of parties present 13 anticipated that this deposition would go forward as 14 scheduled. 15 BY MR. NETTLETON: 16 Q. Dr. Pollman, with regard to the first area you 17 identified, the quality of the data for the refuge, could 18 you tell us what your opinions are concerning the quality of 19 that data? 20 A. My basic opinion of the data that have been used 21 initially to develop the criteria is that the data are 22 rather poor quality. 23 Q. And when you say "poor quality," what do you mean? 24 A. I have concerns about the reliability of the data 25 and whether or not they should be even used for anything of 9 1 scientific value, much less a regulatory value. 2 Q. What precisely are your concerns about the data? 3 What is it that raises these concerns about not being able 4 to use it for a scientific basis? 5 MR. GREEN: Excuse me. If I may interject, I 6 don't object to the question, Mr. Nettleton, but I would 7 reflect that this area was covered fully in the last 8 deposition. 9 MR. NETTLETON: I understand. 10 MR. GREEN: But he may answer. 11 MR. NETTLETON: I believe at the last deposition, 12 though, there were no final opinions. I'm just clarifying 13 the final opinions at this time. 14 MR. GREEN: That's fine. 15 BY THE WITNESS: 16 A. I guess I should state that I've not revisited 17 this issue since my last deposition. I guess I should also 18 state that as part of -- as a practical reality of being 19 conflicted out of the hearing, that I will be transitioning 20 myself out of my relationship with the Cooperative over the 21 next coming weeks and that I will be, I guess, producing 22 some sort of final report that summarizes my opinions, so I 23 will be revisiting this issue over the coming weeks in some 24 form of a report which I have yet not -- which I have yet 25 to write, but to the extent that I can restate what my 10 1 opinions were a year ago, if you would like me to revisit 2 that, I guess you can go ahead and proceed. 3 Q. Well, let me just clarify. Since your deposition 4 last February, you have not looked at this issue any further 5 and your opinions would remain the same as they were stated 6 last February of '93? 7 A. That's correct. 8 Q. Okay. Just for my own edification and for 9 clarification of the record, could you briefly reiterate 10 what those opinions are? 11 A. Certainly. First of all, one of the concerns I 12 have relates to interparameter consistency. When you work 13 with data sets that consist of a number of variables, you 14 expect those variables to be internally consistent, some of 15 the interparameter relationships. 16 We have examined the Loxahatchee data that we were 17 provided by the District with to see if those relationships 18 are fundamentally consistent. We found some 19 inconsistencies, some rather large inconsistencies. 20 Now, these inconsistencies do not explicitly 21 address the problems or the efficacy of the phosphorus data 22 per se which the District is using to establish the criteria 23 limits, but they give us cause for concern because it 24 reflects that there's fundamental problems either with the 25 laboratory or the way the data were collected, that, at any 11 1 rate, the samples were poorly processed or poorly handled 2 and that the data base as a whole appears to be flawed and 3 of rather poor quality. 4 In addition, in the course of, I guess, discovery, 5 trying to acquire particularly QA/QC data from the District 6 regarding their laboratory practices and the performance of 7 the lab at particularly low levels of phosphorus 8 concentrations, we've gotten only limited information. That 9 limited information suggests rather poor recoveries of 10 ambient phosphorus levels and does not -- at least does not 11 give me any level of comfort that the samples are accurate, 12 the sample results are accurate. 13 Moreover, in the course of deposition, and I 14 believe those depositions were taken with Dr. Vidal of the 15 South Florida Water Management District, that's V-i-d-a-l, 16 and Mr. Rosen also of the District, their reflections of 17 historical practice and their indications of how method 18 detection limits are determined also give me very little 19 cause for comfort regarding the reliability of the data. 20 Q. Going to the first area you mentioned, the 21 interparameter consistency, can you tell me what 22 inconsistencies were found? 23 A. Yeah. I'll have to speak rather, I guess, 24 qualitatively at this point because, like I said earlier, 25 it's been a year since I looked at this stuff and I can only 12 1 remember some of the gross overall relationships, but if 2 memory serves me correctly, we got very poor ion balances. 3 In other words, when we summed up the total of the cation 4 and then some of the anion species, you'd expect those sums 5 to be very similar. You would expect them to be 6 equivalent. They're not. 7 You'd also expect to see a relationship between 8 the chemical makeup of the waters that were sampled and the 9 measured electrical conductance or specific conductivity. 10 Those relationships do not exist. 11 If memory serves me correctly, we also saw very, 12 very poor agreement between field measured conductivities 13 and laboratory measured conductivities, and conductivity is 14 a parameter that can be very easily measured. It's rather 15 hard to screw up that particular measurement, and so it's 16 surprising to me that we would find such poor agreement with 17 those species. 18 Q. Okay. 19 MR. GREEN: Excuse me, Mr. Nettleton, if I can 20 just state for the record, I believe that documents 21 concerning this matter were turned over in the first 22 deposition that you have. If you have them today, it may be 23 helpful to you, just for the record. 24 MR. NETTLETON: Okay. I just -- I don't recall 25 seeing documents on the inconsistency analysis, but -- 13 1 MR. GREEN: Yes. 2 BY MR. NETTLETON: 3 Q. Do you recall any additional inconsistencies that 4 appeared? 5 A. Oh, I would have to go back and look at the data 6 again, but I think those are my fundamental concerns. I 7 think that there are also perhaps some calculation errors as 8 far as some of the -- how some of the parameters were 9 presented in the data set. 10 To be honest, there were some pretty funky things 11 in the data set that made me wonder if there were data entry 12 problems with the way the data that were -- the way data 13 were handled, and one of the concerns we had was did we 14 actually have the final data set or did we have some data 15 set that was provided to us that had some problems that were 16 subsequently corrected and we never did receive what I would 17 consider to be a cleaned up, verified data set subsequent to 18 my deposition. 19 Q. When you say there were calculation errors, what 20 do you mean? 21 A. Again, I have to speak from memory. My memory may 22 be faulty on this regard, but I thought that there might 23 have been problems with, say, calcium magnesium values and 24 the hardness values that were being presented. There may 25 have been problems with alkalinity measurements that were 14 1 presented. That I'm not sure. I'd have to go back and look 2 at the data set. 3 Q. And how would you go about determining a 4 calculation error? 5 A. Well, as far as hardness is concerned, hardness is 6 typically the sum of calcium magnesium, so you look at the 7 sum of calcium and you look at -- the sum of calcium 8 magnesium, rather, and you look at the hardness values and 9 see if they match up. 10 If they don't match up, then I would go back to 11 the reporting laboratory and ask why don't they match up and 12 try and ferret out the problem at that point. It may be that 13 hardness was measured directly or it may have been reported 14 as a calculated parameter, but at any rate, they should be, 15 again, internally consistent. 16 Q. Am I correct that you earlier stated that the 17 particular inconsistencies that you've noted do not directly 18 relate to the phosphorus data? 19 A. That is correct. 20 Q. And you mentioned that you thought this may be the 21 result of data entry problems? 22 A. It could be. We saw some very unusual 23 relationships when we started plotting bivariate 24 relationships, in other words, when we were plotting one 25 variable versus another variable, and our a priori 15 1 expectations were that the relationship would be a straight 2 line and what we would see is a series of straight lines 3 that had different intercepts, and, quite frankly, I've 4 never seen anything like it before. 5 My first concern in seeing something like that is 6 that we've done something wrong, but we have checked our 7 plotting routine. I think we have checked our code in terms 8 of how the parameters should have been calculated in setting 9 up these bivariate relationships, and I think we're 10 reasonably satisfied when we first did this that we hadn't 11 made an error and that there appears to be an error in the 12 data, but, again, I would like to go back and look at this 13 before I state unequivocally that these data are flawed, but 14 my -- I have a very strong suspicion at this point, very 15 strong opinion that the data are indeed flawed. 16 Q. I believe you mentioned at your last deposition 17 that, in regard to this matter, that you considered there's 18 a possibility of like a column shift or something like that 19 in the data. Have you gone back and looked at that issue at 20 all? 21 A. Well, we talked about it. We haven't gone back 22 and done it. We talked about it actually before my 23 deposition, and we basically concluded there's no way in the 24 world that we could do that, that we could actually try and 25 clean up the data set. It's not something that's 16 1 straightforward, because in some respects the data looked 2 fine. It's not a universal problem across the data set. 3 In other words, if you take the data, the data are 4 presented in a tabular form, and the data, each parameter 5 appears as a column. Well, if you look at, say, column C, 6 the parameter that might be listed in column C actually 7 looks -- the numbers look actually reasonable, but then if 8 you look at, say, what's in column D and column B, those 9 parameters may be off or appear to be squirrelly in some 10 way, shape, or form, so it's not a simple matter of us 11 taking that data set and shifting everything to the right 12 one column or shifting everything to the left because you're 13 going to affect the entire data set. 14 What may have happened is that there is a data 15 shift problem in the raw data set and that the data that we 16 received then, of course, were output in a different form 17 rather than the way the data are stored, and so somebody 18 back at the District is going to really have to spend some 19 time checking the data to make sure that the data are indeed 20 accurately presented in that data set. It's not something 21 that we can do. 22 Q. Just as a point of clarification, am I correct 23 that the data set we're referring here to relates only to 24 the water quality data from the refuge? 25 A. As far as the interparameter inconsistency 17 1 problems, yes, that's correct. 2 Q. Can you tell me who you received this data set 3 from directly? 4 A. I think we received the data from several 5 different sources. I believe that we received one data set 6 from Mark Maffei through the course of discovery. We may 7 have also received the data directly from the District. 8 That I don't recall. 9 Q. Do you recall receiving a data set from Dr. Davis 10 of Environmental Services? 11 A. Yes. 12 Q. Okay. What particular data set are you 13 utilizing? 14 A. Well, to get the -- get an accurate answer on 15 that, you would have to direct that question to Info Tech. 16 They're the ones that have been handling the data set, and 17 that would be Dr. McClave. 18 Q. And that's Info Tech? 19 A. That's right. That's the name of his firm. 20 Q. Has there been an attempt, to your knowledge, by 21 Info Tech or KBN to merge the various data sets into a 22 single data set? 23 MR. GREEN: Object to the form. 24 A. Could you restate the question for me, please? 25 MR. GREEN: I'm not trying -- just which data 18 1 set? I think that's -- 2 Q. All right. You mentioned that you believe you 3 received a data set from Dr., is it Dr. Maffei? 4 A. That's correct. 5 Q. From Dr. Davis, and possibly one from the 6 District. 7 A. I believe we also received a data set from George 8 Shih, S-h-i-h. 9 Q. And the data sets we're referring to are water 10 quality data from the refuge? 11 A. I don't know if we actually got a data set from 12 John Davis on water quality from the refuge. It may have 13 been included in the data that we got from him originally. 14 That I don't recall. 15 Q. Of the various sources of data sets for the 16 refuge, do you know whether Info Tech or if KBN has 17 attempted to merge those data sets into a single set for 18 quality of the data -- excuse me, for water quality data for 19 the refuge? 20 A. It is a desire that we have, that we believe that 21 there should be a -- we should -- that our team should be 22 working with a unified data set, and actually it is our hope 23 that all the parties could agree to some sort of unified 24 data set that all analyses would proceed from. 25 I mean, philosophically, it would make a lot of 19 1 sense to me that Dr. Jones here or Dr. Walker and ourselves 2 would all be using the same data set that we could all agree 3 upon to use, and that would rule out any ambiguity at least 4 as far as, well, which data did you use, my data set is 5 better than your data set, blah, blah, blah. I don't see 6 that as a productive course of events, so I think it would 7 be beneficial to all parties if we could, indeed, arrive at 8 a unified data set to conduct our analyses, and that's, 9 quite frankly, been one of the real problems in conducting 10 this work, is that the data sets themselves appear to be a 11 moving target, and we're constantly trying to examine the 12 quality of the data and make sure that the data are 13 up-to-date and so on and so forth. 14 Q. Taking the various data sets you have obtained 15 from the individuals you have mentioned, can you tell me 16 whether these data sets purportedly represent the same 17 sampling, or is it different sampling, thus creating 18 different data sets? 19 Do you understand my question? 20 A. Are you asking me if the data sets are the same or 21 are they different? 22 Q. Are they supposed to be the same I guess is the -- 23 A. Well, I believe that they are supposed to be the 24 same. I believe like the Shih data set, if memory serves me 25 correctly, I believe George Shih provided us with 20 1 Loxahatchee data and the Maffei data set are supposed to be 2 the same, and then I know that we've also checked the 3 phosphorus data from the Maffei data set with the data that 4 were reported in the SWIM Plan in a hard copy, and I believe 5 that we found some problems matching the data up but we were 6 eventually able to resolve those problems. And, again, 7 there was -- appeared to be a column shift problem with some 8 of those, with some of those numbers, and we had to work 9 through that. 10 Q. Which parameter was that dealing with? 11 A. That was dealing with total phosphorus. 12 Q. So you were able to resolve the problems with the 13 total phosphorus in the data sets? 14 A. That's correct. 15 Q. I'm not sure yet I'm absolutely clear. As an 16 example, you have a data set from Dr. Davis, Dr. Shih, Dr. 17 Maffei? 18 A. Right. 19 Q. And there's a data point from March 1, 1977, taken 20 at sample site A. Would that point be represented in each 21 data set? 22 A. Well, theoretically, they should be because all 23 the -- the ultimate source of all these data sets is the 24 same, and that's the District. 25 Q. That's what I was trying to get at. Have you 21 1 seen, in fact, have those various data sets -- I guess a 2 single data set from different sources matched up as far as 3 the numbers and so forth? 4 A. Specifically for the Loxahatchee? 5 Q. Yes. 6 A. I couldn't tell you. I can tell you that for 7 other areas that we've encountered problems. For example, 8 we try to match up our data with Dr. Walker's data, the data 9 that we were supplied in the course of discovery of Dr. 10 Walker's files, that we are having a hard time getting an 11 exact match with all of his numbers, and we aren't exactly 12 sure where those differences lie or, rather, what's the 13 cause of those differences. It may be that he preprocessed 14 his data in some way, shape, or form, or maybe he got access 15 to a cleaned up data set. 16 There is a history, I don't know how close to the 17 present this history actually extends, but there is a 18 history of data sets coming out of the District of being 19 flawed in one way, shape, or form, and so we're always a bit 20 concerned about any data set that we're working with that it 21 may have been superseded by another data set released by the 22 District that we may not have obtained. 23 Q. I guess what I'm driving at, you indicated that 24 one of the problems may be the fact of, you know, data entry 25 problems or mistakes, and I'm wondering whether, because 22 1 you've received this data from different sources, whether 2 there's a possibility, for instance, that the data set you 3 received from Dr. John Davis may be the result of some 4 manipulation they have been doing with the data as opposed 5 to any problems from the original source. 6 A. No, I understand what you're saying. 7 MR. GREEN: I object to the form. You may 8 answer. 9 A. One of the things that we're trying to do and I 10 would suggest that you, to get more details, that you would 11 talk to Info Tech and also Tetra Tech, because these data 12 problems really relate to the hydrologic modeling because 13 it's a very vital concern that we have. We're constantly 14 checking one data set against the other to make sure that 15 the data sets match up. That's always an ongoing exercise. 16 Q. And have you determined that the data sets do 17 match up? 18 MR. GREEN: Object to the form. 19 A. I can only speak in general terms because I've not 20 been that intimately involved in the overall data checking 21 exercises, but I think generally we're satisfied that most 22 the data check -- agree well with what we think are accurate 23 representations of the data. 24 Q. Okay. Who's been involved in those data checks? 25 A. Several people, Ron Munson from Tetra Tech, Cindy 23 1 Hewitt from Info Tech, John Good from KBN. 2 One other individual comes to mind. That would be 3 Andrew MacNeill also with Tetra Tech. 4 MR. GREEN: Can you give me 60 seconds? 5 (Thereupon, a brief recess was taken.) 6 BY MR. NETTLETON: 7 Q. The second matter you referenced under the quality 8 of the data referred to the fact that you'd only received 9 limited information from the District on QA/QC? 10 A. Right. 11 Q. Can you tell me what information you have 12 received? 13 A. Well, my concern for QA/QC really lies at low 14 level concentrations, concentrations say below 20 parts per 15 billion, and virtually the only thing that I've seen that 16 really addresses the quality of data at those levels and 17 below was a series of round-robin results that the District 18 received in participation with a study with the USGS over a 19 course of -- I'm not sure when the round-robin started, 20 either 1979 or '80 or '81, somewhere around there, roughly a 21 10-year study, where during the course of this study USGS 22 would provide the District with a known sample of some 23 concentration X, the District would then analyze that sample 24 and report the results back to the USGS. 25 Most of those samples that were analyzed were at 24 1 comparatively high concentrations. There were several 2 samples that were at low, reasonably low concentrations. 3 When you look at those results, the recovery, in 4 other words, how close the District got to the known or true 5 value of the sample was not particularly good and that they 6 were uniformly low. 7 Q. When you say they were uniformly low, what do you 8 mean? 9 A. It means that they were all low to varying 10 degrees, but there was not an example -- it was not a 11 situation where you had some values high and some values 12 low, but the scatter was about some mean true value, if you 13 will. 14 If you plotted the observed versus the expected, 15 you would see that the observed concentrations were always 16 lower than the expected concentrations. That would suggest 17 some sort of a bias to me. 18 Q. The observed concentrations being the results 19 reported by the District? 20 A. That's correct. 21 Q. Okay. And the expected concentrations being the 22 true values as determined by USGS? 23 A. That's right. 24 Q. Is there any other information other than the USGS 25 round-robin data that you're relying on with regard to that 25 1 opinion? 2 A. Well, I have a real concern, I guess, that has 3 developed as I've sat through a couple depositions, again, 4 with Mr. Rosen and Dr. Vidal concerning how they process 5 phosphorus samples through their laboratory. It's my 6 opinion that the phosphorus samples at low levels should be 7 segregated from the high samples before they're analyzed. 8 In other words, ideally, particularly at very low 9 concentrations, you should be running those samples under 10 one set of standard curves, and the higher samples should be 11 run at a different, under a different standard curve, and 12 it's my understanding that's not done. 13 Q. Okay. And I believe in your last deposition we 14 went through your opinion concerning the standard curve. 15 Has your opinions or conclusions in that regard changed from 16 your last deposition? 17 A. No. 18 Q. And the USGS round-robin, am I correct that is the 19 five data points that we looked at at your last deposition? 20 A. I don't recall the precise number. Five sounds 21 about right. Certainly it was not an overabundance of 22 data. 23 Q. When you indicated that the results of this 24 round-robin indicated to you a potential bias in the 25 results, what would you consider a significant deviation 26 1 which would create a problem with the results? 2 MR. GREEN: Object to the form. 3 Q. Let me rephrase it. If I can figure out a way to 4 do it. 5 What I'd like to know, Dr. Pollman, is your 6 opinion on how close, essentially, the observed should be to 7 the expected in order to give you comfort in the validity of 8 the data? 9 A. Well, ideally, I think you'd expect agreement 10 within 5 percent, but I think that's un- -- not necessarily 11 reasonable, particularly at low levels. Maybe something on 12 the order of 15 percent might be more reasonable. 13 Q. And what did you observe with regard to the USGS 14 round-robin results? 15 A. Well, I feel far more comfortable answering that 16 answer or question, rather, if I had the data in front of 17 me. I know that the deviations were on the order of 40 to 18 70 percent in some cases. 19 Q. I think we'll probably come across that later in 20 the depo and we can pin it down a little bit more closely. 21 Other than your discussion concerning the standard 22 curve as described in the Vidal and Rosen depositions, was 23 there any other information that you're relying on either 24 from the Vidal and Rosen depositions or any other source to 25 support your opinions concerning the quality of the data? 27 1 A. Yes. I believe I stated this at my last 2 deposition, that Dr. Wetzel, for example, has written a text 3 on limnological analyses. In that text he states that, when 4 analyzing total phosphorus samples below 10 micrograms per 5 liter, the standard curve should be developed within that 6 range. He also mentions other procedures which should be 7 undertaken to improve the sensitivity of the analyses. 8 I have less concerns about that, but I am 9 concerned about the failure of the District to include 10 standards in that range. 11 Q. This text by Dr., it's Dr. Bob Wetzel? 12 A. That's correct. 13 Q. Do you know when that was published? 14 A. I don't recall the precise date. 15 Q. Approximately? 16 A. Sometime after 1979 and maybe closer to '84 or 17 '88. I don't know exactly. 18 I should also state that it's generally accepted 19 laboratory practice that, when you're analyzing samples in a 20 certain range, you try to bracket the sample with 21 appropriately set standards. It's not just Dr. Wetzel who 22 states that opinion. 23 Q. Okay. And how long has that general practice been 24 in existence? 25 A. I would imagine for a fair amount of -- period of 28 1 time. I couldn't give you a precise date, but I'd really 2 hate to venture. I don't know precisely. 3 Q. Can you give me a decade range? 4 A. Well, I'll state this, I guess, that environmental 5 laboratory practices seem to lag behind pure analytical 6 chemistry practices, and that there is probably -- there is, 7 I'm sure this is true, that there was a period of time when 8 the environmental chemist had not caught up with their 9 brethren in the pure analytical chemistry field. It may be, 10 say, within the past 10 or 15 years that there's been far 11 more attention to QA/QC in the measurement of environmental 12 variables, but I think cognizance of this has been around 13 for quite some time. 14 Q. And by quite some time what do you mean? 15 A. At least 15 to 20 years. 16 You know, as a, I guess, another concern that I 17 have, I'm really surprised by the fact that we don't -- 18 that we do not see other QA checks being reported, that 19 there are other reference samples that are not routinely 20 reported by the District lab, particularly at low levels. 21 It appears that most of the routine performance check 22 samples are usually at much higher levels, and the District 23 historically has not run samples at low levels as 24 performance checks other than what we see in the USGS 25 round-robin results. 29 1 Q. And what do you base that understanding on? 2 A. Well, I base that understanding on the fact that 3 we've asked for that information, didn't receive it. 4 Q. Okay. What is your understanding of the current 5 QA/QC program under which the District laboratory 6 operates? 7 A. Well, I know that their current QA/QC program, as 8 far as I know, has been approved by the state's Department 9 of Environmental Protection. I would imagine that's far 10 more rigorous than what was practiced during the early '80s, 11 and so I would imagine that the performance of laboratory 12 actually may be improved today relative to where it was, 13 say, 10, 15 years ago. 14 Q. Do you know how long the current QA/QC program as 15 approved by DEP has been in existence or in place, I should 16 say? 17 A. I do not know precisely. 18 Q. Are you familiar with any of the QA/QC procedures 19 that existed at the District prior to the current plan, 20 meaning the QA/QC plan? 21 A. I've been present to discussions by Dr. Vidal and 22 Mr. Rosen where those procedures were discussed to some 23 extent. 24 Q. And you're referring to their depositions? 25 A. That's correct. 30 1 Q. Can you tell me what your understanding is of the 2 QA/QC procedures from the mid 1970s through 1990, 3 approximately? 4 A. I'd have to go back and review their depositions 5 to answer that question precisely. 6 Q. Okay. To the best of your recollection, can you 7 tell me what you recall of the QA/QC procedures that were in 8 place from the mid '70s forward? 9 A. Well, I feel very uncomfortable answering that 10 question without reviewing that material. I would not want 11 to be in a position of either overstating or understating 12 that point. 13 Q. Okay. Other than the testimony that was provided 14 by Doctors Vidal and Rosen, do you have any other 15 information or have you seen any other information 16 concerning the QA/QC procedures in place from the mid 1970s 17 forward other than the round-robin that we've discussed? 18 A. I have seen some other internal documents that the 19 District has developed, and it's been about a year since 20 I've looked at that material. My recollection of that 21 material was that the most significant thing that stood out 22 in my mind was that there are reference checks that are 23 periodically run by the lab, but those reference checks 24 typically are at much higher concentrations than, say, the 25 levels where I'm concerned about the accuracy of the data. 31 1 Q. From your recollection of the procedures as you've 2 seen them in the documentation or heard about in the 3 depositions of Dr. Vidal and Dr. Rosen, do you believe that 4 the procedures that were in place from 19 -- mid 1970s 5 forward were typical for laboratories in that particular 6 time period? 7 MR. GREEN: Object to the form. You can answer. 8 A. I don't know if they were typical of all 9 laboratories. I believe not. I believe that those 10 individuals that were concerned, again, looking at very low 11 phosphorus concentrations would set up their laboratory 12 practices differently. 13 My perception of the District lab is that it was 14 a -- sort of like a factory operation. It was set up to 15 process samples and process a lot of samples, and when 16 you're in that mode, it's difficult to pay as strict 17 attention as you need to get good results at low levels. 18 Q. Are you aware of any circumstances that would 19 suggest that the District was particularly concerned in the 20 mid 1970s to late 1970s about obtaining data of low 21 phosphorus concentrations as you've defined them below 20 22 parts per billion? 23 A. Could you define what you mean by circumstances? 24 I mean, are you talking about political or scientific 25 issues? 32 1 Q. Political or scientific. Any circumstance that 2 would at that time period have -- 3 A. Yeah. I know of no driving concern to treat those 4 numbers differently, except for the fact that I believe a 5 good chemist would have been cognizant of the fact that you 6 can get a different response at low levels with your 7 instrumentation as compared to dealing with higher level 8 samples, and I think that was commonly known laboratory 9 practice at the time. 10 Q. With regard to total phosphorus data collected 11 during the or from the mid '70s to the late '80s in the low 12 concentration ranges of below 20 parts per billion, do you 13 know what or are you familiar with what circumstances were 14 involved in the collection of that particular data? 15 MR. GREEN: Object to the form. 16 A. I do not understand the question. 17 Q. Okay. With regard to total phosphorus data as 18 reported by the District's laboratory from the mid 1970s 19 through the late 1980s, do you have an understanding of what 20 percentage of that data related to low phosphorus 21 concentrations of below 20 parts per billion versus data 22 above 20 parts per billion? 23 A. I couldn't -- I couldn't guess. I would -- my 24 gut-level feeling, if that's what you're asking me for, and 25 I'm sure I could be proved wrong because I'm not privy to 33 1 the internal workings of the District lab, was that a large 2 number of the samples were comparatively high. 3 Q. Were comparatively what? 4 A. High. I mean, for example, the District has spent 5 a lot of time and effort working on Lake Okeechobee. 6 Phosphorus concentrations in Lake Okeechobee are on the 7 order of a hundred parts per billion, and included in their 8 routine sampling program would be samples out of the EAA and 9 the upper reaches of that system. Those would be high 10 concentrations. 11 So it may be that the preponderance of samples 12 that they collected were expectedly high concentration 13 samples, but if you're interested in precisely measuring 14 what's going on at low levels, then you need to 15 appropriately treat those samples, and this may be the 16 problem with a laboratory that's being asked to process a 17 lot of samples in a short period of time, that they just are 18 not well set up to handle low level samples and it's just 19 got -- something that got lost in the wash. 20 Q. Given the nature of the data that the District is 21 sampling with regard to total phosphorus in water, is it 22 reasonable -- was it reasonable during that time period of 23 the mid 1970s through the late 1980s, in your opinion, to 24 set the standard curve where they did? 25 MR. GREEN: Object to the form. 34 1 A. Well, that's not how I did it when I was in 2 graduate school. I typically set my standard curve up so 3 that I could measure comparatively low level samples, and if 4 the samples were too high, then we diluted them 5 appropriately so that they would fit within the standard 6 curve. 7 Q. And how many samples were you analyzing as a 8 graduate student? 9 A. On the order of tens at a shot. 10 Q. All right. And how does that compare with the 11 samples being processed by the District? 12 A. Oh, I'm sure that they were processing orders of 13 magnitude more samples than I was. 14 Q. And, again, given your understanding of the nature 15 of those samples and that the majority of those involved 16 high concentration levels of total phosphorus, in your 17 opinion, is it unreasonable for the District to set up their 18 standard curve in the manner in which they did? 19 MR. GREEN: Object to the form. 20 A. I think it's unreasonable for -- well, I guess I 21 believe that they can set up the standard curve any way they 22 want, but I think it's unreasonable to be able to apply a 23 great deal of reliance on the accuracy of the data at low 24 levels based upon the standard curve that they have, and if 25 they want to place emphasis on the reliability of that data, 35 1 then they should have had an appropriate set of standards to 2 precisely quantitate what those sample results would be. 3 Q. Well, am I correct, Doctor, that if -- what you're 4 saying, then, is that it's not necessarily unreasonable for 5 the District to have set up the standard curve the way they 6 did. However, you believe that, in light of the way it was 7 set up, that there is less confidence you can put in the low 8 concentration readings that resulted? 9 MR. GREEN: Object to the form. He never said it 10 was reasonable to do any of that, or not unreasonable to do 11 any of that. 12 A. Could you restate your question, please? 13 MR. NETTLETON: Could you read it back, please? 14 (Thereupon, the question referred to was read back 15 by the reporter as above recorded.) 16 BY THE WITNESS: 17 A. I guess I should be very precise about my answer 18 here. How you set up your standard curve really relates to 19 your goals, and if the goal is to -- if the goal is to look 20 at principally high concentrations, then the District 21 standard curve probably was appropriate. 22 If the goal is to look at low level samples, then 23 a separate standard curve should have been used. 24 Q. Do you know what the goal of the District was 25 during the period of record we've been discussing, the mid 36 1 1970s through the late 1980s? 2 MR. GREEN: Object to the form. 3 A. No. I'm not privy to the goals of the 4 laboratory. 5 Q. Other than the District data concerning water 6 quality parameters in the refuge, are you aware of any other 7 water quality data that exists for the refuge from the mid 8 1970s through the late 1980s? 9 A. Well, the only data that I'm aware of for the 10 refuge -- actually, I guess there's two data sources that 11 I'm aware of, potential data sources, one of which is 12 embodied in the District data, I believe, and that was the 13 data that was from a study by Millar, M-i-l-l-a-r, and that 14 was from the early '70s, and I think that forms the 15 framework for the phosphorus data that the District used in 16 the formulation of their criteria. 17 I also believe that the University of Florida 18 collected data out of the Loxahatchee, including water 19 chemistry data in the late '80s. I have not seen that 20 data. 21 Q. Okay. Let me expand the time period. Since the 22 -- from the mid 1970s to the present, are you aware of any 23 additional data sets or data collected from the refuge on 24 water quality parameters? 25 A. Yes, indeed, I am. 37 1 Q. And what would those other ones be? 2 A. Those additional data would be the data that were 3 collected by the Department of Justice and I believe 4 Environmental Services and Permitting as part of the right 5 to entry into the Loxahatchee, and I believe that sampling 6 started -- geez, I can't recall exactly when it started, but 7 it might have been last spring. 8 Q. And have you seen the data collected by 9 Environmental Servicing or DOJ? 10 A. I have seen some of that data. I have scanned it 11 briefly. 12 Q. All right. With regard to the University of 13 Florida data, who collected that? 14 A. I believe that was John Richardson's group. 15 Q. And have you or anyone else on behalf of the 16 Cooperative, to your knowledge, attempted to obtain John 17 Richardson's data? 18 A. I know that we were interested in obtaining it. 19 We've gone through the reports that have been published, and 20 if memory serves me correctly, we were not able to find any 21 data files or data listings of what those results were. 22 Q. To your knowledge, has anyone retained by the 23 Cooperative been able to obtain the complete data sets of 24 John Richardson? 25 A. To my knowledge, that is incorrect, nobody has. 38 1 Q. Have you or anyone retained by the Cooperative, to 2 your knowledge, seen John Richardson's data concerning 3 phosphorus parameters in the refuge as opposed to a complete 4 data set? 5 A. Which phosphorus parameters are you -- 6 Q. Total phosphorus. 7 A. Are you talking about soils or water? 8 Q. Water. Water. 9 A. Only from what's been listed in his report, which 10 I think is very sketchy, if I remember correctly. 11 Q. I'm sorry. Dr. John Davis's outfit, what's that 12 called again? 13 A. Environmental Services and Permitting. 14 Q. Services. Based upon your scanning, I believe is 15 the term you used, or review of any of the data collected by 16 Environmental Services or DOJ from the refuge, have you done 17 any analysis with regard to that data? 18 A. No, I have not. 19 Q. All right. Has anyone from Info Tech or Tetra 20 Tech done any analysis of that data? 21 A. Info Tech, I believe, is in the process of taking 22 those data and developing computer files with the view of 23 analyzing those data. 24 Q. Have they been analyzed to date, to your 25 knowledge? 39 1 A. Not to my knowledge. They may have done some 2 preliminary stuff, but that I don't know. 3 Q. Okay. Are you aware of whether this data suffers 4 from the same consistency problems that we saw with the 5 District data? 6 A. Well, I don't -- I don't know if I can answer 7 that question accurately. It's my understanding -- I'd 8 really have to take a look at the parameter list in terms of 9 all the parameters that were measured. It may be that 10 insufficient parameters were collected to fully evaluate the 11 interparameter consistency, but, at any rate, assuming that 12 those parameters were collected, I don't know if anybody's 13 done that type of analysis. 14 Q. Okay. I believe at your last deposition you had 15 indicated that, when that data became available, that 16 analysis of that data may dispel some of your concerns in 17 this area, and that's why I'm asking the questions as to 18 whether at this point in time you've had an opportunity or 19 if anyone from Info Tech, Tetra Tech has had an opportunity 20 to review that data in order to dispel any of your concerns 21 related to the refuge data? 22 A. No. We have not looked at that with a view to 23 dispelling those concerns. 24 Q. Do you believe that the data that has been 25 collected in the refuge by the Department of Justice and 40 1 Environmental Services, that that will be sufficient, 2 assuming there are no problems with that data, in order to 3 allow scientists to rely upon that data to reach conclusions 4 concerning appropriate criteria for the refuge? 5 MR. GREEN: I'll object to the form. 6 A. Could you restate the question, please? 7 Q. I'll withdraw it for now and come back to it 8 later. 9 Dr. Pollman, another area you indicated you would 10 be testifying concerning the refuge data concerned the 11 relevance of the data on the cause-and-effect relationship? 12 A. That's right. 13 Q. Can you please tell me what your opinion is in 14 that regard? 15 A. Yes. Basically, I disagree with the notion of 16 using interior marsh concentrations to set criteria for or 17 as trigger points for establishing violations for inflow 18 concentrations through the S-5A and S-6 structures. 19 Q. Okay. Let me try to break this down a little 20 bit. When you say using interior marsh concentrations to 21 set criteria, what are you referring to? 22 A. Well, I don't recall the precise stations. If 23 memory serves me correctly and, again, it's been about a 24 year since I looked at this, that the criteria looked at a 25 couple of interior stations to basically set the threshold 41 1 levels. Those interior stations are hydrologically 2 disjoint, are not affected really by water originating out 3 of the EAA, so their concentration response really in no 4 way, shape, or form, that's a hard stretch of my mind to 5 believe that the dynamics of concentrations at those 6 stations are influenced by anything that comes in through 7 S-5 and S-6. 8 Q. I guess I'd like you to explain to me your 9 understanding of what the criteria is as set in the 10 refuge -- set forth in the SWIM Plan? 11 A. I'd have to go back and review that. 12 Q. Just your general understanding, though. What is 13 your understanding, when you talk in terms of violation of 14 criteria, what are you referring to? 15 A. It's my understanding that the criteria would be 16 based on monitoring of interior marsh concentrations; that 17 there is a stage, I believe, that there is a stage 18 relationship that accounts for the fact that, as stage goes 19 up and down, concentrations are affected by that hydrologic 20 effect, so there's some consideration in the criteria for 21 how concentrations are affected by antecedent conditions 22 that really don't relate to inflow from the EAA, but that if 23 those concentrations exceed some range established by that 24 empirical relationship, that the system is considered to be 25 out of compliance. 42 1 MR. GREEN: Off the record. 2 (Thereupon, a brief discussion was held off the 3 record.) 4 MR. GREEN: Sorry, we're back. I'm sorry, Paul. 5 I'm not trying to disrupt what you were doing. 6 MR. NETTLETON: That's all right. 7 BY MR. NETTLETON: 8 Q. Dr. Pollman, what is your understanding of the 9 basis for the criteria that we've been referring to for the 10 refuge? 11 A. My understanding of the basis for the criteria is 12 that fundamentally it was derived from two stations. It was 13 based on examination, again, I believe it was the Millar 14 data, and it basically stated that -- well, it looked at 15 these two background stations that appeared to have lower 16 concentrations than a number of the other interior stations, 17 and in conjunction with the classical definition of the 18 phosphorus concentration above which you have mesotrophic 19 conditions and below which you have oligotrophic conditions, 20 i.e., 10 ppb, that these two stations, then, were reflective 21 of the true oligotrophic status of the refuge, and I believe 22 that those stations then were used to form the principal 23 basis for setting the criteria for the refuge. 24 Q. Okay. You mentioned two types of systems, an 25 oligotrophic and what was the other one? 43 1 A. Mesotrophic. 2 Q. Okay. Can you just define for me what 3 oligotrophic means? 4 A. Oligotrophic in the strictest definition of the 5 word means nutrient poor. 6 Q. And mesotrophic, what does that mean? 7 A. It means somewhat nutrient enriched. It means it 8 has more nutrients than an oligotrophic system, practically 9 speaking. 10 Q. Okay. And is it your testimony that the 11 approximate line between those, an oligotrophic system and a 12 mesotrophic system, is 10 parts per billion phosphorus? 13 MR. GREEN: Object to form. 14 A. No. That's not my testimony. What my statement 15 was is that's a classical definition. That definition was 16 based on work that was done in the late '40s in Wisconsin by 17 a guy named Sawyer and it's been used by other individuals 18 as a threshold level, but Florida limnological experience 19 suggests that those levels are perhaps not the appropriate 20 criteria to apply to Florida systems. 21 Q. And do you have an opinion as to what an 22 appropriate level would be for the Florida systems, 23 particularly the Everglades? 24 MR. GREEN: Object to the form. 25 Go ahead. 44 1 A. Could you restate your question, please? 2 Q. Well, let me limit it further. With regard to the 3 refuge particularly, do you have an opinion as to what the 4 level would be where you crossed over from an oligotrophic 5 to a mesotrophic system? 6 A. No. I have a real problem with using a threshold 7 value to describe a continuum of response, and so I think 8 it's perhaps disingenuous to or perhaps a bit naive to state 9 that there is a single value for applicable system without 10 doing other work to back up that number that then states 11 this is the magic threshold in which a system crosses the 12 boundary from oligotrophic to mesotrophic and mesotrophic to 13 eutrophic. 14 Q. Is the crossover of boundary from oligotrophic to 15 mesotrophic, would that be defined more in terms of response 16 of the system itself? 17 A. Yes. 18 Q. Okay. And then is it your testimony that 19 different levels of the system may respond to different 20 levels of total phosphorus? 21 MR. GREEN: Object to the form. 22 A. Could you restate your question, please? 23 Q. Okay. I was really trying to restate, I thought, 24 what you were saying in your testimony. Maybe I 25 misunderstood it, and if I did, please clarify me, but am I 45 1 correct that it is your view that, particularly with regard 2 to the refuge or the EPA in general, that there is no 3 specific threshold number where the ecosystem in general 4 responds, but that you must look at each level of the 5 ecosystem and that each level may have a different threshold 6 number? 7 MR. GREEN: I object to the form. You may answer, 8 but the reason is he hadn't talked about different levels of 9 the ecosystem, to my recollection, but you're welcome to 10 answer if you know the answer. 11 A. I have a problem, I guess, a philosophical problem 12 with defining a threshold value per se. It may be possible 13 to achieve a definition of a threshold, but I believe that 14 that threshold is going to be -- must be predicated on a 15 lot of research looking at a lot of different variables. 16 The basic problem I have with a threshold number 17 is that I don't believe that there is a single value that 18 delimits the transition from, say, good to bad or, if that's 19 how you want to define it, or oligotrophic to mesotrophic or 20 what have you. 21 The notion of using 10 milli- -- excuse me, 10 22 micrograms of phosphorus per liter as a critical threshold 23 value in my opinion was largely used as a matter of 24 convenience, and, again, it was based on some work that was 25 done in Wisconsin and it was based on looking at spring 46 1 turnover concentrations. It really has no relevance in its 2 application to, say, Florida systems. We don't have spring 3 turnover concentrations in Florida lakes, for example. 4 Q. Well, I'm a little bit confused because you say 5 that it's your understanding that the criteria was based 6 upon this work done in the '40s, but at the same time you're 7 saying that it was based upon some sampling that was taken 8 at certain interior marsh stations, so -- 9 A. Okay. Yeah, my memory may be a little bit fuzzy 10 on terms of exactly how the data were treated, but my 11 recollection is that the individual who analyzed the data 12 and then used these data to set the criteria had an array of 13 concentration -- had an array of stations and, of course, 14 different concentrations at each station, and those 15 concentrations were generally low, like on the order of, 16 say, 8 or 9 or 9 to 15 parts per billion or something like 17 that. I forget exactly what the range of numbers were, but 18 that there were two stations that were right around 10 or 19 maybe even a little bit below 10, and that this individual 20 said, okay, the classical threshold value between 21 oligotrophy and mesotrophy is 10 parts per billion and this 22 is the value that we should be using, so, therefore, we're 23 going to use these two stations. 24 Q. Who is this person you are referring to? 25 A. I believe it was William Walker. 47 1 Q. Do you know what particular period of record was 2 looked at with regard to these interior stations to set the 3 criteria? 4 A. I don't remember the precise dates. I believe it 5 was '79 to '83. 6 Q. Now, you indicated that you do not believe there 7 is a single threshold number where you would pass through 8 the boundary from oligotrophic to mesotrophic; is that 9 correct? 10 A. Yes. At this stage in time, yes, I believe that's 11 correct. I could be -- I could be proved wrong, I think, 12 with the appropriate research, but I have a hard time 13 envisioning that we're going to be able to relate a 14 continuum of response, of ecological response, to a single 15 parameter. 16 I mean, ecological responses are dictated by a 17 number of different parameters, and to boil it down to one 18 number and precisely one value I think is 19 oversimplification. 20 Q. Well, do you believe, based upon what you have 21 seen and reviewed, that there is a range within which the 22 refuge particularly would pass between an oligotrophic and a 23 mesotrophic system? 24 MR. GREEN: Object to form. 25 Q. Referring specifically to a range of phosphorus. 48 1 A. I believe that there would be a range of values 2 that could be applied, yes. 3 Q. Can you tell me what that range would have 4 encompassed? 5 A. You mean in terms of the actual values? 6 Q. Yes. 7 A. No, I really can't say because I haven't seen the 8 research to do it. I think it needs to be defined by some 9 empirical studies. I can only speak to it in qualitative 10 terms. 11 Q. Well, with those qualifications, can you give me 12 your best professional judgment of what that range would 13 involve? Range would include, excuse me. 14 A. No. I can't give that judgment because I think it 15 really defines in terms -- that range is going to be 16 defined in terms of what is the perceived use of the system 17 or what is it that we're trying to maximize with the system. 18 You know, it may be that, if you want wading birds or 19 something like that, that may be that a more enriched 20 nutrient state might be more applicable. 21 I don't feel, quite frankly, knowledgeable enough 22 about the ecological dynamics of the refuge to start 23 throwing numbers around and what those goals are. 24 Q. Okay. Again, it just seems to me that we're 25 talking about possibly two different things here. One is 49 1 management decisions on what the goal might be for the 2 particular refuge. 3 What I would like to focus on, which I, correct me 4 if I'm wrong, is the scientific question of moving from an 5 oligotrophic to a mesotrophic system and what range of 6 values of total phosphorus would be involved in that 7 particular question. 8 A. You mean in terms of, again, a threshold between 9 oligotrophic and mesotrophic conditions? 10 Q. Yes, sir. 11 A. My feeling is it's probably going to be on the 12 order of, say, 20 to 30 parts per billion. 13 Q. And that's with particular regard to the refuge or 14 the EPA in general? 15 A. Well, I hate to say for the EPA in general. I 16 have a problem -- I really have a problem. I don't want to 17 be pinned down to a particular number because, quite 18 frankly, each system has different needs, and I'm not an 19 aquatic ecologist. I'm not going on the record stating that 20 this is what the phytoplankton need or what have you. 21 My general feeling as far as systems in general is 22 that you start getting much above 20 parts per billion or 23 certainly above 30 parts per billion I think you're going to 24 start changing the trophic state of the system. 25 But we don't know, necessarily, what's appropriate 50 1 for the system, and what may be appropriate for the park may 2 not be appropriate for the refuge. 3 Q. Okay. Again, when you say appropriate, are you 4 talking about in terms of the scientific change in the 5 trophic system or a management question? 6 A. Well, I think that all this boils down to really a 7 management decision where scientists can only provide 8 guidance. 9 Q. Okay. Well, let me, just for clarification, aside 10 from the management question, if we're talking simply about 11 the scientific question of moving from an oligotrophic to a 12 mesotrophic system, do you believe with regard to the park 13 that the range of total phosphorus would be the same 20 to 14 30 parts per billion, or would you expect it to be less than 15 20 to 30 parts per billion? 16 A. I think I'd expect it to be less than 20 parts per 17 billion. 18 Q. And could you provide a range, again, for the 19 park? 20 MR. GREEN: I'd like to assert an objection here. 21 This is all very interesting, but Dr. Pollman has been very 22 careful to disclaim being an ecosystem or an ecological 23 expert. He hasn't been tendered in that regard, and, you 24 know, he may answer the question to the best of his 25 judgment, but that doesn't, by not objecting, doesn't mean 51 1 that we concur that he is qualified to give those opinions. 2 MR. NETTLETON: Okay. 3 MR. GREEN: Okay. 4 A. Well, I really hesitate to throw numbers around 5 without having supporting research behind it. My own belief 6 is that each system is unique and that, if we're going to 7 try and set threshold values, if you will, for, say, the 8 park, what we need to do is understand the ecological 9 dynamics of the park and understand how those dynamics are 10 affected by changes in nutrient concentration, as well as 11 other parameters as well, and that only on the basis of 12 that, on those types of studies, then can we set appropriate 13 limits. 14 Q. Well, Dr. Pollman, in light of Mr. Green's 15 objection, I'm just trying to get clear in my own mind 16 precisely what it is you will be testifying about on this 17 issue of cause and effect with regard to the interior marsh 18 concentrations, and maybe if you could clarify that for me, 19 again, precisely what it is your opinion is concerning the 20 cause-and-effect issue. 21 A. Certainly. It seems to me -- 22 MR. GREEN: Excuse me. I object. I think you 23 have asked him that, and he's answered it. He's welcome to 24 try again. 25 Q. All right. Thank you. 52 1 A. As I understand the process, the idea between 2 setting the criteria is to establish whether or not there 3 are violations and that those violations then relate back to 4 discharges coming out of the EAA. 5 The idea is that, by monitoring interior marsh 6 stations and setting up threshold values, if you will, or 7 flag points at which point violations of water quality 8 criteria are identified, that becomes a trigger point for 9 establishing that the system is out of compliance and that 10 concentrations or loadings coming out of the EAA into the 11 refuge need to be rationed down in some way, shape, or form. 12 My problem with that approach, and this is really 13 what I mean by cause and effect, the effect that is implicit 14 or explicit in the criteria are interior marsh 15 concentration. The link, then, as a cause is what's coming 16 in through the S-5 and S-6A structures. 17 Quite frankly, I have a hard time believing that 18 there is a cause and effect between what comes in through 19 S-5 and S-6 and what happens at the interior part of the 20 Loxahatchee. That's the crux of what I mean by cause and 21 effect. 22 I think the language I used earlier is that I 23 believe that those two systems are hydrologically disjoint. 24 They're not connected, so to speak. 25 Q. Do you have an opinion on the reasonableness of 53 1 the interim or long-term levels that were set for the 2 interior of the marsh? 3 MR. GREEN: Object to form. 4 A. Well, again, you know, those data were based on a 5 data set that I think has some real problems, and so I can't 6 fairly comment on the reasonableness of the, say, the 7 relationships that were established in the criteria like the 8 stage concentration relationships and whatnot with the 9 extant data set. 10 I believe that the newer data set that is being 11 developed through the work that Dr. Jones is performing, as 12 well as ESP, would prove to be a much better data set with 13 which to use to try to establish reasonable criteria. 14 Q. Well, am I correct, Dr. Pollman, that you do not 15 anticipate testifying concerning the reasonableness or 16 appropriateness of the particular levels that were set in 17 the criteria for the refuge as opposed to tying those levels 18 to the inflows to the refuge? 19 MR. GREEN: Object to the form. 20 A. That's, I guess, a question I never really 21 contemplated answering. 22 Q. Well, did you understand my question? 23 A. Well, maybe I don't understand your question. Let 24 me restate it and perhaps see if we're on the same 25 wavelength there. 54 1 If I understand you correctly, what you're driving 2 at is do I think that the threshold -- that the actual 3 numbers are reasonable values, all other questions aside 4 regarding data quality and what have you, if the actual 5 numbers are reasonable limits for the park. 6 Q. Refuge. 7 A. Excuse me, the park -- I mean refuge. That's 8 correct. 9 I -- I really hate to say at this point. I don't 10 feel like I've studied the question long enough with that in 11 view. 12 I would like to caveat my answer also by stating 13 that those concentrations may be entirely reasonable for the 14 interior part of the park -- excuse me, refuge, but, again, 15 we are really talking about a system that's divided in two. 16 You've got the fringe of the refuge that is influenced by 17 inflows out of S-5A and S-6 and then you've got the interior 18 portion of that marsh, and those interior marsh 19 concentrations may be very reasonable. It's a 20 rainfall-driven system, and that may be what's appropriate. 21 Q. Can you tell me what you're relying upon for your 22 understanding that the refuge is hydrologically disjoint 23 between interior and exterior? 24 A. Yeah. There's several things. First of all, 25 there's good direct geochemical evidence that the systems 55 1 are really different. If you look at conductivity, for 2 example, you take a transect across the system, you look at 3 conductivities. You see that the conductivities rapidly 4 drop off, and you have, of course, high conductivity on the 5 exterior part. As you get near the rim of the system, you 6 have very high conductivities. As you grade in or you move 7 in towards the interior portion of the marsh, the 8 conductivities drop off and go from, say, a range of nine 9 hundred to a thousand microsiemens per centimeter to 10 something on the order of, say, a hundred microsiemens per 11 centimeter, and geochemically, those are quite different 12 systems. 13 You also see these differences picked up in other 14 variables, for example, in pH, alkalinity, some of the other 15 ancillary parameters that reflect major ion chemistry. 16 Phosphorus is also less interpenetrating, if you will, than, 17 say, a conservative constituent like chloride. So 18 phosphorus is not going to invade into the interior part of 19 the marsh as far as chloride will, and so these geochemical 20 parameters indicate that you have basically different 21 influences driving the overall chemistry of the system. 22 And, of course, the interior is, I think a lot of people 23 would agree, is rainfall driven. It's reflected in the pH. 24 It's reflected in the low conductivity of the waters. 25 The exterior or the outer fringe of the marsh is 56 1 dominated, the water quality is dominated by flow at S-5A 2 and S-6. 3 Q. Okay. Can you quantify for me the outer fringe? 4 A. You mean in terms of the actual kilometer extent? 5 Q. (Nods head.) 6 A. I couldn't do it here right now. I'd have to sit 7 down and look at the data, particularly have to look at the 8 data that have been collected as part of the right to entry, 9 but I think that that could be done. 10 And, again, it's not going to be a sharp line, I 11 don't believe. I think there's probably going to be a bit 12 of a continuum of response, but I think that we can probably 13 set up a system that might have three zones. You have a 14 zone of almost complete domination, maybe a smaller zone of 15 intermediate influence, and then an interior zone of 16 virtually no influence. 17 Q. Just based upon the data you've reviewed and to 18 the best of your recollection without having it sitting in 19 front of you, do you know approximately how far that fringe 20 would extend? 21 A. No. I really hate to say because, quite frankly, 22 I haven't reviewed the data with that in mind. I've just 23 taken a look at some of the interparameter relationships on 24 a brief cursory scan. The amount of time I've spent with 25 that data is on the order of a couple of minutes, to be 57 1 perfectly honest, and I have not given it a detailed review. 2 Q. Are any of the interior stations that are being 3 used to measure compliance with the criteria in the SWIM 4 Plan within the fringe area as you have defined it? 5 A. I couldn't answer that question at this point. 6 Q. Okay. What particular data does exist that you're 7 referring to? 8 Is it the data that was collected on the entry by 9 Environmental Services? 10 A. Well, it's just -- yeah. That would be, I think, 11 the best data set to look at. The other data set would be 12 the data collected by Richardson, et al., where I believe 13 that they can actually construct, if memory serves me 14 correctly, it's been a long time since I've looked at this 15 stuff, I believe that Richardson in his report actually 16 conducted or constructed, rather, concentration isopleths 17 that show, for example, how conductivity varies within the 18 refuge. 19 Q. And that's John Richardson? 20 A. That's right. 21 Q. And that would be for surface water? 22 A. Yes, I believe so. 23 Q. And is that reported or set forth in his report 24 that was published in the 1990-91 time period? 25 A. Yes. Again, if memory serves me correctly, it is. 58 1 (Thereupon, a brief discussion was held off the 2 record and a recess was taken.) 3 BY MR. NETTLETON: 4 Q. Dr. Pollman, with regard to your opinion 5 concerning the use of interior marsh concentrations to set 6 criteria for violation of the inflow structures at S-5A and 7 S-6, have you done any work or reviewed any additional 8 materials with regard to this area of testimony since your 9 last deposition? 10 A. No, I have not. 11 Q. And with regard to the preliminary opinions that 12 you stated at your last deposition, would those now be 13 essentially your final opinions? 14 A. Well, I would like to see -- I know that Info 15 Tech, like I said before, is taking that entry data and 16 putting it into their system so that they'll statistically 17 analyze the data, and I'd like to see what those results 18 show before I finalize my opinion. 19 Q. Do you know when that will be accomplished? 20 A. Well, I know it's a fast-track item, but I would 21 imagine that's being done in a matter of days, but I don't 22 know precisely when it will be finished. 23 Q. Can you tell me how long Info Tech has had the 24 data from the refuge entry? 25 A. Well, I think the data has been sort of dribbling 59 1 in over the course of time. I think we just recently got 2 some new data over the past several weeks. 3 MR. GREEN: Let me state something lest we get 4 into a hassle about when opinions are final and invite you 5 to question Dr. Pollman further if I stir the pot, but my 6 recollection of what he said about an hour ago was that 7 those data had a bearing only with regard to their potential 8 for resolving some of his concerns about the interparameter 9 comparisons, and that's the only -- so I just want to state 10 that for the record, that's my understanding, and you've 11 covered a lot more turf than that, so that's all I had to 12 say. 13 A. I guess I would like to -- 14 MR. GREEN: No. I didn't ask you a question, 15 unless Paul asks you. It would be inappropriate for me to. 16 Excuse me. 17 Q. All right. I will allow you, Dr. Pollman, to 18 clarify in light of Mr. Green's comments, if that's 19 correct. 20 A. Well, I do think that it would be appropriate to 21 look at the new data and see if the same lack of cause and 22 effect that we saw with the earlier results are borne out by 23 new statistical analysis. That's all. 24 Q. And I'd like to go back again now. When you say 25 cause and effect, what are you referring to? 60 1 A. Well, we should see a relationship and it should 2 show up statistically between changes in, say, loadings 3 coming in through S-5A and S-6 or concentration and flow and 4 what's going on in the interior portion of the marsh. 5 If we do not see that relationship statistically, 6 that gives me great cause for concern that there's any sort 7 of real linkage between the two. 8 Q. Okay. When you say cause and effect, though, in 9 light of your testimony, does that refer only to 10 relationships between the water quality parameters as 11 opposed to ecosystem response? 12 A. That's right. We're not looking at ecosystem 13 response in our analysis. 14 Q. So when you say cause and effect, you're not 15 referring to a cause and effect between inflow and ecosystem 16 response on the interior; is that right? 17 A. Restate that question, please. 18 Q. Okay. I stated it in the negative, but when you 19 are referring to cause and effect in your testimony, you are 20 not referring to cause and effect between inflow parameters 21 and ecosystem response in the interior of the marsh. 22 A. That's correct. We're only looking at whether or 23 not there is a relationship between what comes in through 24 the S-5 and S-6A structures geochemically and what occurs 25 geochemically in the interior portion of the marsh. 61 1 Q. And am I correct that that would be generally a 2 hydrologic question? 3 A. First and foremost a hydrologic question. 4 Q. Would it be driven by anything other than the 5 hydrology of the system? 6 A. No. You've got to have a hydrologic connection 7 first. 8 Q. I'd like to move to another area of your testimony 9 that you mentioned and that is the settlement accumulation 10 rates and the phosphorus settling velocity. 11 A. Right. 12 Q. Can you tell me what your opinions are in that 13 regard? 14 A. I believe that the -- that the approach that has 15 been used to derive the settling velocity is flawed and 16 biases the characteristics for phosphorus or the estimates 17 for phosphorus accumulation are biased upwards by the 18 approach taken. 19 Q. Okay. First of all, can you identify whose 20 approach you're referring to as being flawed? 21 A. Dr. Walker's approach. 22 Q. And can you describe the flaws that you see in 23 that approach? 24 A. Yes. There are several problems or potential 25 problems that I see with the approach that's taken. First 62 1 of all, I think an inherent assumption in the approach that 2 Dr. Walker used is that, when phosphorus is deposited in the 3 sediments, it doesn't move, in other words, what's laid down 4 in a particular horizon, and, of course, you'll get new 5 horizons added on, so to speak, each year, but what is laid 6 down in a particular horizon basically remains intact and is 7 just pushed deeper and deeper within the profile as the 8 phosphorus accumulates. 9 Under such a scenario, what you would expect to 10 see in a system that's unperturbed, in other words, let's 11 assume that you have a system that has received the same 12 phosphorus inputs for decades, with those assumptions you'd 13 expect to see a concentration profile and an accumulation 14 profile, excluding any other variables for the moment, that 15 would be perfectly flat. It would be straight up and down. 16 That's not the way phosphorus behaves in soils. 17 You have a characteristic profile in soils that -- and 18 there's good geochemical evidence to support this -- that 19 almost invariably shows high concentrations in the soil 20 grading down to lower concentrations, even if the 21 accumulation rate or the deposition rate of material was 22 constant for long, long periods of time. In that case, by 23 looking at the upper layer and using that then to derive a 24 sedimentation rate and then using that sedimentation rate to 25 describe the loss of phosphorus out of the water column, 63 1 you're going to bias those loss rates upwards, and the error 2 could be significant. 3 Q. Am I correct that this is what you referred to in 4 your previous deposition as the translocation of phosphorus 5 in the profile? 6 A. No. That's another part of the problem. 7 Q. Okay. 8 A. There's actually several problems that I see with 9 the approach. One is just what I told you. 10 Q. Okay. 11 A. The second thing is that, characteristically, when 12 phosphorus is deposited in sediments -- and, again, let's 13 just assume that this is a system that has been unperturbed 14 for a long period of time, so we're not looking at changing 15 deposition rates. We're looking at constant deposition 16 rates for decades. 17 The solid phase concentration is going to show a 18 profile of high concentrations at the interface grading down 19 to much lower concentrations as you get deeper and deeper in 20 the profile. Those changes in concentration really relate 21 to decomposition of organic matter. That's the principal 22 driving variable there, all other things being held 23 constant. 24 Conversely, the interstitial fluid, which is the 25 water that's between the soil particles, if you look at the 64 1 profile of phosphorus in the interstitial fluid, almost 2 universally you'll see very low concentrations of phosphorus 3 at the interface, at the soil-water interface, grading 4 towards high concentrations as you move deeper and deeper 5 within the profile. 6 The reason for that being is two-fold. First of 7 all, you've got organic matter decomposing. That becomes 8 the source of phosphorus into the interstitial fluid. 9 You also have exchange. As phosphorus builds up 10 in the porewater, it builds up the concentrations higher 11 than what's in the overlying water column. Because of that, 12 then, there's a net flux of material, a net flux of 13 phosphorus across the interface. 14 So what this does is it sets up a system where 15 phosphorus being generated down below from the solid phase 16 being produced and moving into the liquid phase now has a 17 means for moving upwards, so there is a migration of 18 phosphorus upwards through the soil profile, through the 19 interstitial fluid, and then you can end up with a flux rate 20 across the interface that's on the order of, say, a 21 milligram to 2 milligrams of phosphorus per meter 22 squared per day. It can be fairly significant. 23 My problem with the Walker approach is that you're 24 really looking at not net burial. The real net burial is 25 what is contemplated down below in this scenario where we're 65 1 holding deposition constant, and so he's looking at one part 2 of the flux equation. He's looking at the downward flux, 3 but there is also this upward flux, and the sedimentation 4 rate that he's trying to take his soil accumulation rates 5 and extrapolate it back to that settling velocity, if you 6 will, that describes a loss of phosphorus out of the water 7 column is a synthesis of a number of processes, including 8 the net flux material across the interface from the 9 interstitial water into the water column. 10 His approach does not consider that. His 11 approach, therefore, is biased upwards. It assumes too high 12 a settling velocity. 13 The problem is further exacerbated by the fact 14 that typically you have two different zones, oxygen zones in 15 sediments. Down below the interface, well down below the 16 interface you have a lack of oxygen, conditions are known as 17 reducing conditions, and under such a scenario particularly 18 iron minerals are soluble. 19 In the upper zone, and that upper zone may be on 20 the order of a couple of centimeters thick or maybe even 21 less or it may be upwards of 10 meters thick, it all depends 22 on the physics of the local environment, you have oxygenated 23 conditions, and under that type of situation the iron that 24 is reduced and soluble becomes oxidized to form iron (III), 25 that's the name of the species, and iron (III) is rather 66 1 insoluble, forms typically a ferric hydroxide gel, and that 2 gel is a good scavenger for phosphorus. 3 So the solid phase concentration that you measure 4 in the upper zone could actually be enhanced by sorptive 5 capture, if you will, of some of this diffusing upwards 6 phosphorus that's originating from down below. 7 Now, there's a third problem, potential problem 8 that I see with this approach, and that is based on 9 conversations I've had with Dr. Patrick at LSU and Dr. 10 Richardson at Duke University. 11 Macrophytes apparently derive some of their 12 nutritional needs through their roots. In other words, they 13 pull phosphorus out of the soil down below the interface, 14 and, of course, that phosphorus then goes in through the 15 roots into the -- into the leaves and whatnot, and, of 16 course, when the plant dies or it senesces, that material 17 drops, falls, and is redeposited on the soil surface. 18 That also serves to basically move phosphorus from 19 down below, bring it up to the top, and give you an apparent 20 enhanced deposition rate, and, of course, these factors all 21 conspire, if you will, not that I'm saying that there is a 22 conspiracy theory, but they all work in concert to help bias 23 that sedimentation rate, which is an extrapolate to a 24 settling velocity by Dr. Walker, and it helps bias those 25 numbers upwards. 67 1 MR. GREEN: Paul, would you permit me to ask a 2 clarifying question so it won't be hours later? 3 MR. NETTLETON: Sure. 4 MR. GREEN: I think Dr. Pollman might have 5 intended a different unit. I'll just ask. 6 Dr. Pollman, you said there were two different 7 zones and reducing conditions were in the lower zone, the 8 upper zone, an oxidizing zone. You said sometimes the 9 oxidizing zone could be a few centimeters. 10 MR. NETTLETON: Centimeters. 11 MR. GREEN: And other times as much as 10 meters. 12 THE WITNESS: I meant 10 centimeters. 13 MR. GREEN: Thank you. That's what I thought you 14 meant. 15 BY MR. NETTLETON: 16 Q. Well, I won't claim that I understood everything 17 you just told me, Dr. Pollman, so you're going to have to 18 bear with me when I try to get through this. 19 If we broke out the flaws that you just mentioned 20 as you see them in Dr. Walker's approach, I understand that 21 the third one you mentioned was the macrophytes bringing 22 phosphorus upward through the soil and then redepositing it 23 when the -- 24 A. That's correct. 25 Q. The second flaw was the O2 zones, the oxygen zones 68 1 within the soil, is that right, and the release of something 2 to do with iron, and I'm going to go back into this. 3 A. Right, I understand. 4 Q. The first one, I wasn't sure whether that was one, 5 two, or three or how many, the first flaw that you were 6 mentioning about phosphorus being deposited in the 7 sediments, not moving in the profile as assumed by Dr. 8 Walker, I believe. 9 A. That's correct. 10 Q. Okay. Does that involve more than one factor or 11 variable? 12 A. Yes. It involves fundamentally -- there are a 13 number of factors that actually can affect the 14 characteristic profile of phosphorus and sediments, but I 15 think in terms of keeping things simple, I'll reiterate. 16 Let's just assume for the moment that we are considering a 17 system that has been receiving constant rates of deposition 18 for a long period of time. Let's assume that this material 19 is unreactive, undergoes no chemical transformation 20 whatsoever, no biological transformations. 21 If you were to look at a profile of that material, 22 if you were to take a soil core and examine that core and 23 plot the concentration or the accumulation rate as a 24 function of distance down the core, you would see a straight 25 line. It would be vertical, straight up and down. It would 69 1 show no variance in the accumulation rate as a function of 2 distance down the core, and, of course, distance would be a 3 surrogate for time. 4 Now, my problem here is that phosphorus is not 5 conservative. Phosphorus, organic phosphorus is 6 decomposed. It moves out of the solid phase into the liquid 7 phase, and what that does, then, is sets up a gradient for 8 movement upwards and out of the system, and the true net 9 loss, the true net sedimentation rate in this scenario is 10 more accurately reflected by what is the actual movement 11 rate of the material down below, well down below the profile 12 than what you would measure near the surface, which, of 13 course, is what has been used by Dr. Walker and others to 14 infer a settling velocity. 15 Q. This is just for my own edification. I'm trying 16 to keep this straight in my mind. In your last deposition 17 you mentioned a concern about translocation, mobility of 18 phosphorus. Does that relate to the conversations you've 19 had with Dr. Patrick and Richardson? 20 A. That's correct. 21 Q. Okay. 22 A. This first argument that I've tendered, also, 23 falls under the general heading of translocation, if you 24 will, or mobility of phosphorus as well. We could put a 25 term to it if you like. It's call post-depositional 70 1 mobility. 2 Q. Good. I need a term to write down. 3 MR. GREEN: Excuse me. Off the record. 4 (Thereupon, a brief discussion was held off the 5 record.) 6 MR. NETTLETON: Okay. We can go back on. 7 BY MR. NETTLETON: 8 Q. In rendering the opinion concerning your expressed 9 first flaw in the approach, you made an assumption that 10 there were constant rates of deposition of phosphorus, I 11 assume. 12 A. Right. 13 Q. Is, in fact, a constant rate of deposition, is 14 that assumed in Dr. Walker's work as well? 15 A. I believe in his latest work, and I believe we're 16 hindered in our analysis of results because of the available 17 data, quite frankly, but Dr. Walker uses a cesium marker, 18 radioactive cesium marker to define a particular event point 19 in time, i.e., 1962 or 1963. 20 I believe in his most recent paper in which he 21 derives a settling velocity of 10.2 meters per year, he 22 assumes that the deposition rate of material above that 23 marker is constant, the deposition of solid phase material, 24 in other words, the amount of sediment that's accumulated is 25 so many grams per meter squared per year. He assumes that 71 1 that rate is constant. He then uses that. He looks at the 2 total amount of phosphorus, then, that's accumulated over 3 that interval, and then he comes up with a mass accumulation 4 rate as a function of time, basically an average 5 accumulation rate over that interval. 6 Q. Okay. Another assumption that you stated in your 7 analysis was that the system was unreactive. Can you tell 8 me what you meant by that? 9 A. Yes. A system that's not -- does not undergo any 10 chemical transformations or any biological transformations 11 as it's being deposited. In other words, it's inert. 12 Q. And is that assumption made in Dr. Walker's 13 analysis as well? 14 A. I think it's implicit in his analysis, yeah. His