252 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, February 7, 20 1991, commencing at 9:32 a.m. 21 22 23 LINDA MARIE MacDONALD, RPR-CM REGISTERED PROFESSIONAL REPORTER 24 60 LAWRENCE ROAD, PLYMOUTH, MA 02360 (508) 747-6615 253 1 A P P E A R A N C E S: 2 UNITED STATES ATTORNEY'S OFFICE By A.U.S.A Richard Harrison 3 155 South Miami Avenue, Suite 600 Miami, FL 33130 4 for the United States of America. 5 U.S. DEPARTMENT OF JUSTICE By Trial Attorney Beverly Sherman Nash 6 601 Pennsylvania Ave., N.W., Room 868 P.O. Box 6633 7 Washington, D.C. 20044 for the United States of America. 8 SKADDEN, ARPS, SLATE, MEAGHER & FLOM 9 By Attorney Laura B. Ahearn 1440 New York Ave., N.W. 10 Washington, D.C. 20005 for South Florida Water Management 11 District and John R. Wodraska. 12 PEEPLES, EARL & BLANK By Attorney Rick J. Burgess 13 One Biscayne Tower, Suite 3636 Miami, FL 33131 14 for the cities of Belle Glade and Clewiston, defendant intervenors. 15 STATE OF FLORIDA OFFICE OF GENERAL COUNSEL 16 By Asst. Gen. Counsel David A. Crowley Department of Environmental Regulation 17 Twin Towers Office Building 2600 Blair Stone Road 18 Tallahassee, FL 332301 for the Florida Department of 19 Environmental Regulation. 20 A L S O P R E S E N T: 21 George Shih, Statistician, SFWMD 22 Douglas Robson, Consultant, SFWMD John Davis, Consultant, Belle Glade and 23 Clewiston Peter Ghavami, Legal Assistant, Skadden 24 Arps DEPOSITION OF WILLIAM W. WALKER, JR. 254 1 I N D E X Witnesses Examination 2 WILLIAM W. WALKER, JR. 3 (By Ms. Ahearn) 255 4 5 6 7 8 9 10 E X H I B I T S 11 Number For ID 12 DX 20 Letter to Smith from Walker 287 dated 12/11/89, with attachments 13 14 15 16 17 18 19 20 21 22 23 24 DEPOSITION OF WILLIAM W. WALKER, JR. 255 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. 9 Q. I think that we had asked you yesterday to 10 bring a couple of additional items with you 11 this morning. Have you brought any additional 12 materials for your deposition? 13 A. Yes. 14 Q. And what are those? 15 A. I brought copies of my resume and project 16 summaries, and I brought copies of the floppy 17 disks that are essentially -- that contain the 18 same information that was transferred to the 19 District. This is the data that was off my 20 computer. 21 Q. Would this reflect the same number of diskettes 22 as the number you copied and sent to the United 23 States attorneys to be produced? 24 A. Yes. DEPOSITION OF WILLIAM W. WALKER, JR. 256 1 Q. And what was the total number of diskettes? 2 A. Twenty-five. 3 (Off the record) 4 Q. Dr. Walker, yesterday I asked you about more 5 recent entries on your computer that would have 6 been -- files that would have been created 7 after the time you prepared these diskettes, 8 the 25 diskettes, and I believe you told me 9 that you did not have any more recent files 10 that concerned the South Florida litigation. 11 Have you created any new files that 12 concern any project or analysis that relates to 13 the Everglades? 14 A. Not to my recollection, no. 15 Q. Now, you told us that you personally in your 16 mind know the details of your programs and how 17 step by step they operate and function, 18 correct? 19 A. Correct. 20 Q. And there's no other individual who shares that 21 type of detailed understanding of your 22 programs? 23 A. That's correct. 24 Q. Has there been any independent verification of DEPOSITION OF WILLIAM W. WALKER, JR. 257 1 the programs you've written for the South 2 Florida litigation? 3 A. What do you mean by "independent"? 4 Q. Has any other scientist reviewed your programs 5 to see exactly how they're structured, how they 6 run, how they are executed, to ensure that that 7 is all accurate? 8 A. No. 9 Q. Has any other expert taken your program and run 10 it with test data sets? 11 A. No. 12 Q. Has any other scientist reviewed your programs 13 to determine whether it is consistent with 14 generally accepted methods and techniques in 15 the scientific community? 16 A. No other scientists have reviewed the programs 17 that I created. 18 Q. Have your programs been accepted by the 19 scientific community -- I mean the programs you 20 have created for the South Florida litigation? 21 A. No other scientists have reviewed the programs 22 that I wrote. 23 Q. So no other scientist has said, "That's a good 24 program. I would use it. I think it's DEPOSITION OF WILLIAM W. WALKER, JR. 258 1 acceptable, given the standards of the 2 scientific community"? 3 MR. HARRISON: Asked and answered. If 4 they haven't reviewed them -- 5 A. No other scientists have reviewed my programs. 6 Q. So no other scientist would have made such a 7 conclusion, correct? 8 A. No other scientist has reviewed my programs. 9 Q. Are there recognized QA/QC standards for the 10 creation of computer programs? 11 A. There are procedures that one can exercise in 12 the process of creating a program. 13 Q. Where would I find a list or a description of 14 those procedures, recognized QA/QC procedures? 15 A. Oh, there are -- there are textbooks written on 16 that subject. 17 Q. Can you, please, identify those textbooks that 18 you would find authoritative in this regard? 19 A. I can't recall any in particular offhand. 20 Q. Have you relied on any such textbooks in 21 creating the programs you have used in the 22 South Florida litigation? 23 A. Not directly. 24 Q. Have you relied simply on your general DEPOSITION OF WILLIAM W. WALKER, JR. 259 1 background, having a general familiarity with 2 those textbooks? 3 A. I have relied on my general background and my 4 professional experience in creating and testing 5 programs. 6 Q. Have you tested programs created by other 7 scientists? 8 A. Yes. 9 Q. On how many occasions? 10 A. Once that I can recall. 11 Q. Can you tell me about those circumstances? 12 A. That was in conjunction with the work for the 13 Environmental Protection Agency on the stream 14 water quality model QUAL-IIE. 15 Q. And that was the model you told me yesterday 16 that was generated by EPA? 17 A. Yes. 18 Q. In your review of that model, did you find that 19 the model was flawless? 20 A. I made some suggestions regarding the processes 21 that that model was simulating. In other 22 words, I don't recall finding any problems in 23 the computer program per se; more in what the 24 model was attempting to do, the way it was DEPOSITION OF WILLIAM W. WALKER, JR. 260 1 simulating the processes in the stream. 2 Q. So it was more a theoretical point as opposed 3 to the -- 4 A. Correct. 5 Q. -- technical application through a computer 6 model? 7 A. Correct. 8 Q. How long did it take to develop the QUAL-IIE 9 model? 10 A. The QUAL-IIE model was developed from an 11 earlier version which was called QUAL-II, and I 12 believe the first version of that came out in 13 the mid 1970s. 14 Q. And QUAL-II was also created by EPA or under a 15 contract? 16 A. It was under -- I believe by the EPA. 17 Q. And what was the time period that it took to 18 develop the QUAL-II model from initiation of 19 the project to production of the final model? 20 A. I don't know exactly. 21 Q. Do you know if it was over a period of two 22 years? 23 A. I don't know how long it took. 24 Q. Are you familiar with a program known as WASP? DEPOSITION OF WILLIAM W. WALKER, JR. 261 1 A. I'm generally familiar with it. 2 Q. Could you, please, explain your general 3 familiarity? 4 A. WASP is short for water analysis simulation 5 program. That is another program that was 6 developed for or by the EPA, and it is for use 7 in predicting, simulating water quality in a 8 wide variety of surface water systems. 9 Q. Could it be applied appropriately to inflow 10 structures to Everglades National Park? 11 A. I have never used the model myself, and I'm not 12 familiar enough with it to be able to state 13 whether or not it could be adapted for use to 14 the inflow structures. 15 Q. Would that also be true, then, to inflow 16 structures to the Water Conservation Areas, 17 marsh stations and EAA canals? Can you tell me 18 if the WASP model would be appropriate to apply 19 to any of those other locations in South 20 Florida? 21 A. I can't say. 22 Q. You can't say whether or not you would be able 23 to tell me the model is appropriate? 24 A. I just stated I'm not familiar enough with the DEPOSITION OF WILLIAM W. WALKER, JR. 262 1 details of the model to be able to state 2 whether or not it could be applied to 3 particular structures. 4 Q. Do you anticipate writing an operations manual 5 or operating instructions for the programs you 6 have created for the South Florida litigation? 7 A. Which programs are you referring to? 8 Q. Well, yesterday we talked about a number of 9 them. How about the TREN programs which I 10 believe we identified? I believe we called 11 them the KTEST, the RMED, those TREN programs? 12 A. No, I do not anticipate writing an operations 13 manual for those programs. 14 Q. Do you anticipate writing operation manuals for 15 any of the programs that are among the computer 16 diskettes that you have supplied for this 17 deposition? 18 A. No. 19 Q. And currently do written operating instructions 20 exist for any of those programs? 21 A. No. 22 Q. Could I, please, have you turn to Exhibit 18. 23 Dr. Walker, do the diskettes that you 24 have provided, the 25 diskettes, contain all of DEPOSITION OF WILLIAM W. WALKER, JR. 263 1 the files needed to run all of the programs 2 which you have offered or prepared for the 3 South Florida matter? 4 A. Yes. 5 Q. And am I correct, these programs are designed 6 and the databases that go with them are 7 designed all to be run on one computer 8 independently? 9 A. Yes. 10 Q. So you don't need to interface or access some 11 other computer or distant database in order to 12 have everything you need to run the program? 13 A. That's correct. 14 Q. Could you, please, identify in Exhibit 18 each 15 directory entry that reflects surface water 16 quality data? 17 A. Would you like that identification on a 18 page-by-page basis, or do you just want the 19 directories? 20 Q. Why don't you go through and, when you find a 21 page that has such an entry, tell us the page 22 number and the directory name. For example, on 23 page 2 is there a directory named "BLANK" that 24 contains -- DEPOSITION OF WILLIAM W. WALKER, JR. 264 1 A. Surface water quality data? 2 Q. Yes. 3 A. On page 3 in the directory entitled 4 G:\FLOPPIES\DISK2. 5 Q. I think it might help us expedite it if each 6 time you identify that surface water data, 7 could you tell us what the source of the data 8 is in terms of agency or generator of the data? 9 Then we won't have to go back through this 10 again. 11 A. Okay. Going back to page 3 in the directory 12 G:\FLOPPIES\DISK2, the file -- the directory 13 contains data supplied by the District. On 14 page 4 the directory G:\FLOPPIES\DISK4\STDS 15 contains data supplied by the District as well 16 as some data files created by myself. On page 17 7 in the directory G:\FLOPPIES\DISK9, that 18 directory contains water quality data supplied 19 by the US Geological Survey. On page 7 the 20 directory G:\FLOPPIES\DISK10 also contains 21 files of surface water quality data supplied by 22 the US Geological Survey. 23 On page 8 the directory 24 G:\FLOPPIES\DISK11 contains water quality data DEPOSITION OF WILLIAM W. WALKER, JR. 265 1 supplied by the District. On page 8 the 2 directory G:\FLOPPIES\DISK11 also contains 3 water quality data supplied by the District. 4 Q. Excuse me. Was that last reference to DISK12? 5 A. DISK12. On page 8 the directory 6 G:\FLOPPIES\DISK13 also contains surface water 7 quality data supplied by the District. On 8 page 9 the directory G:\FLOPPIES\DISK14 9 contains water quality files that were supplied 10 by Everglades National Park, but I believe they 11 reflect data collected by the District. 12 On page 11 the directory 13 G:\FLOPPIES\DISK22 contains surface water 14 quality data supplied by the District. On 15 page 11 the directory G:\FLOPPIES\DISK23 16 contains surface water quality data supplied by 17 the District. On page 12 the directory 18 G:\FLOPPIES\DISK24 contains surface water 19 quality data supplied by the District. On 20 page 24 the directory G:\DBASE contains water 21 quality files that were derived from surface 22 water quality data supplied by the District. 23 Q. Is there a particular extension on the file 24 names here that would allow us to identify DEPOSITION OF WILLIAM W. WALKER, JR. 266 1 those data files? 2 A. Some of the water quality data would have the 3 extension WK1. Some of the water quality data 4 would have the extension DAT. On page 27 the 5 directory G:\COE contains water quality data 6 supplied by the Corps of Engineers as well as 7 water quality data supplied by the District. 8 Q. Can you tell us which files represent which 9 source? 10 A. No. I cannot recall. On page 28 the directory 11 G:\ANAL contains surface water quality data 12 files that were derived from data files 13 supplied by the District. On page 30 the 14 directory G:\SLACK contains surface water 15 quality data files that were derived from files 16 supplied by the District. 17 Q. Is there a particular extension here that will 18 identify those data files? 19 A. The extension -- certain of the files with the 20 extension DAT would be the water quality files. 21 Q. Who performed that derivation? 22 A. Would you be more specific? 23 Q. Who did the work that created these files that 24 are derived from the District data? DEPOSITION OF WILLIAM W. WALKER, JR. 267 1 A. I did. I believe that's the extent of the 2 directories containing surface water quality 3 data. 4 Q. Can you, please, identify the surface water 5 quality data set or sets that you rely upon in 6 Exhibit 17, your water quality trends report of 7 September 1990? 8 MR. HARRISON: Was your question 9 directed toward the final report, the September 10 1990 -- 11 MS. AHEARN: That is the final report. 12 Yes. 13 MR. HARRISON: Okay. 14 A. Those files would be contained in a directory 15 G:\DBASE on pages 24 through 26. 16 Q. When you told us that those surface water 17 quality data files were derived from District 18 data, what do you mean by "derived"? 19 A. The District supplied the data in the form of 20 an ASCII printout similar to a word processing 21 file. The process of derivation involves 22 converting that word processing file into a 23 data structure format that can be accessed by 24 the software that does the trend analysis. DEPOSITION OF WILLIAM W. WALKER, JR. 268 1 Q. Do any of the data values change through this 2 derivation process? 3 A. The only values that were changed as a result 4 of setting up these data files is -- has to do 5 with the assignment of small positive values 6 for the measurements that were reported below 7 detection limits, and that process is described 8 in Exhibit 17. 9 Q. Other than that, we didn't change any of the 10 numbers in deriving the G:\DBASE directory from 11 the District ASCII printouts? 12 A. That's correct. 13 Q. Dr. Walker, have you performed trend analyses 14 on the other water quality data sets that you 15 have now identified in Exhibit 18? 16 MR. HARRISON: Asked and answered. I 17 think we went through that yesterday, which 18 trend analyses he had and had not performed. 19 MS. AHEARN: I don't think I could have 20 asked this question because we hadn't 21 identified data sets. 22 MR. HARRISON: We didn't apply it to 23 these. 24 A. Certain of the other water quality data sets DEPOSITION OF WILLIAM W. WALKER, JR. 269 1 have been used in trend analysis, yes. 2 Q. Would it be easier for you to tell me what you 3 did do trend analyses on or which of them you 4 didn't do trend analyses on? I'd like to go 5 through and have you make that distinction, and 6 if you can tell me which you think would be 7 more expeditious. 8 MR. HARRISON: Counsel, I think your 9 question needs to be clarified as to whether he 10 has begun, whether he has completed trend 11 analysis. I mean, "doing trend analyses" is a 12 little general at this point. 13 MS. AHEARN: Thank you for the point of 14 clarification. 15 Q. If you can, please, identify for me all 16 additional databases -- surface water quality 17 sets which you have employed in trend analyses 18 to date. 19 A. Exclusive of the ones contained in the 20 directory G:\DBASE? 21 Q. You've obviously performed a trend analysis of 22 that. 23 A. Trend analyses were also conducted using 24 information contained in the directory G:\ANAL DEPOSITION OF WILLIAM W. WALKER, JR. 270 1 on page 16 -- 28. Page 28. Excuse me. 2 MR. BURGESS: I'm sorry. Page 28, what 3 was the file name? 4 THE WITNESS: The directory is G:\ANAL. 5 MR. BURGESS: Thank you. 6 Q. Is this surface water quality data set 7 different from the surface water quality data 8 set you used for Exhibit 17? 9 A. Yes. 10 Q. When did you perform the trend analysis on the 11 water quality data set that's in G:\ANAL? 12 A. That is an ongoing process. The initial work 13 was begun in December of 1990. 14 Q. Does Exhibit 18 reflect output files for that 15 ongoing work? 16 A. Yes. 17 Q. And where will we find those? 18 A. Those would be found on page 21 in the 19 directory G:\TOOLS\MULTI. 20 Q. Any particular extension that denotes these 21 output files? 22 A. .PRN, .LST, .RXD. 23 Q. How does the period of record for the data set 24 in G:\ANAL compare to the period of record DEPOSITION OF WILLIAM W. WALKER, JR. 271 1 employed for Exhibit 17? 2 (Pause) 3 MR. BURGESS: Madam Court Reporter, 4 could you read back the pending question? 5 (The record was read as requested.) 6 MR. BURGESS: Thank you. 7 A. You would have to be more specific about which 8 particular file you're referring to in order 9 for me to answer that question. 10 Q. Do the files within G:\ANAL differ from one 11 file to the other? 12 A. Yes. 13 Q. Would you be able to tell us the period of 14 record reflected in each file entry in G:\ANAL? 15 A. Approximately, yes. 16 Q. Okay. If you could give us those approximate 17 periods of record, please. 18 A. For each file? 19 Q. Please. 20 A. The total period of record reflected in the 21 file BOTH.RXD would be December of 1977 through 22 September of 1989. The total period of record 23 reflected in the file MARSH.WK1 would be 24 approximately 1985 through 1989. DEPOSITION OF WILLIAM W. WALKER, JR. 272 1 The total period of record reflected in 2 the file INFLOWS.WK1 would be December 1977 3 through September 1989. The same period of 4 record would be appropriate for the file 5 BOTH.WK1, and the file MARSH_D.WK1 would 6 reflect the period of record 1985 through 1989, 7 approximately. The remaining file in that 8 directory is not a data file. 9 Q. Do any of the surface water quality data sets 10 you have identified in Exhibit 18 include data 11 that is more recent than 1989? 12 A. No. 13 Q. Do you have in your possession surface water 14 quality data from Southern Florida that is more 15 recent than 1989? 16 A. Yes. 17 Q. In what form is that data at the present time? 18 A. It's not in raw form. 19 Q. In what form is it? 20 A. It's in the form of a flow-weighted mean 21 concentration calculated by the South Florida 22 Water Management District for the S12 structure 23 and for the S333 structure for 1990. 24 Q. And how did you acquire this more recent data? DEPOSITION OF WILLIAM W. WALKER, JR. 273 1 A. That was faxed to me a week or two ago. 2 Q. Faxed by whom? 3 A. I believe it was the Justice Department. 4 Q. Is this among the documentation you provided 5 for your counsel to be produced in conjunction 6 with your deposition? 7 A. No. It's not part of the data that I have 8 analyzed or used in formulating my opinions. 9 Q. Have you reviewed that data yet? 10 A. I have not analyzed it. 11 Q. Have you looked it over? 12 A. I have -- I have looked at the page, but I have 13 not analyzed or interpreted it or used it to 14 formulate any opinions. 15 Q. Will you be looking at this data? 16 A. I expect to, yes. 17 MS. AHEARN: Counsel, could I ask that a 18 copy of that be produced? 19 MR. HARRISON: Yes, you can. I think 20 that he just -- and I have no problem producing 21 it. He said he just got it two weeks ago from 22 the Water Management District. Do we know any 23 more about the source of this? Do you have it 24 in your possession at your house? DEPOSITION OF WILLIAM W. WALKER, JR. 274 1 THE WITNESS: Excuse me. It was faxed 2 to me by the Justice Department. It was 3 supplied originally -- it was generated by the 4 Water Management District and it was part -- 5 essentially, it was overheads presented -- 6 given in a presentation to the South Florida 7 Water Management board a number of weeks ago. 8 MS. AHEARN: If you could bring a copy. 9 MR. HARRISON: I have no problem. 10 MS. AHEARN: Thank you. 11 Q. Any other data in your possession on South 12 Florida water quality that is more recent than 13 1989? 14 A. No. 15 Q. Could you turn to page 4 in Exhibit 18? I 16 believe you told us that entries for 17 G:\FLOPPIES\DISK4 contained data files both 18 from the District and data files created by 19 you. 20 What is the source of the data from 21 which you created data files contained in this 22 directory? 23 MR. HARRISON: Counsel, I believe that 24 the witness said it was the DISK -- and I may DEPOSITION OF WILLIAM W. WALKER, JR. 275 1 be mistaken, but it was the DISK4\STDS that he 2 just testified to. 3 MS. AHEARN: Thank you. 4 MR. HARRISON: I don't know if there's a 5 difference or not. 6 Q. I guess I should phrase my question in terms of 7 the subdirectory just identified by 8 Mr. Harrison. 9 A. The source of the data in this directory is 10 ultimately South Florida Water Management 11 District. 12 Q. The derivation process for the files that you 13 created here in this subdirectory, is that 14 different from the derivation process you 15 explained in connection with the prior set of 16 files which you identified as having been 17 derived by you from ASCII disks or ASCII- 18 formatted data from the District? 19 A. No. 20 Q. So it's the same process reflected here? 21 A. Yes. 22 Q. On -- excuse me. Were about to say something? 23 A. Nothing. 24 Q. On page 9 under directory FLOPPIES\DISK15, are DEPOSITION OF WILLIAM W. WALKER, JR. 276 1 those data files? 2 A. I am not certain what's in those data files. 3 They could be water quality files. They could 4 be hydrology files. 5 Q. But you believe that they are data files? 6 A. I believe they are data files. 7 Q. What is the source of this data? 8 A. I don't recall for certain. 9 Q. Have you performed any type of analysis of the 10 data on DISK15? 11 A. I may have. 12 Q. If you had, would that be reflected in output 13 files among your computer entries? 14 A. I can't say for certain. 15 Q. If you had generated output files, can you tell 16 us how you would have named them such that we 17 can identify them? 18 A. Well, I'm not sure what's in those data files, 19 so I can't tell you what I would have done with 20 any output from any processing of those files. 21 Q. Under the directory entry FLOPPIES\DISK16, is 22 that data? 23 A. What type of data? 24 Q. Could you tell me what kind of data is DEPOSITION OF WILLIAM W. WALKER, JR. 277 1 contained on FLOPPIES\DISK16? 2 A. I don't recall exactly what's in that file. 3 Q. So would you recall its source? 4 A. No. 5 Q. And do you recall if you have analyzed this 6 data? 7 A. I can't -- I can't recognize the file name, so 8 I can't tell you whether I've analyzed it or 9 not. 10 Q. On DISK17 does that contain data? 11 A. That contains data, yes. 12 Q. And do you remember the type of data here? 13 A. I believe that would contain rainfall quality 14 data supplied by the District. 15 Q. Have you analyzed this data? 16 A. A portion of it. 17 Q. When did you do those analyses? 18 A. In the summer of 1989. 19 Q. Did you rely on this data in any memoranda you 20 have prepared in conjunction with the South 21 Florida case? 22 A. I prepared a preliminary report on rainfall 23 phosphorus concentrations at the Everglades 24 Research Center. DEPOSITION OF WILLIAM W. WALKER, JR. 278 1 Q. Have you used this data in any analyses 2 conducted more recently than summer of 1989? 3 A. Not to my recollection. 4 Q. You've identified two surface water quality 5 data sets which you have employed in trend 6 analyses. 7 Are there any additional surface water 8 quality data sets reflected in Exhibit 18 on 9 which you have performed trend analyses? 10 A. If you could be specific about which two 11 surface water data sets you think I've 12 identified, I'll answer your question. 13 Q. I believe you identified the data set which you 14 employed and rely upon in Exhibit 18, and you 15 also identified the data set that is on 16 directory G:\ANAL. 17 A. That's one. 18 Q. That is one -- you treat that as one data set? 19 A. That's one directory that contains a data set 20 used in trend analysis. 21 Q. Dr. Walker, let me make sure I'm straight. My 22 understanding is that you've identified two 23 directories that contain surface water quality 24 data that you have used in trend analyses. DEPOSITION OF WILLIAM W. WALKER, JR. 279 1 Those directories are G:\DBASE and G:\ANAL. 2 Are there any other directories that 3 contain surface water quality data on which you 4 have conducted trend analyses? 5 A. No. 6 Q. Do the surface water quality data entries which 7 you have identified in Exhibit 18 reflect all 8 of the surface water quality data for South 9 Florida which you have reviewed or utilized in 10 your work on South Florida? 11 A. Yes. 12 Q. Dr. Walker, could you, please, give me 13 sequentially the instructions on how to execute 14 your RMED program? 15 Dr. Walker, I recognize this is maybe a 16 tedious task for you but, you know, we've 17 established that this information exists in 18 your head and nowhere else. It seems to me 19 that the RMED program is maybe smaller than 20 your other two, and that's why I've selected 21 that. 22 If you believe that you could go through 23 this process with one of your other programs 24 more expeditiously, I'd ask that you let me DEPOSITION OF WILLIAM W. WALKER, JR. 280 1 know that. But the RMED program has been 2 selected by me because I would anticipate you 3 can do that most easily. 4 A. I can tell you in general terms the steps 5 involved in executing the RMED program. 6 Q. Thank you. 7 MR. HARRISON: Just for the record, 8 Counsel, in response to your statement, 9 Dr. Walker has also testified that from 10 Exhibit 18 itself, without additional 11 instructions, that a computer-literate person 12 should be able to put these files up on the 13 screen and figure out how to use them. That's 14 my recollection. 15 MR. BURGESS: Do you want to define 16 "computer-literate"? 17 MR. HARRISON: Somewhere beyond me, I'll 18 tell you that much. 19 (Laughter) 20 A. Assuming that one has the data files prepared 21 in the format that I have prepared them and as 22 are contained on the disks in the directories 23 that are identified, in order to run the RMED 24 program, one would have to use a word processor DEPOSITION OF WILLIAM W. WALKER, JR. 281 1 or other editor to edit the file RMED.DAT. 2 In that file, RMED.DAT, are the 3 instructions that essentially define which data 4 files are accessed, which stations are 5 analyzed, which water quality variables are to 6 be analyzed, and possibly some other 7 directions, possibly period of record or date 8 range. I don't recall exactly. And once one 9 is through editing that file RMED.DAT, then one 10 executes the program from the DOS prompt by 11 typing "R-M-E-D." 12 Q. Then the computer runs the program? 13 A. Correct. 14 Q. And generates an output file at that point? 15 A. Yes. 16 Q. Are all of the files which need to be accessed 17 or called up in the course of executing the 18 RMED program found within the same directory? 19 A. No. 20 Q. How many directories must be accessed to run 21 the RMED program? 22 A. There would be one directory other than the 23 RMED directory. 24 Q. And that directory is? DEPOSITION OF WILLIAM W. WALKER, JR. 282 1 A. That directory would depend upon -- would be 2 specified in the file RMED.DAT. 3 Q. And that is identifying a separate directory 4 that includes the data files to be accessed? 5 A. That's correct. 6 Q. Do your other trend analyses programs run on 7 basically the same principles? 8 A. The same general concept. The level of 9 complexity may vary from one program to 10 another, but the same general approach is used. 11 Q. Which is the most complex program? 12 A. The KTEST program. 13 Q. And how is it more complex than the others? 14 A. From the point of view of operating or running 15 the program, the procedure is exactly the same. 16 It's just that the amount of information that 17 you have to provide in the input data file is 18 more extensive. 19 Q. Do you need to access more than the KTEST 20 directory to run the KTEST analysis? 21 A. Yes. 22 Q. How many additional directories? 23 A. One. 24 Q. And is that to specify within the program as DEPOSITION OF WILLIAM W. WALKER, JR. 283 1 being a data retrieval command? 2 A. It's specified in the input data file to the 3 program. 4 Q. And what is the code you type to execute the 5 program? 6 A. "K-T-E-S-T." 7 Q. Are there any of your programs here where you 8 type something other than the name of the 9 directory containing the program in order to 10 execute that program? 11 A. Some of the programs may contain what are 12 called batch files that provide different ways 13 of executing -- executing the specific program 14 by accessing different data -- input data 15 files, but essentially the procedure is the 16 same as I have described. 17 (Off the record) 18 Q. Dr. Walker, does Exhibit 18 reflect any 19 directories or files containing inflow water 20 quality data from the Corps of Army Engineers? 21 A. Inflow to what? 22 Q. Let me just say inflow as opposed to marsh 23 water quality data. 24 A. Again, inflow -- inflow to what? DEPOSITION OF WILLIAM W. WALKER, JR. 284 1 Q. Does Exhibit 18 contain water quality data 2 collected by the Corps of Army Engineers at any 3 structure within the Central and South Florida 4 Flood Control Project? 5 A. Yes. 6 Q. And could you, please, identify those entries 7 in Exhibit 18 for us? 8 A. The only one that I recognize with certainty is 9 the directory G:\COE on page 27. 10 Q. There may be other Corps data entries here? 11 A. Possibly. 12 Q. Does this directory G:\COE contain water 13 quality data collected from within canals? 14 A. Yes. I believe there would have been some 15 canal stations included. 16 Q. Does it also contain water quality samples 17 collected from marshes? 18 A. To my recollection, no. 19 Q. Have you reviewed any marsh water quality data 20 from the Corps of Army Engineers? 21 A. No, not to my recollection. 22 Q. Have you done any type of analysis on the data 23 which is in directory G:\COE? 24 A. Yes. DEPOSITION OF WILLIAM W. WALKER, JR. 285 1 Q. And what was that type of analysis? 2 A. Essentially, a statistical summary of the data 3 collected by the Corps at various stations 4 represented in those files. 5 Q. Did you use one of your programs to do this 6 analysis? 7 A. Which program are you referring to? 8 Q. I guess that's my question. You know, you have 9 identified programs here that you authored that 10 do various things with data sets. 11 Have you used any of those computer 12 programs in performing this analysis of the 13 Corps data? 14 A. Yes. I would have used some of them. 15 Q. Can you identify those? 16 A. Well, I would have used Lotus 1-2-3, and I 17 would have used the FLUX program, F-L-U-X. And 18 that's all I recall. 19 Q. When did you perform this analysis? 20 A. In the fall of 1989. 21 Q. Did you create output files as a result of this 22 analysis? 23 A. I believe I created a listing of the data with 24 a statistical summary. DEPOSITION OF WILLIAM W. WALKER, JR. 286 1 Q. Is that an entry that we can find in 2 Exhibit 18? 3 A. I'm not certain. 4 Q. Did you create this summary in a hard copy 5 form? 6 A. Yes. 7 Q. Is that among the materials you provided for 8 this deposition? 9 A. It's among the materials I provided to the 10 Justice Department. 11 Q. Have you previously provided that summary to 12 any other entity or individual prior to passing 13 a copy on to the Justice Department for your 14 deposition? 15 A. I provided a copy of it to Dr. Bo Smith of the 16 Army Corps of Engineers in Jacksonville. 17 Q. And when was that? 18 A. In the fall of 1989. 19 Q. Can you tell me if this summary is entitled or 20 labeled in such a way that I can sort through 21 documents and see if I can identify it? 22 A. It would be attached to a letter to Dr. Smith 23 with my letterhead on it. 24 Q. Did you give that letter to the Department of DEPOSITION OF WILLIAM W. WALKER, JR. 287 1 Justice? 2 A. Yes. 3 Q. Do you know if the Department of Justice has 4 passed that on to the other parties? 5 A. I do not know. 6 Q. Other than by reference to that letter, can you 7 tell me what this summary would look like so 8 that I can try and identify it? 9 A. There would be a letter containing three or 10 four pages of text and three or four pages of 11 listing of data. There may be a graph, and 12 some references. 13 (Exhibit No. 20 marked for 14 identification) 15 Q. Dr. Walker, we have just had the court reporter 16 mark a document which Mr. Harrison has 17 characterized as work product. I recognize you 18 just described your letter to Dr. Smith as 19 being on your letterhead. 20 Apart from that difference, can you 21 identify what's been marked as Exhibit 20 as 22 the letter and attachment concerning your 23 analysis of Corps data? 24 A. It appears that the text of the letter is DEPOSITION OF WILLIAM W. WALKER, JR. 288 1 complete, but the exhibit does not contain all 2 of the attachments that were included in that 3 original -- that were included with that 4 original letter to Dr. Smith. 5 Q. And is that because the last page should 6 contain graphs which are not printed, they do 7 not appear on the last page here of Exhibit 20? 8 A. That is one of the items missing, to my 9 recollection. 10 Q. What are the other omissions that you recall 11 here? 12 A. I believe there were excerpts from a manual 13 prepared by the North American Lake Management 14 Society describing recommendations for 15 phosphorus analyses conducted under the clean 16 lakes monitoring program. 17 Q. That would have been attached to the hard copy 18 version printed on your letterhead? 19 A. Well, I wouldn't have printed the manual on my 20 letterhead, but that would have been attached 21 to the original -- my original correspondence 22 with Dr. Smith. 23 Q. And that correspondence you would have printed 24 out on your personal letterhead or your DEPOSITION OF WILLIAM W. WALKER, JR. 289 1 business letterhead? 2 A. I believe so. The first page of this 3 attachment would have been on my letterhead. 4 Q. Does Exhibit 20 appear to you to lack any text 5 or attachments which you would have created on 6 your own computer? 7 A. Well, I don't recall exactly what -- all the 8 details of the attachments and the tables that 9 were included in the original transmission. I 10 know that this particular item I'm looking at, 11 Exhibit 20, is missing the figure on the last 12 page. The figures that are -- and those 13 figures would have been created on my own 14 computer. 15 Q. Can I turn your attention to page 28 of 16 Exhibit 18. Can you tell me if Exhibit 20 17 represents a printout of the file called 18 COE.TXT? 19 A. I can't say with certainty, but it could very 20 well contain that. 21 Q. Have you a belief whether Exhibit 20 represents 22 a printout -- 23 A. I believe that's a reasonable assumption. 24 Q. Who asked you to prepare this analysis for DEPOSITION OF WILLIAM W. WALKER, JR. 290 1 Dr. Smith? 2 A. The Justice Department. 3 Q. In your letter you say it was "at the request 4 of the National Park Service and your office," 5 meaning Dr. Smith's office, correct? 6 A. But I was working all the time for the Justice 7 Department. The National Park Service and the 8 Corps of Engineers had had some discussions 9 regarding the issues described in this letter, 10 and I was requested by the Justice Department 11 and by the National Park Service to prepare 12 this analysis. 13 Q. Who originated the request for the analysis? 14 A. That was in a meeting that -- the meeting that 15 was held at the Everglades Research Center with 16 the Justice Department attorneys and Everglades 17 National Park staff in December of 1989. 18 Q. This is the meeting at which you outlined the 19 research projects? 20 A. That's correct. 21 Q. Who at the National Park Service requested this 22 analysis? 23 A. I believe it was Dr. Soukup. 24 Q. Who at Dr. Smith's office requested the DEPOSITION OF WILLIAM W. WALKER, JR. 291 1 analysis? 2 MR. HARRISON: I would caution the 3 witness to not speculate. If you know, 4 certainly give her the answer. 5 A. I do not know who at the -- at Dr. Smith's 6 office specifically requested the analysis. 7 Q. Did you discuss that with Dr. Smith? 8 A. No. 9 Q. Did you discuss with Dr. Smith why the analysis 10 was requested? 11 MR. HARRISON: Asked and answered. 12 A. No. 13 Q. Did you discuss with Dr. Soukup why the Park 14 Service was requesting the analysis? 15 A. Yes. 16 Q. And what did Dr. Soukup tell you? 17 MR. HARRISON: If -- I want to interpose 18 an objection. If the witness can answer with 19 respect to any scientific reason that 20 Dr. Soukup may have requested this data, I have 21 no problem with that answer. If the reason, 22 however, does get into litigative strategy as 23 to the use to be made by the United States, I 24 would ask the witness not to answer that DEPOSITION OF WILLIAM W. WALKER, JR. 292 1 question. 2 MS. AHEARN: I think there's been a 3 clear waiver if in fact this is all litigation 4 strategy. 5 Q. Dr. Walker, could you, please, answer my 6 question? 7 MR. HARRISON: I certainly disagree with 8 that, Counsel. There's certainly been no 9 waiver. I'm giving the witness very broad 10 latitude to give you the science, even the 11 science that has come out of these various 12 meetings which are privileged. But I will not 13 let him go into the use to be made of that 14 science. If the reasoning has to do with uses 15 to be made by United States attorneys in this 16 case, I'm not going to let him answer that. 17 A. I'd like to confer with counsel before I can 18 answer this question. 19 Q. Because you don't know if Dr. Soukup was 20 telling you -- you've told me he did explain to 21 you why the analysis was requested, correct? 22 A. In general terms, yes. 23 Q. Okay. And you don't know if those reasons are 24 counsel's litigation strategy or scientific DEPOSITION OF WILLIAM W. WALKER, JR. 293 1 reasons? 2 A. I don't know what counsel construes as 3 litigation strategies. 4 Q. That's right. Neither do I. And that's why 5 this is so very difficult, because we have 6 attorneys deciding ad hoc what they think is 7 science or litigation strategy. 8 MR. HARRISON: I resent that statement. 9 It is not ad hoc. We have let you go into the 10 science that was generated at many of these 11 meetings regardless of whether the meetings 12 were privileged. And I'm just going to give 13 you an example, and I don't know the answer, 14 either. 15 MS. AHEARN: I -- 16 MR. HARRISON: But if Dr. Soukup 17 requested this because of a request that came 18 from Steve Herman to analyze Corps data for 19 some reason or another in use in this 20 litigation, I can understand Dr. Walker's 21 reluctance to blurt that out without consulting 22 with counsel. 23 MS. AHEARN: I think if the Department 24 of Justice is asking scientists to do DEPOSITION OF WILLIAM W. WALKER, JR. 294 1 scientific inquiries and not informing them 2 that this is for litigation, the litigation 3 only, and is privileged work product and should 4 remain confidential, you have not preserved any 5 privilege in the first instance. 6 Since this witness doesn't know that 7 this was work for the Department of Justice, it 8 should be maintained confidential, I think by 9 definition no privilege applies. 10 MR. HARRISON: That's very interesting 11 considering last week Larry Grosser was shut 12 down on a question when Dr. Shih brought two 13 gentlemen into his office and he had no idea 14 there was any confidentiality with the remarks. 15 Counsel, you have taken identical 16 positions; and until the witness is comfortable 17 that this is not litigation strategy that 18 you're asking him to reveal, I'm going to have 19 him not answer the question. Let's move on. 20 Q. Dr. Walker, Dr. Soukup did give you reasons for 21 conducting the analysis; that's correct? 22 MR. HARRISON: Counsel, I'm not going to 23 let him go into this any further until he has a 24 chance to consult. It is now eleven o'clock. DEPOSITION OF WILLIAM W. WALKER, JR. 295 1 We have been going at least an hour and a half. 2 I think it's time for about a five-minute 3 break. 4 MS. AHEARN: I will be ready to stop in 5 just one moment, please. I think that that is 6 not an objectionable question. 7 Q. Would you, please, answer it? 8 MR. HARRISON: He's already answered 9 that, yes, there were reasons given. The 10 answer is on the record, Counsel. 11 A. At the meeting that was held in December of 12 1989 Dr. Soukup and the attorneys from the 13 Justice Department described reasons for why 14 they wanted me to perform this analysis. 15 Q. And you can't tell if Dr. Soukup's reasons were 16 scientific reasons or litigation strategy 17 reasons unless you go confer with your counsel 18 first, correct? 19 MR. HARRISON: Objection. It is not up 20 to Dr. Walker, who is a scientist, to determine 21 what is and is not privileged, Counsel. It's 22 up to me and the court ultimately. And if he 23 feels that he is stepping over this line, he 24 has a right to confer. I will make the DEPOSITION OF WILLIAM W. WALKER, JR. 296 1 decision as to whether we're claiming 2 privilege. Dr. Walker has no business making 3 these decisions. 4 MS. AHEARN: I'm only asking Dr. Walker 5 what he knows. 6 MR. HARRISON: No, you're not. You're 7 asking his opinion as to whether it's strategy 8 or science, Counsel, and I completely object to 9 that line of questioning. It calls for a legal 10 conclusion. 11 MS. AHEARN: Could you, please, reread 12 my question? 13 (The record was read as requested.) 14 MR. HARRISON: I direct you not to 15 answer. 16 MS. AHEARN: Let me rephrase my 17 question. 18 Q. Do you know, Dr. Walker, sitting here whether 19 the reasons Dr. Soukup gave you for this 20 analysis were scientific reasons or litigation 21 strategy reasons? 22 MR. HARRISON: Objection. Calls for 23 legal conclusion. And there's also no basis to 24 know whether or not he participated in those -- DEPOSITION OF WILLIAM W. WALKER, JR. 297 1 in the reasons if they were litigation 2 strategy. There's no foundation and it calls 3 for a legal conclusion, and it also may get 4 into attorney/client privilege. I direct the 5 witness not to answer the question. 6 Q. I'm only asking you what you know, Dr. Walker. 7 MR. HARRISON: I direct the witness not 8 to answer the question. Ms. Ahearn, we can sit 9 here all day and do this if you want. He is 10 not going to answer the question. 11 MS. AHEARN: Let's take a break. 12 MR. HARRISON: Thanks. 13 (Short recess) 14 15 MR. HARRISON: Before the break there 16 was a discussion -- there was a question 17 regarding, as I recall, correct me if I'm 18 wrong, Counsel, you had asked Dr. Walker 19 whether Dr. Soukup had given him any reasons 20 for why the Park Service want the Corps' 21 statistical water quality data analyzed, and he 22 was uncomfortable because it was certainly in 23 the presence of attorneys. 24 After consultation with him, the reason DEPOSITION OF WILLIAM W. WALKER, JR. 298 1 that was given to him by Dr. Walker I believe 2 although certainly could be considered work 3 product and attorney/client but prior -- after 4 the court's order, since it is of a scientific 5 nature and it does not deal specifically with 6 litigation strategy, I'm going to let 7 Dr. Walker answer the question. 8 MS. AHEARN: Dr. Harrison -- excuse me. 9 Mr. Harrison -- 10 MR. HARRISON: Yes. 11 MS. AHEARN: -- do we have a pretty 12 clear formula now of when Dr. Walker can tell 13 me what scientists have told him if it is of a 14 scientific nature and does not absolutely 15 necessarily relate to the lawsuit? 16 MR. HARRISON: Counsel, the formula 17 clearly is that this was told to him at the 18 request of and in the presence of Department of 19 Justice trial lawyers, and I can defend it 20 under attorney/client privilege, period. 21 That's the formula, and that's the formula that 22 the District has taken in its privilege list 23 throughout. But I am going to allow him to 24 answer that because even though it certainly DEPOSITION OF WILLIAM W. WALKER, JR. 299 1 could be attorney/client privilege and I could 2 sit here and withhold it, it is my belief, I 3 think that it does go to a scientific nature. 4 And, no, there is never going to be a 5 clear formula when I am letting you wade into 6 meetings that are privileged meetings. I am 7 also going to analyze what the substance of 8 that information is that's going to come out 9 because I think all of it is technically 10 privileged. 11 Q. Dr. Walker, what were the reasons given to you 12 by Dr. Soukup for performing the analysis of 13 the Corps data reflected in Exhibit 20? 14 A. This analysis was conducted approximately one 15 month before we began discussions with the 16 District regarding ONRW standards for the Park 17 inflows. There were a variety of water quality 18 databases collected by various agencies, 19 including the Corps of Engineers and including 20 the District, that could be used in setting 21 those standards, and the purpose of this 22 particular exercise that I went through was to 23 examine the applicability of the data produced 24 by the Corps of Engineers for the purpose of DEPOSITION OF WILLIAM W. WALKER, JR. 300 1 setting water quality standards at the Park 2 inflows. 3 Q. In your mind, are analyses for the purpose of 4 setting water quality standards analyses which 5 are performed for litigation purposes? 6 MR. HARRISON: I object to the form of 7 the question. 8 A. In my mind, if the analysis is requested by an 9 attorney or in the presence of an attorney, 10 then it is possibly subject to confidentiality 11 because of the attorney/client relationship. 12 Q. Is the ONRW standards setting process a part of 13 this litigation? 14 MR. HARRISON: Asked and answered. 15 Dr. Walker already testified yesterday that he 16 considered it part of the same project he was 17 hired by the Department of Justice to do. 18 MS. AHEARN: The DOJ project. I have 19 asked him a different question here. 20 A. It was -- one of the tasks that I was assigned 21 in working for the Justice Department was to 22 work with the Park Service and attend these 23 meetings under the ONRW process. 24 Q. Would the ONRW process proceed if there was no DEPOSITION OF WILLIAM W. WALKER, JR. 301 1 litigation? 2 A. I could only speculate on that. I don't know. 3 Q. Is the ONRW process provided for by law 4 independent of this litigation? 5 A. I'm not familiar with the legal aspects of the 6 ONRW process. 7 Q. Are you familiar with the statutory provisions 8 that require and define the ONRW standards 9 setting process? 10 MR. HARRISON: Asked and answered. I 11 object. Calls for a legal conclusion. 12 A. No. 13 Q. You're not familiar with those statutes -- 14 A. No. 15 Q. -- correct? 16 Do you anticipate that the court in this 17 litigation will set ONRW standards? 18 MR. HARRISON: Objection. Calls for a 19 legal conclusion, entirely beyond the scope of 20 this witness' expertise as to what the court 21 will or will not do. It's pure speculation. 22 A. I would not speculate on that. 23 Q. Do you have any anticipation, any belief on 24 that whatsoever? DEPOSITION OF WILLIAM W. WALKER, JR. 302 1 MR. HARRISON: Objection. Same grounds. 2 Q. You can still answer. 3 A. No, I have no particular anticipation whether 4 the court will specify ONRW standards. 5 Q. One way or another, you don't know whether the 6 court will or will not? 7 MR. HARRISON: Same objection. 8 A. I cannot speculate what the court will do. 9 MR. HARRISON: Asked and answered three 10 times now, Counsel. It borders on badgering. 11 Q. Is it your understanding that the relief that 12 the United States seeks through this litigation 13 will impact the ONRW standards? 14 MR. HARRISON: Objection. Same grounds. 15 Same question by a different guise. Calls for 16 a legal conclusion, calls for speculation, 17 beyond this witness' basis of knowledge or 18 foundation. 19 A. I do not know whether any such relief would be 20 explicitly linked to ONRW. 21 Q. Do you anticipate that the court will need to 22 be informed about the scientific analyses you 23 have performed -- 24 MR. HARRISON: Objection. DEPOSITION OF WILLIAM W. WALKER, JR. 303 1 Q. -- in connection with the ONRW standards 2 setting process? 3 MR. HARRISON: Objection to any question 4 what Dr. Walker anticipates the court will do 5 or will need with respect to an outcome in this 6 litigation. It is completely an improper 7 question, Counsel, and you're wasting time. 8 Q. Can you answer my question? 9 A. No, I cannot. 10 Q. You have performed certain analyses, prepared 11 materials which relate specifically to the ONRW 12 standards process; isn't that correct? 13 A. That's correct. 14 Q. Did you perform those analyses and prepare 15 those materials with the anticipation that they 16 would be used as evidence in the litigation? 17 MR. HARRISON: I'm going to object, but 18 I'll let him answer it. I think you're moving 19 into attorney/client privilege. 20 A. The thought of whether or not these particular 21 materials would be used as evidence in the 22 litigation never -- never occurred to me. 23 MR. HARRISON: By "these materials," I 24 think that needs to be clarified. Are you DEPOSITION OF WILLIAM W. WALKER, JR. 304 1 talking about ONRW materials? 2 THE WITNESS: The materials I prepared 3 in conjunction with ONRW. 4 Q. Were there any other reasons Dr. Soukup gave 5 you for analyzing the Corps data in December of 6 1989? 7 A. Not to my recollection. 8 Q. Do you recall any reasons voiced by the Corps 9 of Army Engineers for this analysis? 10 A. No reasons, no. 11 Q. Didn't the Corps want to see its database used 12 in the ONRW standard process? 13 MR. HARRISON: Objection. Calls for 14 speculation. No foundation to show he would 15 know that. You have not laid a foundation. 16 But you may answer if you can. 17 A. I previously stated that one -- the reason for 18 this analysis was to examine the -- whether or 19 not the Corps data were appropriate for 20 inclusion in the process. 21 Q. Did the Corps have a position on that? 22 A. I did not speak to anyone at the Corps or have 23 any discussions with people at the Corps on 24 that topic. DEPOSITION OF WILLIAM W. WALKER, JR. 305 1 Q. Did you have discussions with anyone at the 2 Corps about the analysis of the Corps water 3 quality data? 4 A. I had contacts with people at the Corps 5 regarding obtaining the data for my analysis. 6 Q. You didn't discuss with anyone at the Corps the 7 reasons for performing the analysis? 8 MR. HARRISON: Asked and answered. 9 A. No. 10 Q. Have you discussed with anyone at the Corps 11 whether they would like to see their data used 12 in the ONRW standards? 13 MR. HARRISON: Asked and answered. 14 A. Would you repeat that question? 15 MS. AHEARN: Could you read it back, 16 please? 17 (The record was read as requested.) 18 A. No. 19 Q. Have you discussed with anyone at the Corps 20 whether they would like to see their data used 21 in conjunction with the litigation? 22 A. No. 23 Q. Have you discussed that with Dr. Soukup, 24 whether he would like to see you use the Corps DEPOSITION OF WILLIAM W. WALKER, JR. 306 1 data in conjunction with the litigation? 2 A. The discussion I had with Dr. Soukup was a 3 request for me to analyze the data and 4 determine whether or not it was valid to 5 include the data in setting ONRW standards. 6 Q. So from your answer I understand that you never 7 discussed with Dr. Soukup this other issue of 8 using the Corps data for litigation purposes? 9 MR. HARRISON: Objection. 10 Mischaracterization. 11 A. The discussion I had with Dr. Soukup regarding 12 this particular task was -- occurred in the 13 presence of attorneys, and it was a task that 14 was agreed among attorneys and Dr. Soukup and 15 myself, and I was asked to perform the 16 analysis. I can't separate objectives. 17 MR. HARRISON: The witness obviously 18 cannot go into Dr. Soukup's mind as to any 19 other reasons that were not directly 20 communicated to this witness. If he has a 21 mental impression from a meeting that included 22 attorneys, there is no way that you can 23 separate that mental impression from 24 attorney/client privilege. DEPOSITION OF WILLIAM W. WALKER, JR. 307 1 He has already told you what Dr. Soukup 2 told him the reasons were, and that's as far as 3 this needs to go where you are clearly getting 4 into the mental impressions of the attorneys as 5 to perhaps other reasons why we wanted this 6 data analyzed. But that is -- he has already 7 testified as to what Dr. Soukup told him, and 8 that's as far as this issue is going to go. 9 Q. Dr. Walker, on Exhibit 20 in the first line you 10 state that you have reviewed water quality data 11 collected by the Corps. When did that review 12 take place? 13 A. In the fall of 1989. 14 Q. When did you obtain that water quality data? 15 A. In the fall of 1989. 16 Q. Who provided that data to you? 17 A. The Corps of Engineers, Jacksonville district 18 office. 19 Q. Any particular individual there who you 20 contacted to obtain this data? 21 MR. HARRISON: If you recall, 22 Dr. Walker. Please don't speculate. 23 A. The person's name was Jim McAdams. 24 Q. Did you tell Mr. McAdams why you wanted the DEPOSITION OF WILLIAM W. WALKER, JR. 308 1 data? 2 A. I don't recall. 3 Q. Do you recall if you discussed with him what 4 you were going to do with the data? 5 A. I don't recall. 6 Q. The data which Mr. McAdams provided to you, was 7 that entered onto your computer after you 8 received it? 9 A. Yes. 10 Q. Is it the Corps data which you have identified 11 for us on page 27 of Exhibit 18? 12 A. Page 27 of Exhibit 18 contains the directory 13 G:\COE, which contains the water quality data 14 which I would have extracted from files 15 provided by the Corps of Engineers. 16 Q. Do you still have those original files you 17 received from the Corps? 18 A. Yes, I do. 19 Q. Were they produced in conjunction with this 20 deposition? 21 A. Yes, they were. 22 Q. What format are they in? 23 A. They are in the form of -- there may have been 24 some printouts that were included in the box DEPOSITION OF WILLIAM W. WALKER, JR. 309 1 that I supplied to the Justice Department as 2 well as there are some data files contained on 3 the floppy disks that I provided. 4 Q. At any other time did you obtain water quality 5 data for Park inflows from the Corps of Army 6 Engineers? 7 A. The only time that I recall receiving such data 8 was in the fall of 1989. 9 Q. From Mr. McAdams? 10 A. Correct. 11 Q. In the third sentence of Exhibit 20 you state 12 that you have focused exclusively on total 13 phosphorus. 14 Subsequently, have you looked at any 15 other parameters in the Corps water quality 16 data? 17 A. Not to my recollection. 18 Q. Would you have any reason at this time to 19 reject the Corps data for use with any 20 parameter other than total phosphorus? 21 MR. HARRISON: Objection. Foundation. 22 If he hasn't looked at it, how can he know what 23 to reject? 24 A. Reject for what purpose? DEPOSITION OF WILLIAM W. WALKER, JR. 310 1 Q. For the purpose of use in ONRW standards 2 setting. 3 A. I have not looked at other parameters. And the 4 other -- the other reason why I suspect that 5 the Corps data would not be appropriate is 6 because the stations are not appropriately 7 located, as is described in my letter of 8 December 11th, 1989. 9 Q. Other than the location of the stations, have 10 you other suspicions as to why you wouldn't 11 want to use the Corps data for other 12 parameters? 13 A. I have no suspicions. I have not analyzed the 14 other parameters. I have no opinion. 15 Q. Would you be able to render such an opinion 16 regarding potential use of the Corps data for 17 parameters other than total phosphorus for the 18 purpose of use in the litigation? 19 A. I can't speculate on whether I -- what I would 20 be able to say about the Corps data. 21 Q. Do you intend to be looking at the Corps data 22 further in conjunction with this litigation? 23 A. I don't know. 24 Q. And is that because an attorney hasn't yet told DEPOSITION OF WILLIAM W. WALKER, JR. 311 1 you? 2 MR. HARRISON: Objection. If he doesn't 3 know, he doesn't know. 4 Q. Is there a reason why you don't know whether 5 you'll use this data or not? 6 A. I don't know whether I will examine this data 7 further as part of the litigation or not. 8 Q. Now, in Paragraph 1 you state that the data are 9 adequate for determining compliance with the 10 existing MOA standard. Do you maintain that 11 opinion as of today? 12 A. The stations are inadequately located for 13 determining compliance at all of the ENP inflow 14 points. 15 Q. What are the locations specified in the MOA for 16 determination of compliance? 17 A. I don't recall exactly. 18 Q. As of December 11, 1989, had you had any 19 discussions with the District in terms of 20 revised standards they were considering for 21 Park inflows? 22 A. No. 23 Q. Had you had any discussions with the Department 24 of Environmental Regulation about standards DEPOSITION OF WILLIAM W. WALKER, JR. 312 1 that they were considering for Park inflows? 2 A. No. 3 MR. HARRISON: Counsel, just so it's 4 clear, are you talking about Park inflows 5 regardless of whether it's the litigation, 6 ONRW, the MOA, anything? Or were you focusing 7 still on the MOA? 8 MS. AHEARN: I'll ask more questions to 9 clarify that if you like. 10 MR. HARRISON: Well, thus far I took it 11 to mean it was in conjunction with the MOA 12 because it followed those questions. 13 Q. Dr. Walker, isn't it true that at this time 14 there is a Memorandum of Agreement dated in 15 1984 which specifies numeric standards for 16 water quality inflows to the Everglades 17 National Park? 18 MR. HARRISON: I object to the 19 characterization "MOA." You may answer. 20 A. Yes, I believe there is such an agreement. 21 Q. Are there other potential or revised standards 22 for inflows into Everglades Park that have been 23 considered over the last two years? 24 MR. HARRISON: I object to form. In any DEPOSITION OF WILLIAM W. WALKER, JR. 313 1 context, Counsel? Are we still dealing with 2 the MOA? 3 Q. We have MOA standards today, correct? 4 A. My answer is yes. 5 Q. Okay. There are some prospective standards 6 under consideration. What kinds of standards 7 are those that you're aware of? 8 A. The ONRW standards. 9 Q. Okay. Any other revised or potential standards 10 which you have discussed with other parties 11 interested in South Florida water quality? 12 MR. HARRISON: Counsel, I'm still going 13 to object. I don't know whether you're going 14 to the scientific number of the standard or the 15 legal nature of a standard, such as a state 16 water quality standard. 17 MS. AHEARN: How about a label on a 18 standard? You were concerned that my question 19 was vague because I wasn't discriminating among 20 types of standards. 21 MR. HARRISON: Okay. 22 MS. AHEARN: So I want to find out when 23 Dr. Walker uses particular terms, which of the 24 particular standards is he referring to. DEPOSITION OF WILLIAM W. WALKER, JR. 314 1 A. Could you repeat your question, please? 2 Q. Okay. You are aware of existing Memorandum of 3 Agreement standards and potential ONRW 4 standards, correct? 5 A. Correct. 6 Q. What other types of standards for water quality 7 inflows to Everglades National Park are you 8 aware of? 9 A. Those would be standards that are associated 10 with the federal remedy for the lawsuit. 11 Q. Any other types of standards that you're aware 12 of? 13 MR. HARRISON: Counsel, do you mean 14 standards specifically applying to the Park or 15 state standards which might apply to all 16 Class 3 waters? I mean, is this specifically 17 to the Park? 18 A. There may be others, but I'm unsure. 19 Q. Let me ask it this way: You have dealt with 20 MOA standards, potential ONRW standards and 21 potential standards that might be part of a 22 remedy through the litigation, correct? 23 A. I have not dealt with MOA standards. 24 Q. You are aware of their existence? DEPOSITION OF WILLIAM W. WALKER, JR. 315 1 A. Yes. 2 Q. And you have dealt with the other two types of 3 standards? 4 A. That's correct. 5 Q. Have you dealt with any other types of 6 standards for inflows to the Park? 7 A. I'm not sure what you mean by "types of 8 standards." 9 Q. Any other category of standards for total 10 phosphorus concentrations in inflows to the 11 Park. I mean, is there some alternative 12 program to ONRW? Is there a national 13 standard? 14 A. The only other one program that I recall is the 15 OFW program. 16 Q. Have you been involved in analysis and 17 development of OFW standards for the Park? I 18 don't mean these to be trick questions. I'm 19 just -- 20 A. It's hard to distinguish that from the other 21 standards. 22 Q. It probably is. I just want to make sure that 23 our terminology is clear, that we recognize 24 that you would refer to MOA standards, ONRW DEPOSITION OF WILLIAM W. WALKER, JR. 316 1 standards as those being -- that are discussed 2 in your meetings on behalf of the Park with the 3 District and DER and sometimes EPA, and then 4 another type of standard which might be part of 5 the litigation remedy. 6 A. Correct. 7 Q. When you refer to revised standards, are you 8 referring to that ONRW type of standard? 9 MR. HARRISON: Objection. I don't know 10 that it's been shown that he refers to revised 11 standards. 12 A. I'm not sure where the term "revised" comes 13 from. What are you referring to? 14 Q. Have you ever used that term? 15 A. I may have. 16 Q. As of December 11, 1989, had you discussed the 17 ONRW standards with anyone other than someone 18 affiliated with the federal government either 19 as an employee of the federal government or a 20 consultant on the South Florida litigation? 21 A. Not to my recollection. 22 Q. In Paragraph 1 here if you look down on the 23 fifth line, you talk about the revised 24 standards. Does that reference to the revised DEPOSITION OF WILLIAM W. WALKER, JR. 317 1 standards refer to the ONRW standards? 2 A. It could have referred to the ONRW standards 3 and/or to the standards that were referenced in 4 the -- I believe it was the first draft of the 5 SWIM plan. 6 Q. You don't know what you were referring to 7 there? 8 A. New standards for Park inflows were discussed 9 both in the draft of the SWIM plan and with 10 respect to the ONRW. I have trouble 11 distinguishing the two. 12 MR. HARRISON: Counsel, he is not an 13 attorney, and it's very easy for choices of 14 words to be used like "standards" or "revised 15 standards." But if you're going to be asking 16 him to compare the legal criteria of MOA 17 standards versus ENP inflows, it's beyond the 18 scope. 19 MS. AHEARN: I wasn't asking for a legal 20 explication, just a definition of the term he 21 used in his own writing. 22 MR. HARRISON: I think he's given you 23 that. 24 Q. Could you, please, turn to page 2 of DEPOSITION OF WILLIAM W. WALKER, JR. 318 1 Exhibit 20? At the bottom you state: 2 ...the Corps of Engineers could 3 provide potentially important data sets 4 independent of those provided by SFWMD 5 for tracking phosphorus concentrations 6 at Park inflows. 7 MR. HARRISON: I'm going to note that 8 that's not where the sentence began, that there 9 were some provisos and conditions attached to 10 that. 11 MS. AHEARN: Thank you. And I'll admit 12 that I read only part of that sentence. 13 Q. To your knowledge, is the Corps of Army 14 Engineers currently undertaking to do this? 15 A. You're referring to the sentence that says: 16 With future refinements to the 17 sampling program design and analytical 18 procedures, the Corps of Engineers could 19 provide potentially important data sets 20 independent of those provided by SFWMD 21 for tracking phosphorus concentrations 22 at Park inflows? 23 Q. Correct. 24 A. To my knowledge at this time there are no plans DEPOSITION OF WILLIAM W. WALKER, JR. 319 1 for that exercise. 2 Q. Are there any plans for any other federal 3 agency to undertake this exercise? 4 A. There have been no such programs that have been 5 designed to my knowledge. 6 Q. At the top of page 2, the first paragraph, the 7 second line you write: 8 I suggest that these values be 9 verified by referring to laboratory 10 records and field notes. 11 MR. HARRISON: Second line? That's 12 about the fourth -- 13 MS. AHEARN: Excuse me. Second 14 sentence. 15 Q. Has that been done? 16 A. I don't know. 17 Q. Have you obtained laboratory records and field 18 notes from the Corps? 19 A. No. 20 Q. Have you obtained laboratory records and field 21 notes from the District? 22 A. No. 23 Q. Have you reviewed such records and notes from 24 either the Corps or the District? DEPOSITION OF WILLIAM W. WALKER, JR. 320 1 A. I have not had access to them, and I have not 2 reviewed them. 3 Q. To your knowledge, has any other person working 4 on the South Florida litigation reviewed 5 laboratory records and field notes for the 6 Corps water quality monitoring? 7 A. I don't know. 8 Q. Do you know if anyone's done that for the 9 District water quality monitoring? 10 A. I don't know. 11 Q. How about for water quality monitoring 12 conducted by the National Park Service? 13 A. The Park Service does not conduct an 14 independent water quality monitoring program. 15 The Park Service collects samples that are 16 analyzed by the District. 17 Q. To your knowledge, has anyone reviewed the 18 laboratory records and field notes that reflect 19 the sampling effort that the Park does 20 undertake? 21 MR. HARRISON: You mean the laboratory 22 notes that are prepared by the Water Management 23 District on those -- 24 MS. AHEARN: That relate to samples DEPOSITION OF WILLIAM W. WALKER, JR. 321 1 collected by the Park. 2 MR. HARRISON: He just testified those 3 are performed by the Water Management District, 4 those analyses of those samples. 5 MS. AHEARN: That's fine. 6 Q. There are samples collected by the Park, 7 correct? 8 A. Correct. 9 Q. Have you looked at laboratory records and field 10 notes that relate to those samples? 11 MR. HARRISON: Is the question just 12 whether he is aware of whether someone else -- 13 what the Government in this case is reviewing, 14 those records? 15 A. I'm aware that Daniel Scheidt has 16 responsibility for running that monitoring 17 program. Whether he's looked at the records 18 and examined the field notes, I'm unaware. 19 Q. And you haven't done that, just so we make sure 20 this is clear -- 21 MR. HARRISON: Asked and answered. 22 Q. -- correct? 23 A. That's correct. 24 Q. Does the USGS collect water quality samples in DEPOSITION OF WILLIAM W. WALKER, JR. 322 1 South Florida? 2 A. Not currently to my knowledge. 3 Q. They did previously? 4 A. On occasion, yes. 5 Q. To your knowledge, has anyone working on the 6 South Florida litigation reviewed laboratory 7 records and field notes for the water quality 8 samples that USGS has collected? 9 A. Not to my knowledge. 10 Q. Are you aware of any other agencies that have 11 collected water quality samples within the 12 Everglades Agricultural Area, the Water 13 Conservation Areas and Everglades National 14 Park? 15 MR. HARRISON: Any other agency other 16 than what, Counsel? 17 MS. AHEARN: Than those that we have 18 just discussed in the last few prior questions. 19 MR. HARRISON: I object. I think it's 20 ambiguous. We have been talking about a lot of 21 agencies. 22 A. Are you talking about state or federal 23 agencies? 24 Q. Dr. Walker, is it accurate that the following DEPOSITION OF WILLIAM W. WALKER, JR. 323 1 agencies have collected water quality samples 2 within the Water Conservation Areas and the 3 Park, that geographic range, let's say from 4 1950 to present: the South Florida Water 5 Management District, Corps of Army Engineers, 6 USGS and the National Park Service? To your 7 knowledge, is that accurate? 8 MR. HARRISON: I'm going to object to 9 form. It's not clear whether you mean have 10 they all collected samples in all of those 11 areas or any of those areas. 12 Q. Within that geographic area I defined, anyplace 13 within that geographic area. 14 A. To my knowledge, sampling activities have been 15 undertaken by each of those agencies within 16 those broad geographic bounds. 17 Q. Are you aware of any entities, including 18 governmental agencies, that have collected 19 water quality samples within those geographic 20 bounds? 21 MR. HARRISON: Object to form. 22 "Entities" is not defined. Would that include 23 a single person, Counsel? 24 MS. AHEARN: It wouldn't unless that DEPOSITION OF WILLIAM W. WALKER, JR. 324 1 person is, for example, acting on behalf of a 2 university or a company that's doing a study. 3 MR. HARRISON: I object to form. 4 A. I'm totally confused as to what you're asking. 5 Q. All right. Well, thanks for letting me know. 6 Are you aware of any other water quality 7 samples that have been taken by anyone within 8 the geographic area we have described, the 9 Water Conservation Areas and Everglades 10 National Park? 11 A. Yes. 12 Q. Would you identify those persons and/or 13 entities which you are aware have taken those 14 types of samples within that geographic range? 15 A. Dr. Ronald Jones, the University of Florida. 16 There may have been some samples collected by 17 consulting firms. That's all that I can 18 recall. 19 Q. How about the Environmental Protection Agency? 20 A. I don't recall any sampling activities -- oh, 21 excuse me. I'm not sure whether the 22 Environmental Protection Agency has taken 23 samples for water quality. 24 Q. How about the Florida Department of DEPOSITION OF WILLIAM W. WALKER, JR. 325 1 Environmental Regulation? 2 A. I'm not aware that they have any routine 3 monitoring activity in that region. 4 Q. Are you aware of them taking any samples on a 5 nonroutine basis? 6 A. Not specifically. I don't recall. 7 Q. How about the Florida Sugar Cane League? 8 A. I believe that would have been included in my 9 category of consultants. 10 Q. Can you identify those consultants? 11 A. I believe Dr. Curtis Richardson, Duke 12 University, and possibly some other engineering 13 firms. 14 Q. How about the Fish and Wildlife Service? 15 A. I don't recall any routine monitoring activity 16 on their part. 17 Q. How about nonroutine water quality sampling? 18 A. I don't recall any. 19 Q. Have you used or relied upon the water quality 20 samples collected by Dr. Jones in any of the 21 work you have performed on behalf of the 22 Department of Justice? 23 A. No. 24 Q. Have you seen that data? DEPOSITION OF WILLIAM W. WALKER, JR. 326 1 A. No. 2 Q. How do you know that he's done this, collected 3 the samples? 4 A. From conversations with him. 5 Q. Direct conversations with Dr. Jones? 6 A. In the presence of attorneys when we were at 7 research planning meetings. 8 Q. Has he told you what his data show? 9 A. I don't recall specifically. 10 Q. Now, you identified the University of Florida. 11 Are there particular projects or researchers 12 there that you are aware of that have generated 13 water quality samples? 14 MS. NASH: Read back that question, 15 please? 16 (The record was read as requested.) 17 MR. HARRISON: Okay. You may answer. 18 A. There was a sampling program on rainfall 19 quality conducted by the University of Florida 20 in that region. 21 Q. Do you know the dates of that project? 22 A. Late 1970s. 23 Q. And do you know who conducted that project? 24 A. I believe it was Hendry and Brezonik. DEPOSITION OF WILLIAM W. WALKER, JR. 327 1 MR. BURGESS: I'm sorry? I couldn't 2 hear you. 3 THE WITNESS: Hendry, H-E-N-D-R-Y, and 4 Brezonik, B-R-E-Z-O-N-I-K. 5 Q. Both of those researchers are affiliated with 6 the University of Florida? 7 A. At the time that the sampling was done, I 8 believe so. 9 Q. Do you know where those two researchers are 10 working now? 11 A. I believe that Dr. Brezonik is at the 12 University of Minnesota. I do not know where 13 Mr. Hendry is located. 14 Q. Have you used or relied upon this water quality 15 data from the late seventies by Hendry and 16 Brezonik in your work on the South Florida 17 matter? 18 A. Not directly as yet. 19 Q. Do you intend to use or rely upon this data? 20 A. I may. 21 Q. Have you seen any water quality data from 22 Dr. Curtis Richardson? 23 A. Not that I recall, no. 24 Q. Why is it that you think he has collected such DEPOSITION OF WILLIAM W. WALKER, JR. 328 1 data? 2 A. Well, I am aware that he is conducting a 3 research project in the Water Conservation 4 Areas. 5 Q. And you presumed that that research project 6 would just naturally include water quality? 7 A. Would involve some water quality sampling. 8 Q. Have you seen any presentations by Dr. Curtis 9 Richardson concerning his research in South 10 Florida? 11 A. Yes. 12 Q. Is this a presentation you personally attended? 13 A. Yes. 14 Q. And when and where was that? 15 A. It would have been in the fall of 1989 at -- 16 the fall or summer of 1989 at the South Florida 17 Water Management District headquarters. 18 Q. Did you see presentations by other scientists 19 at that time? 20 A. At that same meeting? 21 Q. At that same meeting. 22 A. Yes. 23 Q. And what other scientists' presentations did 24 you observe? DEPOSITION OF WILLIAM W. WALKER, JR. 329 1 A. A presentation by Walt Dineen. That's all I 2 recall. 3 Q. Have you used or relied upon any of the 4 information presented during this presentation 5 at the District in your work on the South 6 Florida matter? 7 A. Those presentations provided me with general 8 background information. 9 Q. Have you looked at, considered any specific 10 data or conclusions presented during this 11 session? 12 A. No. 13 Q. Did you stay throughout the whole set of 14 proceedings at the District there that day? 15 (The witness gave no response.) 16 Q. I guess my question is: Did you just show up 17 for the Richardson and Dineen presentations, or 18 were you there and probably saw the 19 presentations, you just don't recall them? 20 MR. HARRISON: I'll let him answer if he 21 can, but no foundation laid that he knows when 22 the proceedings began or ended. 23 A. I did not stay for the entire day. 24 Q. Were there other presentations that you DEPOSITION OF WILLIAM W. WALKER, JR. 330 1 observed that you just can't recall right now? 2 MR. HARRISON: Objection. If he can't 3 recall, how does he know if he observed them? 4 A. Not that I remember. 5 Q. I just want it clear, it's not that there were 6 people, you just can't remember their names; 7 you just don't remember other presentations? 8 A. I don't recall whether there were other 9 presentations or whether I heard other 10 presentations, but those are the only two that 11 I remember. 12 Q. Okay. Thank you. 13 Dr. Walker, on Exhibit 20 would you, 14 please, turn to the second page of Enclosure 15 No. 1? Just so I'm clear, I don't see a 16 legend, what do the question marks that we see 17 to the right of the most right-hand column 18 signify? 19 A. Well, if you refer to page 1 of that same 20 exhibit, Item No. 3 on the bottom, it says 21 Enclosure 1 reveals two dates, February 23rd of 22 1987 and March 22nd of 1988, when reported 23 phosphorus concentrations were unusually high 24 at all stations. So those were particular DEPOSITION OF WILLIAM W. WALKER, JR. 331 1 observations that -- where the numbers were 2 generally higher than they were reported on the 3 other dates. And further in that paragraph 4 I suggested to Dr. Smith that those values be 5 checked by referring to field and laboratory 6 notes. 7 Q. Do the question marks denote that these are 8 potential outliers? 9 A. Possibly. 10 Q. An outlier is a number reported by the lab that 11 seems aberrant? Would that be an accurate 12 description of an outlier? 13 MR. HARRISON: Objection. It's not been 14 established whether the lab reports them as 15 outliers or whether somebody analyzing the 16 data. I think it's better just to ask, What is 17 an outlier? There's been no basis for your 18 characterization. 19 A. An outlier is a sample that is not 20 representative of the population that is 21 reportedly being sampled. 22 Q. So an outlier could be not representative 23 either because it's unusually high or because 24 it's unusually low, correct? DEPOSITION OF WILLIAM W. WALKER, JR. 332 1 A. That's correct. 2 Q. Have you identified any items in the Corps 3 water quality database that are potential 4 outliers because they may be inaccurately low? 5 A. Well, that would be very difficult because of 6 the very low or -- very low analytical 7 resolution of the Corps data. By "low," I mean 8 the detection limit is .01. There are several 9 values that are reported at or below .01. So 10 it would be impossible to identify outliers 11 that are low because of the low analytical 12 resolution. 13 Q. Those outliers may exist in the database, but 14 we don't have the technical ability to identify 15 them? 16 A. The resolution of the database is inadequate to 17 identify those values. 18 Q. If you were to find in a given database that a 19 particular percentage of data points could be 20 determined to be outliers because they're 21 overly high, does that suggest that you should 22 have caution about the number of outliers that 23 you cannot see because they're inordinately 24 low? DEPOSITION OF WILLIAM W. WALKER, JR. 333 1 MR. HARRISON: Objection to form. 2 A. That would depend upon how the data were being 3 used. 4 Q. If the data were being used to determine 5 whether a trend in water quality could be 6 detected in a five-year-period-of-record 7 database, would that be relevant for purposes 8 of looking for the existence of overly low 9 outliers? 10 MR. HARRISON: I object to form. 11 A. In examining data for trends, I would not use 12 statistical methods that are sensitive to 13 outliers. 14 Q. As a categorical matter in a trend analysis, 15 you would always use a technique insensitive to 16 outliers? 17 A. That's right. 18 Q. Are there any number of such techniques that 19 would be available to you? 20 A. There is an array of techniques. 21 Q. Could you identify those techniques? 22 A. Techniques for trend analysis, is that what 23 you're asking? 24 Q. Yes. DEPOSITION OF WILLIAM W. WALKER, JR. 334 1 A. The Seasonal Kendall test, which is the one 2 that I have used in Exhibit 17, is such a 3 technique. 4 Q. Are there others? 5 A. There are other techniques as well that are -- 6 that have been applied to analyzing data for 7 trends. 8 Q. Are those techniques also insensitive to 9 outliers? 10 A. Some of them are. 11 Q. Would you tell me which of those other 12 techniques which are insensitive to outliers? 13 Could you give me their identities? 14 MR. HARRISON: Which are not sensitive 15 to outliers? 16 MS. AHEARN: Yes. 17 A. They are generally any technique that is based 18 upon ranking of the data rather than on 19 absolute values. 20 Q. We have a test commonly referred to as the 21 Seasonal Kendall test. Are there other 22 commonly recognized names for these additional 23 techniques which are insensitive to outliers? 24 A. Spearman's rank correlation might be one. DEPOSITION OF WILLIAM W. WALKER, JR. 335 1 Q. Can you identify any others? 2 A. That's all I can recall. 3 Q. And then there are some additional techniques 4 that have been applied to do trend analyses 5 which you would characterize as being sensitive 6 to outliers? 7 A. There are other techniques that have greater 8 sensitivity to outliers, correct. 9 Q. Can you identify those techniques for me? 10 A. Those would be regression analysis, time series 11 analysis, t-tests. 12 Q. Can you think of any others? 13 A. Those are representative. 14 Q. Have you considered the use of each of these 15 techniques you have just identified for us in 16 your work on the South Florida matter for the 17 Department of Justice? 18 A. Yes, I have. 19 Q. Through that consideration are there any 20 techniques which you have decided not to use 21 after just a conceptual consideration of using 22 that technique? 23 A. In selecting the techniques that I have used in