1227 1 UNITED STATES DISTRICT COURT FOR THE 2 SOUTHERN DISTRICT OF FLORIDA 3 **************************** 4 UNITED STATES OF AMERICA, * Plaintiff * 5 * Case Number VS. * 88-1886-CIV 6 * Hoeveler SOUTH FLORIDA WATER * 7 MANAGEMENT DISTRICT, ET AL., * Defendants * 8 ***************************** 9 10 Deposition of WILLIAM W. WALKER, JR., 11 taken on behalf of the defendants South Florida 12 Water Management District and John R. Wodraska 13 pursuant to the applicable rules of the Federal 14 Rules of Civil Procedure, before Linda Marie 15 MacDonald, Registered Professional Reporter and 16 Notary Public within and for the Commonwealth 17 of Massachusetts, at the offices of Skadden, 18 Arps, Slate, Meagher & Flom, One Beacon Street, 19 Boston, Massachusetts, on Thursday, 20 February 14, 1991, commencing at 9:05 a.m. 21 22 23 LINDA MARIE MacDONALD, RPR-CM REGISTERED PROFESSIONAL REPORTER 24 60 LAWRENCE ROAD, PLYMOUTH, MA 02360 (508) 747-6615 1228 1 A P P E A R A N C E S: 2 UNITED STATES ATTORNEY'S OFFICE By AUSA Richard Harrison 3 155 South Miami Avenue, Suite 600 Miami, FL 33130 4 for the United States of America. 5 SKADDEN, ARPS, SLATE, MEAGHER & FLOM By Attorney Laura B. Ahearn 6 1440 New York Ave., N.W. Washington, D.C. 20005 7 for South Florida Water Management District and John R. Wodraska. 8 PEEPLES, EARL & BLANK 9 By Attorney Rick J. Burgess One Biscayne Tower, Suite 3636 10 Miami, FL 33131 for the cities of Belle Glade and 11 Clewiston, defendant intervenors. 12 STATE OF FLORIDA OFFICE OF GENERAL COUNSEL By Asst. Gen. Counsel David A. Crowley 13 Department of Environmental Regulation Twin Towers Office Building 14 2600 Blair Stone Road Tallahassee, FL 332301 15 for the Florida Department of Environmental Regulation. 16 17 18 19 20 21 22 23 24 DEPOSITION OF WILLIAM W. WALKER, JR. 1229 1 I N D E X Witnesses Examination 2 WILLIAM W. WALKER, JR. 3 (By Ms. Ahearn) 1230 (By Mr. Crowley) 1284 4 (By Mr. Burgess) 1297 5 E X H I B I T S 6 Number For ID 7 DX 79 Fax Cover Sheet dated 11/22/89 1312 8 to Higer from Walker, with attachments (S12 Flows retrieved 9 from SWFMD Hydro. Database) 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 DEPOSITION OF WILLIAM W. WALKER, JR. 1230 1 P R O C E E D I N G S 2 WILLIAM W. WALKER, JR., 3 having been previously duly sworn, was deposed 4 and testified as follows: 5 CONTINUED DIRECT EXAMINATION 6 BY MS. AHEARN: 7 Q. Good morning, Dr. Walker. 8 A. Good morning, Ms. Ahearn. 9 Q. By whom is Jim Loftis employed? 10 A. I believe it's Colorado State University. 11 Q. And that's Jim Loftis who performed the 12 analysis of your draft trends analysis report 13 in Exhibit 10? 14 A. Yes. 15 Q. I just wanted to make sure we have the right 16 individual. 17 Dr. Walker, can you, please, identify 18 Exhibit 77? 19 A. Exhibit 77 is a table entitled Wetland P 20 Balance Data, with six figures attached to it. 21 Q. Did you create this document or the documents 22 comprising Exhibit 77? 23 A. Yes, I did. 24 Q. Could you, please, explain to us what appears DEPOSITION OF WILLIAM W. WALKER, JR. 1231 1 on the first page? 2 A. The first page contains data on phosphorus and 3 nitrogen loadings and removal efficiencies in 4 wetlands as derived from the literature. 5 Q. Am I correct that the first approximately 6 one-third of the first page reflects data 7 derived from Richardson and Nichols, a 8 publication in 1984? 9 A. Approximately. But I believe the correct date 10 would be 1985. 11 (Witness writing on exhibit) 12 Q. What is the source of the information that 13 appears on the lower two-thirds of this page? 14 A. I believe that information was extracted from 15 nutrient balance calculations that are 16 summarized in the Everglades SWIM plan. 17 Q. Do you recall which draft of the SWIM plan? 18 A. No. 19 Q. Do you recall when it is you created this 20 page 1? 21 A. Fall of 1990. 22 Q. Do the labels that appear at the top of the 23 page also apply to the columns on the lower 24 two-thirds of the page? DEPOSITION OF WILLIAM W. WALKER, JR. 1232 1 A. I'm not sure, but I believe so, with the 2 possible exception of the column labeled YRS. 3 That's short for "years." 4 Q. So the third column from the left on the bottom 5 two-thirds of the page refers to something 6 other than the number of years in the period of 7 record? 8 A. Yes. 9 Q. What does this third column from the left on 10 the bottom two-thirds of the page reflect? 11 A. I believe it identifies the different Water 12 Conservation Areas 1, 2 or 3. 13 Q. Do the columns on the bottom two-thirds of the 14 page reflect simply your organization of data 15 from the draft SWIM plan as opposed to 16 calculations that you then performed on that 17 data? 18 A. There may have been some conversion of units 19 that was necessary in order to take the 20 information from the draft plan and put it into 21 this spreadsheet. I don't recall. 22 Q. But, for example, you didn't take some loading 23 figures and some other figures and from that 24 calculate the numbers that appear in the far DEPOSITION OF WILLIAM W. WALKER, JR. 1233 1 right-hand column for P removal? 2 MR. HARRISON: Object to form. 3 A. Well, it could very well be that the far 4 right-hand column was a figure that was 5 calculated from the loading figures and the 6 phosphorus removal figures that were contained 7 in the SWIM plan. 8 Q. My basic question is: If I were to go to the 9 draft SWIM plans and look through it for these 10 data, will I find them there, or have you gone 11 beyond those data to calculate new values? 12 A. To the best of my recollection, the figures for 13 phosphorus load in grams per square meter per 14 year and phosphorus removal in percent were 15 derived directly from the SWIM plan, whereas 16 the figure for phosphorus removal in grams per 17 square meter per year appears to have been 18 calculated from those other two values. 19 Q. Could you, please, explain to us what the 20 remaining pages of Exhibit 77 reflect? 21 A. These are graphs of the data that's contained 22 in Table 1. 23 Q. And you created these graphs, as well? 24 A. Yes. DEPOSITION OF WILLIAM W. WALKER, JR. 1234 1 Q. And what was your purpose in creating 2 Exhibit 77? 3 A. The purpose was to summarize phosphorus balance 4 data from wetlands that had been studied and 5 reported in the literature that were used for 6 wastewater treatment as well as phosphorus 7 balance data from the Water Conservation Areas 8 as described in the SWIM plan and to use that 9 information to examine empirical relationships 10 between phosphorus loading into wetlands and 11 phosphorus outflow from wetlands. 12 Q. How did you plan to employ this information in 13 the work you are doing or anticipate doing in 14 the South Florida litigation? 15 A. Primarily to provide some independent 16 perspective on whether the design criteria that 17 were being proposed by the District for the 18 Water Management Areas were consistent with 19 data from other wetland systems. 20 Q. Were those proposed design criteria consistent? 21 MR. HARRISON: Object to form. The 22 witness has already stated he is not quite sure 23 which SWIM plan draft or what scenario we're 24 discussing here. DEPOSITION OF WILLIAM W. WALKER, JR. 1235 1 A. I can -- from -- as is shown in the first 2 figure, the design criteria for what is termed 3 the ENR, the Everglades Nutrient Removal 4 project, the pilot project, appear to be 5 consistent with the wetland data that I'm 6 examining here. Whether or not the full-scale 7 design of the nutrient -- or Water Management 8 Areas is consistent, I still have not evaluated 9 that because I frankly don't know what the 10 full-scale design looks like or I haven't seen 11 anything that specifies what those designs 12 would involve in any detail. 13 Q. Other than what's reflected here in Exhibit 77, 14 have you performed any other analysis 15 specifically of the Everglades Nutrient Removal 16 project, also known as the Knight's Farm 17 project? 18 A. Other than reading the report -- one of the 19 draft reports, I believe, on that project, no, 20 I have done no quantitative analysis or 21 modeling. 22 Q. Based on the comparative analysis in reading 23 the ENRP report, can you estimate the maximum 24 rate of phosphorus removal achievable through DEPOSITION OF WILLIAM W. WALKER, JR. 1236 1 the Everglades Nutrient Removal project? 2 A. Well, I can state that the design criteria for 3 the ENR project are consistent with the 4 regression model that is shown in the first 5 figure of this exhibit, and that would imply 6 some predicted removal efficiency at some given 7 loading rate. But in terms of stating at this 8 point what that removal efficiency would be, I 9 would have to go through the calculations. But 10 it's a fairly straightforward calculation. 11 Q. Do you know what the removal efficiency for the 12 Iron Bridge Orlando wetlands is? 13 A. Well, according to the data summary on the 14 first page of Exhibit 77, the Iron Bridge 15 system had an average removal efficiency of 16 88 percent. 17 Q. That was in one particular year, 1989? 18 A. I don't recall whether that was just for 1989. 19 That reference to 1989 may have been the date 20 of the document that I used to get that 21 information. I don't recall. 22 Q. Could you, please, explain to me the elements 23 of the regression reflected on page 2 of 24 Exhibit 77? DEPOSITION OF WILLIAM W. WALKER, JR. 1237 1 A. The regression is a bivariate regression 2 involving only two variables, an X variable and 3 a Y variable. The X variable, or the 4 predictor, is the total phosphorus load 5 entering the wetland expressed in terms of 6 grams per square meter per year. The Y 7 variable, or the predicted variable, is the 8 total phosphorus leaving the wetland, 9 discharged from the wetland, also expressed in 10 terms of grams per square meter of wetland 11 surface area per year. 12 The regression equation is shown in 13 Figure -- in the first figure of this exhibit, 14 and it is developed using standard regression 15 techniques and applying it to the data from the 16 wetlands that were summarized by Richardson and 17 Nichols. In other words, only the -- the 18 regression is actually fit to the data from the 19 first 16 wetlands identified on the first page 20 of Exhibit 77. 21 Q. So the diamonds that are plotted on the second 22 page are not among the values -- 23 A. They were not among the values that were used 24 to calculate the regression line. DEPOSITION OF WILLIAM W. WALKER, JR. 1238 1 Q. Okay. Could you turn to the third page? Could 2 you explain the entry "Extrapolation of 3 Regression" on this version of the graph? 4 A. That refers to the fact that, as I just 5 mentioned, the regression equation was 6 developed using only data from the wastewater 7 treatment systems and did not include the Water 8 Conservation Areas. 9 The fact that -- the reference to 10 extrapolation means that when I'm drawing this 11 line beyond the bounds of the wetland 12 wastewater treatment systems, I'm extrapolating 13 that regression equation into the lower loading 14 regimes which are characteristic of the 15 Everglades Water Conservation Areas. 16 Q. In other words, you've drawn regression lines 17 of the same slope among these other lower 18 values? 19 A. Those aren't regression lines on the left side 20 of the second figure. The only regression line 21 on the left side is the line that is on the 22 lower part of that portion of the figure, and 23 that is the extrapolation of the regression 24 line which generally goes through the region DEPOSITION OF WILLIAM W. WALKER, JR. 1239 1 where the data points for Water Conservation 2 Area 3 are located. 3 Q. What are the lines labeled 1 and 2 with circles 4 around them? 5 A. The other two lines are just handwritten lines 6 that are parallel to the regression line that 7 approximately are -- on the average cover the 8 or reflect the general regions where points 9 from Water Conservation Areas 1 and 2 are 10 located. 11 Q. Did you use a particular program on your 12 computer to generate these graphs and perform 13 the analysis? 14 A. These graphs were generated from within a Lotus 15 1-2-3 work sheet. The regressions were also 16 done within a work sheet. I believe the first 17 graph was also -- was finalized with a -- with 18 the Freelance program. 19 Q. Dr. Walker, have you performed any analysis of 20 the potential effects on hydrology, water 21 quantity and water supply of proposed or 22 potential actions intended to remedy or address 23 alleged water quality threats to the Park? 24 A. Yes. DEPOSITION OF WILLIAM W. WALKER, JR. 1240 1 Q. Okay. And what analysis is that? 2 A. This analysis was contained in a memo that I 3 submitted to the Justice Department. 4 Q. Is that memo among the deposition exhibits we 5 have identified thus far? 6 A. No, it is not. 7 Q. Does that memo exist on your computer, computer 8 diskettes or hard drive? 9 A. Not to my recollection. 10 Q. Did you provide a copy of this memo to be 11 produced in conjunction with your deposition? 12 A. Yes, I did. 13 Q. Do you recall any recommendations or 14 conclusions you report in this memo? 15 MR. HARRISON: Could I have the memo 16 described again? That was back in your 17 original question, memo regarding modeling or 18 regarding hydrologic impacts? 19 MS. AHEARN: You want me to ask a 20 question for you? 21 MR. HARRISON: No. I'm asking you, to 22 avoid going back on the record, is this one 23 looking at hydrologic impacts? 24 MS. AHEARN: Yes. DEPOSITION OF WILLIAM W. WALKER, JR. 1241 1 MR. HARRISON: Okay. Go ahead. 2 Q. Let's try to characterize the memo. 3 When did you provide this memo to the 4 Department of Justice? 5 A. Either spring or summer of 1990. 6 Q. And to whom was it addressed? 7 A. I don't recall. 8 Q. Does it have a title or "re" line? 9 A. I don't recall the specific title. 10 Q. Do you recall findings, recommendations or 11 conclusions you report in this memo? 12 A. Generally. 13 Q. Okay. What are those findings, recommendations 14 or conclusions you generally recall? 15 A. The memo outlines some calculations that were 16 designed to put an approximate scale on the 17 magnitude of water losses that might be 18 associated with construction and operation of 19 Water Management Areas being proposed to 20 provide water quality protection for the Water 21 Conservation Areas. 22 Q. Anything else you recall? 23 A. No. 24 Q. Have you made any actual application of these DEPOSITION OF WILLIAM W. WALKER, JR. 1242 1 calculations? 2 A. No. 3 Q. Can you give me any more detail on what these 4 calculations were that you outlined? 5 (The witness gave no response.) 6 Q. Am I correct that this was -- when you said 7 outline calculations, it was a description of 8 how one might calculate hydrologic water 9 quality or water supply changes from the Water 10 Management Areas -- due to Water Management 11 Areas? 12 A. Yes. There was a description on how one might 13 estimate the magnitude of water losses 14 associated with the Water Management Areas. 15 Q. And can you describe these calculations? 16 A. Yes. 17 Q. Okay. Would you, please? 18 A. Well, these calculations were intended to 19 provide, as I said, a scale or rough estimate 20 of the magnitude of water loss, and essentially 21 the calculations involved assuming first a 22 certain area of the Water Management Areas 23 which I believe was derived from one of the 24 SWIM plans and then applying to that area a DEPOSITION OF WILLIAM W. WALKER, JR. 1243 1 certain magnitude of water loss in terms of 2 inches per year that would reflect the net 3 increase in evapotranspiration that would be 4 expected when converting acreage of 5 agricultural land or barren land, open land, 6 into a flooded marsh. 7 Q. Do you recall any other elements that are 8 included in the calculation other than expected 9 change in ET? 10 A. That was the extent of the calculations that I 11 performed. 12 Q. Do you know of anyone who has taken the 13 calculations you have outlined and applied them 14 to determine predictions of the magnitude of 15 water losses? 16 A. Yes. 17 Q. Who has done that? 18 A. Myself. 19 Q. Other than yourself? 20 A. I don't know of anyone who has taken the 21 precise methodology that I outlined and done 22 those calculations. 23 Q. Do you know of other persons employed by or 24 working with the federal government who have DEPOSITION OF WILLIAM W. WALKER, JR. 1244 1 used other methodologies to analyze the 2 potential effects of hydrology, water quantity 3 and water supply of proposed or potential 4 actions to address water quality in South 5 Florida? 6 A. Yes. 7 Q. Who are those persons? 8 A. People from the Corps of Engineers, 9 Jacksonville district. 10 Q. Do you know names of these Corps personnel? 11 A. The work would have been done under the 12 direction of Mike Choate, C-H-O-A-T-E. 13 Q. Was Mr. Choate himself involved in this work? 14 A. All I know is he is -- he was involved, in 15 charge of the work. I don't know the extent to 16 which he performed the work himself. 17 Q. And what do you know about the work that the 18 Corps has done on this issue? 19 A. The Corps has done some simulation, hydrologic 20 simulation of a Water Management Area scenario 21 in order to quantify the water supply impacts. 22 Q. Do you know what the results of these 23 simulations are? 24 A. The results are expressed to my recollection in DEPOSITION OF WILLIAM W. WALKER, JR. 1245 1 the form of a series of graphs and figures, and 2 I don't recall the quantitative aspects of the 3 results. 4 Q. Are those graphs and figures in your 5 possession? 6 A. Yes, they are. 7 Q. Did you produce copies of those to be provided 8 in conjunction with this deposition? 9 A. Yes, I did. 10 MS. AHEARN: Mr. Harrison, I'm not sure 11 if I can identify these. If they weren't among 12 the box of materials sent to us, I would 13 request that they do be provided. 14 MR. HARRISON: Counsel for the United 15 States is still claiming privilege. I'm going 16 to have to check when I get back to Miami, but 17 I think we're claiming privilege on the nature 18 of that work. 19 MS. AHEARN: The Corps is studying 20 hydrology of its own project and is not willing 21 to give the results of those scientific and 22 technical analyses to its local sponsor? 23 MR. HARRISON: If that characterization 24 were accurate, you may have a different DEPOSITION OF WILLIAM W. WALKER, JR. 1246 1 situation. That is not what the Corps is 2 doing, and it certainly is not their original 3 work. 4 The Corps is doing work for the 5 Department of Justice analyzing certain 6 strengths and/or weaknesses in the District's 7 proposed SWIM plans. And depending on whether 8 the District chooses to use this information as 9 its defense in this lawsuit, it may or may not 10 be rebuttal evidence. It's certainly nothing 11 that the United States intends to make or has a 12 burden to use as part of its case-in-chief. 13 MS. AHEARN: This is amazing. 14 Q. Dr. Walker, do you remember in what format the 15 Corps has expressed the potential magnitude of 16 water losses associated with the Water 17 Management Areas? 18 A. As I said earlier, they produced a series of 19 graphs. 20 Q. Do you recall, are they in terms of percentage 21 losses, acre-foot losses? 22 A. I don't recall anything expressed in terms of 23 percentage. There may have been some graphs 24 that reflect flow volume in some measure, DEPOSITION OF WILLIAM W. WALKER, JR. 1247 1 whether it was acre-feet or thousand-acre-feet 2 or whatever. 3 Q. When did you first see these graphs and 4 figures? 5 A. January of 1991. 6 Q. Have you discussed these graphs and figures 7 with anyone? 8 A. Briefly, yes. 9 Q. And with whom did you discuss those? 10 MR. HARRISON: You may give the 11 identities of anyone that was there during the 12 discussions. 13 A. To my recollection, it would have been Bob 14 Johnson, Jim Vearil, Lewis Hornung and Mike 15 Choate, Geoff Garver. There may have been 16 others. I don't recall. 17 Q. And what did you discuss? Can you give me any 18 particulars of what you recall that you 19 discussed? 20 MR. HARRISON: I'm going to object to 21 any response which would disclose reasons why 22 the United States wants the data used or wants 23 the data generated. By Dr. Walker's answer, 24 Geoff Garver was present at the discussions. DEPOSITION OF WILLIAM W. WALKER, JR. 1248 1 The discussions took place in privileged 2 meetings. 3 I will, however, let Dr. Walker go into 4 any scientific knowledge he has about the 5 results or purely scientific discussions. I 6 think this is an area, Counsel, that before we 7 finally come to the in-camera inspection on the 8 documents, I'm not aware that we've gotten 9 together a meeting yet to discuss privileged 10 documents. I know we were supposed to try to 11 do that by the 8th, and I think Mr. Jackson and 12 I have both been busy on other depositions. 13 But this is an area that we would like 14 to discuss to get some categorical agreements 15 between the District and the United States as 16 to types of things that we are or are not going 17 to claim privilege on for the purposes of 18 either being on equal ground and turning such 19 documents over to each other or going ahead and 20 submitting it to the court for in-camera 21 inspection. 22 This is one of the categories I wanted 23 to discuss with Mr. Jackson. We just have not 24 had the opportunity. But I won't shut DEPOSITION OF WILLIAM W. WALKER, JR. 1249 1 Dr. Walker down on any scientific knowledge or 2 even the quantitative impacts which he recalls 3 from those documents. 4 Q. This is very important, Dr. Walker. 5 A. I realize. But I would appreciate it since -- 6 I would appreciate it if you would repeat the 7 question. And then we'll go on. 8 Q. Can you, please, tell me any of the particulars 9 you recall from your discussion with Johnson, 10 Vearil, Hornung, Choate, at which Mr. Garver 11 was apparently present? 12 A. Well, as I recall from my perspective this was 13 the first time that I had really sat down and 14 looked at the document and tried to understand 15 it. As I stated, the document consists largely 16 of a series of figures and there's very little 17 discussion or description of the results. 18 We had a phone conversation and a 19 conference call in the context of this meeting 20 with Mike Choate and with the technical person 21 who assisted Mike Choate in conducting the 22 analysis, I don't recall his name, in order to 23 better understand what the various figures and 24 graphs were showing. And I don't recall the DEPOSITION OF WILLIAM W. WALKER, JR. 1250 1 numerical aspects. I don't recall the 2 magnitudes that we were discussing. 3 The only other aspect that I recall in 4 that meeting is discussing what follow-up work 5 might be done, what additional analyses or what 6 additional summaries of the results might be 7 developed in order to permit us to better 8 understand what the results were saying. 9 Q. And what is the follow-up work -- 10 MR. HARRISON: I won't permit Dr. Walker 11 to go into that until we have some sort of 12 agreements as to certain categories. This work 13 all was in the nature of privileged work. The 14 memos which are reflected on the privilege list 15 are all to the Department of Justice; and under 16 the rules that Judge Bandstra and we have all 17 operated under this far, they are going to be 18 protected. I'm saying the United States -- 19 MS. AHEARN: If I could, please, 20 complete my question, Mr. Harrison? 21 MR. HARRISON: I'm not going to allow 22 you to go into what future work is planned in 23 that area. If you can ask some other question, 24 that's fine. DEPOSITION OF WILLIAM W. WALKER, JR. 1251 1 MS. AHEARN: I never even asked that 2 question. 3 Q. Dr. Walker, could you describe for me the 4 future follow-up work that was discussed in 5 terms of what would be necessary to better 6 understand the issue? 7 MR. HARRISON: Objection. That work has 8 not been decided upon yet. 9 MS. AHEARN: I didn't ask what's been 10 decided upon. I'm asking what were the 11 analyses that were discussed that would reflect 12 what was needed to better understand the issue. 13 MR. HARRISON: In that case, Counsel, 14 you are asking for confidential discussions 15 between an attorney and a client and 16 confidential representatives, and that is 17 privileged information. And I direct 18 Dr. Walker not to go into it. 19 Q. What were the issues that the technicians, the 20 scientists in the group felt they did not 21 adequately understand based on the work 22 performed to produce these graphs and figures? 23 MR. HARRISON: Objection. Don't answer, 24 Dr. Walker. Same grounds, attorney/client DEPOSITION OF WILLIAM W. WALKER, JR. 1252 1 privilege. 2 Q. Did Mr. Choate have issues regarding this 3 analysis that he felt he did not at that point 4 adequately understand? 5 MR. HARRISON: Attorney/client 6 privilege. Don't answer. Object. 7 Q. Same question for Messrs. Johnson, Vearil and 8 Hornung. None of those individuals are 9 attorneys, am I correct, Johnson, Vearil and 10 Hornung? 11 A. That's correct. 12 Q. Did any of those three nonattorneys have 13 questions, outstanding issues regarding the 14 analysis that the Corps had performed to 15 produce these graphs and figures? 16 MR. HARRISON: Objection. Attorney/ 17 client privilege. If you want to satisfy 18 yourself as to the nature of these discussions, 19 Counsel, you can ask him the predicate 20 questions, which would then satisfy you and the 21 record that it was attorney/client. I will 22 represent that these meetings were called 23 together by the Department of Justice for the 24 purposes of determining which directions to go DEPOSITION OF WILLIAM W. WALKER, JR. 1253 1 in this lawsuit. And these were confidential 2 discussions with the attorney -- with 3 litigation counsel present. 4 Now, if you want to ask those questions, 5 elicit testimony from the witness as to what 6 his understanding of these meetings were, that 7 is fine. But they are attorney/client 8 communications, and you are not going to be 9 allowed to go into them any further. 10 Q. Does the Corps as the builder, the creator and 11 the entity ultimately in charge of the Central 12 and South Florida Flood Control Project have 13 concern over potential effects on hydrology, 14 water quantity and water supply of proposed or 15 potential actions that may be taken to protect 16 water quality in South Florida? 17 MR. HARRISON: Object to the 18 characterization. Object to the form of the 19 question, the generalities. And also object, 20 calls for speculation as to what Dr. Walker 21 knows about what the Corps' concerns are. 22 A. I don't know. 23 Q. Do you know if the Corps has performed any work 24 on this issue other than that which the DEPOSITION OF WILLIAM W. WALKER, JR. 1254 1 Department of Justice has requested the Corps 2 to do? 3 MR. HARRISON: You may answer that. 4 A. Not to my knowledge. 5 Q. Do you recall the approximate number of graphs 6 and figures that you saw from the Corps? 7 A. Approximately between five and twenty. 8 Q. Are these on letter-sized paper? 9 A. Yes. 10 Q. When you applied the calculations outlined in 11 your prior memo, do you recall the assumed area 12 of Water Management Areas that you looked at? 13 MR. HARRISON: Object to form. Which 14 prior memos, Counsel? One that's already been 15 introduced that Dr. Walker had just done, 77? 16 MS. AHEARN: Dr. Walker described a memo 17 to the Department of Justice which described a 18 method of calculating the magnitude of water 19 losses associated with WMAs. 20 MR. HARRISON: Oh. 21 MS. AHEARN: And he's also testified 22 that he's applied those calculations. 23 Q. My question is: When you applied the 24 calculation, do you recall the area of Water DEPOSITION OF WILLIAM W. WALKER, JR. 1255 1 Management Areas that you employed? 2 MR. HARRISON: You can answer that. 3 A. Not precisely. It was somewhere in the range 4 of fifty to seventy thousand acres. 5 Q. Do you recall the magnitude of water loss that 6 your calculations indicated? 7 MR. HARRISON: Objection. Asked and 8 answered. He already stated he didn't. 9 A. I don't recall the numerical results of the 10 calculation. 11 Q. Can you describe them qualitatively? 12 MR. HARRISON: Objection to form. 13 A. I can describe -- they were -- as I stated, 14 they were in the form of a certain number of 15 acre-feet per year. That's all I can describe 16 them in terms of. 17 Q. As an environmental engineer, is there a 18 magnitude of water loss that would be 19 associated with constructing and operating the 20 Water Management Areas that you would find 21 unacceptable? 22 MR. HARRISON: Objection. Calls for a 23 conclusion on the part of this witness that is 24 not his to make. DEPOSITION OF WILLIAM W. WALKER, JR. 1256 1 Q. As an environmental engineer, are you able to 2 make that decision for yourself to form a 3 judgment about this? 4 A. As an environmental engineer, I am able to 5 consider such issues. But in order to answer 6 that question, that question is really somewhat 7 -- that question should be answered by people 8 who can define the water needs of the Park, and 9 I'm not in that kind of position, the water 10 needs of the other users -- water users in the 11 system. 12 MR. HARRISON: Counsel, you're free to 13 ask him his opinion of -- his own opinion of 14 whether or not the proposed Water Management 15 Areas that have been in the District's various 16 SWIM plans will or will not have adverse 17 impacts on the Park. 18 MS. AHEARN: Thank you, Mr. Harrison. 19 Q. Dr. Walker, have you performed any analysis or 20 collected information concerning the water 21 needs of the users of the Central and South 22 Florida water control project? 23 A. No, I have not. 24 Q. If the Water Management Areas were to be DEPOSITION OF WILLIAM W. WALKER, JR. 1257 1 constructed and operated resulting in a water 2 loss of 30 percent to the system, would that be 3 acceptable to you as a matter of your own 4 personal opinion? 5 A. I have no way of stating what would be 6 acceptable and what would be unacceptable 7 because that would be a matter of policy. 8 Q. Do you know what as a matter of policy would be 9 acceptable in this regard to the managers of 10 Everglades National Park? 11 MR. HARRISON: Object to form. Also 12 object if that information is derived from 13 confidential meetings between the attorneys and 14 the clients and the representatives. 15 Q. I don't ask you what the attorneys may have 16 told the Park managers. I'm wondering if you 17 know what the Park managers think, Dr. Walker. 18 MR. HARRISON: You can answer that if 19 you know. 20 A. No, I don't know. 21 Q. Do you know what the refuge -- the people in 22 charge of the refuge think in this regard? 23 MR. HARRISON: Think of what? I'm 24 sorry. I didn't hear. DEPOSITION OF WILLIAM W. WALKER, JR. 1258 1 Q. What magnitude of water loss would not be 2 acceptable? 3 A. No. 4 Q. Do you know what the Corps thinks in this 5 regard? 6 A. No. 7 Q. Dr. Walker, can you, please, identify 8 Exhibit 78? 9 A. Exhibit 78 is a single page of numbers and 10 handwritten notes. 11 Q. Are those notes yours? 12 A. No. 13 Q. I believe that the top left-hand corner as 14 you're looking at this chart, you'll see the 15 entry "Implementing 1-6 in 4/11 memo"? Do you 16 know what that refers to? 17 A. I don't recall. 18 MR. HARRISON: Just for the record, 19 Counsel, I see something with "p." I can't get 20 the word "implementing" out of that upper left, 21 so I'll simply object to your characterization 22 of it. It's not been established that's what 23 it says. 24 Q. Do you recognize whose handwriting this is? DEPOSITION OF WILLIAM W. WALKER, JR. 1259 1 A. No. 2 Q. Dr. Walker, are you aware that the United 3 States has filed with the court a revised 4 designation of expert witnesses that identifies 5 you as an expert expected to testify at trial 6 in the South Florida litigation? 7 A. I'm unaware of the specific filing, but I am 8 aware of the fact that I have been designated 9 as a potential witness. 10 Q. I'd like to hand you a copy of "United States' 11 Revised Designation of Expert Witnesses" and 12 ask you to read what is here as the substance 13 of expected testimony under the entry for 14 Dr. William W. Walker. 15 (Witness examining document) 16 A. I've read it. 17 Q. Dr. Walker, have you performed work concerning 18 water quality in South Florida outside the 19 scope of that described testimony in the 20 revised designation? 21 A. I view this -- these designations to encompass 22 a wide range of potential tasks, and to my 23 knowledge and to my interpretation of these 24 tasks, I don't believe I have performed DEPOSITION OF WILLIAM W. WALKER, JR. 1260 1 anything outside of this scope. 2 Q. In the course of the work you've performed 3 concerning South Florida water quality, have 4 you formulated any opinions, including 5 preliminary or tentative opinions, regarding 6 matters within the scope of that description of 7 anticipated testimony which you have not voiced 8 during this deposition so far? 9 MR. HARRISON: Objection, Counsel. You 10 had seven days of this deposition, and I'm not 11 about to let the witness try to pin himself 12 down without sitting here and having a 13 transcript as to what he has or has not. 14 MS. AHEARN: No. But Dr. Walker's been 15 very good about reminding me as to what he's 16 testified to previously, even several days 17 previously, and obviously I wouldn't want to -- 18 if there is an opinion he is aware of and he is 19 also aware that he has not voiced it in the 20 course of this deposition, I would just ask 21 that he identify those opinions. 22 MR. HARRISON: Fine. If it's one he is 23 aware of sitting here, fine. I'm not going to 24 let you ask him whether there simply is or is DEPOSITION OF WILLIAM W. WALKER, JR. 1261 1 not. That's an improper question after seven 2 days. I still note my objection on the record 3 to form. 4 A. I can't recall having formulated any opinions 5 or preliminary opinions that we have not 6 discussed in the previous seven days. 7 Q. Has your work led to any findings or 8 conclusions in this regard that we haven't 9 discussed yet in this deposition? 10 A. Not to my recollection. 11 Q. Are you knowledgeable of any work that 12 Dr. Edward Maltby has performed in conjunction 13 with the South Florida litigation? 14 A. Yes. 15 Q. Can you give me a summary of your understanding 16 of Dr. Maltby's work? 17 A. To my recollection, Dr. Maltby's role has been 18 that of an adviser to the case, to provide some 19 perspective from an international viewpoint. 20 Q. Have you relied or do you anticipate that you 21 will rely on any work by Dr. Maltby? 22 A. It is hard for me to separate out my -- the 23 extent to which I have relied on Dr. Maltby's 24 results as compared with all the other things DEPOSITION OF WILLIAM W. WALKER, JR. 1262 1 that I have been exposed to and read in this 2 case. 3 MS. AHEARN: Off the record. 4 (Off the record) 5 Q. Dr. Walker, let's try it this way. I would 6 just like to know if you have a general 7 familiarity with the work that the other 8 experts identified by the Government have done 9 and if you either have relied on or anticipate 10 you will rely on the work of those experts in a 11 particular way. 12 I understand how all of the work adds to 13 your general understanding. But if there are 14 particular findings or opinions that you have 15 incorporated or anticipate you will incorporate 16 or rely upon in your own work, if you could 17 just identify those, and then I think we can 18 move through this pretty quickly. 19 MR. HARRISON: Counsel, I just want to 20 note for the record that this is an expert 21 witness deposition, and I have no problem with 22 you asking Dr. Walker matters of science which 23 he has relied upon or anticipates relying upon. 24 However, to let you dissect the case DEPOSITION OF WILLIAM W. WALKER, JR. 1263 1 with what Dr. Walker knows from every witness 2 when a great deal, if not most, of that 3 information that he knows comes from clearly 4 privileged meetings between all of the 5 Government's witnesses and experts is another 6 matter. 7 I am not saying that I will shut that 8 down. But I am going to note right now that if 9 you believe that that is both ethical and 10 proper in the context of an expert witness 11 deposition, then be forewarned, we intend to do 12 it with your witnesses as well, ask what each 13 one knows. 14 I think at this stage of the case this 15 is the type of information that should be 16 coming out, and I'm not going to stop him from 17 doing it. But if you ask the same type of 18 questions, I also likewise will be asking the 19 same type of questions. 20 Q. I don't care if the research is anointed with 21 the holy water of attorneys or not. I don't 22 care if the information comes from privileged 23 meetings or from your review of primary 24 research or reading their publications. I'll DEPOSITION OF WILLIAM W. WALKER, JR. 1264 1 just ask you to tell me if you know what these 2 individuals have done in terms of investigating 3 South Florida water quality and if you have or 4 anticipate you will rely on some part of that 5 work on your own. 6 MR. HARRISON: That's fine. 7 MS. AHEARN: Thank you. 8 Q. For Dr. Paul Parks? 9 A. I'm not aware of specifically what he has done 10 for the litigation. 11 Q. Dr. Ronald Raschke? 12 A. I'm generally aware of some of the work that he 13 has performed. 14 Q. And your general awareness encompasses what? 15 A. Encompasses the fact that he has done some 16 field work and collected some samples and 17 investigated periphyton relationships in the 18 Everglades. 19 Q. Dr. Wiley Kitchens? 20 A. I believe that he has performed some research 21 focusing on Water Conservation Area 1. 22 Q. Are you acquainted with the particulars of his 23 research? 24 A. No. DEPOSITION OF WILLIAM W. WALKER, JR. 1265 1 Q. Dr. John Richardson? 2 A. I believe that Dr. Richardson has also done 3 some work on Water Conservation Area 1. I'm 4 not familiar with the details. 5 Q. Dr. Mark Maffei? 6 A. Mark Maffei is also focused on Loxahatchee 7 National Wildlife Refuge. 8 Q. Are you acquainted with any actual field work 9 or research that Dr. Maffei has performed? 10 A. Dr. Maffei has been involved in the 11 interpretation of data collected by others, and 12 he may have also collected -- done some of his 13 own field work. I'm not certain. 14 Q. Delbert Hicks? 15 A. I believe that Delbert Hicks would have worked 16 with Dr. Ronald Raschke on the topic of 17 periphyton. 18 Q. Robert Doren? 19 A. Robert Doren has performed to my knowledge work 20 defining the spatial distribution of various 21 types of vegetation in the Park and the Water 22 Conservation Areas. 23 Q. All three Water Conservation Areas? 24 A. I don't know the extent to which his work has DEPOSITION OF WILLIAM W. WALKER, JR. 1266 1 been involved in the Water Conservation Areas. 2 I know that he has done work in the Park. 3 Q. Michael Rose? 4 A. I am unaware of specific research having been 5 conducted by Michael Rose. 6 Q. Dr. John W. Duxbury? 7 A. I'm not familiar with research by Dr. Duxbury. 8 Q. Are you acquainted with Dr. Duxbury? 9 A. I may have met him. I don't recall. 10 Q. Richard Bonner? 11 A. Richard Bonner would be involved in issues 12 relating to hydrology. 13 Q. Are you familiar with any work he's performed 14 for the litigation? 15 A. I believe he was also involved in analysis of 16 the hydrologic impacts that we discussed 17 earlier this morning. 18 Q. For Lewis Hornung, anything other than that 19 hydrologic impact study? 20 A. Lewis Hornung has provided general information 21 on operation of the Central and Southern 22 Florida Flood Control Project and on plans for 23 future modification of that project to achieve 24 alternative deliveries -- delivery schedules DEPOSITION OF WILLIAM W. WALKER, JR. 1267 1 and so forth. 2 Q. Dr. Dennis Helsel? 3 A. Dr. Dennis Helsel has provided assistance in 4 the form of review of the statistical -- the 5 trend analysis work that I have performed. 6 Q. Are you aware of any other work that Dr. Helsel 7 has done in conjunction with the litigation? 8 A. He has also reviewed the methodology and 9 results of -- the development of the interim 10 standards for Park inflows that we discussed 11 yesterday. 12 Q. John Burt? 13 A. I'm not familiar with any research that he has 14 done. 15 Q. Dr. David Lean? 16 A. Dr. Lean has been involved to my knowledge in a 17 review capacity and also providing information 18 on phosphorus cycling, phosphorus analyses and 19 ecological impacts of phosphorus. 20 Q. But you're aware of no primary research 21 conducted by Dr. Lean? 22 A. In the Everglades, I'm not aware of that, no. 23 Q. Martin Fleming? 24 A. I'm not aware of work -- research conducted by DEPOSITION OF WILLIAM W. WALKER, JR. 1268 1 Martin Fleming. 2 Q. Ronald Smola? 3 A. I'm not aware of any research conducted by 4 Ronald Smola. 5 Q. Dr. Ian Nisbet? 6 A. Dr. Nisbet to my knowledge has not as yet 7 conducted any research on the Everglades. 8 Q. Are you familiar with any review or other 9 secondary work of that nature he's done? 10 A. I believe that he has or is in the process of 11 -- or he is in the process of reviewing 12 information pertaining to pesticides, mercury 13 in the Everglades. 14 Q. Do you know when he started that work? 15 A. I believe that work is just now getting under 16 way. 17 Q. Dr. Walter Adey? 18 A. I'm not familiar with work by Dr. Adey. 19 Q. Do you know Dr. Adey? 20 A. No. 21 Q. Dr. Guy Lanza? 22 A. I'm not aware of specific research that 23 Dr. Lanza has conducted for the case. 24 Q. Dr. Robert Kadlec? DEPOSITION OF WILLIAM W. WALKER, JR. 1269 1 A. Dr. Kadlec is conducting research pertaining to 2 phosphorus cycling and phosphorus removal in 3 wetlands. 4 Q. Will Dr. Kadlec be performing field research in 5 the Everglades? 6 A. I do not know. 7 Q. Can you describe the nature of the research by 8 Dr. Kadlec that you are familiar with? 9 A. I believe I just described the topic that he is 10 working on, and that is the area of phosphorus 11 cycling or phosphorus removal in the wetlands. 12 Q. Are you knowledgeable of any of the details 13 about this work? 14 A. No. 15 Q. Dr. Walker, as an environmental engineer, what 16 specific feasible alternatives can you suggest 17 to the District which the District is not 18 already implementing or planning to implement 19 for achieving and maintaining water quality in 20 the Everglades? 21 MR. HARRISON: I object to form. A 22 question like that could call for a great deal 23 of speculation, and I simply caution the 24 witness not to speculate. I am going to permit DEPOSITION OF WILLIAM W. WALKER, JR. 1270 1 him to answer. Answer the question, however 2 broad it is. 3 I note for the record also, Counsel, we 4 don't know very much about what the District is 5 planning other than what's been in the SWIM 6 plan. 7 A. I have difficulty answering that question 8 because in reading the last draft of the SWIM 9 plan, I have trouble understanding exactly what 10 it is is being proposed by the District. So I 11 can't -- 12 Q. Well, what is your understanding of what's 13 being proposed by the District? 14 A. As I stated, it's -- I have -- I have read 15 concepts. I read about concepts and 16 possibilities, but I -- from my reading of the 17 SWIM plan, I don't see specific plans. I don't 18 see specific proposals. I see concepts and 19 possibilities described. 20 Q. Are there any concepts that are missing from 21 the District's SWIM plan that you would 22 recommend? 23 A. There may be. 24 Q. And what would be those concepts? DEPOSITION OF WILLIAM W. WALKER, JR. 1271 1 A. If we could start from a list of the specific 2 concepts that are in the SWIM plan, maybe I 3 could then amend that list or add to it if I 4 felt it was necessary. But as I stated, I have 5 a hard time understanding from my reading the 6 SWIM plan what exactly is being proposed. 7 Q. In terms of Water Management Areas, what 8 specific feasible alternatives would you 9 suggest? 10 MR. HARRISON: To which Water Management 11 Areas, Counsel? The District has put forth two 12 or three different versions. 13 MS. AHEARN: As proposed in the final 14 draft SWIM plan. 15 A. The final draft of the SWIM plan is not 16 specific enough for me to be able to evaluate 17 or develop an opinion on whether that plan is 18 adequate. 19 Q. So what you need first is more specificity? 20 A. Yes. 21 Q. Can you provide us what specific and feasible 22 measures you think would be best for the 23 District to incorporate in the SWIM plan? 24 MR. HARRISON: Object to form. DEPOSITION OF WILLIAM W. WALKER, JR. 1272 1 A. The SWIM plan should incorporate specific 2 standards over certain time frames for water 3 quality entering the Water Conservation Areas 4 and for water quality at each of the Park 5 inflow points, and the SWIM plan should be more 6 specific about how that water quality -- what 7 specific technical approaches would be taken to 8 achieve those water quality measures. 9 My interpretation of the Water 10 Management Area concept, I can see the concept 11 in the SWIM plan. But I don't see, for 12 example, which basin is hooked up to which 13 Water Management Area. I don't see the -- 14 there's not enough information on how these 15 systems would be operated hydrologically. That 16 information is something that needs to be 17 developed and specified. 18 Q. Such as the Corps is apparently doing at least 19 in part. 20 Let's put the SWIM plan aside. As an 21 environmental engineer -- 22 MR. HARRISON: Object to the 23 self-serving characterization. 24 Q. -- what specific feasible alternatives would DEPOSITION OF WILLIAM W. WALKER, JR. 1273 1 you like to see actually implemented for 2 maintaining water quality and achieving water 3 quality standards in the Everglades? 4 MR. HARRISON: Could I have the question 5 read back, please. 6 (The record was read as requested.) 7 MR. HARRISON: Object to form. The 8 question is too broad. The doctor may answer 9 it if he can. 10 A. I can outline my recommendations in general. 11 They would include four components. The 12 problem we're talking about here has to do with 13 phosphorus and eutrophication, and the general 14 approach to solving such a problem is to reduce 15 as much as possible the source of phosphorus 16 entering a water body. 17 So I would recommend as the first 18 control -- set of controls would involve 19 application of best management practices to try 20 to reduce the source of phosphorus leaving the 21 agricultural areas as well as the urban areas 22 that discharge into the Water Conservation 23 Areas. I believe as another control measure 24 the concept of the Water Management Area is DEPOSITION OF WILLIAM W. WALKER, JR. 1274 1 important. 2 So those first two items I would lump as 3 one category, as one -- one category of items 4 that is directed at reducing the source of 5 phosphorus to the Water Conservation Areas. 6 The second item would involve setting 7 standards or limits on the loadings or the 8 concentrations at the inflows to the Water 9 Conservation Areas to provide a frame of 10 reference for tracking the success of efforts 11 to limit or reduce phosphorus loadings from the 12 Water Conservation -- from the watersheds 13 discharging into the conservation areas. 14 The third area would be reviewing the 15 operation -- the schedules and the whole 16 operation of the Water Conservation Area system 17 from the point of view of the hydrology to 18 perhaps take a harder look at water quality as 19 one of the additional objectives that one might 20 incorporate into the water -- into the 21 management of these systems -- that is, water 22 quality in addition to water quantity, 23 providing a wildlife habitat, providing 24 vegetative habitat, providing flood control; in DEPOSITION OF WILLIAM W. WALKER, JR. 1275 1 other words, a harder look at how the system is 2 operated to see if there isn't some way that 3 the water quality objectives could be given 4 somewhat greater weight. 5 And that general approach, I believe, is 6 difficult because these Water Conservation 7 Areas are already being used for several 8 things, and we're also asking these Water 9 Conservation Areas to be used as wastewater 10 treatment systems. 11 And I think some of the effects and some 12 of the trends that I have observed reflect the 13 fact that you're asking too many things of the 14 Water Conservation Areas. And the way to 15 reduce that stress and to alleviate the risk -- 16 reduce the risk of water quality problems, that 17 the best way to do that is to reduce the 18 loading of phosphorus to the system. 19 The fourth category that I think is very 20 important is another set of standards that 21 would be designed to protect water quality in 22 the Park, setting standards at the Park at each 23 inflow point to the Park or, as I have 24 described it, for each separate basin to ensure DEPOSITION OF WILLIAM W. WALKER, JR. 1276 1 that phosphorus concentrations and loadings do 2 not increase over time and that levels that are 3 consistent with the five-year baseline period 4 that we have developed are eventually achieved 5 at those inflow points. 6 Q. Is there any category among your four which the 7 District has not undertaken the work on? 8 MR. HARRISON: Object to form. Basis of 9 Dr. Walker's knowledge. 10 A. I have seen reference to work in these areas in 11 various documents, including drafts of the SWIM 12 plan. But, as I stated, I have a hard time 13 understanding exactly what -- you know, the 14 extent of the -- the extent to which the work 15 has progressed and what has actually been 16 planned and committed to, that's where I'm 17 confused. 18 Q. Do you consider each of your four categories to 19 be specific feasible alternatives and measures? 20 A. Yes. 21 Q. You talked about reducing the source of 22 phosphorus to the Water Conservation Areas. If 23 the source of phosphorus is agricultural 24 activity, would you support reducing DEPOSITION OF WILLIAM W. WALKER, JR. 1277 1 agricultural activity? 2 A. The methods that I described -- namely, the use 3 of best management practices or essentially 4 refinements in the agricultural operations so 5 that they are conducted with water quality 6 considerations in mind -- would be a preferable 7 approach. But the decision about whether one 8 should eliminate agriculture is really not -- 9 that's not a scientific decision. That's a 10 policy decision. 11 Q. How is it that the South Florida Water 12 Management District should refine agricultural 13 practices? 14 MR. HARRISON: Object to form and also 15 to any predicate showing that Dr. Walker would 16 know what capabilities the District has or 17 doesn't. He may testify to whatever he knows, 18 but I think the question calls for speculation. 19 A. Well, there are a range of specific techniques 20 that I have seen discussed with regard to best 21 management practices and ways that may be 22 effective in reducing phosphorus loss from 23 agricultural lands, and the role of the 24 District it would seem to me would be to see DEPOSITION OF WILLIAM W. WALKER, JR. 1278 1 that those techniques are implemented. 2 Q. Do you have anything in mind as to exactly how 3 the District should do that? 4 A. Well, in general, the approach a regulatory 5 agency would take -- in my experience, I've 6 seen regulatory agencies put standards to apply 7 numeric limits on dischargers as a way of 8 providing an incentive for a given discharger, 9 whether it's an agricultural piece of land or 10 whether it's an industrial discharge, to 11 provide some limit that has to be met in the 12 water coming off a given piece of land or out 13 of a given wastewater treatment plant. 14 Q. Do you know if it's the District or some other 15 regulatory agency that should do that in South 16 Florida? 17 MR. HARRISON: Objection. Calls for a 18 legal conclusion. 19 MS. AHEARN: I asked what Dr. Walker 20 knows. 21 A. I think that gets more into the range of 22 regulatory framework and governmental 23 structure. I'd as soon stay out of that. 24 MS. AHEARN: I'm ready to stop my DEPOSITION OF WILLIAM W. WALKER, JR. 1279 1 examination of Dr. Walker on behalf of the 2 District at this time. Given that we did 3 receive such a significant volume of documents 4 just a couple days before the deposition 5 commenced in a shorter time period than what is 6 envisioned by the court in terms of preparation 7 for expert depositions, given that the 8 materials included approximately 40 million 9 bytes of computerized information that was 10 provided to other parties participating in this 11 deposition much later and which just simply 12 could not be physically examined in its 13 entirety for use in this deposition, given that 14 many of Dr. Walker's opinions are preliminary 15 or tentative, given that he has much work that 16 is ongoing or just starting or anticipated for 17 the future and given that we have several 18 dozens of questions which I believe are 19 appropriately framed on the record which the 20 deponent was not allowed to answer, the 21 District does reserve all rights to continue 22 this examination when Dr. Walker's deposition 23 resumes in the future. 24 MR. HARRISON: The United States does DEPOSITION OF WILLIAM W. WALKER, JR. 1280 1 disagree with the District's position, 2 obviously. The documents that you referred to 3 were provided some seven, not a couple, days 4 prior to this deposition. Both you and the 5 court were warned early on that this deposition 6 was scheduled and it was scheduled prior to the 7 court's order and that we would do our best to 8 comply. For the record, we are the only party 9 that has provided expert witness documents in 10 advance of an expert witness deposition to 11 date. Larry Grosser showed up with no 12 documents or even knowing that he was going to 13 be a witness in this case. 14 But, nevertheless, the United States 15 does not believe that the District has any 16 right to secure the second deposition of 17 Dr. Walker. You were informed prior to this 18 deposition that many of his opinions were 19 preliminary, and you chose to depose him at 20 this point in time. 21 MS. AHEARN: Well, the Government 22 apparently thinks this work is advanced enough 23 that there are no material issues of fact as to 24 liability based largely on Dr. Walker's work. DEPOSITION OF WILLIAM W. WALKER, JR. 1281 1 So -- 2 MR. HARRISON: And, Counsel -- if I may 3 finish, Counsel. You have had full rein to 4 depose him, and you had the declaration 5 provided with the summary judgment motion and 6 you have your own experts who have been working 7 on many of these same issues for 20 years. You 8 are certainly not hampered by that. 9 Nevertheless, that will be a question reserved 10 for the court as to whether the United States 11 will or by agreement of the parties as to 12 whether we will produce Dr. Walker to the 13 District for a second set of questioning. 14 MS. AHEARN: Thank you. 15 (Off the record) 16 (Short recess) 17 18 MR. HARRISON: Before Mr. Crowley begins 19 examination of Dr. Walker, I would like to just 20 note for the record that throughout the week I 21 have been checking on the availability of 22 Colonel Malson with the Corps of Engineers as 23 the District has been trying to get his 24 deposition scheduled and has sent notices, and DEPOSITION OF WILLIAM W. WALKER, JR. 1282 1 he has for one reason or another been 2 unavailable. 3 Colonel Malson will be available for 4 deposition, and I'm requesting that the 5 District notice him while that calendar is 6 open. And I have directed the Corps to keep 7 that calendar open, but he will be available 8 March 7th and 8th for deposition. And should 9 the need arise to continue that deposition, the 10 Government will also do its best to make him 11 available and he is currently available on 12 April 22nd through the 24th. 13 The only conflicts that I'm aware of in 14 that scheduling, not to say that there aren't 15 others, was the United States currently has 16 Gary Goforth noticed I believe for the March 17 time frame. I also believe that we have 18 availability to switch and depose Gary Goforth 19 during the first week of May, which I think was 20 one of the time frames that was going to be 21 slotted for Colonel Malson. We're trying to 22 provide Colonel Malson earlier than that. So 23 if we can shift Goforth back to that time, that 24 would be one possibility. DEPOSITION OF WILLIAM W. WALKER, JR. 1283 1 Even if Goforth can't be shifted, the 2 United States will see whether we can get other 3 counsel to do Mr. Goforth during the originally 4 scheduled time frame. And the only other 5 conflict is that should the District or the 6 Cities feel or DER feel that they have to go 7 into the April 22nd to 24th time frame with 8 Colonel Malson, that would conflict with a 9 deposition planned for Dick Slyfield, and that 10 deposition I think can be slid to the week of 11 April 29th to May 3. And I'm offering these 12 and we will attempt to confirm these in a 13 letter and await the District's response as to 14 when you would desire to notice Colonel Malson. 15 And if -- I am telling you that he will not be 16 available prior to March 7th and 8th, and I 17 believe we have communicated that information. 18 I do not see the need to go for 19 protective order. If the District intends to 20 pursue the February time frame, I would request 21 that they let me know so that I can file such a 22 motion for protective order. I don't see the 23 need for the pleadings. The scheduling is 24 complicated enough. But we will do whatever we DEPOSITION OF WILLIAM W. WALKER, JR. 1284 1 have to do. 2 CROSS-EXAMINATION 3 BY MR. CROWLEY: 4 Q. Dr. Walker, I'm David Crowley. I'm 5 representing the Florida Department of 6 Environmental Regulation and Carol Browner, the 7 Secretary of the Department. I have just a 8 couple questions here, and I'll try to be as 9 brief as possible. 10 At the end of your testimony just a few 11 minutes ago, you went over recommendations in 12 the four areas that you mentioned, I believe, 13 that you thought attention should be given to 14 in solving some of these problems, and I just 15 wanted to pursue in a little more detail some 16 of your recommendations along the lines of the 17 third category you mentioned, which I believe 18 was reviewing the operation and schedules of 19 the water management system to see if water 20 quality objectives could be given greater 21 weight. 22 Have you done any work yourself in that 23 regard? 24 A. No, I haven't. DEPOSITION OF WILLIAM W. WALKER, JR. 1285 1 Q. Do you know of any other scientists who have or 2 who are currently doing such work? 3 A. I believe that the concept of revising the 4 operation schedules for delivery to the Park 5 has been discussed both by the Park and by the 6 District. The extent to which water quality 7 considerations would factor into those -- would 8 factor into the discussions that have already 9 taken place, I'm uncertain. 10 Q. Okay. Just so I'm clear on your earlier 11 opinions, would those recommendations deal only 12 with the delivery schedules to the Park and 13 possible modifications thereto, or might they 14 also deal in a broader sense with the overall 15 water delivery within the whole system? 16 A. Well, the overall way that water is distributed 17 and moved in the system. There may be some 18 modifications in that. Essentially the concept 19 is trying as much as possible to promote sheet 20 flow as compared with canal flow. 21 Q. To your knowledge, is anyone doing any work in 22 terms of the whole system -- in other words, 23 outside of just simply delivery schedules to 24 the Park? DEPOSITION OF WILLIAM W. WALKER, JR. 1286 1 A. No. 2 Q. Might such work involve review of the schedules 3 of how water is moved around in some of the 4 adjacent watersheds to the Water Conservation 5 Areas in the Park? 6 MR. HARRISON: Object to form. 7 A. Are you referring to a specific watershed or a 8 specific Water Conservation Area? 9 Q. I was referring generally to adjacent 10 watersheds, but we can limit it to specific 11 ones piece by piece if you prefer. I'm just 12 kind of asking as a general concept. 13 A. Well, as a general concept, as I stated, I 14 think that the objective would be to provide as 15 even a distribution of flow across the marshes 16 as possible as one additional way of sort of 17 promoting phosphorus removal within the Water 18 Conservation Areas. As something that would 19 not necessarily solve the problem but something 20 that would help to achieve better water quality 21 downstream, I believe that the source control 22 reduction in phosphorus going into the Water 23 Conservation Areas would be necessary in 24 combination with these measures. DEPOSITION OF WILLIAM W. WALKER, JR. 1287 1 Q. So this might influence the way water is pumped 2 or moved through particular structures? 3 A. Inflow points to the water quality areas in the 4 Park? 5 MR. HARRISON: Object to form. 6 A. I'm not so much talking about the way in which 7 water is released into the Park as I am the way 8 in which water is released into the water 9 quality areas. The path that water takes as it 10 moves through the Water Conservation Areas down 11 to the Park inflow points. 12 Q. How about the way that water enters the 13 conservation areas? Is that also important? 14 A. I believe that's what I just stated. The way 15 that water enters the Water Conservation Areas, 16 whether it enters through a -- in a 17 concentrated form at a structure and flows down 18 a canal, which is something that promotes 19 transport of flow and nutrients downstream, as 20 compared with say a situation where you had 21 multiple inflow points and tried to introduce 22 it more as sheet flow as compared with canal 23 flow. 24 Q. What about the way that water moves from or is DEPOSITION OF WILLIAM W. WALKER, JR. 1288 1 moved from one Water Conservation Area to 2 another? Should that also be included in such 3 an analysis? 4 A. Well, from the point of view of the water 5 quality entering the Park, I wouldn't view that 6 as being as important as the way that water 7 enters the Park from the external watersheds. 8 And that's primarily because the nutrient 9 budget of Water Conservation Area 3A is 10 dominated largely by inflows from the external 11 watersheds as compared with inflows from the 12 other Water Conservation Areas. 13 Q. So are you saying, then, that Water 14 Conservation Area -- it's more important to 15 look at Water Conservation Area No. 3 with 16 regard to reviewing the operations and 17 schedules of the water management system than 18 it is No. 2 and No. 1? 19 A. Well, I would think I would want to look at the 20 entire system. But I'm just saying that in 21 terms of the operation of or the way the water 22 moves through Water Conservation Area 3A has a 23 greater direct impact on the Park because 3A is 24 the direct source of water to the releases into DEPOSITION OF WILLIAM W. WALKER, JR. 1289 1 Shark slough at the Park. 2 Q. Would you also want to look at the way that 3 water is moved, for example, within the 4 Everglades Agricultural Area before it enters 5 any of the Water Conservation Areas? 6 MR. HARRISON: Object to form only for 7 the reason that the purpose for the inquiry as 8 to what Dr. Walker would or would not want to 9 look for may be misleading. And I have no 10 issue with counsel going into broad discovery 11 issues with the understanding that many of the 12 questions you are asking now are not the areas 13 to which the United States has purported to 14 proffer Dr. Walker as a witness for the United 15 States. 16 MR. CROWLEY: Okay. I understand. 17 Q. But I'm merely trying to follow up on your 18 third recommendation, your third component of 19 your general recommendations regarding 20 reviewing the operations and schedules of the 21 water management system as you have testified 22 earlier, and I'm trying to get a little more 23 specific information on what we're talking 24 about when we refer to the water management DEPOSITION OF WILLIAM W. WALKER, JR. 1290 1 system and how we would look at this review of 2 the operation and schedules of that system. 3 A. Well, the concept of alternative distributions 4 of flow from the Everglades Agricultural Area I 5 believe has been discussed either in the SWIM 6 plan or discussed by the District elsewhere 7 regarding using different canals to divert load 8 in various directions, and that I believe was 9 also discussed in relation to the Water 10 Management Areas, essentially replumbing the 11 system to provide a way for the runoff from 12 various basins to reach the Water Management 13 Areas, and then designing the Water Management 14 Areas in such a way that -- and here's where we 15 get into this third area -- in such a way that 16 instead of releasing the flow and the 17 phosphorus load all at one point, that it 18 releases it at several points along say the 19 northern boundary of the Water Conservation 20 Area 3A, for example, so that the flow as it 21 enters the Water Conservation Area has a 22 greater tendency to start off as sheet flow in 23 addition to being -- having a much reduced 24 phosphorus concentration as a result of the DEPOSITION OF WILLIAM W. WALKER, JR. 1291 1 phosphorus uptake in the Water Management Areas 2 and whatever best management practices would 3 have been applied the agricultural areas. 4 Q. So would enhancing and promoting sheet flow, 5 then, in your opinion be the major thing that a 6 review of the operation and schedules of the 7 water management system would be concerned 8 with? 9 MR. HARRISON: Object to form. 10 A. That would be one of the factors. Another 11 factor would be to provide not only even 12 distribution of flow but to try to maintain as 13 high a stage as possible in operating the Water 14 Conservation Areas. 15 In other words, the correlations that I 16 have identified in the process of looking at 17 water quality at the S12s in relation to 18 hydrologic factors shows that there is a 19 negative correlation between concentration and 20 flow; that is, water that is delivered to the 21 Park at low stage tends to have a higher 22 concentration. So that if we are -- if we are 23 to try to modify the way in which the system is 24 operated to provide lower phosphorus DEPOSITION OF WILLIAM W. WALKER, JR. 1292 1 concentrations to the Park, then another 2 objective aside from promoting sheet flow would 3 be to try to keep the stage levels in -- the 4 storage of water in the Water Conservation 5 Areas as high as possible. 6 This is where you get into juggling the 7 various other objectives for operating the 8 Water Conservation Areas. And the objectives 9 for flood control and water supply aren't 10 always consistent with the objectives for 11 providing high stage and lower -- and thereby 12 lower phosphorus concentrations. 13 And that's why I believe that it's going 14 to be difficult to answer or to solve this 15 problem exclusively by changing operations 16 within the system and some control on the 17 external load is going to be required. 18 Q. Do you have an opinion as to why high stage 19 produces lower phosphorus concentrations in 20 inflows? 21 A. I believe some ideas along those lines are 22 discussed in Exhibit 17 in the report that I 23 prepared to the Justice Department. 24 Essentially -- on pages 16 and 17 of Exhibit 17 DEPOSITION OF WILLIAM W. WALKER, JR. 1293 1 there are three reasons that are discussed, one 2 having to do with at higher stage, there's just 3 more volume stored in the Water Conservation 4 Areas and water -- the time it takes for water 5 to pass through the system or the hydraulic 6 residence time is longer, and this promotes 7 phosphorus uptake. 8 The second reason that I discuss has to 9 do with when the water level is drawn down just 10 because of the topographic situation and 11 location of the canals and the marshes, a 12 higher proportion of the total flow that 13 reaches the Park in the S12s is from the 14 perimeter canals -- namely, L67 -- as compared 15 with marsh sheet flow; so that when water is 16 released at low elevation, it tends to be more 17 canal water as compared with sheet flow. 18 In that type of situation it would be 19 desirable to avoid that or to give -- the 20 alternative to -- again, to having problems 21 that are related to discharge of high- 22 concentration water at low stage is to improve 23 the quality of the water entering the Water 24 Conservation Areas to begin with so this kind DEPOSITION OF WILLIAM W. WALKER, JR. 1294 1 of relation would not be as sensitive. 2 The third reason why nutrient 3 concentrations or phosphorus concentrations in 4 particular may be higher during periods of low 5 stage, that it's a characteristic that may be a 6 general -- that generally is found in the marsh 7 stations themselves. As the water level is 8 drawn down, there's more mineralization of the 9 peat, greater contact between the water and the 10 peat and a tendency for higher concentrations 11 to be present. 12 Q. So if you're talking about holding the water at 13 a higher stage, then you're also talking about 14 modifying the hydroperiod of the water body; is 15 that correct? 16 A. That would be part of it, correct. 17 Q. Would that also mean that you're talking about 18 minimizing the variations in that hydroperiod? 19 A. I don't know if I could get into that level of 20 detail. But I'm just saying that the general 21 concept of a higher water level would be -- 22 would generally promote lower phosphorus 23 concentrations. It's tricky because of the -- 24 you know, the interactions in the multiple DEPOSITION OF WILLIAM W. WALKER, JR. 1295 1 objectives that you have in operating these 2 Water Conservation Areas. 3 Q. Might it also, for example, have potential 4 adverse effects that should be investigated on 5 wildlife if you hold the water at a higher 6 stage? 7 MR. HARRISON: Object to form. 8 A. That's a possibility. 9 Q. In your opinion, should a review of the 10 operation and schedules of the water management 11 system also include a review of flood control 12 measures in the adjacent agricultural lands? 13 MR. HARRISON: Object to form. There's 14 been no foundation laid to show that Dr. Walker 15 is familiar with the flood control measures in 16 the EAA. 17 A. Well, if one -- in general I can say that if 18 one were to propose changes in the operation of 19 the Water Conservation Areas to provide some 20 increased level of water quality protection, 21 one would have to review the impacts of that 22 change on the entire operation of the system to 23 meet the other objectives, including flood 24 control. DEPOSITION OF WILLIAM W. WALKER, JR. 1296 1 Q. Would that answer also hold true for the 2 agricultural areas down around Homestead, which 3 I believe you testified earlier might influence 4 the discharge through S332? 5 MR. HARRISON: Same objection to 6 foundation. 7 A. I wonder if you could rephrase your question. 8 Q. Well, I guess it's a very general question. In 9 essence, I'm asking you if we're going to be 10 looking at flood control measures in the EAA 11 and that's part of the watershed for some of 12 the Water Conservation Areas, is it logical 13 that we would be doing the same thing in some 14 of the agricultural watershed for inflows 15 through the S332 structure? 16 A. Yes. It is logical that you would do that 17 there, as well. 18 Q. If changes were to be implemented, do you have 19 any opinions as to how this would be 20 accomplished between or among the various 21 regulatory agencies involved? 22 MR. HARRISON: Objection. Calls for 23 speculation and for legal conclusions. 24 A. That's well beyond the scope of my involvement. DEPOSITION OF WILLIAM W. WALKER, JR. 1297 1 MR. CROWLEY: Okay. I think that's all 2 the questions I have. Thank you, Dr. Walker. 3 CROSS-EXAMINATION 4 BY MR. BURGESS: 5 Q. Good morning, Dr. Walker. 6 A. Good morning, Mr. Burgess. 7 Q. As you know, I represent the cities of Belle 8 Glade and Clewiston, and I appreciate your 9 attendance and patience and time during the 10 past week. And while Ms. Ahearn did cover a 11 lot of the issues that I would have covered and 12 documents also if it was my turn to go first, 13 she hasn't covered all of it. 14 It's now almost 11:30 a.m. on Thursday, 15 February 14th, and I'm about to begin my 16 examination on behalf of my client. 17 I understand from Mr. Harrison that you 18 are not available to attend this deposition 19 tomorrow or next week. Is that correct? 20 A. That's correct. 21 Q. Do you know when you might next be available 22 for a period of perhaps two or three 23 consecutive days after next week to appear for 24 the continuation of this deposition? DEPOSITION OF WILLIAM W. WALKER, JR. 1298 1 A. Well, I have obligations to complete other work 2 on different projects under contract by the 3 beginning of April, so the entire month of 4 March is going to be infeasible for me to 5 continue with this deposition. I would say 6 that the second week in April would be the 7 earliest date that I would be willing to commit 8 myself for that purpose. 9 Q. That would be the week beginning Monday, 10 April 8th? 11 A. Yes. 12 Q. Are there specific days that you know you would 13 be available during that week? 14 A. I don't have my calendar with me. 15 MR. BURGESS: Rick, on behalf of the 16 United States, would you work with Dr. Walker 17 and see if you can confirm in writing to the 18 Cities a date that we could resume his 19 deposition? 20 MR. HARRISON: You bet. And I would 21 appreciate it if you and I could sort of also 22 work together on our scheduling. I'm not sure 23 -- I mean, there's obviously some way that we 24 can provide him in April; we'll just find a way DEPOSITION OF WILLIAM W. WALKER, JR. 1299 1 and we'll work it out. 2 MR. BURGESS: Thank you. 3 Q. That being the case, I'm going to try in the 4 limited amount of time I have available to 5 cover as much ground as possible. 6 Dr. Walker, could you turn to Exhibit 7 No. 17? And specifically, it is the second 8 page, but it has the word "abstract" on the top 9 in the middle. 10 The second paragraph on that page, if 11 you would, Doctor, read to yourself so you can 12 familiar yourself for purposes of my questions 13 the first two sentences of that paragraph. 14 (Witness examining exhibit) 15 Q. Dr. Walker, did you expect when you adjusted 16 the data to account for variations in 17 antecedent rainfall and water surface elevation 18 that you would in fact have seen more trends 19 and not less trends as you in fact found? 20 A. I don't recall having an expectation one way or 21 the other. 22 Q. Would another way of saying that you adjusted 23 to account for variations in antecedent 24 rainfall and water surface elevation be to say DEPOSITION OF WILLIAM W. WALKER, JR. 1300 1 that when you removed the deterministic effects 2 of antecedent rainfall and water surface 3 elevation? 4 MR. HARRISON: Object to form. I'm not 5 sure that was -- I didn't understand it to be a 6 completed question. 7 MR. BURGESS: Okay. Let me clear it up. 8 Q. The second sentence of that paragraph says: 9 When the data are adjusted to 10 account for variations in antecedent 11 rainfall and water surface elevation... 12 And my question to Dr. Walker would be: 13 Would it have been proper if you would have 14 begun that sentence, When the data were 15 adjusted such that the deterministic effects of 16 antecedent rainfall and water surface 17 elevation? 18 MR. HARRISON: Object to form. 19 A. Well, as is stated in the report, the objective 20 of the hydrologic adjustment or Series C is to 21 remove those variations that were correlated 22 with antecedent rainfall and/or antecedent 23 water surface elevation. 24 Q. And when you remove those effects, are you in DEPOSITION OF WILLIAM W. WALKER, JR. 1301 1 effect removing what you scientists term 2 sometimes background noise? 3 A. I don't know that we have to give it any other 4 term. All I'm saying is that I'm removing the 5 variations that are correlated with rainfall 6 and water surface elevation. 7 Q. Are you removing those variations in order to 8 make your trends clearer? 9 MR. HARRISON: Asked and answered. 10 A. I wouldn't use the word "clearer." I would 11 state that I'm removing the variations in order 12 to provide a test that is not influenced by 13 variations that are correlated with antecedent 14 rainfall and water surface elevation. 15 Q. And the fact that once you removed them, you in 16 fact saw less trends than you saw when they 17 were not removed, did that lead you to question 18 whether you really captured the effects of 19 antecedent rainfall and water surface 20 elevation? 21 MR. HARRISON: Objection to the 22 predicate characterization. 23 A. The Series C calculations removed the 24 variations that were correlated with antecedent DEPOSITION OF WILLIAM W. WALKER, JR. 1302 1 rainfall and water surface elevation. I had no 2 reason to suspect that I did not capture those 3 effects. The time series that I tested were 4 independent of antecedent rainfall and water 5 elevation. There was no reason to suspect 6 regardless of the outcome on the trend test 7 that I did not remove the variations that were 8 correlated with those hydrologic factors. 9 Q. And your testimony is that you had no 10 expectation one way or the other as to whether 11 or not your trends -- likelihood of trends 12 would have increased or decreased after you 13 removed antecedent rainfall and water surface 14 elevation? 15 MR. HARRISON: Asked and answered. 16 A. That's correct. When I conducted these tests, 17 I designed a methodology and I implemented the 18 methodology. I was not anticipating results in 19 one way or another for any of the stations or 20 any elements. 21 Q. Would you turn to page 3, please. 22 The last sentence of the first full 23 paragraph reads: 24 DEPOSITION OF WILLIAM W. WALKER, JR. 1303 1 The ongoing SFWMD monitoring 2 program provides a consistent water 3 quality data base which is not subject 4 to difficulties which can be encountered 5 in interpreting data derived from 6 multiple agencies, multiple 7 laboratories, and/or variable sampling 8 intervals. 9 Dr. Walker, what was your basis for 10 making that statement? 11 MR. HARRISON: Asked and answered 12 extensively the first couple of days. 13 A. The basis of that statement was in my 14 experience and in my review of the literature 15 on the topic of data analysis, water quality 16 data analysis and trend analysis in particular, 17 it is inappropriate to mix data from different 18 laboratories and different agencies and in some 19 cases highly variable sampling intervals; 20 mixing data from two different sources is 21 inappropriate and can lead to false 22 impressions. 23 Q. What was your basis for making the portion of 24 the statement that reads "The ongoing SFWMD DEPOSITION OF WILLIAM W. WALKER, JR. 1304 1 monitoring program provides a consistent water 2 quality database..."? 3 A. The term "consistent" I used in reference to 4 the fact that this was a program that was 5 collected by one agency, that it was collected 6 with a specified sampling interval and it was 7 -- the analyses were done within the same 8 laboratory. That was my definition of 9 "consistent." 10 Q. Were you aware that for the period of record 11 the South Florida Water Management District had 12 changed methods, instruments and labs as well 13 as sampling personnel and location of sampling 14 sites? 15 MR. HARRISON: Object to form. Also 16 assumes a fact not in evidence. 17 A. I do not know any of those statements to be 18 facts. 19 Q. Were you aware prior to making the sentence 20 which we have just read into the record and 21 appears on page 3 that the South Florida Water 22 Management District lab had employed labs with 23 new pieces of analytical equipment during the 24 period of record and during the sampling series DEPOSITION OF WILLIAM W. WALKER, JR. 1305 1 and that the analytical methods employed by 2 those labs had been subject to change, 3 inaccuracy and precision of detection limits 4 during the period of record? 5 MR. HARRISON: Object to counsel's 6 characterization. It's asking the witness 7 about a fact that's not in evidence in this 8 deposition, if in fact it is a fact. 9 A. Of the statements which you have just made, the 10 only statement that I am aware of as being a 11 fact and something that we have already 12 discussed in this deposition is that there was 13 a change in the detection limit for total 14 phosphorus during this time period and, as I 15 described, effects of that change in detection 16 limit were considered in the trend analysis. 17 Q. Let's turn to page 6 of the report where I 18 think that is addressed. About the middle of 19 the second full paragraph on that page there is 20 a sentence which reads: 21 The detection limit for total and 22 ortho phosphorus increased from .002 to 23 .004 milligrams per liter in 1981. 24 Dr. Walker, does that mean that up until DEPOSITION OF WILLIAM W. WALKER, JR. 1306 1 1981, a figure of .002 milligrams per liter was 2 detectable; but that after 1981 for the 3 remainder of the period of record, the 4 analytical equipment could not detect less than 5 .004 milligrams per liter? 6 MR. HARRISON: Object to form in that 7 Dr. Walker has not testified to the analytical 8 equipment. It's been clear from his testimony 9 he's been testifying from what was presented in 10 the data. So I object to that as a fact not in 11 evidence. Other than that, Dr. Walker may 12 answer. 13 A. That statement on page 6 refers to the fact 14 that in the data set that was provided to me by 15 the District, the lowest recorded value 16 increased from .002 to .004 in approximately 17 1981. 18 Q. So that in approximately 1981 is it your 19 understanding, Dr. Walker, that up until that 20 time a reading of .002 milligrams per liter 21 total and ortho phosphorus could be detected; 22 and that after 1981, the lowest reading that 23 could be detected was .004 milligrams per 24 liter? DEPOSITION OF WILLIAM W. WALKER, JR. 1307 1 MR. HARRISON: Same objection. 2 A. The values which appear in the database as 3 created by the District to my knowledge reflect 4 the values that were entered and analyzed by 5 the District laboratory. And the detectability 6 of a specific concentration depends not only on 7 the equipment involved; it depends upon the 8 procedures and upon the confidence of the 9 analyst, the laboratory person in charge, in 10 recording values down to a certain level. 11 Q. Well, the fact that the detection limit 12 changed, was that fact only made known to you 13 by a review of the raw data when after 1981 you 14 all of a sudden did not see any readings for 15 total or ortho phosphorus less than .004? 16 A. I believe I testified earlier that that -- that 17 the change in detection limit to my