Chevron Case: Re 25 - Public - Short Expert Report (nov. 7, 2014)

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1.0 INTRODUCTION
This Supplemental Expert Report responds to comments of Claimants, Chevron
Corporation and Texaco Petroleum Company (hereafter collectively, Chevron), on
my opinions contained in the Rejoinder Expert Report of Jeffrey W. Short, Ph.D.
Regarding Activities and Environmental Conditions in the Former Texaco‐
Petroecuador Concession, Republic of Ecuador (hereafter Short December 2013
Rejoinder Report).
I reaffirm my opinions expressed in my December 2013 Rejoinder Report, and
provide additional evidence to support these opinions in this Supplemental Expert
Report. In addition, I offer here supplemental opinions to address issues raised in
the three rebuttal documents filed by Chevron listed above.
* * * *
2.0 MATERIALS REVIEWED
I have been retained by the Louis Berger Group, Inc. (hereafter Louis Berger) to review
and comment on the above Chevron documents. I have also been retained to interpret
data from the chemical analysis of soil, sediment and water samples collected by Louis
Berger from oil contaminated sites in Chevron’s former Concession Area during the
spring and summer of 2014. In preparation of this Supplemental Expert Report, I have
reviewed the following:
 Expert Opinion of John A. Connor, P.E., P.G., B.C.E.E. Regarding Remediation
Activities and Environmental Conditions in the Former Petroecuador – Texaco
Concession, Oriente Region, Ecuador, Response to LBG Report of December
2013, Issued 7 May 2014 (hereafter Connor May 2014 Response Report),
 Second Expert Report by Robert E. Hinchee, Ph.D., P.E., Issued 9 May 2014
(hereafter Hinchee May 2014 Response Report),
 The Matter of An Arbitration Under the Rules of the United Nations on
International Trade law; Chevron Corporation and Texaco Petroleum
Company, Claimants, v. The Republic of Ecuador, Respondent, Claimants’
Supplemental Memorial, Track 2, Issued 9 May 2014 (hereafter Claimants’ May
2014 Supplemental Memorial),
 Louis Berger’s Supplemental Expert Report, Issued 7 November 2014,

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 Preliminary results1 of chemical analyses for hydrocarbons produced by Axys
Laboratory, Katahdin Laboratory, and Battelle Memorial Institute provided to me
by Louis Berger,
 all scientific literature and deposition documents cited herein,
 numerous chemical analysis reports produced by Dr. Gregory Douglas at
Newfields Environmental Forensics Practice, and associated chemical analysis
reports produced by Alpha Woods Hole Group and Severn Trent Laboratories.
I am currently an independent consultant and have never been an employee of Louis
Berger or of Winston & Strawn LLP.
My opinions in this expert report are given to a reasonable degree of scientific certainty.
They are based on my education, professional experience, information and data available
in the scientific literature, and information and data about this lawsuit identified herein
and in my earlier report.
I continue to review available information, and I reserve the right to amend or
supplement this report and the opinions contained in this report on the basis of any
subsequently obtained material information.
* * * *
3. SUMMARY OF SUPPLEMENTAL OPINIONS
3.1 Results from Louis Berger’s Sampling in 2014 Confirm My Previously
Expressed Opinions:
 Measurement of total petroleum hydrocarbons by Method 8015B – the
method employed and relied upon by Claimants’ experts ‐ detects less than
20% of the petroleum actually present in contaminated soils and sediments
in former Concession Area oil fields.
 US EPA Method 418.1 was much more accurate for determining the extent of
petroleum hydrocarbon contamination in former Concession Area oil fields
than was Method 8015B.
 The weathering state of petroleum in samples collected in 2014 was little
changed from samples collected in 2013, consistent with my prior opinion
that petroleum weathering is now largely arrested in the former Concession
Area. Given these results and the observed conditions of contamination, I do
1 As of the writing of this report the laboratories and Louis Berger had not yet
completed validation of the 2014 sampling data.

not believe that weathering will naturally remediate the contaminated areas
to an appreciable extent within the next few decades.
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3.2 Based on My Analysis of Results from Louis Berger’s Sampling in 2014, I
Conclude the Following:
 The average natural background of organic material extractable with
dichloromethane in soils and sediments of the former Concession Area is
about 160 mg/Kg, and is almost certainly less than 400 mg/Kg, which is
negligible for most concerns.
 The natural background for total polycyclic aromatic compounds (total PAC)
in soils and sediments of the former Concession Area is most likely less than
about 0.05 mg/Kg and almost certainly less than about 0.1 mg/Kg,
 The natural background for total petroleum hydrocarbons measured by
Method 8015B (TPH8015) in soils and sediments of the former Concession
Area is most likely about 50 mg/Kg and almost certainly less than 100
mg/Kg,
 When PACs and TPH8015 are detected above background concentrations the
detected compounds were almost certainly derived from petroleum that was
originally produced at the oil field where sampling occurred,
 Petroleum contamination in groundwater samples is predominantly present
as whole, free‐phase oil rather than as compounds dissolved from petroleum.
 Most petroleum detected in the samples analyzed was only moderately
weathered but still fluid at ambient temperatures within the former
Concession Area, and could be readily dispersed into water and transported
by groundwater.
3.3 Criticisms by Dr. Robert Hinchee of My Prior Reports are Without Merit:
 Contrary to Dr. Hinchee’s claims, the Toxicity Characteristic Leaching
Procedure (TCLP) as applied in the former Concession Area was not intended
to evaluate the mobility of free‐phase oil in soils and sediments, but TCLP
was instead applied according to the procedure specified for evaluating
dissolution of oil components into receiving water.
 The most important consequence of the flawed method used by Dr. Hinchee
and Mr. Connor to evaluate oil weathering, that I pointed out in my previous
report, is the greater fluidity implied by the less‐weathered oil, enabling it to
be more readily transported in ground‐ and surface waters, not the effect this

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error had on their inferences regarding the solubilities of oil components, a
relatively minor concern in comparison.
 Dr. Hinchee objects to the weathering scale I used to evaluate the extent of
weathering of petroleum‐contaminated samples, yet this is the very same
scale used by Chevron’s own experts, on whose interpretations and reports
Dr. Hinchee himself had previously relied. Also, Dr. Hinchee simply ignores
fundamental principles of scientific inference when he concludes that the
Louis Berger samples from 2013 show significant additional weathering
compared with samples collected nearly a decade earlier for the Judicial
Inspections.
3.4 Comparison of Toxic Polycyclic Aromatic Compounds in Petroleum from
the Former Concession Area and Bunker Oil from the Prestige Oil Spill
 I compared distributions of relative PAC abundances in Bunker oil
discharged during the Prestige oil spill off the Spanish coast in 2002 with un‐weathered
Shushufindi crude oil to confirm that they broadly shared the
same suites of toxic PAC, which validates the relevance of toxicological
studies performed after the Prestige oil spill to conditions in the former
Concession Area.
* * * *
4.0 SUPPLEMENTAL OPINIONS
4.1 Results From Louis Berger’s Sampling in 2014 Confirm My Previously
Expressed Opinions
Results from chemical analysis of samples collected from the former Concession
Area during Louis Berger’s 2014 sampling campaign confirm opinions I set forth in
my previous report2. Some of the collected soil and sediment samples were analyzed
by three methods: (1) USEPA Method 8015B for “total petroleum hydrocarbons”
(TPH, hereafter denoted as TPH8015), (2) gravimetrically for total extractable
material (TEM) based on dichloromethane extraction (which I recommended in my
earlier report3), and (3) USEPA Method 8270 for polycyclic aromatic compounds
(PAC), alkanes and petroleum biomarkers. These analyses were performed on
portions of the same samples so that the results are directly comparable. The
results corroborate several conclusions in my previous report4.
2 Short December 2013 Rejoinder Report
3 Ibid.
4 Ibid.

The gravimetric TEM method is especially simple, involving extraction of petroleum
into dichloromethane, separation of the extract from soil or sediment particles by
filtration, evaporation of the dichloromethane and weighing the petroleum residue
left behind. This gravimetric TEM method is an adaptation of US EPA Method 413.1,
Oil and Grease (gravimetric, separatory funnel extraction)5. The adaptations
include: (1) use of dichloromethane as the extraction solvent instead of the now
banned trichlorotrifluoroethane specified in Method 413.1; and (2) application to
soils and sediments. This method for gravimetric determination of TEM was
successfully used to quantitatively determine residual petroleum on beaches of
Prince William Sound, Alaska, 12 years after the petroleum was deposited by the
1989 Exxon Valdez oil spill6. These and other closely related methods, including US
EPA Method 418.17, ASTM D7066‐048, and APHA Standard Method 5520B and
5520C9 all use chemically similar extraction solvents into which petroleum can
dissolve completely, and use detection methods that can detect all the low‐volatility
components of petroleum (i.e. by infrared spectroscopy or by gravimetric
weighing)10, so they produce closely comparable results.
Comparison of TEM results with TPH8015 results confirms that Method 8015B
detects less than 20% of the petroleum actually present in samples of soils or
sediments. This finding is illustrated in Figure 1, where results for TPH8015 are
plotted against the gravimetrically‐determined TEM. The regression line coefficient
r2 of 0.96 indicates that the gravimetric TEM measurement accounts for 96% of the
variation in the TPH8015 measurements. The regression line slope of 0.189 indicates
that Method 8015B detects about 19% of the petroleum actually present. At lower
levels of petroleum contamination, this regression slope decreases to 0.124,
indicating detection of only 12% of the petroleum actually present, consistent with
the trend toward greater weathering in less contaminated soils and sediments
noted in my earlier reports11. This finding is expected because Method 8015B
5 see http://www.cromlab.es/Articulos/Metodos/EPA/400/413_1.PDF
6 Short JW, Lindeberg MR, Harris PM, Maselko JM, Pella JJ, and Rice SD (2004)
Estimate of oil persisting on the beaches of Prince William Sound 12 years after the
Exxon Valdez oil spill. Environmental Science and Technology 38:19‐25
7 This method was discontinued by EPA because vapors from the
trichlorotrifluoroethane used as the extraction solvent depletes atmospheric ozone.
8 American Society for Testing and Materials International Method D7066‐04 is a
replacement method for EPA Method 418.1 and uses chlorotrifluoroethylene,
9 The American Public Health Association Standard Method 5520 for oil and grease
determination provides for both gravimetric (Method 5520B) and infrared (Method
5520C) detection of oil and grease extracted from samples; see
http://www.standardmethods.org/store/ProductView.cfm?ProductID=41
10 American Petroleum Institute Publication Number 4709 (2001), Risk‐based
methodologies for evaluation petroleum hydrocarbon impacts at oil and natural gas
E&P sites, p. 35
11 Short December 2013 Rejoinder Report; Expert Opinion of Kenneth J. Goldstein,
M.A., CGWP and Jeffrey W. Short, Ph.D. Regarding the Environmental Contamination
6

cannot detect a substantial fraction of the crude oil present, for reasons stated in my
earlier report12. Moreover, this undetected fraction increases as crude oil weathers
following release into the environment. These results also corroborate the
greater than 4:1 DRO:TPH relationship between Method 8015B and TPH as
determined by USEPA Method 418.1 and discussed in our first report.13
Figure 1. Comparison of TPH8015 and TEM by gravimetric extraction in soil and
sediment samples collected from the former Concession Area during spring and
summer 2014.
Furthermore, the PACs found in the samples indicate that the TEM in these samples
is almost always weathered crude oil. This finding is illustrated in Figure 2, where
results for total PAC are plotted against the gravimetrically‐determined TEM. The
regression line coefficient r2 of 0.65 indicates that the gravimetric TEM
measurement accounts for 65% of the variation in the total PAC measurements. The
regression line slope of 0.00528 indicates that on average the weathered crude oil in
the samples collected contained about 0.53% total PAC, compared with 0.85%
7
From Texpet’s E&P Activities in the Former Napo Concession Area Oriente Region,
Ecuador” (hereafter Louis Berger, 2013)
13 Louis Berger, 2013, p. 35‐37

typical of un‐weathered Oriente crude oils.14 Concentrations of total PAC that were
lower than expected on the basis of the gravimetric TPH are almost certainly the
result of weathering losses. The weaker association of total PAC with gravimetric
TEM (65%) in comparison with the TPH8015 by Method 8015B and gravimetric TEM
(96%) mainly reflects the greater susceptibility of PACs to weathering losses in
comparison with crude oil components measured by Method 8015B.
Figure 2. Total PAC concentrations in soil and sediment samples collected from the
former Concession area during spring and summer 2014.
These strong correlations between TPH8015 by Method 8015B and total PAC with
gravimetric TEM indicates that concerns raised by Chevron’s experts that Method
418.1 is susceptible to serious positive interferences from naturally occurring
organic compounds in environmental samples are considerably overstated. As I
noted in my previous report15, substantial interferences of this sort are unlikely
based on simple mass balance considerations. Results from the Louis Berger 2014
samples corroborate this view. Substantial interferences from natural sources of
organics would be evident in anomalously high concentrations of PAC or alkane
hydrocarbons, with abundance distributions differing markedly from those typical
14 Alpha Woods Hole Group, laboratory sample number 0406054‐01 at GSD305171,
identified as Shushufindi Suroeste oil at GSD 207000 (hereafter GSD305171)
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of petroleum, and that are associated with higher concentrations of gravimetric
TEM. Instead, the strong association of TPH measured by Method 8015B and
TPH measured gravimetrically as TEM (Fig. 1) shows that contributions of
organics from unknown, natural sources are generally negligible in the Oriente,
especially after making appropriate allowance for weathering on the Method
8015B results.
Finally, gravimetric TEM concentrations in soils or sediments above about 2,000
mg/Kg are accompanied by biomarker distributions characteristic of Oriente crude
oils, and concentrations above 1,000 mg/Kg are almost always associated with PAC
abundance distributions characteristic of crude oil. These results corroborate the
argument I presented in my earlier report16 that interference from natural sources
is negligible in comparison to crude oil contamination above 1,000 mg/Kg.
Consequently, results based on Method 418.1 should not be dismissed on the
basis of speculative assumptions, now clearly shown to be incorrect, and
especially not in deference to Method 8015B, which is shown to be susceptible to
far worse bias towards false negative results.
4.2 Genetic Relationships Among Petroleum Contaminants
The petroleum biomarker fingerprints are remarkably constant throughout the
samples analyzed, based on 16 diagnostic biomarker ratios recommended for
fingerprinting crude oils17 (Table 1). This indicates that all of the soil and sediment
samples analyzed for petroleum biomarkers have crude oil sources, most likely from
their respective oil fields. The slight departures that do occur from the overall
biomarker fingerprint are most likely the combined result of varying susceptibility
to alteration through weathering processes and variation associated with low
biomarker concentrations as detection limits are approached, although comparison
of two diagnostic ratios suggest real differences in the biomarker fingerprints
characterizing the Aguarico and Shushufindi oil fields (Table 1). Conversely, there is
scant evidence of the presence of petroleum from sources outside the Oriente oil
fields of Ecuador. Results for diagnostic biomarker ratios are listed in Table 1 for
soil and sediment samples containing at least 2,000 mg/Kg TEM as measured by the
gravimetric method to ensure sufficient biomarker concentrations for accurate
determinations of all the constituent biomarkers used to calculate the ratios
detected.
Table 1. Petroleum hydrocarbon biomarker used for computation of 16 diagnostic
ratios and their ranges in soil and sediments at each of the three former Concession
Area oil fields sampled during spring and summer 2014. Numbers in parentheses
following the oil field labels indicate the number of samples included for
9
16 Ibid. p. 14
17 Daling PS, Faksness LG, Hansen AB and Stout SA (2002) Improved and
standardized methodology for oil spill fingerprinting. Environmental Forensics
3:263‐278

determination of the range for each oil field. Biomarker ranges in boldface indicate
potential differences in the biomarker fingerprints of crude oils from the Aguarico
compared with the Shushufindi oil fields.
4.3 Weathering State of Petroleum Contamination
Most samples collected by Louis Berger in 2014, whether soils, sediments or
groundwater, contained petroleum at the Kaplan and Galperin (1996)18 weathering
index of 5, indicated by extensive losses of volatile compounds and of n‐alkanes, but
only slight to modest losses of PACs, mainly naphthalenes (Tables 2 – 4). Several
samples were more weathered, having weathering indexes of 6 or 7, indicated by
more extensive losses of PACs. However, some samples had a weathering index of 4,
indicated by loss of most n‐alkanes but of scant PACs. Two samples, collected from
the same bore hole at SSF‐13, had a weathering index of 2, retaining all but the
lightest n‐alkanes, suggesting the oil was either remarkably well preserved, or more
likely was spilled relatively recently.
As expected, the petroleum contaminating stream sediments is generally more
weathered than petroleum in soils. The weathering index for stream sediments is
often 6 or 7, whereas it is usually 5 and sometimes 4 or less in soils. Weathering
indexes could often be assigned to the more contaminated groundwater and surface
water samples, and when assigned were usually 5 or 6.19
18 Kaplan, I.R., Galperin, Y., Alimi, H, Lee, R.P., and Lu, S.T. 1996, Patterns of Chemical
Changes during Environmental Alteration of Hydrocarbon Fuels, Groundwater
Monitoring and Remediation 113 – 114 (hereafter Kaplan and Galperin 1996)
19 Weathering states were assigned when total PAC exceeded 0.5 mg/Kg in soils or
stream sediments, or exceeded 0.5 ug/L in groundwater or surface water samples.
These thresholds for assigning weathering states do not reflect thresholds for the
10

Overall, the samples collected during the 2014 sampling campaign show little
indication of additional weathering since the previous sampling campaign
conducted by Louis Berger in 2013. The samples taken in 2014 further confirm my
conclusion that weathering has been largely arrested for oil contamination in the
Oriente. As I discussed in my 2013 Reports20, this is most likely because the
petroleum has been buried where oxygen and other conditions conducive for
weathering are largely absent. To be clear, I have never opined that no weathering
has occurred. Weathering can substantially change the composition of petroleum
on time scales that range from hours to hundreds of years or more, in which latter
case the weathering rate becomes “largely arrested”21. I recognize that some
weathering has occurred and continues to occur, but mostly at rates that are now
negligible over the course of years to decades. As a result, while some volatile
fractions of crude oil are no longer present, other toxic and carcinogenic
components, like PACs, are still present in substantial concentrations. Given these
results and the observed conditions of contamination, I do not believe weathering
will naturally remediate the contaminated areas to an appreciable extent within the
next few decades.
4.4 Interpretation of Hydrocarbon Analyses of Field Samples Collected from
Ecuador in 2014
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4.4.1 Amount and Extent of Petroleum Contamination
Although concentrations varied widely among the samples collected, indications of
heavy petroleum contamination were evident at all three of the Oriente oil fields
(Shushufindi, Lago Agrio and Aguarico) where samples were collected and analyzed
for petroleum hydrocarbons. Lower concentrations of oil contamination in soil,
sediments, and groundwater were also evident at these sites. In contrast, PAC
evidence of surface water contamination by petroleum was evident only in water
samples from the Lago Agrio field, and the concentrations were modest (i.e. less
than 2.2 g/L total PAC22, or parts per billion).
Most of the petroleum hydrocarbons in the samples are present as whole oil,
meaning oil as a distinct phase separate from water, rather than as components of
natural background of hydrocarbons in soils, sediments or groundwaters of the
former Concession Area soils. The natural background concentrations are
considerably lower.
20 Louis Berger, 2013, Short December 2013 Rejoinder Report
21 Louis Berger, 2013, p. 61
22 Total PAC refers to the sum of 48 parent polycyclic aromatic compounds, PAC, and
classes of alkylated PAC, ranging from naphthalene with two aromatic rings
through benzo[g,h,i]perylene with six. Excepting dibenzothiophene and the
alkylated dibenzothiophenes, the other PAC are all polycyclic aromatic
hydrocarbons, or PAH.

oil dissolved into water. This association with whole oil is indicated by the
concurrent presence of aliphatic hydrocarbons, especially pristane and phytane,
which are relatively persistent branched alkane hydrocarbons, along with PAC. This
evidence supports the conclusion that whole oil is migrating through or along with
ambient media.
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4.4.2 Shushufindi
Samples collected from the Shushufindi oil field contained some of the most and
least contaminated samples of the 2014 sampling campaign (Table 2). The lowest
concentration samples serve to indicate the background concentrations of total PAC,
n‐alkanes, TPH8015 and gravimetric TEM in the region. The highest concentration
samples include the least‐weathered samples analyzed.
Table 2. Summary of hydrocarbon analyses for samples collected during spring and
summer 2014 from Shushufindi oil field, Ecuador. Analytical results are presented
as mg/Kg for soils and sediments and ug/L for water samples, all given with two
significant figures.
Site
Total
PAC
Total n‐
Alkanes TEM
TPH by
8015B
Weathering
State23
Diagnostic
Biomarkers24
Soils
SSF13‐SL001 0.021 0.55 400 26 NA
SSF13‐SL002 (1)25 0.027 0.77 100 28 NA
SSF13‐SL003 0.030 1.3 120 10 NA
SSF13‐SL004 (2) 0.026 0.53 92 41 NA
SSF13‐SL005 0.032 0.27 140 9 NA
SSF13‐SL006 0.020 0.22 250 27 NA
SSF13‐SL007 0.69 2.7 760 39 5
SSF13‐SL008 0.022 0.40 80 9 NA
SSF13‐SL009 0.036 0.47 80 9 NA
SSF13‐SL010 1.85 100 47 5
SSF13‐SL011 (3) 650 2300 19,000 9,700 2 Y
SSF13‐SL012 (4) 2.0 1.2 710 90 5
SSF13‐SL013 (1) 330 23 NA
SSF13‐SL015 (3) 660 2500 2
SSF13‐SL016 (4) 560 86
SSF13‐SL017 (2) 0.028 0.36 NA
SSF25‐SL029 0.025 0.28 100 10 NA
SSF34‐SL001 0.052 0.48 640 87 NA
SSF34‐SL002 0.040 0.33 110 15 NA
23 Weathering state is based on Kaplan & Galperin 1996.
24 Diagnostic biomarker symbols “Y” indicates a definite petroleum biomarker
fingerprint consistent with the pattern presented in Table 1 above; “Y‐“ indicates a
biomarker fingerprint indicative of petroleum but probably altered by weathering.
25 Numbers in parentheses following the site identification labels in column 1
indicate field duplicate samples.

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Site
Total
PAC
Total n‐
Alkanes TEM
TPH by
8015B
Weathering
State23
Diagnostic
Biomarkers24
SSF34‐SL003 0.054 0.20 120 15 NA
SSF34‐SL004 0.051 0.55 130 17 NA
SSF34‐SL006 0.083 0.90 120 38 NA
SSF34‐SL007 0.076 1.4 360 25 NA
SSF34‐SL008 0.068 0.61 1,700 24 NA
SSF34‐SL009 4000 410 140,000 53,000 4 Y
SSF34‐SL010 630 63 33,000 7,000 4 Y
SSF34‐SL011 780 71 40,000 11,000 4 Y
SSF34‐SL012 0.91 1.7 150 80 5
SSF43‐SL001 15 31 2,300 1,200 4 Y
Sediments
SSF13‐SE001 0.048 0.40 930 12 NA
SSF13‐SE002 0.075 13 26,000 30 NA
SSF13‐SE003 1.2 9.3 880 75 7
SSF13‐SE004 (5) 1.4 9.9 39,000 460 7 Y‐SSF13‐
SE006 2.6 38 1,500 77 7
SSF13‐SE007 0.65 8.6 2,200 100 7 Y‐SSF13‐
SE008 0.86 13 1,100 54 7
SSF13‐SE009 1.7 33 2,000 140 7 Y‐SSF13‐
SE010 0.74 3.0 320 27 6
SSF13‐SE011 (5) 2.0 17 11,000 330 6 Y‐SSF55‐
SE001 (6) 900 211 53,000 14,000 5 Y
SSF55‐SE002 240 65 11,000 5,000 5 Y
SSF55‐SE003 3.3 9.3 2,700 230 5 Y
SSF55‐SE004 250 76 53,000 6,500 5 Y
SSF55‐SE005 80 60 30,000 2,800 5 Y
SSF55‐SE006 0.87 11 1,800 120 7
SSF55‐SE007 18 77 22,000 5,000 5 Y
SSF55‐SE008 150 69 50,000 5,900 5 Y
SSF55‐SE009 (6) 410 85 23,000 6,900 5 Y
Groundwater
SSF13‐GW001 0.75 12 130 6
SSF13‐GW002 (7) 0.44 2.4 130 NA
SSF13‐GW003 0.52 3.5 200 5
SSF13‐GW004 0.32 3.1 39 NA
SSF13‐GW005 (7) 0.53 3.4 150 6
SSF25‐GW008 0.25 7.9 210 NA
SSF25‐GW009 0.19 1.7 39 NA
SSF25‐GW010 83 11 2,100 5
SSF25‐GW011 11 1.9 1,100 6
SSF34‐GW001 (8) 0.19 7.6 53 NA
SSF34‐GW002 0.22 21 55 NA
SSF34‐GW003 0.28 46 61 NA
SSF34‐GW004 0.23 21 110 NA
SSF34‐GW005 (8) 0.17 5.9 43 NA
SSF43‐GW002 0.18 1.9 140 NA
SSF43‐GW003 3.4 3.1 210 5

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Site
Total
PAC
Total n‐
Alkanes TEM
TPH by
8015B
Weathering
State23
Diagnostic
Biomarkers24
Surface Water
SSF13‐SW001 0.22 0.56 62 NA
SSF13‐SW002 0.21 0.94 30 NA
SSF13‐SW003 0.13 0.41 35 NA
SSF13‐SW004 0.25 0.41 110 NA
SSF13‐SW005 0.068 0.73 33 NA
SSF13‐SW006 0.076 0.83 60 NA
SSF13‐SW007 0.26 8.6 100 NA
SSF13‐SW008 0.076 1.3 62 NA
SSF13‐SW009 0.13 4.3 90 NA
SSF13‐SW010 0.12 1.4 140 NA
4.4.2.1 SSF‐13
Most of the Shushufindi soil and sediment samples were collected from this site. Of
the 14 soil samples collected and analyzed for PAC, 9 had very low concentrations of
total PAC ranging from 0.021 – 0.036 mg/Kg (parts per million; Table 2). This
concentration range for total PAC most likely reflects the natural PAC background of
soils and sediments in the region. This natural background pattern of PAC
abundance is depicted in Fig. 3, and is characterized by relatively little increase of
alkyl‐substituted PAC abundance in comparison with the respective un‐substituted
parent PAC of a homologous series, in contrast to soils contaminated with low
concentrations of petroleum. Petroleum contamination in the LA16‐SL002 sample
is indicated by the increased abundances of the alkyl‐substituted PAC in comparison
with respective un‐substituted parent PAC, by the presence of chrysene and the
alkyl‐substituted chrysene homologues, and the low abundances of the
unsubstituted 5‐ring PAH (i.e. BBF, BKF, BEP, BAP, GHI, DA and IND).26
The comparison depicted in Fig. 3 suggests that the upper limit for the natural PAC
background lies between 0.040 mg/Kg and 0.16 mg/Kg total PAC. The TPH8015
concentrations corresponding to this PAC background are less than 50 mg/Kg
(Table 2), suggesting that the natural background for TPH8015 is almost certainly less
than twice this concentration (i.e. 100 mg/Kg). Similarly, the TEM concentrations
corresponding to the PAC background range from 80 – 400 mg/Kg, with an average
of 160 mg/Kg.
26 Abbreviations for these compound classes are as follows: N=naphthalene,
B=biphenyl, AY=acenaphthylene, AE=acenaphthene, B=biphenyl, F=fluorene,
A=anthracene, P=phenanthrene, D=dibenzothiophene, FL=fluoranthene, PY=pyrene,
BA=benzo[a]anthracene, C=chrysene, BBF=benzo[b]fluoranthene,
BFK=benzo[k]fluoranthene, BEP=benzo[e]pyrene, BAP=benzo[a]pyrene,
BP=benzopyrenes, PER=perylene, IND=indenopyrene, DA=dibenzoanthracene,
GHI=benzoperylene; numbers following PAH abbreviations indicate the number of
carbon atoms of alkyl substituents.

Figure 3. Distribution of background PAC in soil (blue bars) compared with a soil
sample (LA16‐SL002) containing a low level of contamination by petroleum (red
bars).
Soil samples from three other sites at SSF‐13had total PAC concentrations that
ranged from 0.69 – 2.0 mg/Kg of total PAC. However, two soil samples, collected
from the same bore hole inside the reserve pit (i.e. SSF13‐SL011 and –SL‐015), had
total PAC concentrations of about 650 mg/Kg, associated with a total n‐alkane
concentration of 2,300 – 2,500 mg/Kg, a TEM of 19,000 mg/Kg (or 1.9%) and a
biomarker fingerprint indicating contamination by petroleum. The weathering state
of these samples was 2, indicating loss of volatile alkanes and aromatics but little
else. Comparison of the ratio of pristane to n‐heptadecane, or of phytane to n‐octadecane
15
shows little difference from respective ratios of un‐weathered
Shushufindi crude oil, indicating little biodegradation has occurred. These results
strongly suggest that petroleum was recently (less than a year) discharged to the
soil that was sampled.
Only 2 of the 10 samples of stream sediments from the SSF‐13 site contained
background concentrations of total PAC, one at 0.048 and the other at 0.075 mg/Kg.
Concentrations in the remaining 8 samples ranged from 0.65 to 2.6 ug/g, indicating
low but clear contamination by petroleum.

16
Total PAC concentrations in the 5 groundwater samples analyzed from SSF‐13
ranged from 0.32 – 0.750 ug/L (i.e. parts per billion). While low, these
concentrations indicate clear contamination of the sampled groundwater by
petroleum, confirmed by the concurrent presence of pristane and phytane.
Total PAC concentrations in the 10 surface water samples analyzed from SSF‐13
ranged from 0.068 – 0.26 ug/L, with PAC distributions indicative of petroleum
contamination.
4.4.2.2 SSF‐25
This site was more extensively analyzed in 2013 and my overall conclusions as
relate to this site are included in my December 2013 Report. I maintain those
conclusions. Limited sampling was conducted in 2014 at this site which I discuss
below.
The single soil sample analyzed from the SSF‐25 site contained only the background
concentration of total PAC (i.e. 0.025 mg/Kg).
Concentrations of total PAC in 2 of the 4 groundwater samples collected from the
SSF‐25 site were 0.19 and 0.25 ug/L, and as with surface water samples at SSF‐13,
have PAC distributions indicative of petroleum contamination. Two other samples
contained total PAC concentrations of 11 and 83 ug/L, indicating clear
contamination of the sampled groundwater by petroleum, confirmed by the
concurrent presence of pristane and phytane.
4.4.2.3 SSF‐34
Seven of the 11 soil samples from SSF‐34 contained background concentrations of
total PAC, ranging from 0.028 – 0.083 mg/Kg, with corresponding concentrations of
TPH8015 ranging from 15 – 87 mg/Kg. Although corresponding TEM concentrations
were usually less than 400 mg/Kg, one sample (SSF‐34 SL008) had a TEM
concentration of 1,700 mg/Kg, despite concentrations of total PAC and TPH8015 of 68
mg/Kg and 24 mg/Kg, respectively. This sample was collected from 3.3 m depth
near a pit, and inspection of the Method 8015B chromatogram revealed an unusual
broad, large peak spanning a retention time window of nearly a minute, suggesting a
possible contaminant associated with a product used by oil‐production operations,
which are often proprietary.
One sample (SSF‐34 SL012) contained low (0.91 mg/Kg) total PAC that was clearly
derived from petroleum, and the other 3 were heavily contaminated by petroleum,
with total PAC concentrations ranging from 630 mg/Kg to 4,000 mg/Kg. In addition
to a PAC abundance distribution typical of petroleum contamination, the biomarker
fingerprint provides additional confirmation of the petroleum source for these
samples. The sample from SSF34‐SL009 was the most contaminated of all the soil

and stream sediment samples collected from the Shushufindi oil field, and with TEM
at 140,000 mg/Kg (or 14%) implies soil that is near or at saturation with petroleum.
No stream sediment samples were analyzed from SSF‐34.
The 5 groundwater samples analyzed from SSF‐34 contained total PAC
concentrations ranging from 0.17 – 0.28 ug/L, generally consistent with the low‐level
17
petroleum contamination PAC pattern depicted in Fig. 3.
4.4.2.4 SSF‐43
The single soil sample analyzed from SSF‐43 contained a concentration of 15 mg/Kg
total PAC, indicating moderate petroleum contamination and confirmed by the
biomarker fingerprint.
One of the 2 groundwater samples contained a total PAC of 0.18 ug/L, generally
consistent with the low‐level petroleum contamination PAC pattern depicted in Fig.
3. The other sample contained 3.4 ug/L, indicating moderate petroleum
contamination.
4.4.2.5 SSF‐55
Only stream sediment samples were analyzed from SSF‐55. Most of these were
heavily contaminated by petroleum. Of the 9 samples analyzed, 7 had total PAC
concentrations ranging from 80 mg/Kg to 900 mg/Kg, while the other 2 samples
had concentrations of 0.87 and 3.3 mg/Kg, indicating moderate petroleum
contamination. All of these samples except the one containing 0.87 mg/Kg total PAC
had positive biomarker fingerprints consistent with oil contamination found
elsewhere in the Shushufindi oil field.
4.4.3 Lago Agrio
Petroleum contamination was evident in analyzed samples of soil, stream
sediments, groundwaters and surface waters from the Lago Agrio sites (Table 3).
The overall pattern and distribution of results is similar to those at the Shushufindi
field.

summer 2014 from Lago Agrio oil field, Ecuador. Analytical results are presented as
mg/Kg for soils and sediments and ug/L for water samples, all given with two
18
Site
Total
PAC
Total n‐
Alkanes TEM
TPH by
8015B
Weathering
State27
Diagnostic
Biomarkers28
Soils
LA02‐SL022 0.98 1.9 130 44 5
LA02‐SL023 35 18 2,800 6
LA02‐SL024 1.2 18 130 6
LA16‐SL001 130 18 7,600 2,400 5 Y
LA16‐SL002 0.16 2.7 1,800 15 NA
LA16‐SL003 0.16 1.2 300 8 NA Y?
LA16‐SL004 (1)29 9.1 7.9 520 280 5 Y
LA16‐SL005 0.072 1.1 130 14 NA
LA16‐SL006 0.069 0.12 590 10 NA
LA16‐SL007 23 2,500 710 5 Y
LA16‐SL008 0.22 0.66 91 12 NA
LA16‐SL009 0.63 1.3 220 55 5 Y?
LA16‐SL010 0.86 2.4 200 37 5 Y?
LA16‐SL011 (2) 0.91 1.4 320 41 5 Y?
LA16‐SL012 0.95 4.0 92 75 6
LA16‐SL014 (2) 260 90 Y?
LA16‐SL015 (1) 9.7 5
Sediments
LA35‐SE001 270 456 88,000 5,200 5 Y
LA35‐SE002 600 71 29,000 6,500 5 Y
LA35‐SE003 36 19 14,000 5,400 6 Y
LA35‐SE004 4.5 5.8 9,000 570 6 Y
LA35‐SE005 2.4 6.9 44,000 320 7 Y
Groundwater
LA16‐GW001 66 7.3 1,100 5
LA16‐GW002 0.32 15 78 NA
LA16‐GW003 0.24 2.8 130 NA
LA16‐GW005 0.30 2.4 72 NA
LA02‐GW007 2.1 6.5 290 6
LA02‐GW008 3.8 1.9 110 5
LA02‐GW009 (3) 42 6.1 91 5
27 Weathering state is based on Kaplan & Galperin 1996
fingerprint consistent with the pattern presented in Table 1 above; “Y?“ indicates a
biomarker fingerprint indicative of petroleum but with the least abundant
biomarker compounds not detected.
29 Numbers in parentheses following the site identification labels in column 1
indicate field duplicate samples.

19
Site
Total
PAC
Total n‐
Alkanes TEM
TPH by
8015B
Weathering
State27
Diagnostic
Biomarkers28
LA02‐GW010 200 32 2,000 5
LA02‐GW011 0.070 2.1 61 NA
LA02‐GW012 (3) 42 6.0 780 5
Surface Water
LA35‐SW002 0.82 4.3 67 5
LA35‐SW003 (4) 0.49 3.8 82 NA
LA35‐SW004 2.2 17 55 5
LA35‐SW005 1.86 2.3 2,700 6
LA35‐SW006 (4) 0.72 1.8 190 6
4.4.3.1 LA‐02
This site was more extensively analyzed in 2013 and my overall conclusions as
relate to this site are included in my December 2013 Report. I maintain those
conclusions. Limited sampling was conducted in 2014 at this site which I discuss
below.
Two of the 3 soil samples analyzed for PAC from LA‐02 had low but clear levels of
petroleum contamination, with total PAC concentrations of 0.98 and 1.2 mg/Kg.
Petroleum contamination in the third sample analyzed was heavy, with the
concentration of total PAC at 35 mg/Kg. Biomarkers were not analyzed in this
sample because of insufficient sample mass collected for all the analyses to be
performed.
Petroleum contamination of groundwater at LA‐02 was also clearly evident. While 1
sample contained a background concentration of total PAC at 0.070 ug/L,
concentrations in the other 5 samples ranged from 2.1 ug/L to 200 ug/L, and 3 of
the 5 samples had concentrations above 40 ug/L. Elevated concentrations of
pristane and phytane indicate this contamination was mainly present as whole, free‐phase
oil. The hydrocarbons detected in these 5 samples were sufficiently abundant
that weathering states could be assigned, all of which were 5.
4.4.3.2 LA‐16
Four of the 13 soil samples analyzed for PAC from LA‐16 had moderate or heavy
levels of petroleum contamination. The highest total PAC concentration was 130
mg/Kg, followed by 23 mg/Kg in another sample and concentrations above 9 mg/Kg
in the remaining two. Another 5 soil samples had low but clear petroleum
contamination, with total PAC concentrations ranging from 0.63 – 0.95 mg/Kg.
Petroleum in most of these samples was confirmed by biomarker fingerprints. The
remaining 4 samples had total PAC concentrations near or at the natural
background, ranging from 0.069 – 0.16 mg/Kg.

Of the 4 groundwater samples analyzed for PAC, one was heavily contaminated by
petroleum, with a total PAC concentration of 66 ug/L at a weathering state of 5.
Concentrations in the other 3 samples ranged from 0.24 – 0.32 ug/L, and consisted
of PAC distributions depicted in Fig. 3 as indicative of low‐level petroleum
contamination.
20
4.4.3.3 LA‐35
Only stream sediment and surface water samples were analyzed for PAC from LA‐
35. Of the 5 stream sediment samples, the highest concentration of total PAC was
600 mg/Kg, followed by another sample containing 270 mg/Kg. A third sample
contained about 36 mg/Kg, all indicating heavy petroleum contamination. The
remaining two samples contained 2.4 and 4.5 mg/Kg, indicating modest petroleum
contamination. Petroleum contamination in all these samples was confirmed by the
biomarker fingerprints, and the weathering states ranged from 5 to 7, the latter
indicating very weathered oil.
All 5 of the surface water samples analyzed for PAC contained elevated
concentrations indicative of petroleum contamination, ranging from 0.49 ug/L to
2.2 ug/L.
4.4.4 Aguarico
As with the samples from Lago Agrio, samples from the Aguarico oil field sites
reflect the general pattern of petroleum contamination in the region (Table 4).
summer 2014 from Aguarico oil field, Ecuador. Analytical results are presented as
mg/Kg for soils and sediments and ug/L for water samples, all given with two
Site
Total
PAH
Total n‐
Alkanes TEM
TPH by
8015B
Weathering
State30
Diagnostic
Biomarkers31
Soils
AG04‐SL001 3285 1362 690,000 120,000 5 Y
AG04‐SL002 2894 1137 590,000 120,000 5 Y
AG06‐SL001 7.7 5.7 890 230 5 Y?
AG06‐SL002 0.18 1.9 150 18 NA Y?
AG06‐SL003 0.15 1.2 2,100 16 NA Y?
AG06‐SL004 0.35 7.8 300 26 NA Y?
AG06‐SL005 12 12 3,600 360 5 Y
30 Weathering state is based on Kaplan & Galperin 1996
fingerprint consistent with the pattern presented in Table 1 above; “Y?“ indicates a
biomarker fingerprint indicative of petroleum but with the least abundant
biomarker compounds not detected.

21
Site
Total
PAH
Total n‐
Alkanes TEM
TPH by
8015B
Weathering
State30
Diagnostic
Biomarkers31
AG06‐SL006 31 11 2,000 580 5 Y
AG06‐SL007 13 6.7 2,500 390 5 Y
AG06‐SL008 126 14,000 2,300 5 Y
AG06‐SL009 75 20 6,800 1,600 5 Y
Sediments
AG06‐SE001 0.52 29 1,000 66 7
AG06‐SE002 2.1 2.7 2,200 100 6 Y
AG06‐SE003 0.59 4.2 1,900 34 5 Y
AG06‐SE004 0.33 11 780 34 NA Y
AG06‐SE005 0.63 5.8 740 31 7 Y
Groundwater
AG06‐GW005 5.5 6.6 130 5
AG06‐GW007 0.60 4.5 220 5
AG06‐GW008 26 10 2,800 5
AG06‐GW009 3.2 21 320 5
AG06‐GW010 214 86 3,500 5
AG06‐GW011 7.2 13 490 5
Surface Water
AG06‐SW001 0.091 1.0 42 NA
AG06‐SW002 0.078 9.7 39 NA
AG06‐SW003 0.10 0.51 40 NA
AG06‐SW004 0.094 0.48 40 NA
AG06‐SW005 0.089 0.85 50 NA
4.4.4.1 AG‐04
Only 2 samples, both of heavily contaminated soils, were collected from the AG‐04
site. Both were heavily contaminated by petroleum, with concentrations of total
PAC of 2,900 and 3,300 mg/Kg. The associated TEM concentrations of 590,000 –
690,000 mg/Kg imply samples consisting of more oil than inorganics (i.e. 59% ‐
69% oil). The biomarker fingerprints corroborate the petroleum source.
4.4.4.2 AG‐06
Concentrations of total PAC in the 9 soil samples analyzed from AG‐06 ranged from
near background concentrations (3 samples ranging from 0.15 to 0.35 mg/Kg total
PAC) to heavily contaminated by petroleum. The highest total PAC concentration at
AG‐06 was 130 mg/Kg, with 5 other samples ranging from 7.8 – 75 mg/Kg. All of
these samples had biomarker fingerprints indicative of oil, and the 5 most
contaminated samples had weathering states of 5.
Five samples of stream sediments were collected and analyzed for PAC, and had
concentrations of total PAC ranging from 0.33 – 2.1 ug/L. The PAC distribution

indicates a petroleum source, confirmed by the biomarker fingerprint in 4 of the
samples. The weathering states of these samples ranged from 5 – 7, again
consistent with the pattern of more advanced weathering in oil‐contaminated
stream sediments than in soils.
Six groundwater samples had concentrations of total PAC as high as 210 ug/L.
Another sample contained 26 ug/L, and three more samples contained from 3.2 –
7.2 ug/L The lowest concentration found was 0.60 ug/L. All of these concentrations
are clearly above the natural background, and the PAC distribution indicates a
petroleum source. The weathering states of the oil in these samples were all 5.
Finally, 5 surface water samples were collected and analyzed for PAC.
Concentrations of total PAC ranged from 0.078 – 0.11 ug/L, with abundance
distributions reflecting mainly the natural background distribution of PAC depicted
in Fig. 3.
4.5. Response to Hinchee Memorial of May 2014
In his May 2014 Reply Memorial, Hinchee raised objections to three of the points I
made in my December 2013 Rejoinder Report.32 The first objection is with regard to
the appropriateness of the Toxicity Characteristic Leaching Procedure (TCLP) for
use in conjunction with the RAP remediation. The second is with regard to my
criticism of Hinchee’s and Connor’s method to determine the extent of oil
weathering. The third is with regard to my characterization of oil weathering and
evidence for the rate of weathering of oil‐contaminated soils and sediments in the
former Concession Area. I find all three of Dr. Hinchee’s objections without merit,
and I stand by the positions I stated in earlier reports. My responses to Dr.
Hinchee’s objections follow, in the order presented above.
4.5.1 Appropriateness of the Toxicity Characteristic Leaching Procedure
In my December 2013 Rejoinder Report33 I noted that it is in principle not possible
for any combination of oil components to reach the regulatory threshold
concentration of 1000 mg/L (or even 200 mg/L) through dissolution alone.
Consequently, I concluded that to reach this threshold, soils or sediments would
have to be saturated with oil, allowing the oil to drain out of soils or sediments as a
separate organic phase.
In his objection, Dr. Hinchee asserts that this was actually the intention of the test34,
that is, to determine whether the oil was sufficiently mobile in soils or sediments to
move as a separate phase under application of pressure. But this assertion is belied
22
32 Short 2013 Rejoinder Report
33 Ibid., p. 23
34 Hinchee May 2014 Response Report, p. 6

by the instructions given by the EPA for this test,35 which state that when
multiphasic samples (i.e. samples that consist of an oil phase and a solid inorganic
phase such as oiled soil or sediment samples) are involved, the liquid phase must
first be separated from the solid phase, prior to addition of the acidified aqueous
phase and subsequent mixing, followed by a second filtration step to separate the
added water from the solids. This is not how the tests were actually conducted for
the RAP.36 Instead, the acidified water was added immediately before evaluating
whether oil could flow out of the soil or sediment sample. The addition of acidified
water at the start of the procedure impaired the ability of the oil to flow through the
filtration device, an issue noted in our initial February 2013 report.37
4.5.2 Consequences of the Flawed Oil Weathering Method used by Drs.
Hinchee and Connor
Dr. Hinchee claims that the most important consequence of the flaws I pointed out
in the O’Reilly and Thorsen method38 for determining the extent of oil weathering is
the effect it has on the solubility of oil components.39 I have never disputed that oil
composition changes resulting from differential losses of some components during
weathering do affect the effective solubility of the components remaining in the oil.
But I do not believe that is the most important consequence of the flawed O’Reilly
and Thorsen method for determining oil weathering.
Both Dr. Hinchee and Mr. Connor relied on the flawed O’Reilly and Thorsen method
to support their claim that the overwhelming majority of oil remaining in
contaminated soils and sediments is so weathered that it has become an immobile
hardened solid. By showing how this claim is seriously flawed, I raise the likelihood
that contaminating oils that remain in the region’s soils and sediments could flow
through them. If some of the remaining oil is still sufficiently fluid to be carried by
water through flow channels in subsurface clays, a mechanism for transporting free‐phase
23
weathered crude oil from inside to outside un‐lined pits becomes plausible.
Louis Berger has observed sites where this transportation mechanism seems likely
and my analysis shows that it is not precluded as Dr. Hinchee and Mr. Connor
believe. This is a much more serious consequence of the mistaken inferences based
on the flawed O’Reilly and Thorsen method.
4.5.3 Characterization of Weathering Rates for Crude Oil Remaining in
Concession Area Soils and Sediments
35 USEPA Method 1311, July 1992, p. 11
37 Ibid., p. 54
38 O’Reilly, K. and Thorsen, W., 2010, Impact of Crude Oil Weathering on the
Calculated Effective Solubility of Aromatic Compounds: Evaluation of Soils from
Ecuadorean Oil Fields, Soil and Sediment Contamination, 19:391 – 404

Dr. Hinchee claims that the method I relied on for determining the weathering state
of oil in the former Concession Area is qualitative and questionable, and in any case
my application of this method to samples collected in 2013 by Louis Berger in
comparison with samples collected earlier and summarized by Chevron expert Dr.
Douglas do not support my conclusion regarding weathering rates, inaccurately
portrayed by Dr. Hinchee as “arrested biodegradation”. I reject these claims on the
basis of the following three observations:
1. Dr. Hinchee states that I claimed that “...hydrocarbons in the former Concession
area are in a state of arrested biodegradation...”40. What I actually said was that
hydrocarbons are in a state of largely arrested biodegradation41 – a crucially
important difference. Under conditions of low oxygen and high oil concentration in
soils or sediments, biodegradation rates may be orders of magnitude slower than
when oil is spread out as thin layers or small droplets at the soil surface. A state of
largely arrested biodegradation does not mean that biodegradation has stopped, but
instead that it is so slow that oil may persist, largely unchanged, for decades or
longer.
2. The method I relied on to determine oil weathering states is presented in Kaplan
and Galperin,42 which is exactly the same method used by Chevron expert Dr.
Gregory Douglas to characterize the weathering states of hundreds of oiled soil and
sediment samples.43 I used this method in part to avoid the sort of objection raised
here by Dr. Hinchee, reasoning that adopting the method used by Chevron’s experts
would be viewed as reasonable. In any case I view the qualitative basis of the
method as a strength rather than a weakness, because it recognizes the regular
sequence of composition changes as oil products weather in the environment, and
hence is not vulnerable to quantitative disputes that arise when different analytical
methods are applied. For example, complete loss of all the normal alkanes from
crude oil by weathering is unmistakable, regardless of the subtle differences in the
gas chromatographic or other methods used to measure them.
3. Finally, Dr. Hinchee asserts that comparison of results for determining
weathering rates should (ideally) be from the same locations and depths44, but then
proceeds to ignore his own advice to arrive at unjustified conclusions regarding
weathering rates. Samples collected from the same locations and depths at the
beginning and again at the end of a time interval of sufficient duration for reliable
detection of weathering are not available. In their absence, weathering changes
might be inferred from averaged weathering states of a representative set of
42 Kaplan and Galperin , 1996
43 Summary of Forensic Analyses of Crude Oil Weathering from 45 Judicial
Inspections, August 2004 – November 2006, Chevron, Oriente Region, Ecuador. GSI
Environmental, Inc., 2211 Norfolk, Suite 1000, Texas 77098‐4054, May 17, 2007
24

samples. Unfortunately, neither the samples collected for the Judicial Inspections by
Chevron in the mid‐2000’s, nor the samples collected by Louis Berger in 2013, can
be taken as representative in this sense of the environment sampled, because
neither sampling program included a random selection component to the sampling
selection process.
When Chevron claims their sampling was “representative”45, they are using the term
loosely as a synonym for “typical” or “indicative” of results that may be expected at
or very near the precise location sampled, and not in the strict scientific sense of the
term “representative”. Scientifically, “representative sampling” indicates the
sampling locations were selected in a manner such that every possible sampling
location within the area represented has an equal chance of actually being sampled.
Sampling in this “equal‐probability” manner is the only way to guarantee that the
results of the sampling truly represent the entire area sampled. Neither sampling in
“typical” areas, nor even “haphazard” sampling, can be taken as truly
“representative” in this sense.
The sampling conducted by Louis Berger in 2013 and in 2014 was also not truly
“representative” in the strict scientific sense of this term, nor has it made out to be
so. Instead, the Louis Berger sampling was conducted to evaluate other specific
questions such as the plausibility of petroleum migration pathways from the inside
to the outside of oiled pits and beyond. Such targeted sampling, tailored for specific
purposes that are explicitly stated in advance, is perfectly legitimate, as was
acknowledged by Chevron expert Dr. Robert Hinchee46. But this kind of targeted
sampling still cannot be taken as “representative” of the broad area where sampling
occurred, and especially not for quantitative comparisons on which computations
of petroleum weathering rates are based. For example, sampling results indicate
that residual petroleum in stream sediments is generally more weathered than
petroleum buried in soils. Hence, if sampling one year includes a substantially
smaller proportion of stream sediments in comparison to a succeeding year, then
the change in the average weathering between these two years may simply reflect
the differences in the proportions of sediment and soil samples between the two
years, instead of actual differences in weathering.
When Dr. Hinchee compares results from Chevron’s Judicial Inspections (JI) during
the mid‐2000’s with the 2013 Louis Berger samples to conclude that the average
Kaplan & Galperin weathering index increased from 4.6 in to 6.1, he presumes
implicitly that both sampling programs were truly representative in the strict
scientific sense, and he simply ignores a host of plausible alternative explanations
for these results. These alternative explanations are plausible because the sampling
45 Expert Opinion of John A. Connor, P.E., P.G., B.C.E.E. Regarding Remediation
Activities and Environmental Conditions in the Former Petroecuador – Texaco
Concession, Oriente Region, Ecuador, Response to LBG Report of February 2013, Issued
3 June 2013, p. 12
25

was in fact not truly representative, and so the results compared may reflect
primarily differences in the proportions of stream sediments, of surface oil samples
(which also tend to be more weathered than buried oil) and of oil buried in soils
between the sample sets collected for the mid‐2000’s JI sampling and the 2013
Louis Berger sampling, rather than the actual progress of oil weathering during the
intervening time interval. Consequently, Dr. Hinchee’s comparison of average
weathering states from the two sampling programs to make inferences with regard
to the statistical significance of their differences rests on the clearly unjustifiable
assumption that these samples are representative, in flagrant disregard for
fundamental principles of scientific inference.
In my December 2013 Rejoinder Report47 I noted that the ranges of weathering
states from Chevron’s and Louis Berger’s sampling programs broadly overlap,
suggesting that little weathering had occurred during the nearly 10 years between
them. This in itself is a remarkable testament to the slow rate of weathering. But I
did not infer more broadly because any such inferences are limited by the way that
sampling was conducted for both the Chevron and the Louis Berger sampling
campaigns.
4.6. Comparison of Ecuador Oriente Crude Oil with Bunker Oil Spilled from
the Prestige Oil Spill
Considerable research has been done on the toxicological effects of other oil spills,
especially the Prestige oil spill off the Spanish coast in 2002. To compare this
research with conditions in the Oriente requires establishing that the oils involved
share at least a broadly similar suite of toxic compounds. The product released in
the Prestige oil spill was number 6 fuel oil, also known as Bunker oil, a heavy oil
consisting mainly of residual hydrocarbons, resins and asphaltenes that remain
after distillation of lighter components during the petroleum refining process.
Although removal of these lighter components alters the concentrations of the
compounds that remain in the number 6 fuel oil, the abundance distribution of
PAHs, usually considered the most persistent class of toxic compounds in
petroleum, is broadly similar to that of the original petroleum.
The distribution of PACs in the number 6 fuel oil released from the Prestige is
presented in Figure 4, along with the comparable distribution in Shushufindi crude
oil. Note that both contain the same types of PACs in generally similar proportions,
although concentrations of some of the PACs in the Prestige oil are substantially
greater than their counterparts in Shushufindi crude oil. However, as Shushufindi
crude oil weathers these concentrations will tend to converge, because losses of the
lighter petroleum components during weathering mimics to an extent the
distillation process in a refinery. The result is that after even modest weathering
the toxicity of the Shushufindi crude oil caused by PACs would be broadly
comparable with that of the Prestige oil.
26
47 Short 2013 Rejoinder Report

Figure 4. Concentrations of polycyclic aromatic compounds in No. 6 fuel oil
released by the T/V Prestige (blue bars)48 and in un‐weathered Shushufindi crude
oil49 (red bars). BF=benzofluoranthenes; see Fig. 3 legend for other abbreviations.
48 Alzaga A., Montuori P, Ortiz L, Bayona JM, Albaigés J (2004) Fast solid‐phase
extraction‐gas chromatography‐mass spectrometry procedure for oil fingerprinting
Application to the Prestige oil spill. Journal of Chromatography A 1025:133‐138
49 GSD305171
27

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