1
1 Division of Administrative Hearings
2 Department of Administration, State of Florida
3 SUGAR CANE GROWERS COOPERATIVE )
of FLORIDA; ROTH FARMS, INC.; and, )
4 WEDGEWORTH FARMS, INC., )
Petitioners, )
5 V ) DOAH
SOUTH FLORIDA WATER MANAGEMENT ) Case 92-3038
6 DISTRICT, an agency of the State )
of Florida; et al., )
7 Respondents. )
FLORIDA SUGAR CANE LEAGUE, INC.; )
8 UNITED STATES SUGAR CORPORATION; )
and NEW HOPE SOUTH, INC., )
9 Petitioners, )
V ) DOAH
10 SOUTH FLORIDA WATER MANAGEMENT ) Case 92-3039
DISTRICT, an agency of the State )
11 of Florida; et al., )
Respondents. )
12 FLORIDA FRUIT and VEGETABLE )
ASSOCIATION; LEWIS POPE FARMS; )
13 W.E. SCHLECHTER & SONS, INC., )
and HUNDLEY FARMS, INC., )
14 Petitioners, )
V ) DOAH
15 SOUTH FLORIDA WATER MANAGEMENT ) Case 92-3040
DISTRICT, an agency of the State )
16 of Florida; et al., )
Respondents. )
17
18 Volume I
Deposition of Douglas Robson, Ph.D.
19
Taken before April Y. Sapp, Court Reporter
20 and Notary Public in and for the State of Florida at
large, pursuant to notice of taking deposition filed
21 by the Petitioners in the above cause.
- - -
22
Tuesday March 30, 1993
23 319 Clematis Street
West Palm Beach, Florida 33401
24 9:05 - 11:50 a.m.
1:05 - 5:10 p.m.
25 - - -
2
1 APPEARANCES:
2 On behalf of the Petitioners Florida Sugar
Cane League, Inc., United State Sugar Corp.,
3 and New South Hope, Inc.:
Peeples, Earl & Blank, P.A.
4 One Biscayne Tower, Suite 3636
Two South Biscayne Boulevard
5 Miami, Florida 33131
By: ROBERT H. BLANK, ESQUIRE
6
On behalf of the Respondent SFWMD:
7 Popham, Haik, Schnobrich & Kaufman, Ltd.
4000 International Place
8 100 S.E. Second Street
Miami, Florida 33131
9 By: DANIEL J. MCGRATH, ESQUIRE
10 On behalf of the Intervenor United States of America:
Assistant United States Attorney
11 Department of Justice
155 South Miami Avenue, Suite 627
12 Miami, Florida 33130-1693
By: THOMAS A.W. FITZGERALD, ESQUIRE
13
On behalf of the Sugar Cane Growers Cooperative,
14 Roth Farms, Inc. and Wedgeworth Farms, Inc.:
Hopping, Boyd, Green & Sams
15 123 South Calhoun Street
Tallahassee, Florida 32314
16 By: GARY V. PERKO, ESQUIRE
17 Also Present: Dr. James T. McClave
Dr. James Grimshaw
18
19 - - -
3
1 - - -
2 I N D E X
3 - - -
4
5 WITNESS: DIRECT CROSS REDIRECT RECROSS
6 Douglas Robson, Ph.D.
7
BY MR. PERKO 6
8
9
4
1 - - -
2 E X H I B I T S
3 - - -
4
5 NUMBER PAGE
6 EXB. NO. 1 27
7 Notice of taking Deposition Duces Tecum
8 EXB. NO. 2 32
9 Expert Witness & Consultant Designation
10 EXB. NO. 3 52
11 Draft on Derivation of Phosphorous 9-19-91
12 EXB. NO. 4 59
13 Phosphorous Limits for Lox. Wildlife Refuge
14 EXB. NO. 5 70
15 Handwritten paper by Robson
16 EXB. NO. 6 78
17 Letter to Federico
18 EXB. NO. 7 84
19 Analysis of Refuge phosphorous concentrations
20 EXB. NO. 8 93
21 Appendix E SWIM Plan
22 EXB. NO. 9 118
23 Comments on settlement agreement by Walker
24 EXB. NO. 10 122
25 Print out and graph
5
1 - - -
2 E X H I B I T S
3 - - -
4 NUMBER PAGE
5 EXB. NO. 11 123
6 Handwritten note by Robson
7 EXB. NO. 12 124
8 Calculations of Seasonal Kendall Test
9 EXB. NO. 13 125
10 Calculations of Seasonal Kendall Test
11 EXB. NO. 14 126
12 Vita of Robson
13
14
6
1 P R O C E E D I N G S
2 - - -
3 Thereupon,
4 Douglas Robson, Ph.D.,
5 being by the undersigned Notary Public first duly
6 sworn, was examined and testified as follows:
7 THE WITNESS: I do.
8 DIRECT (Douglas Robson, Ph.D.)
9 BY MR. PERKO:
10 Q. Please state your name and address for the
11 record.
12 A. Douglas Robson. 150 MacLaren Street,
13 Penthouse 6, Ottawa, Ontario.
14 Q. Dr. Robson, my name is Gary Perko. I'm an
15 attorney for the Sugar Cane Growers Cooperative, Roth
16 Farms and Wedgeworth Farms in the pending
17 administrative challenge of the Everglades SWIM Plan.
18 Have you ever been deposed before, sir?
19 A. Not in this case.
20 Q. Have you ever been deposed before?
21 A. Yes.
22 Q. How many times?
23 A. Just in one case, several depositions in
24 one case.
25 Q. What did that case involve?
7
1 A. It was a lawsuit by Alpo versus Ralston
2 Purina concerning misleading advertising.
3 Q. So it did not involve water quality?
4 A. No.
5 Q. So you are generally familiar with the
6 procedure here. I'll be asking you questions about
7 your expected testimony in this proceeding as well as
8 other knowledge you have of relevant facts. And I
9 have to caution you. I've only had six hours of
10 statistics, so if you don't understand my question,
11 please tell me and I'll try to rephrase it and if you
12 ever need a break, just let me know. We'll take a
13 few minutes, get some fresh air or drink of water or
14 whatever.
15 Dr. Robson, you've been listed as a
16 potential expert witness in this proceeding, is that
17 correct?
18 A. Yes.
19 Q. What is your understanding of your expected
20 testimony?
21 A. To review the statistical analyses that
22 were done by Walker.
23 Q. Done by William Walker?
24 A. Yes.
25 Q. What statistical analyses are you referring
8
1 to?
2 A. Analyses of the water quality and inflow to
3 the Park and water quality in the Refuge.
4 Q. Are you referring to the derivation of
5 phosphorous concentration levels for the Refuge and
6 phosphorus concentration limits for the Park that are
7 explained in Appendix E of the SWIM Plan?
8 A. Yes. I don't remember the Appendix E.
9 Q. But you are referring to the levels and
10 limits?
11 A. Yes.
12 Q. Have you reached final opinions that you
13 anticipate providing at final hearing in this matter?
14 A. Yes.
15 Q. And what are those opinions?
16 MR. MCGRATH: Gary, I have to just object
17 to the breadth of that question. That's
18 terribly over broad.
19 I'd also state on the record that, as far
20 as final opinions, it's my understanding that
21 there has yet to be anyone in this case whose
22 reached any final conclusions. We would then
23 state as of this moment it is not anticipated
24 that Dr. Robson would need to perform any
25 additional work. We would not want to preclude
9
1 the possibility, should the circumstances arise,
2 based on the incomplete work of all the other
3 experts to, you know, have Dr. Robson do some
4 additional analysis, so to the extent that he's --
5 Dr. Robson is saying his opinions are final, we
6 don't anticipate additional work at this time.
7 We don't want to preclude the need for
8 additional work should facts arise and the
9 analyses be done.
10 BY MR. PERKO:
11 Q. Dr. Robson, I'm just asking you what
12 opinions you've reached at this time. If you could
13 identify those for me that's what I'm interested in.
14 A. These are opinions concerning standards set
15 for the Park and for the Refuge.
16 Q. And what is your opinion of those
17 standards?
18 MR. MCGRATH: Again, let me object to the
19 over breadth. I don't know if, in this
20 particular instance, if that's a question that
21 can be answered just on its face. I mean if you
22 want to go through and find out what work he's
23 done, you know, having established that
24 foundation, based on the opinions, that might be
25 a better way to approach it.
10
1 Doctor, if you can answer the question as
2 stated please feel free. If you can't, then let
3 us know.
4 BY MR. PERKO:
5 Q. Can you answer the question, Dr. Robson?
6 A. I'm not sure what the -- what you are
7 referring to.
8 Q. You have reviewed the statistical methods
9 utilized in developing the limits for inflows to the
10 Park and Refuge, is that correct?
11 MR. MCGRATH: I would object to the form of
12 the question. It mischaracterizes his
13 testimony. I don't believe there's been any
14 testimony regarding how you phrased the
15 question, analysis of statistical methods.
16 MR. PERKO: I'm simply quoting what was
17 listed on the expert designation.
18 MR. MCGRATH: Ask him what's listed on the
19 expert witness designation.
20 BY MR. PERKO:
21 Q. Dr. Robson, have you reviewed the
22 statistical methods utilized to develop the
23 phosphorous concentration limits for inflows to the
24 Park and the Refuge?
25 A. I've reviewed the analyses.
11
1 Q. You have not -- are you saying that you
2 have not reviewed the statistical methods used for --
3 derived for those methods?
4 A. Statistical methods are standard methods.
5 I've reviewed the analyses.
6 Q. Is there a distinction between analyses and
7 statistical methods?
8 A. There's a distinction, yes. In reviewing
9 methods, I would say one would consider alternative
10 methods.
11 Q. Have you reviewed alternative methods for
12 setting phosphorus concentration limits for inflows
13 to the Park and Refuge?
14 A. No.
15 Q. Do you know if Dr. Walker did?
16 A. I know that he did many Seasonal Kendall
17 tests for trend.
18 Q. Any other statistical methods other than
19 those identified in the SWIM Plan?
20 MR. MCGRATH: I would just object to the
21 form of the question. I -- I don't particularly
22 understand what you are referring to.
23 BY MR. PERKO:
24 Q. Do you understand what I'm referring to
25 when I say the statistical methods identified in the
12
1 SWIM Plan for setting the phosphorous limits for the
2 Park and Refuge?
3 A. Vaguely.
4 Q. When you say you reviewed the analyses
5 utilized to develop the phosphorus concentration for
6 the inflows to the Park and Refuge what are you
7 referring to?
8 A. Referring to the regression analyses that
9 Walker performed.
10 Q. What is your opinion of those regression
11 analyses?
12 MR. MCGRATH: Opinion about what? Again,
13 I'm objecting.
14 BY MR. PERKO:
15 Q. Is it your opinion those regression
16 analyses are appropriate?
17 A. That was not really my role to decide
18 whether they were appropriate.
19 Q. What was your role?
20 A. To verify the numerical correctness of the
21 results.
22 Q. Is it fair to say that your role was
23 limited to determining whether to reduce the
24 calculations?
25 A. Essentially, yes.
13
1 Q. Do you have an opinion as to whether the
2 analyses performed by Dr. Walker are appropriate for
3 setting limits on the phosphorous inflows to the Park
4 and Refuge?
5 A. I am comfortable with his analyses, yes.
6 Q. When you say you are comfortable with the
7 analyses, what do you mean?
8 A. It indicates approval.
9 Q. Dr. Robson, are you currently under
10 contract with the District? By District I mean the
11 South Florida Water Management District.
12 A. Yes.
13 Q. When were you first contacted by the
14 District in this proceeding -- in connection with
15 this proceeding?
16 A. You mean the current contract or --
17 Q. The first time you were contacted.
18 MR. MCGRATH: I would need to object as far
19 as the vagueness of the question. I mean with
20 this proceeding are you referring to the
21 administrative proceeding presently ongoing?
22 BY MR. PERKO:
23 Q. When were you first contacted by the
24 District regarding statistical methods for analyzing
25 environmental data associated with the Everglades?
14
1 MR. MCGRATH: I just need to object to the
2 mischaracterization of Dr. Robson's role.
3 BY MR. PERKO:
4 Q. Dr. Robson --
5 MR. MCGRATH: He can answer the question.
6 I know what you are saying, but how you
7 said it, I needed to place an objection on the
8 record.
9 BY MR. PERKO:
10 Q. Dr. Robson, do you understand the question?
11 A. Not entirely because I was not first
12 contacted by the District. I was contacted by
13 Scadden, Arps.
14 Q. Who at Scadden, Arps first contacted you?
15 A. I can't remember the names.
16 Q. When were you first contacted?
17 A. It was in the fall of '89.
18 Q. What were you first asked to do by Scadden,
19 Arps?
20 A. I don't remember any specific instructions.
21 Q. Do you know why they contacted you?
22 A. I know they needed a statistician.
23 Q. Do you know why they needed a statistician?
24 MR. MCGRATH: Let me just object to the
25 form as a formality to the extent it encroaches
15
1 on work product of my client's former counsel,
2 as far as -- I mean Dr. Robson's free to testify
3 as to his understanding of his role at the time
4 he was initially contacted.
5 MR. PERKO: I'm only asking for
6 Dr. Robson's knowledge.
7 THE WITNESS: My understanding is that
8 because the other side had a statistician expert
9 on their team, that Scadden, Arps needed one
10 also.
11 BY MR. PERKO:
12 Q. Was that statistician expert Dr. Walker?
13 A. That was my understanding.
14 Q. By the other side, are you referring to the
15 United States?
16 A. Yes.
17 Q. Were you asked by Scadden, Arps to review
18 any work of Dr. Walker?
19 A. Not initially.
20 Q. When were you first asked to do something
21 by Scadden, Arps? What was the first task that you
22 were given by Scadden, Arps?
23 A. First task was to study some of the
24 background documents produced by the District.
25 Q. What background documents?
16
1 A. One I remember was authored by Swift.
2 MR. BLANK: Excuse me. I didn't hear the
3 answer.
4 MR. PERKO: Swift.
5 MR. MCGRATH: One of the documents was
6 authored by a Swift.
7 BY MR. PERKO:
8 Q. Is that regarding periphyton?
9 A. Right.
10 Q. Do you remember any other documents you
11 were asked to study?
12 A. I remember a document. I'm not sure that
13 it was presented to me at this time. It was a
14 document in which Tony Federico was one of the
15 authors.
16 Q. Do you remember what that document was
17 about?
18 A. No, I don't.
19 Q. Do you recall what the -- any other
20 documents that you may have reviewed at that time?
21 A. No.
22 Q. Did you review any of the work by
23 Dr. William Walker?
24 MR. MCGRATH: At what period of time?
25 BY MR. PERKO:
17
1 Q. How -- when did you first review
2 Dr. Walker's work?
3 A. Early 1990.
4 Q. What did you review at that time?
5 A. The one I remember is the Seasonal Kendall
6 Test.
7 Q. Was that an analysis of trends in inflows
8 to Everglades National Park?
9 A. Yes.
10 Q. Did you provide the District or Scadden,
11 Arps with any written comments regarding that work?
12 A. Not that I can recall.
13 Q. Would you have retained copies of those
14 written comments had you provided them?
15 A. Yes.
16 Q. Would you have produced them in connection
17 with this deposition?
18 A. Yes.
19 Q. What was your opinion of Dr. Walker's
20 Seasonal Kendall Test analysis?
21 A. The analysis was arithmetically correct.
22 Q. Did you have any opinion as to the analyses
23 that Dr. Walker chose to perform, the methodology?
24 A. The Seasonal Kendall Test was new to me at
25 that point in time.
18
1 Q. Does that mean you did not have an opinion
2 on it?
3 A. I developed an opinion.
4 Q. What was that opinion?
5 A. That there were problems with the Seasonal
6 Kendall Test.
7 Q. What problems?
8 A. There was a problem with serial correlation
9 which invalidates the size of the test.
10 Q. I'm sorry. I didn't hear the last part.
11 A. The size of the test.
12 MR. BLANK: Did you say invalidates the
13 size of the test?
14 THE WITNESS: Yes.
15 BY MR. PERKO:
16 Q. What do you mean by serial correlation?
17 A. Temporal correlation.
18 Q. How did that invalidate the size of the
19 test?
20 A. There is a published paper which I believe
21 I included in the material I provided you -- perhaps
22 not -- by the same authors that originally devised
23 the test and they demonstrated the impact of auto
24 correlation showing that it inflates the size of the
25 test.
19
1 Q. Do you recall the names of the authors of
2 that paper?
3 A. I remember one of the names was Hirsh.
4 Q. Do you recall what publication that
5 appeared in?
6 A. I'm not sure of the name of the journal.
7 Q. Do you remember the name of the paper?
8 A. No.
9 Q. Did you say no?
10 A. No.
11 Q. Did you have any other problems with
12 Dr. Walker's analysis of the inflows to Everglades
13 National Park?
14 A. Nothing serious.
15 Q. I take it that you did have other problems.
16 A. No two statisticians can agree on anything.
17 MR. FITZGERALD: We've noticed that.
18 BY MR. PERKO:
19 Q. Did you perform any analysis to correct the
20 problems with Walker's analysis?
21 A. Are you referring to any particular one?
22 Q. Yes. The problem with serial correlation
23 that you identified previously.
24 A. I did some simulations.
25 Q. What type of simulations did you do?
20
1 A. Generating synthetic data that incorporate
2 auto correlation and model misspecification.
3 Q. What were the results of your simulations?
4 A. Well, that these violations do, in effect,
5 destroy the validity of the test.
6 Q. Did you reanalyze the data that Dr. Walker
7 analyzed?
8 MR. MCGRATH: I just have to say I believe
9 he testified that he used synthetic data.
10 MR. PERKO: He may have testified to that.
11 I'm asking him a different question.
12 MR. MCGRATH: Okay. Excuse me.
13 THE WITNESS: Could you tell me which data
14 you are referring to?
15 BY MR. PERKO:
16 Q. The inflow data that Dr. Walker analyzed.
17 MR. MCGRATH: Let me just ask with respect --
18 are you still talking about the Seasonal Kendall
19 analysis?
20 MR. PERKO: Yes.
21 MR. MCGRATH: Okay.
22 THE WITNESS: My recollection is I checked
23 his calculations.
24 BY MR. PERKO:
25 Q. Did you reproduce his results?
21
1 A. That's my recollection, yes.
2 Q. Did you do any additional analyses of
3 Dr. Walker's work on the Seasonal Kendall Test?
4 A. I did some sort of back of the envelope
5 calculations at one point.
6 Q. Did you make any conclusions based on those
7 calculations?
8 A. I concluded that the Spearman correlation
9 was producing results very similar to the Seasonal
10 Kendall Test.
11 Q. The Spearman correlation?
12 A. Right.
13 Q. Is this a different analyses than the
14 Seasonal Kendall Test? The Spearman, I mean.
15 A. Slightly different, yes.
16 Q. To your knowledge, did anyone including
17 Dr. Walker, ever correct the problems with serial
18 correlation with this Kendall -- Seasonal Kendall
19 Test analysis?
20 A. No.
21 Q. Is it your -- is it still your opinion that
22 the serial correlation invalidates the size of the
23 test?
24 A. Yes.
25 Q. Do you have an opinion as to whether the
22
1 Spearman's correlation analysis is more appropriate
2 than the Seasonal Kendall Test?
3 A. I am undecided.
4 Q. What would you need to do to decide?
5 A. Examine the power of the two tests.
6 Q. Does the Spearman's correlation have any
7 serial correlation problem?
8 A. Yes.
9 Q. Same type of problem as with the Seasonal
10 Kendall Test?
11 A. Yes.
12 Q. Are you aware of any other type of analyses
13 that could be used to examine the trends and inflows
14 to Everglades National Park?
15 A. There are a number of non-parametric
16 analyses that are standard.
17 Q. Have you ever performed any of those
18 analyses?
19 A. Not on these data.
20 Q. Prior to February of 1991 did you review
21 any other work of Dr. Walker?
22 A. I don't recall the exact dates, but it was
23 around that time I did review documents he had
24 prepared for the Park.
25 Q. Let me back up for one second.
23
1 You stated that there are a number of
2 non-parametric analyses that could be used to examine
3 trans -- ENP inflows. Do any of these non-parametric
4 analyses not have a serial correlation problem?
5 A. Offhand, I can't think of any that would
6 circumvent that.
7 Q. Are you aware of any other methodology,
8 non-parametric or otherwise, that would not have a
9 serial correlation problem?
10 A. There are time series methods which attempt
11 to take into account serial correlation.
12 Q. Did you ever perform any of these time
13 series analysis?
14 A. No, I did not.
15 Q. Do you know if Dr. Walker did?
16 A. I don't know.
17 Q. You previously testified that sometime
18 around February 1991 you reviewed some additional
19 documents prepared by Dr. Walker for the Park, is
20 that correct?
21 A. Yes.
22 Q. What additional documents were you
23 referring to?
24 A. I recall one that dealt with exceedances.
25 Q. Exceedances of what?
24
1 A. As I recall, the document did not deal with
2 any specific data. It was a document concerning the
3 methodology.
4 Q. Methodology for setting limits?
5 A. Limits on exceedance, yes.
6 Q. I'm a little bit confused by your use of
7 the word, "exceedance." Exceedance of what?
8 A. In this case, it would be the frequency of
9 samples in which the concentration exceeded any
10 specified limit.
11 Q. That's the phosphorus concentration in
12 inflows to Everglades National Park?
13 A. That would be one application, yes.
14 Q. Could it also be applied to inflows to the
15 Loxahatchee National Wildlife Refuge?
16 A. I don't know the nature of that data.
17 Q. Do you know what specific concentrations
18 Dr. Walker performed or developed his exceedance
19 methodology for?
20 A. Initially, it was for a number of different
21 levels.
22 Q. Do you remember the levels?
23 A. No.
24 Q. Was 10 parts per billion one of the levels?
25 A. I don't know.
25
1 Q. Do you recall if 50 parts per billion was?
2 A. I don't recall.
3 Q. What methodology did Walker use for this
4 exceedance analysis?
5 A. Are you referring to this document that I
6 was --
7 Q. Yes.
8 A. The document, as I recall, utilized model,
9 a log normal model.
10 Q. Did you develop an opinion as to the
11 appropriateness of Dr. Walker's model?
12 MR. MCGRATH: With respect to that paper?
13 MR. PERKO: The same paper we've been
14 talking about for ten minutes, counsel.
15 THE WITNESS: I wouldn't call it
16 Dr. Walker's model. It's log normal
17 distributions. Nobody's in particular model.
18 BY MR. PERKO:
19 Q. Do you have -- did you develop an opinion
20 as to the appropriateness of that log normal model
21 for examining exceedances in ENP inflows?
22 A. The document I'm referring to didn't
23 address ENP data directly.
24 Q. Did this document have a title?
25 A. I'm sure it did.
26
1 Q. You don't recall what it was?
2 A. No.
3 MR. PERKO: Did you want to take a break,
4 Doctor?
5 THE WITNESS: Yes, please.
6 (Thereupon, a recess was taken.)
7 MR. PERKO: Back on the record.
8 BY MR. PERKO:
9 Q. Dr. Robson, before we took a little break,
10 we were discussing a paper that you reviewed by
11 Dr. Walker dealing with methodology for determining
12 exceedances. Did you provide any written comments on
13 that report?
14 A. No, I did not.
15 Q. You mentioned a couple of -- or additional
16 documents prepared by Dr. Walker that you reviewed
17 about that time period. Do you recall what those
18 documents were?
19 A. No, I don't recall.
20 Q. Do you recall what the subject matter of
21 those documents were?
22 A. The subject matter was setting standards.
23 Q. Approximately how many additional documents
24 were there?
25 A. One or two.
27
1 Q. Did you retain copies of the documents?
2 A. Yes.
3 Q. Did you produce them in connection with
4 this deposition?
5 A. I'm not sure that I did, since they were
6 not produced by me.
7 Q. Did you review the notice duces tecum for
8 your deposition?
9 A. Will you repeat the question?
10 Q. Did you review the notice of taking
11 deposition duces tecum for your deposition?
12 A. I think so, yes.
13 MR. PERKO: I'd like to mark this as an
14 exhibit.
15 (The document was marked Exb. No. 1.)
16 BY MR. PERKO:
17 Q. Doctor, I'm showing you what's been marked
18 as Exhibit Number 1. Do you recognize that document?
19 A. I'm not certain.
20 Q. Did you review a document request in
21 connection with this deposition?
22 A. Yes.
23 Q. Did you review it with counsel for the
24 District?
25 A. No.
28
1 Q. Did you have any discussions with counsel
2 for the District regarding the documents that you
3 were to produce in connection with this deposition?
4 MR. MCGRATH: Dr. Robson, as far as
5 discussions with the District and counsel for
6 the District, if you had discussions, please --
7 MR. PERKO: I'm just asking if he had
8 conversations. I'm not asking for any work
9 product or anything.
10 MR. MCGRATH: I'm instructing the witness
11 in case his answer goes further.
12 Right now he's just asking you if you had
13 discussions with counsel for the District
14 regarding the request to produce for your
15 deposition.
16 THE WITNESS: I had a telephone call.
17 BY MR. PERKO:
18 Q. How did you go about compiling responsive
19 documents?
20 A. I went through my, quote, files, unquote,
21 or, quote, piles, unquote.
22 Q. And how did you determine which documents
23 to produce?
24 A. I tried to produce all documents that
25 pertained to the -- this investigation. I should
29
1 point out that these piles included documents from
2 other projects of mine. My filing system is chaotic.
3 Q. Did you produce the reports that you
4 reviewed that were authored by Dr. Walker?
5 MR. MCGRATH: I think a more appropriate
6 question first would be: Did he have the
7 reports?
8 MR. PERKO: He's already testified to that,
9 counsel. He said he retained copies of the
10 documents that he reviewed.
11 THE WITNESS: I don't recall whether I
12 found them.
13 BY MR. PERKO:
14 Q. Did you specifically look for them?
15 A. Yes.
16 Q. Did you make any notes on the Walker
17 reports that you did review?
18 A. Not that I recall.
19 Q. Dr. Robson, you previously testified that
20 you were contacted by Scadden, Arps in the fall of
21 1989, is that correct? And we've talked about some
22 reports of Dr. Walker that you reviewed, including
23 his work on the Seasonal Kendall Test and a number of
24 documents that you have reviewed, approximately
25 February of 1991.
30
1 What else did you do for Scadden, Arps
2 prior to February 1991?
3 A. In December I attended a orientation
4 meeting here in West Palm.
5 Q. December of 1989?
6 A. Oh. Maybe I've got the year wrong, huh?
7 December '90. Let me think a minute. I must have
8 the year wrong.
9 Q. So is it -- are you correcting your
10 testimony that you were contacted in the fall of
11 1990?
12 Let me see if we can get through it another
13 way. How many contracts have you had with the
14 District or Scadden, Arps?
15 A. Two.
16 Q. Were those annual contracts?
17 A. I don't recall.
18 Q. Do you recall the terms of the first
19 contract?
20 A. You mean the time limits?
21 Q. Right.
22 A. No, I don't recall.
23 Q. Was that contract with Scadden, Arps?
24 A. No.
25 Q. Was it with the District?
31
1 A. Yes.
2 Q. Do you recall when you entered the second
3 contract?
4 A. It was mid 1991. I don't recall the exact
5 date.
6 Q. Had the first contract expired?
7 A. Well, I didn't -- I don't recall how long
8 that contract was for.
9 Q. Do you know why you entered a second
10 contract?
11 A. No, I don't.
12 Q. What did you contract -- with regard to the
13 first contract what did you contract to provide to
14 the District?
15 A. I was simply to serve as an expert witness.
16 Q. And this was in the federal lawsuit --
17 A. Right.
18 Q. -- brought by the United States against the
19 South Florida Water Management District --
20 A. Yes.
21 Q. -- and DER and others?
22 And what expert testimony did you
23 anticipate providing in that case?
24 MR. MCGRATH: Let me clarify. I think the
25 more appropriate question first would be to ask
32
1 him if he reached any opinions in this case and
2 that would seem to be the foundation for any
3 expert testimony that would have been expected.
4 MR. PERKO: Counsel, he testified that he
5 contracted to provide -- to serve as an expert
6 witness for the District.
7 MR. MCGRATH: You are right.
8 MR. PERKO: I assume if he was going to be
9 an expert witness he anticipated providing
10 testimony. I'm asking him what his
11 understanding of his anticipated testimony was.
12 THE WITNESS: At this point I can't recall
13 the terms of the contract in any detail.
14 MR. PERKO: I apologize. I didn't mean to --
15 first couple of exhibits I didn't provide
16 copies.
17 I'd like to mark this as Exhibit Number 2.
18 (The document was marked Exb. No. 2.)
19 BY MR. PERKO:
20 Q. Dr. Robson, I show you Exhibit Number 2 and
21 ask if you recognize that document?
22 MR. FITZGERALD: Counsel, since you don't
23 have copies of that, I would ask you to identify
24 it just for the rest of us.
25 MR. PERKO: Sure. It's the expert witness
33
1 designation of the South Florida Water
2 Management District in the federal suit.
3 MR. MCGRATH: Exhibit Number 2, let me just
4 read. It's case captioned United States of
5 America versus South Florida Water Management
6 District, case number 88-1886. This particular
7 pleading is titled, Designation by the
8 Defendants South Florida Water Management
9 District and Wodraska of Expert Witnesses and
10 Consultants.
11 BY MR. PERKO:
12 Q. Do you recognize that document?
13 A. Yes.
14 Q. Dr. Robson, I'll show you page 4, item #13,
15 which is the expert witness designation for Douglas
16 S. Robson. Does that refresh your recollection
17 regarding the anticipated expert testimony -- your
18 anticipated expert testimony in the federal suit?
19 A. Yes.
20 Q. What was that anticipated expert testimony?
21 A. It says, "Statistical analysis of
22 environmental data."
23 Q. Did you actually perform statistical
24 analysis of environmental data in preparation for
25 your testimony in the federal suit?
34
1 A. I don't recall whether I did under this
2 contract.
3 Q. Other than reviewing the Walker reports
4 that you've already testified about do you recall any
5 other work that you performed on behalf of the
6 District prior to February 1991?
7 A. No.
8 Q. Did you provide any written reports to the
9 District prior to February 1991?
10 A. No.
11 Q. Did you formulate any opinions regarding
12 statistical analysis of environmental data prior to
13 February 1991?
14 MR. MCGRATH: You are asking him if he
15 formulated opinions based on work he can't
16 remember doing?
17 MR. PERKO: No, counsel.
18 The question stands.
19 THE WITNESS: You are referring to
20 environmental data in general?
21 BY MR. PERKO:
22 Q. Environmental data in connection with the
23 federal lawsuit.
24 A. I had not formed firm opinions at that
25 stage.
35
1 Q. Had you formed any preliminary opinions?
2 A. I don't recall.
3 Q. Dr. Robson, you previously testified that
4 you reviewed -- early in 1990 that you reviewed the
5 work of Dr. Walker on the Seasonal Kendall Test for
6 ENP inflows and you were of the opinion that there
7 were problems with the Seasonal Kendall Test,
8 specifically with serial correlation.
9 MR. MCGRATH: Let me just object to the
10 form, because I don't think it's clear, the time
11 periods, so to the extent the question
12 mischaracterizes testimony, the record will
13 reflect what he said.
14 MR. PERKO: That's exactly right, counsel.
15 BY MR. PERKO:
16 Q. Did you agree with the conclusions of
17 Dr. Walker's report on the Seasonal Kendall Test?
18 A. What I agreed on was the correctness of the
19 calculations.
20 Q. Did you agree with the conclusions of the
21 report, that there was an increasing trend in
22 phosphorus inflows?
23 A. I had not formed a firm opinion at this
24 point.
25 Q. Have you since formed a firm opinion?
36
1 A. One that I already expressed that the
2 Seasonal Kendall Test has problems.
3 Q. Does that mean that you disagree with the
4 conclusions of the report?
5 A. No.
6 Q. Do you have any opinion as to the
7 conclusions, the correctness of the conclusions in
8 Dr. Walker's report?
9 A. I conclude that you cannot reach an
10 opinion -- reach a conclusion based upon the Seasonal
11 Kendall Test.
12 Q. And that is your opinion as you sit here
13 today?
14 A. Yes.
15 Q. Do you have an opinion as to whether
16 there's a more appropriate methodology for examining
17 trends in phosphorous inflows?
18 MR. MCGRATH: Asked and answered.
19 BY MR. PERKO:
20 Q. You can answer the question, Doctor.
21 A. You are referring to non-parametric
22 methods?
23 Q. Any methods.
24 A. Would you repeat the question again?
25 Q. Do you have an opinion as to whether there
37
1 are -- there is more appropriate methods than the
2 Seasonal Kendall Test methodology for examining
3 whether there are trends in phosphorus inflows to
4 Everglades National Park?
5 MR. FITZGERALD: Objection. Asked and
6 answered.
7 THE WITNESS: Yes.
8 BY MR. PERKO:
9 Q. What is that opinion?
10 A. That there are better methods.
11 Q. What methods are you referring to?
12 A. The method Walker ultimately used, the
13 regression method.
14 MR. FITZGERALD: I'm sorry. Doctor, I
15 couldn't hear the very last part of your answer.
16 THE WITNESS: The regression method.
17 BY MR. PERKO:
18 Q. Is that reflected in a report, the
19 regression method of Dr. Walker?
20 A. Yes.
21 Q. Do you recall the approximate date on that
22 report?
23 A. Oh. I thought you were referring to
24 Appendix E when you said report.
25 What report were you referring to?
38
1 Q. I asked if the regression method that
2 Dr. Walker ultimately used is reflected in that
3 report?
4 A. It's reflected in the Appendix E.
5 Q. Appendix E of the SWIM Plan?
6 A. If I have the letter correct, yes.
7 Q. Okay. Does the regression method that
8 Dr. Walker ultimately used have a serial correlation
9 problem?
10 A. Since he used annual averages, serial
11 correlation problem is a minor problem.
12 Q. Did you have any discussions with
13 Dr. Walker regarding appropriate method -- methods to
14 use, be they regression or Seasonal Kendall Test?
15 A. Not directly.
16 Q. When did you first learn that Dr. Walker
17 was using a regression method?
18 A. I'm not sure when I first learned it.
19 Q. Early 1991, perhaps?
20 A. Perhaps.
21 Q. Do you recall if that was -- let me first
22 ask: Are you aware that a stay was granted in the
23 federal suit in February of 1991?
24 A. No.
25 Q. Are you aware that settlement negotiations
39
1 started on or about February 1991 in the federal
2 suit?
3 A. No.
4 Q. Are you aware that settlement negotiations
5 occurred in early 1991?
6 A. What do you mean by early?
7 Q. Before June.
8 A. Yes.
9 Q. Did you have any involvement in those
10 settlement negotiations?
11 A. I attended some of the meetings.
12 Q. How many meetings did you attend?
13 A. I'm not sure.
14 Q. More than five?
15 A. I doubt it.
16 Q. Less than five?
17 A. Yes.
18 MR. FITZGERALD: To be technically correct
19 with a statistician you have to say less than or
20 equal to.
21 BY MR. PERKO:
22 Q. Do you remember when the first meeting you
23 attended was?
24 A. I have to look at my records.
25 Q. Do you have a calendar that indicates what
40
1 meetings you attended or any other records for that
2 matter?
3 A. I rely upon invoices that I sent in.
4 Q. How often do you send invoices to the
5 District?
6 A. At that time it was monthly.
7 Q. What was discussed at the first meeting
8 that you attended?
9 A. I can't remember what was discussed at the
10 individual meetings.
11 Q. What was discussed generally at the
12 meetings? Did you discuss phosphorus limits or
13 levels for the Park and Refuge?
14 A. Yes.
15 Q. Did you discuss different methodologies for
16 determining those limits or levels?
17 A. Briefly.
18 Q. Who did you discuss those methodologies
19 with?
20 MR. MCGRATH: I would just object to the
21 form of the question as stated. It would
22 indicate that the witness had those discussions.
23 BY MR. PERKO:
24 Q. Did you personally participate in any
25 discussions regarding the methodologies to set limits
41
1 or levels for the Park and Refuge?
2 A. That's what I meant when I said briefly.
3 Q. You participated in those discussions?
4 A. Yes.
5 Q. Who else participated in those discussions?
6 A. Bill Walker was present.
7 Q. Anyone else?
8 A. Federico, MacVicar and I don't remember the
9 names of these other people.
10 Q. Do you remember if Mark Maffei was one of
11 the participants?
12 A. What is his role?
13 Q. He's with the Loxahatchee National Wildlife
14 Refuge.
15 A. There were one or two people there from the
16 Refuge.
17 Q. But you don't remember their names?
18 A. No.
19 Q. Was anyone there on behalf of Everglades
20 National Park?
21 A. Yes.
22 Q. Do you remember who that was?
23 A. I don't remember the name.
24 Q. How many people were there on behalf of
25 Everglades National Park?
42
1 A. I believe there were two.
2 Q. I believe you testified that Mr. Federico
3 and Mr. MacVicar were there on behalf of the
4 District, is that correct?
5 A. Correct.
6 Q. Was there anyone else there on behalf of
7 District?
8 A. There were other people there, but I'm not
9 sure whether they represented the District or not.
10 Q. Do you recall who those other people were?
11 A. No.
12 Q. What methodologies did you briefly discuss
13 at that time?
14 A. The use of tolerance limits as a potential
15 alternative to confidence limits.
16 Q. Any other methodologies?
17 A. No.
18 Q. What methodology was ultimately chosen?
19 A. Confidence limits.
20 Q. Do you know why tolerance limits were
21 rejected?
22 A. I would have to guess. I'm reluctant to
23 guess.
24 Q. What is your understanding of why the
25 tolerance limits were rejected?
43
1 MR. MCGRATH: Doug, let me instruct you.
2 If you have an understanding that's based on
3 more than just guesswork or sheer speculation.
4 THE WITNESS: My understanding is that
5 there was a lack of familiarity and
6 understanding of the conceptive tolerance
7 limits.
8 BY MR. PERKO:
9 Q. Who ultimately calculated the levels and
10 limits for the Park and Refuge?
11 A. I'm having a problem with ultimately. They
12 were calculated a number of times along the way.
13 Q. Okay. Who first calculated the levels and
14 limits?
15 A. Walker.
16 Q. Do you know if anyone else calculated the
17 limits and levels?
18 A. I did.
19 Q. Did you use the same methodologies as
20 Dr. Walker?
21 A. Yes.
22 Q. Did you use any other methodologies other
23 than confidence limits to calculate levels or limits?
24 A. Not to calculate the limits, no.
25 Q. I take it you did use other methodologies
44
1 in some way.
2 A. Yes.
3 Q. What were the results of those analyses?
4 A. These were outlier analyses.
5 Q. Did you ever calculate limits or levels
6 using tolerance limits?
7 A. Not using real data, no.
8 Q. Using synthetic data?
9 A. Yes.
10 Q. Do you know if Dr. Walker ever calculated
11 limits or levels using tolerance limits?
12 A. I don't know.
13 Q. Do you know if Dr. Walker used any
14 methodologies other than the confidence limits to
15 calculate limits or levels?
16 A. I don't know.
17 Q. Approximately how many times did Dr. Walker
18 calculate limits or levels?
19 A. I can't say. I didn't see all of his
20 calculations.
21 Q. How about you -- how many times did you
22 calculate limits and levels?
23 A. Two or three times for the Park, I would
24 guess.
25 Q. Over what period of time?
45
1 A. May through August.
2 Q. Did you ever calculate limits for the Park?
3 Prior to May 1991 that is.
4 A. I may have.
5 Q. Did you ever calculate levels for the
6 Loxahatchee National Wildlife Refuge?
7 A. Yes.
8 Q. How many times?
9 A. I'm not sure.
10 Q. In the range of two to three or four?
11 A. Four I will say.
12 Q. Over the same period of time?
13 A. No. It would be the latter part of that
14 period.
15 Q. The latter part of May to August?
16 A. No. I guess it would be in late June,
17 July.
18 Q. Do you know when Dr. Walker first
19 calculated levels for the Loxahatchee?
20 A. I don't recall.
21 Q. Was it prior to June or July?
22 A. Yes.
23 Q. Did you -- during this time period,
24 February through July of 1991 did you review any
25 written reports or documents authored by Dr. Walker?
46
1 A. Is that period starting February 1 or end
2 of February?
3 Q. After the documents you previously talked
4 about.
5 A. In February I did review some documents
6 which were presented as exhibits at his deposition.
7 Q. Did you review any other documents authored
8 by Dr. Walker during that time period?
9 A. I don't recall any.
10 Q. Did you review Dr. Walker's calculations of
11 the limits and levels for the Park and Refuge?
12 MR. MCGRATH: In what period of time, that
13 February period?
14 BY MR. PERKO:
15 Q. I'm speaking now from February to July of
16 1991.
17 A. Yes.
18 Q. Do you recall approximately how many -- how
19 many series of calculations you reviewed of
20 Dr. Walker's?
21 A. I would have to guess again.
22 Q. Approximately how many?
23 A. Two or three.
24 Q. Okay. Did you review any other documents
25 authored by Dr. Walker during that time period?
47
1 A. I don't recall.
2 Q. Did anyone else besides you and Dr. Walker
3 calculate levels for the Loxahatchee or limits for
4 Everglades National Park?
5 A. I recall that somebody from the Refuge
6 checked calculations.
7 Q. Do you recall who that was?
8 A. No.
9 Q. Did they check your calculations?
10 A. I don't recall if it was mine or Walker's.
11 Q. They simply checked the calculations, they
12 didn't do any other -- is that correct?
13 A. That's correct.
14 Q. Did the actual limits and levels calculated
15 change during that time period?
16 MR. MCGRATH: Gary, do you mind if I have
17 that question read back? I don't know if I
18 caught it all.
19 MR. PERKO: That's fine.
20 Did the actual limits calculate change
21 during that time period?
22 MR. MCGRATH: Okay.
23 THE WITNESS: The calculated limits depend
24 upon which pieces of data are excluded.
25 BY MR. PERKO:
48
1 Q. But the equations themselves stayed the
2 same?
3 A. The models stayed the same.
4 Q. Were different data bases used to calculate
5 levels at different times?
6 A. To my knowledge the only difference was in
7 the matter of exclusion of data.
8 Q. Were different data excluded at different
9 periods of time?
10 A. Yes.
11 Q. Ultimately, 2 of the 16 stations were
12 excluded, is that correct?
13 A. Correct.
14 Q. Do you know if the levels or limits -- I'm
15 speaking of the Loxahatchee now -- do you know if the
16 Loxahatchee levels were ever calculated using all 16
17 stations?
18 A. I don't recall.
19 Q. Were the levels calculated different --
20 using different combinations of the 16 stations?
21 A. You mean subsets?
22 Q. Right, exactly.
23 A. Not to my knowledge.
24 Q. Just the 14?
25 A. Just the 14.
49
1 Q. Do you know why the two stations were
2 excluded?
3 A. That decision was not made by me, so I'm
4 not sure.
5 Q. Do you know who made the decision?
6 A. I don't know if it was one individual.
7 Q. Would Dr. Walker have had input into that
8 decision?
9 MR. FITZGERALD: Objection. Calls for
10 speculation.
11 THE WITNESS: Yes.
12 BY MR. PERKO:
13 Q. Anyone else to your knowledge?
14 A. No. I don't know who all had input into
15 it.
16 Q. Do you know why the two stations were
17 excluded?
18 MR. MCGRATH: That was asked, plus
19 answered.
20 MR. PERKO: I'm sorry. Strike that.
21 MR. BLANK: Counsel, I'm not sure it was
22 answered.
23 MR. MCGRATH: The answer was he didn't
24 know.
25 BY MR. PERKO:
50
1 Q. I'll ask it again just to make sure.
2 Do you know why the two stations were
3 excluded?
4 A. I don't know for certain.
5 Q. What is your understanding?
6 A. Which may be incorrect.
7 Q. I understand.
8 A. That the stations were infrequently
9 sampled.
10 Q. Anything else?
11 A. I would have to guess.
12 Q. In addition to the two stations that were
13 excluded there were two sampling dates that were
14 excluded, is that correct?
15 A. Correct.
16 Q. Do you know why those sampling dates were
17 excluded?
18 A. Again, this decision was not made by me.
19 Q. Would it have been the same people that
20 decided on excluding the two stations?
21 A. I would have to guess.
22 Q. What is your understanding of why the two
23 sampling dates were excluded?
24 A. Well, I misspoke before. It was the
25 frequency of sampling in these -- no. No. Sorry.
51
1 Sampling dates. Let me think a minute. No. Oh. I
2 recall. The stage was below the 15.12 feet.
3 MR. BLANK: I'm sorry. I didn't hear the
4 response. 15. what?
5 THE WITNESS: I said 15.12. I'm not sure
6 if I'm correct in that.
7 BY MR. PERKO:
8 Q. How was the minimum stage determined, do
9 you know that?
10 A. I don't know the details.
11 Q. From a statistical standpoint, do you agree
12 with the exclusion of the two stations and dates?
13 A. I have to rely on the judgment of the
14 subject matter experts in this issue.
15 Q. In what subject matter would you say that
16 decision was based on? Was it the result of a
17 statistical analysis or was it --
18 A. I recall that there was an analysis. I
19 wouldn't call it a statistical analysis, using a
20 model.
21 Q. Do you know who developed the model?
22 A. Pardon me?
23 Q. Do you know who developed the model?
24 A. I didn't hear you.
25 Q. Do you know who developed the model?
52
1 A. No, I don't.
2 Q. When you said that you would have to rely
3 on the experts in the subject matters, did you have
4 someone specific in mind?
5 A. Not some single individual, no.
6 Q. Do you have anyone in mind?
7 A. Yes. The representatives of the Park or
8 the Refuge and Bill Walker.
9 MR. MCGRATH: Gary, when you find a good
10 break point, do you mind if we take a short
11 break?
12 MR. PERKO: We can do it right now.
13 (Thereupon, a recess was taken.)
14 Mark this, please.
15 (The document was marked Exb. No. 3.)
16 BY MR. PERKO:
17 Q. Dr. Robson, I'm showing you what's been
18 marked as Exhibit Number 3. Do you recognize this
19 document?
20 A. Yes.
21 Q. And what is it?
22 A. Derivation of Phosphorus Limits for
23 Everglades National Park and Phosphorous Levels for
24 Loxahatchee National Wildlife Refuge dated August 19,
25 1991.
53
1 Q. That's a draft, correct?
2 A. Draft.
3 Q. Do you know who drafted this document?
4 A. I did. I did a first draft.
5 Q. Prior to this August 19th version?
6 A. Yes.
7 Q. Did you produce that first draft in
8 connection with this deposition?
9 A. Yes.
10 Q. Are there any substantive changes between
11 the first draft and this August 19th draft?
12 A. I would have to see that earlier draft to
13 answer that.
14 Q. Did anyone review your earlier draft?
15 A. I believe Walker did.
16 Q. Did he provide you with written comments?
17 A. I recall one page of written comments.
18 These were not provided to me by Walker. They were
19 provided to me by Federico.
20 Q. Were those written comments dated, do you
21 recall?
22 A. I don't recall.
23 Q. Do you remember the approximate time you
24 received those comments?
25 A. I couldn't --
54
1 Q. Would it have been in July, perhaps?
2 A. Perhaps.
3 Q. But you are not sure?
4 A. No.
5 Q. Did you produce those written comments in
6 connection with this deposition?
7 A. Yes.
8 Q. Did you actually develop the calculations
9 that are reflected in this draft document?
10 A. Yes.
11 Q. Did the -- to your knowledge, did the
12 calculations in the earlier draft differ from the
13 calculations included in this August 19th draft?
14 A. I don't believe so.
15 Q. These calculations for the Loxahatchee
16 phosphorous concentration levels exclude the two
17 stations and two sampling dates, is that correct?
18 A. Correct.
19 Q. Were you instructed to exclude these two
20 stations and dates?
21 A. Yes.
22 Q. By whom?
23 A. Federico.
24 Q. Let me ask you this. What were
25 Mr. Federico's instructions to you?
55
1 A. It would have been to drop those two dates
2 and stations.
3 Q. Okay. Who instructed you to draft this
4 document, Exhibit Number 3?
5 A. Federico.
6 Q. Did he give you any other instructions
7 other than telling you to draft it and exclude the
8 two stations and dates?
9 A. This draft was prepared after I had done
10 the analysis. His instructions to exclude were prior
11 to his instructions about the draft.
12 Q. Do you know when he instructed you to
13 exclude the two stations and dates?
14 A. July 5th.
15 Q. Did you ever question that instruction?
16 A. Not directly to him, no.
17 Q. Did you have any problems with the
18 instruction? Did you feel comfortable with it?
19 A. Yes.
20 Q. Why?
21 A. Because I had analyzed the data and
22 satisfied myself that these merited exclusion.
23 Q. Why did they merit exclusion?
24 A. The stations merited exclusion because of
25 the low sampling rate.
56
1 Q. What about -- I'm sorry. Go ahead.
2 A. The dates merited exclusion on the basis I
3 mentioned earlier, experts in subject matter
4 judgment.
5 Q. Did you do any statistical analysis to
6 determine that it was reasonable to exclude these
7 dates and stations or was that based on a qualitative
8 judgment of someone else?
9 A. The latter.
10 Q. I believe you previously testified that you
11 would rely on the judgment of representatives from
12 the Refuge as well as Dr. Walker, is that correct?
13 A. Correct.
14 Q. Did you receive any written comments from
15 anyone other than Dr. Walker on the draft of Appendix
16 E, Exhibit Number 3 or the earlier draft?
17 A. None that I recall.
18 Q. Are you familiar with the settlement
19 agreement that was entered into in the federal
20 lawsuit?
21 A. I think so, yes.
22 Q. Are the calculations used to derive the
23 limits and levels in the settlement agreement the
24 same as in Exhibit Number 3?
25 A. The calculations are the same. I believe
57
1 there was a minor change in the data base.
2 Q. What was the change in the data base?
3 A. At one point there was a change in one of
4 the phosphorus concentrations.
5 Q. Do you recall or could you tell from
6 Exhibit Number 3 and/or the settlement agreement what
7 change was made?
8 A. You couldn't tell.
9 Q. Do you know?
10 A. I just mentioned it.
11 Q. Okay. But you don't specifically know what
12 change was made?
13 A. Not offhand.
14 Q. Could you tell from looking at the
15 documents?
16 A. No.
17 Q. Why was that change made?
18 A. It was considered an erroneous datum.
19 Q. On what basis?
20 A. I'm not qualified to say.
21 Q. Did you do any work on the limits or levels
22 for the Park and Refuge after drafting Exhibit Number
23 3?
24 A. No.
25 Q. Have you performed any other work for the
58
1 District after drafting Exhibit Number 3 after August
2 1991?
3 A. All I can recall is attending the McClave
4 deposition.
5 Q. That was in December of 1992?
6 A. Yes. And phone conversation with
7 Fitzpatrick concerning another deposition.
8 Q. Do you mean Fitzgerald?
9 A. Fitzgerald. Sorry.
10 Q. What deposition was that concerning?
11 A. Millard.
12 Q. Did you attend the Millard deposition?
13 A. No.
14 Q. Did you provide Mr. Fitzgerald with any
15 areas of inquiry for the Millard deposition?
16 A. Yes.
17 Q. Do you recall specifically what those
18 inquiries were?
19 A. I don't recall the inquiries. I just
20 recall a table I prepared for him.
21 Q. What was that table concerning?
22 A. Concerned the frequency distribution of the
23 number of base year stations generated by the Millard
24 simulations.
25 Q. Did you reach any conclusions regarding the
59
1 Millard simulations?
2 A. Well, the conclusions were represented in
3 that frequency distribution that I presented.
4 Q. What were they?
5 A. That a substantial fraction of his
6 simulations included less than five base year dates.
7 Q. What's the significance of that conclusion?
8 A. That the simulations are not representative
9 of the data that were used.
10 Q. Have you done any additional work since the
11 McClave deposition?
12 A. Only in reviewing some of the documents
13 that I provided you.
14 Q. Did you review those documents in
15 preparation for this deposition?
16 A. Some of them, yes.
17 Q. Do you recall which documents you reviewed?
18 A. The one I have in hand, Exhibit 3.
19 Q. Any others?
20 A. The earlier draft.
21 MR. PERKO: Mark this, please.
22 (The document was marked Exb. No. 4.)
23 BY MR. PERKO:
24 Q. Dr. Robson, I show you what's been marked
25 as Exhibit 4. Do you recognize this document?
60
1 A. Yes.
2 Q. Is that the draft -- earlier draft that you
3 have been speaking of?
4 A. It's part of it.
5 Q. Part of it.
6 The part pertaining to phosphorus limits
7 for the Loxahatchee National Wildlife Refuge,
8 correct?
9 A. It is part of that part, yes.
10 Q. Okay. Let's see. Appears to be the only
11 part I received.
12 Dr. Robson, do you anticipate doing any
13 additional statistical analyses in preparation for
14 the final hearing in this matter?
15 A. No, I do not anticipate any.
16 MR. MCGRATH: Just for the record, that
17 goes with the caveat in the event that
18 circumstances arise, that will not preclude us
19 from doing so and, of course, given proper
20 notice if any additional work is done, but not
21 as of this date and time.
22 MR. BLANK: Can we take a short break?
23 MR. PERKO: Sure.
24 (Thereupon, a recess was taken.)
25 BY MR. PERKO:
61
1 Q. Dr. Robson, I'd like to refer you again to
2 Exhibit Number 3, which is the August 19, 1991 draft
3 of Appendix E. Whose calculations were ultimately
4 included in this draft, yours or William Walker's?
5 A. Mine. There is one of William Walker's
6 included.
7 Q. And which one is that?
8 A. It's on page 11.
9 Q. Could you read it into the record, please?
10 A. There are two formulas there for the
11 exceedance limit. One of them is based on my
12 calculations and the other on Walker's.
13 Q. Which one was based on your calculations?
14 A. I was just trying to recall. I would have
15 to check the settlement agreement to know which one
16 was mine and which one was Walker's.
17 Q. Whose calculations went into the settlement
18 agreement?
19 A. His with respect to this particular
20 formula.
21 Q. Okay. What about the other formulas?
22 A. For the Park, they're all Walker's. For
23 the Refuge, they're mine.
24 Q. Just so I understand your testimony, in the
25 August 19th draft of Appendix E, all the calculations
62
1 are yours except for one of the two relating to
2 exceedance formulas?
3 A. Correct.
4 Q. And in the settlement agreement all of the
5 calculations relating to the Park limits are
6 Dr. Walker's and all of the calculations relating to
7 Refuge levels are yours?
8 A. Correct.
9 Q. Are the calculations related to the Refuge
10 the same in the draft Appendix E as they are in the
11 settlement agreement?
12 A. Yes.
13 Q. What about the calculations related to the
14 Park? I assume there's differences.
15 A. There are small differences.
16 Q. Do you know what those differences are?
17 A. All of the equations are slightly
18 different. The coefficients are slightly different.
19 Q. Why are the coefficients different in the
20 draft Appendix E? Why didn't you use the same
21 coefficients?
22 A. My recollection is that one data point was
23 changed.
24 Q. Okay. It is fair to say that the
25 methodology is the same in Appendix E as it is in the
63
1 settlement agreement, the only difference is related
2 to that single datum change?
3 A. Yes.
4 Q. Dr. Robson, did you draft any portion of
5 the settlement agreement?
6 A. No.
7 Q. Do you know who drafted the provisions of
8 the settlement agreement relating to the ENP limits?
9 A. I would have to guess.
10 Q. Do you know who drafted the Refuge -- the
11 portions relating to the Refuge limits -- levels
12 rather?
13 A. Again, I'd have to guess.
14 Q. Who do you have in mind?
15 MR. FITZGERALD: Objection.
16 MR. MCGRATH: The question calls for
17 speculation. Either he knows or he doesn't
18 know.
19 BY MR. PERKO:
20 Q. You can answer the question, Doctor.
21 MR. FITZGERALD: Counsel, are you going to
22 persist in that question?
23 MR. PERKO: If he knows, if he has an
24 answer to the question I'd like to hear it.
25 MR. FITZGERALD: You are expressly going to
64
1 seek speculative answers from the witness?
2 MR. PERKO: I'll withdraw the question.
3 BY MR. PERKO:
4 Q. Dr. Robson, have you reviewed any of the
5 work of Dr. Walker relating to phosphorous uptake or
6 settling rates?
7 A. No.
8 Q. Do you plan to?
9 A. I have no plans to, no.
10 Q. Okay. Dr. Robson, what was the purpose of
11 setting limits -- or I'm sorry -- phosphorus
12 concentration levels for the Refuge?
13 A. I'm not qualified to say.
14 Q. When you set out to calculate levels, what
15 were you trying to do?
16 A. To calculate limits based on base year
17 conditions.
18 Q. And what was the base year?
19 A. It was the first year of record.
20 Q. 1979 -- '78-'79, rather?
21 A. Yes.
22 Q. Are you familiar with the 50 PPB discharge
23 concentration target included in the settlement
24 agreement?
25 A. I know there is such a limit. That's the
65
1 extent of my knowledge.
2 Q. Do you know how that was derived?
3 A. No, I don't.
4 Q. Were you present at any meetings during the
5 settlement negotiations in which the 50 PPB target
6 was discussed?
7 A. I don't recall any specific discussion.
8 Q. During the settlement negotiations did you
9 participate in any discussions on topics other than
10 the phosphorus concentration limits for the Park and
11 levels for the Refuge?
12 A. No.
13 Q. Is it fair to say that your input was
14 limited to that particular topic?
15 A. Yes.
16 Q. Did you ever correspond directly with
17 Dr. Walker during settlement negotiations?
18 A. No. Let me add, not to my knowledge, not
19 to my recollection.
20 MR. PERKO: I think we're at a good
21 breaking point for lunch.
22 MR. FITZGERALD: Fine with me.
23 (Thereupon, a recess was taken.)
24 BY MR. PERKO:
25 Q. Dr. Robson, just before we broke for lunch
66
1 I asked you about the purpose of setting the limits
2 for the Park and the levels for Refuge. I believe
3 you said the purpose was to set levels or limits
4 reflecting the conditions on the base line period --
5 A. Right.
6 Q. -- of 1978 through '79.
7 A. Right.
8 Q. Do you know why the '78 through '79 base
9 line period was selected?
10 A. I don't know. I thought it was dictated by --
11 again, I'm not sure -- OFW. I'm speaking out of
12 ignorance.
13 Q. So I take it you hadn't had any experience
14 applying the OFW rule before?
15 A. No.
16 Q. Now, in setting the levels for the Refuge,
17 the calculations used data outside the '78 through
18 '79 base period, is that correct?
19 A. Yes.
20 Q. If the goal is to set limits at the
21 conditions during the base period, why would you use
22 data outside the base period?
23 A. In order to improve the precision.
24 Q. What do you mean by the precision?
25 A. Magnitude of the standard area used in
67
1 calculating elements.
2 Q. Was there a concern that if only 1978
3 through '79 data were utilized that the magnitude of
4 the standard error would be too large?
5 A. Yes.
6 Q. At what threshold would you consider the
7 magnitude of standard error to be too large?
8 A. I wouldn't have a threshold.
9 Q. Do you know who determined or who decided
10 that data outside the '78 through '79 base period
11 should be utilized?
12 A. Again, it's my understanding that OFW rules
13 require us to utilize all available data.
14 Q. Did you utilize all available data?
15 A. I used all that was available to me.
16 Q. Okay. Who did you obtain the data from?
17 A. Kevin Rodberg.
18 Q. Is Rodberg, is he with the District?
19 A. Yes.
20 Q. Did you request specific data or did he
21 send you what was available?
22 A. He sent me. I didn't request anything
23 specific.
24 Q. Did you ever request additional data?
25 A. I don't recall that I did, no.
68
1 Q. Were you ever concerned that there was not
2 sufficient data to calculate these?
3 A. My understanding was that we were obliged
4 to use whatever data are available.
5 Q. Is it your opinion that the available data
6 was sufficient to calculate enforceable limits?
7 A. I'm not qualified to say on that.
8 Q. Why aren't you qualified?
9 A. For one thing, you said enforceable. I
10 don't know what's involved in the enforcement.
11 Q. Well, if I deleted the word enforceable,
12 would you have an opinion?
13 A. Would the question be -- read it again,
14 then.
15 Q. Do you have an opinion as to whether the
16 available data is sufficient to establish limits or
17 levels for the Refuge? And by that I mean
18 statistically reliable limits or levels.
19 A. I don't see it as a question of
20 reliability.
21 Q. Do you have questions about the sufficiency
22 of the data?
23 A. No.
24 Q. Did you ever express a concern to the
25 District or anyone else that there was insufficient
69
1 data to establish limits for the Refuge?
2 A. No, I did not.
3 Q. Once again, Dr. Robson, before we broke for
4 lunch, you testified regarding Dr. Walker's Seasonal
5 Kendall methodology for examining whether there's a
6 trend in phosphorous inflows to Everglades National
7 Park and I believe you testified that you cannot
8 reach a conclusion regarding trends based upon the
9 Seasonal Kendall Test, is that correct?
10 A. Yes.
11 Q. I believe you said that the regression
12 analysis would be a more appropriate methodology, is
13 that correct?
14 A. Yes.
15 Q. When -- let me ask you this. Does the
16 regression methodology indicate that there is a trend
17 in phosphorus inflows to Everglades National Park?
18 A. Yes.
19 Q. How would you describe that trend?
20 A. There's a significantly positive slope to
21 the regression.
22 Q. Do you know what that slope is?
23 A. No.
24 Q. Did you actually perform a regression
25 analysis to determine whether there was a trend?
70
1 A. Yes.
2 Q. Is that reflected in any of the documents
3 that you produced in connection with this deposition?
4 A. It's reflected in the standard of the
5 slopes.
6 Q. In Appendix E?
7 A. Yes.
8 Q. Who first proposed to use the regression
9 methodology?
10 A. I don't know.
11 Q. Referring you to Exhibit Number 3, the
12 draft Appendix E, could you identify for me the slope
13 to which you were referring to just a minute ago or
14 slopes?
15 A. On page 6 equation that says, "fitted TP as
16 11.8309 plus 5932." 5932 is the slope I'm referring
17 to.
18 Q. And that indicates a trend --
19 A. Yes.
20 Q. -- in phosphorus inflows?
21 MR. PERKO: Mark this, please.
22 (The document was marked Exb. No. 5.)
23 BY MR. PERKO:
24 Q. Dr. Robson, I'd like you to look at what's
25 been marked as Exhibit Number 5 to this deposition.
71
1 Could you tell me if you recognize that document?
2 A. I do.
3 Q. And what is this document?
4 A. This is a note which I sent to Federico
5 attempting to explain the concept of tolerance
6 limits.
7 Q. When did you send this note to Mr. Federico --
8 Dr. Federico?
9 A. March 26, '91.
10 Q. Did you send this letter before or after
11 you learned of the proposed use of regression
12 analysis?
13 A. After.
14 Q. Do you know if any limits or levels have
15 been calculated using the regression analysis before
16 you prepared this note?
17 A. By whom?
18 Q. Anyone.
19 A. Are you asking whether tolerance limits can
20 be applied in a regression context?
21 Q. No. No. No. I'm asking whether any
22 limits or levels had been calculated using the
23 regression approach before you drafted the note in
24 Exhibit 5?
25 A. Yes.
72
1 Q. By whom?
2 A. Walker.
3 Q. Had you critiqued those limits before you
4 wrote this note?
5 A. You mean prepare a written critique?
6 Q. Had you reviewed them at all?
7 A. I knew they existed and I knew what they
8 were. I had seen them.
9 Q. Did you prepare a written critique?
10 A. No.
11 Q. Did you provide any oral comments to
12 Dr. Walker or anyone else regarding those limits?
13 A. Other than --
14 MR. MCGRATH: At what point? Are we
15 talking before the drafting of the Exhibit 5?
16 MR. PERKO: Yes.
17 THE WITNESS: Other than my suggestion that
18 tolerance limits be considered as an
19 alternative.
20 BY MR. PERKO:
21 Q. None other than that, is that what you're
22 saying?
23 A. Right.
24 Q. Dr. Robson, I'd like to refer you to the
25 second full paragraph on page 1 of Exhibit Number 5.
73
1 A. Yes.
2 Q. About the middle of that paragraph it
3 states that, "We begin with the simulation of upper
4 tolerance levels since (to my mind) they are more
5 relevant to standard setting than are confidence
6 limits. This relevance derives from the fact that in
7 the standard setting mode of operation we have one
8 POR for calculating the upper limit followed by a
9 sequence of years of compliance checking."
10 Was this a true statement when you wrote it
11 in March of 1991?
12 A. Yes.
13 Q. Do you agree with it today?
14 A. Yes.
15 Q. What is the basis for that statement?
16 A. I think it's explained here in subsequent
17 pages.
18 Q. So you would simply refer to the document?
19 A. Yes.
20 Q. When you speak of confidence limits is that
21 essentially the regression approach?
22 A. Confidence limits is a very general
23 concept. It applies not only in regression but in a
24 variety of circumstances.
25 Q. Let me ask you this. Why did you write
74
1 this note?
2 MR. MCGRATH: Asked and answered.
3 BY MR. PERKO:
4 Q. You can answer the question.
5 A. Because at a meeting shortly before this I
6 had offered the suggestion that we consider tolerance
7 limits and the audience I was addressing didn't seem
8 to understand what tolerance limits constituted.
9 Q. Who was the audience that you were
10 addressing?
11 A. The ones I mentioned earlier, Federico,
12 MacVicar and --
13 Q. The ones you mentioned in connection with
14 the settlement agreement meeting?
15 A. Yes.
16 Q. Or settlement negotiation meeting?
17 A. Yes.
18 Q. Did you have concerns about the confidence
19 limit approach?
20 A. Well, concerns enough to mention the
21 consideration of this alternative.
22 Q. Dr. Robson, I refer you to page 3 at the
23 very bottom. States, "Since the 1978-'90 POR is now
24 history the SFWMD/ENP is locked into a row of either
25 table. The question therefore becomes: Knowing you
75
1 had to be locked into a randomly chosen row which
2 table (i.e., which upper limit procedure), would be
3 the more appropriate choice?"
4 Did you ever receive an answer to this
5 question?
6 A. Indirectly, no.
7 Q. Indirectly?
8 A. This was followed by some discussion with
9 Federico.
10 Q. And what did Mr. Federico say in those
11 discussions?
12 A. He asked me whether the confidence limit
13 could be interpreted as a tolerance limit --
14 Q. And what did you tell him?
15 A. -- at a certain level of confidence.
16 Q. What did you tell him?
17 A. I said yes.
18 Q. Did you have any other discussions with
19 Mr. Federico regarding tolerance limits?
20 A. No.
21 Q. Did you discuss anything else at the time
22 you discussed whether tolerance limits could be
23 interpreted in such a manner?
24 A. Not with Federico, no.
25 Q. Did you discuss it with anyone else?
76
1 A. I discussed it with George Shih.
2 Q. What did Mr. Shih say?
3 A. The concept was also new to him and he
4 expressed interest in it.
5 Q. At what level is the tolerance limit
6 equivalent to a confidence limit?
7 A. It's impossible to say in general.
8 Q. Dr. Robson, who ultimately decided on the
9 methodology to be used in calculating the levels for
10 the Refuge?
11 A. My understanding it was a group decision.
12 Q. Who was among the group?
13 A. The same people I mentioned earlier.
14 Q. Dr. Walker?
15 A. Yes.
16 Q. Mr. MacVicar?
17 A. Yes.
18 Q. Mr. Federico?
19 A. Yes.
20 Q. And others from the Park and Refuge?
21 A. Right.
22 Q. Were you among the group?
23 A. No.
24 Q. Is it your opinion, as you sit here today,
25 that the tolerance limit approach is more appropriate
77
1 than the confidence limit approach in establishing
2 limits?
3 A. Yes.
4 Q. What is the basis for that opinion?
5 A. Exhibit 5.
6 Q. Was the confidence limit approach
7 ultimately utilized to develop the limits for the
8 Refuge?
9 A. Yes.
10 Q. Did you ever -- I may have asked you this
11 question, but I want to make sure the record is
12 clear. Did you ever utilize the tolerance limit
13 approach to calculate levels for the Refuge or limits
14 for the Park?
15 A. I did some calculations but I think it was
16 with synthetic data rather than Park data.
17 Q. Is there any reason why you cannot use the
18 tolerance limit approach to calculate levels for the
19 Refuge or limits for the Park?
20 A. No.
21 Q. Do you know why the group that you referred
22 to previously rejected tolerance limits in favor of
23 confidence limits in establishing the limits of the
24 Park and Refuge?
25 MR. MCGRATH: That's been asked and it's
78
1 been answered.
2 THE WITNESS: I don't know why, no.
3 (The document was marked Exb. No. 6.)
4 BY MR. PERKO:
5 Q. Dr. Robson, if you could, direct your
6 attention to Exhibit Number 6 and I ask you if you
7 recognize this document?
8 A. Yes.
9 Q. What is that document?
10 A. It's a letter to Federico.
11 Q. Does this reflect your use of the tolerance
12 limit methodology?
13 A. I'm sorry. I was studying this. Would you
14 repeat?
15 Q. You previously mentioned that you used the
16 tolerance limit approach to calculate levels,
17 utilizing synthetic data, I believe you said.
18 A. That's what I said, yes.
19 Q. Does this document reflect that analysis
20 that you performed?
21 A. This document appears to use real data
22 rather than synthetic data.
23 Q. Did you prepare this document?
24 A. Yes.
25 Q. Did you -- does it utilize the tolerance
79
1 limit approach?
2 A. Yes, it does.
3 Q. Did you actually calculate levels for the
4 Refuge utilizing the tolerance limit approach?
5 A. Yes.
6 Q. And where does it reflect the results of
7 that analysis or does the document reflect the
8 results?
9 A. For the Refuge it appears at 614.
10 Q. That's bates page 0850614?
11 A. Yes.
12 Q. How do the limits reflected in this
13 document compare to those ultimately included in
14 Appendix E?
15 A. This analysis appears to have made no
16 attempt to incorporate the stage effect in the model
17 so there's a single tolerance limit.
18 Q. And what is the single tolerance limit?
19 A. Listed as 15.04 or 1411 depending on the
20 level of confidence.
21 Q. Could you use the tolerance limit approach
22 to establish limits and still incorporate stage into
23 the model?
24 A. Yes.
25 Q. Did you do that?
80
1 A. No.
2 Q. Dr. Robson, refer your attention to bates
3 pages 0850612 through 14. There's a discussion in
4 here regarding station effects, in particular, on
5 page 613.
6 MR. MCGRATH: Is there a question?
7 MR. PERKO: I'm sorry.
8 BY MR. PERKO:
9 Q. What does the discussion of station effects
10 on page 613 concern? What were you doing here?
11 A. Well, I was utilizing an additive model,
12 additive in a logarithmic scale --
13 Q. For what purpose? I'm sorry. Go ahead.
14 A. -- in which I incorporated three factors,
15 year effect, bimonth effect and station effect,
16 treating stations as fixed effects.
17 Q. And what did you conclude for station
18 effects?
19 A. They are listed, the estimates are listed
20 on page 613.
21 Q. Were the station effects significant?
22 A. A few were.
23 Q. Does Appendix E take station effects into
24 account for the Loxahatchee?
25 A. It does in the outlier analysis.
81
1 Q. How does it take station effects into
2 account in the outlier analysis?
3 A. I can't be sure looking at these tables.
4 Q. How are station -- how, if at all, are
5 station effects taken into account in the actual
6 setting of the limits in Appendix E?
7 A. The data are averaged across stations.
8 Q. Why were the data averaged across the
9 station?
10 A. In order to produce an index which is
11 non-specific to station.
12 Q. Why did you want to produce an index that
13 was non-specific to station?
14 A. It wasn't me who wanted to, but it would
15 otherwise require setting limits individually for
16 each station.
17 Q. Do you lose any information regarding
18 variability from station to station when you average
19 data across the stations?
20 A. You would lose an interaction effect.
21 Q. What effect would that have on the limits
22 themselves? Would it raise them or lower them?
23 A. The limit on the average across stations
24 would be considerably less than the limit on an
25 individual station.
82
1 Q. Given the fact that in Exhibit Number 6 you
2 determined that at least some -- that their station
3 effects were significant for at least some of the
4 stations, did you have concerns about averaging
5 across the stations?
6 A. No.
7 Q. Why not?
8 A. For the reason I just cited.
9 Q. Because you were seeking to produce an
10 index that was non-specific to station?
11 A. Yes.
12 Q. Could a model with station effects
13 incorporated have been used to set a limit for the
14 average station?
15 MR. MCGRATH: Just want to object to the
16 extent it calls for speculation.
17 THE WITNESS: Could be done, yes.
18 BY MR. PERKO:
19 Q. Did you ever, in fact, utilize such a
20 model?
21 A. Not for setting confidence limits, no.
22 Q. For setting tolerance limits?
23 A. I would have to look.
24 Q. Direct your attention to page 614 to help
25 refresh your recollection.
83
1 A. If I remember the question, the answer is
2 yes.
3 Q. You did --
4 A. I did utilize stations in this.
5 Q. In the tolerance limits reflected in
6 Exhibit Number 6?
7 A. Yes.
8 Q. In your opinion, as a statistician, is it
9 more appropriate to incorporate station effects into
10 the model before averaging or to average before you
11 set the limits?
12 A. It depends.
13 Q. What does it depend on?
14 A. There's a problem here of spatial auto
15 correlation.
16 Q. What is the problem with spatial
17 correlation?
18 A. In this tolerance limit analysis I ignored
19 the issue of say neighboring stations being
20 positively correlated.
21 Q. Is it your opinion that averaging solves
22 the spatial correlation problem?
23 A. Yes.
24 Q. How so?
25 A. The effect of the spatial correlation is
84
1 automatically incorporated into the estimate for
2 standard error.
3 MR. PERKO: Mark this as Exhibit 7, please.
4 (The document was marked Exb. No. 7.)
5 BY MR. PERKO:
6 Q. Dr. Robson, if you would, please direct
7 your attention to Exhibit Number 17 and tell me if
8 you recognize this document.
9 MR. BLANK: Exhibit 7.
10 MR. FITZGERALD: Exhibit 7.
11 BY MR. PERKO:
12 Q. I'm sorry. 7.
13 A. Yes.
14 Q. What is that document?
15 A. This is an analysis of the Refuge
16 phosphorus concentrations --
17 Q. What does this analysis -- go ahead.
18 A. -- using a linear model which incorporated
19 a dummy model for base year, a dummy variable for
20 stations and stage.
21 Q. What do you mean by the term, "dummy
22 variable"?
23 A. Variable that takes on values 1 or 0 where
24 the 1 indicates the date falls in a base year and the
25 0 indicates that it's not in the base year.
85
1 Q. Did you actually utilize the model
2 reflected in Exhibit Number 7 to develop limits
3 for -- or levels for the Loxahatchee?
4 A. No.
5 Q. Why not?
6 A. Maybe I misspoke. This does calculate
7 limits right here.
8 Q. Okay. You're referring to the table
9 underneath the heading, Example of 90 Percent
10 Confidence Limits?
11 A. Yes. Yes.
12 Q. Does this exhibit provide an example of a
13 model that determines confidence limits taking into
14 account station effects?
15 A. Yes.
16 Q. Were you still considering the use of
17 tolerance levels when you drafted this document in
18 June 1991?
19 A. I don't believe so.
20 Q. Why had you foregone the use of tolerance
21 levels by that point -- tolerance limits?
22 A. I agreed to go along with the idea that
23 confidence limits do represent tolerance limits at
24 some unknown level of confidence.
25 Q. Why had you agreed to go along with that
86
1 assumption?
2 A. Because the people that I was dealing with
3 were not familiar with the concept.
4 Q. Were you instructed to adopt that
5 assumption by the District?
6 A. I wouldn't say I was instructed to. I
7 agreed to.
8 Q. Okay. Dr. Robson, in your opinion, as a
9 statistician, do you -- is it your opinion that the
10 model reflected in Exhibit Number 7 is more
11 appropriate than the models in Appendix E?
12 MR. MCGRATH: Let me just raise an
13 objection for the record to the series of "more
14 appropriate" questions that have been asked,
15 just so -- as much as they're misleading and
16 ambiguous and may incorrectly or improperly
17 suggest that, while something in Dr. Robson's
18 opinion may be more appropriate, that models or
19 methods actually used are not appropriate. So
20 just to the extent that when we are having these
21 "more appropriate" questions, I object to the
22 question.
23 BY MR. PERKO:
24 Q. Do you understand the question?
25 A. Could you repeat it?
87
1 Q. From a statistical standpoint is it your
2 opinion that the model reflected in Exhibit Number 7
3 is more appropriate than the model used to develop
4 the levels for the Refuge in Appendix E?
5 A. No. I would still be concerned about the
6 effect of this spatial correlation.
7 Q. Did you ever calculate the spatial
8 correlation?
9 A. No.
10 Q. Do you know if anyone else did?
11 A. I don't know.
12 Q. Dr. Robson, you have indicated that in
13 various models you looked at station effects, stage
14 and base years. Did you consider any other
15 parameters in developing models for the Loxahatchee
16 levels?
17 A. One of these documents include a bimonth
18 effect.
19 Q. Any other parameters?
20 A. No.
21 Q. Did you ever try to determine whether there
22 was a correlation between phosphorous inflows to the
23 Loxahatchee and interior marsh concentrations?
24 A. No.
25 Q. Do you know if anyone else has tried to
88
1 determine that, if there's such a correlation?
2 A. Yes.
3 Q. Who?
4 A. McClave.
5 Q. Anyone else?
6 A. I don't know.
7 Q. Dr. Robson, is it your understanding that
8 the interim and long term levels for the Refuge are
9 ultimately going to be used to regulate inflows to
10 the Loxahatchee?
11 A. That's my understanding today.
12 Q. Given that understanding, do you think it's
13 important to know if there's a correlation between
14 inflows and interior marsh concentrations?
15 A. Yes, but.
16 MR. BLANK: I'm sorry. I didn't hear the
17 answer.
18 THE WITNESS: Yes, but.
19 BY MR. PERKO:
20 Q. Why are you qualifying your answer?
21 A. Because I wouldn't know what antecedent
22 period to use.
23 Q. Could you -- I'm not sure I understand why
24 would that be a concern of yours, an antecedent
25 period.
89
1 A. Well, the concentration in the marsh today
2 is related to inflow of some previous period, not
3 today's inflow.
4 Q. Okay. Do you have any intention of
5 determining whether there's a correlation between
6 inflows into the Refuge and interior marsh
7 concentrations?
8 A. No.
9 Q. Do you know if anyone else plans to look at
10 that?
11 A. I don't know.
12 Q. Dr. Robson, how is stage incorporated into
13 the models used to set the limits for the
14 Loxahatchee?
15 A. As a independent variable in linear
16 regression.
17 Q. Is it fair to say that the model predicts a
18 relationship between stage and concentration?
19 A. Yes.
20 Q. What stage data are utilized in the model?
21 A. There were three gauges. Offhand, I don't
22 know how they are identified.
23 Q. I'm sorry?
24 A. Offhand, I don't know how they are
25 identified, but there are three gauges involved.
90
1 Q. They are identified in Appendix E?
2 A. Yes. CA1-7, 9.
3 Q. What page --
4 A. CA1-7, 9 and 8C. Page 18.
5 Q. Is it your opinion, Dr. Robson, that these
6 three gauge stations are representative of stage
7 throughout the Loxahatchee National Wildlife Refuge?
8 A. I wouldn't know.
9 Q. Do you think it's important to determine
10 whether these stations are representative?
11 A. It would be desirable to know.
12 Q. And why is that?
13 A. Well, these are being used as an index, the
14 water level in the Refuge. It would be desirable to
15 have them interspersed among the stations.
16 Q. Dr. Robson, on page 18 of Exhibit 3 which
17 is the draft Appendix E, states that, "The POR data
18 includes stage measurement at the three marsh gauges
19 CA1-7, 9 and 8C on each sampling date and average of
20 these three readings is taken as index of stage for
21 the marsh on that date."
22 Why did you average across these three
23 gauge stations?
24 A. To produce a single number which is an
25 index.
91
1 Q. Could you develop a model that uses
2 individual stage values rather than the average?
3 A. You mean a model to determine limits?
4 Q. Yes, sir.
5 A. Are you suggesting a limit for each stage,
6 each gauge?
7 Q. Well, first of all, could you use such a
8 model to develop a -- the type of limits that are
9 explained in Appendix E?
10 A. Well, ultimately I would somehow have to
11 average over the station -- over the gauges,
12 otherwise you have gauge specific limit.
13 Q. Do you lose any information by averaging
14 across the gauge stations?
15 A. Any information you lose I'm not sure how I
16 could exploit it to begin with.
17 Q. Let me ask you this. What effect would --
18 does averaging across the three stations have on the
19 limits?
20 A. As compared to what?
21 Q. Would it -- do you know if the limits would
22 be higher or lower if you did not average across the
23 stations?
24 A. No, I don't know.
25 Q. Dr. Robson, Appendix E establishes a
92
1 threshold stage of 15.42 feet, is that correct?
2 A. Yes.
3 Q. And below -- any reading below that value
4 is -- compliance isn't determined whenever there's a
5 reading below that value, is that right?
6 A. I think so.
7 Q. I believe you previously testified -- I
8 think you spoke about a 15.12 threshold value. Were
9 you referring to this 15.42?
10 A. Yes, I was.
11 Q. I believe you stated that was based on
12 qualitative judgment of others --
13 A. Right.
14 Q. -- is that correct?
15 Was that judgment -- let me refer you to
16 Appendix III of Exhibit Number 3 page -- I believe it
17 is 18.
18 A. 48.
19 Q. 48. I'