Section 02200 - Kuwait Oil Company · Web viewA designated area, at South and East Kuwait Greater...

Project ManagementConsultancy Services for

Kuwait Environmental Remediation Projects (KERP)Contract 12050669

LIMITED SCOPE SITE CHARACTERIZATION REPORT

Issued for Information

S. Kalimuthu / N. Huyg

M.Lush / E.Fahnline

G. Connor

Rev Date Reason for Issue Prepared by Checked by Approved by Client

AMEC

Notes: Category Code Description

Document Type RPT Limited Scope Site Characterization Report

Project No Area Disc Document Type

Sequence No Revision

Number of Sheets: 77 050669 0000 DA00 RPT 0001 A1

Doc No. 050669-0000-DA00-RPT-0001, Rev. A1Doc Title: Limited Scope Site Characterization Report

TABLE OF CONTENTS

1 INTRODUCTION.......................................................................................................71.1 OBJECTIVES....................................................................................................................7

1.2 SCOPE OF WORK............................................................................................................8

1.3 REPORT STRUCTURE.......................................................................................................8

2 PROJECT BACKGROUND.....................................................................................102.1 SITE CONTAMINATION HISTORY.....................................................................................10

2.1.1 Wet Oil Lake Features.................................................................................................102.1.2 Dry Oil Lake Features.................................................................................................102.1.3 Tarcrete....................................................................................................................... 112.1.4 Oil Contaminated Piles................................................................................................11

2.2 GEOLOGY.....................................................................................................................11

3 SITE CHARACTERIZATION DESIGN AND SCOPE..............................................123.1 SITE CHARACTERIZATION DESIGN..................................................................................12

3.2 OVERVIEW OF SCOPE....................................................................................................12

3.2.1 UXO Support...............................................................................................................123.2.2 Trial Pit Excavation......................................................................................................13

3.3 SAMPLING.....................................................................................................................15

3.4 EQUIPMENT DECONTAMINATION.....................................................................................17

3.5 SAMPLE ANALYSIS SUMMARY........................................................................................17

3.6 QUALITY ASSURANCE....................................................................................................18

3.7 SURVEYING...................................................................................................................19

3.8 WASTE HANDLING.........................................................................................................19

4 HEALTH, SAFETY, AND ENVIRONMENT.............................................................205 DISCUSSION OF FINDINGS..................................................................................22

5.1 INTRODUCTION..............................................................................................................22

5.2 OVERVIEW OF VISUAL OBSERVATIONS...........................................................................22

5.2.1 Layer 1........................................................................................................................ 235.2.2 Layer 2........................................................................................................................ 235.2.3 Layer 3........................................................................................................................ 235.2.4 Tarcrete....................................................................................................................... 24

5.3 ZONING.........................................................................................................................24

5.3.1 Zone 1.........................................................................................................................245.3.2 Zone 2.........................................................................................................................255.3.3 Zone 3.........................................................................................................................255.3.4 Zone 4.........................................................................................................................265.3.5 Zone 5.........................................................................................................................265.3.6 Zone 6.........................................................................................................................275.3.7 Zone 7.........................................................................................................................27

5.4 REVIEW AND ASSESSMENT OF DATA..............................................................................28

5.4.1 Wet Oil Lakes..............................................................................................................29

1 Jun 15 Page 2 of 78


5.4.2 Dry Oil Lakes...............................................................................................................385.4.3 Background................................................................................................................. 47

5.5 COMPARISON OF DATA...................................................................................................50

5.5.1 Layer 1........................................................................................................................ 505.5.2 Layer 2........................................................................................................................ 51

5.6 ESTIMATED VOLUME OF LAYER 2 MATERIAL...................................................................68

5.7 SUMMARY OF FINDINGS.................................................................................................70

6 CONCLUSIONS AND RECOMMENDATIONS.......................................................73

LIST OF FIGURESFigure 1 Overview Greater Burgan Oilfield

Figure 2 Overview of Limited Scope by Sample Type

Figure 3a/b Limited Scope Sample by Feature Type

Figure 4a/b Limited Scope Samples: Layer 2 TPH (HEM) results

Figure 5 Limited Scope Samples: Zone 1







Figure 12a/b Limited Scope Samples: Samples Interpretation

APPENDIX

Appendix A: Figures and Drawings

Appendix B: Trial Pit Logs

Appendix C: Laboratory Analytical Data

Appendix D: Horizon UXO report



ABBREVIATIONS AND ACRONYMS

AFW - Amec Foster Wheeler

ASARP - As Low As Reasonably Practicable

ATG - Analytical Test Group

BGL - Below Ground Level

BS&W - Basic Sediment and Water

CIC - Consortium of International Consultants

COC - Chain of Custody

Company - Kuwait Oil Company

DOL - Dry Oil Lake

DRO - Diesel Range Organics

EOD - Explosive Ordnance Disposal

EQS - Environmental Quality Standard

GC - Gathering Centre

GRO - Gasoline Range Organics

HHMD - Hand Held Metal Detector

HSE - Health, Safety, and Environment

ID - Identification Number

m - Meter

KEPA - Kuwait Environmental Public Authority

KERP - Kuwait Environmental Remediation Project

KOC - Kuwait Oil Company

LLMD - Large Loop Metal Detector

LOD - Limit of Detection

LSSC - Limited Scope Site Characterization

MACD - Mina Ahmadi Construction Datum

ODC - Other Direct Cost

PAH - Polycyclic Aromatic Hydrocarbon

PMC - Project Management Consultant

PPE - Personal Protective Equipment

PSD - Particle Size Distribution

PTB - Pounds per Thousand Barrels

QA - Quality Assurance

QAPP - Quality Assurance Project Plan

QC - Quality Control



RBA - Risk Based Approach

RRO - Residual Range Organics

SAP - Sampling and Analysis Plan

SAR - Sodium Absorption Ratio (Measurement of Salinity)

SEK - South and East Kuwait Oilfield

SOP - Standard Operating Procedures

TKN - Total Kjeldahl Nitrogen

TPH - Total Petroleum HydrocarbonsTPH –CWG

- Total Petroleum Hydrocarbons –Criteria Working Group

TPH –HEM

- Total Petroleum Hydrocarbons –Hexane Extractable Material

TPH –SARA

- Total Petroleum Hydrocarbons –Saturates Aromatics Resins Asphaltines

UTM - Universal Transverse Mercator

UXO - Un-Exploded Ordnance

VOC - Volatile Organic Compound

WOL - Wet Oil Lake



EXECUTIVE SUMMARY

Introduction

As a precursor to the main Site Soil Characterization, the Limited Scope Site

Characterization (LSSC) was designed to obtain information to assist the Phase I

Remediation Project, and to provide more detailed understanding of the contamination

profile for the Risk Based Approach to remediation. As such the LSSC looked at the

contamination constituents, depth profile and extent of Dry Oil Lakes and transition

areas between Wet and Dry Oil Lakes within an area of the South and East Kuwait

Greater Burgan Oilfield.

The field work consisted of:

Unexploded Ordnance (UXO) anomaly avoidance;

218 hand dug trial pits; and

Collection and laboratory analysis of 251 samples from multiple depths per trial

pit.

Findings

The LSSC used the same layering classification of the contamination as the Consortium

of International Consultants (CIC):

Layer 1: For the Dry Oil Lakes this surface layer comprised a soft to hard and often

brittle crust. Within the transition zone with Wet Oil Lakes, this surface layer can be soft

and plastic/rubbery in consistency. These properties can change depending on the

season, a hard surface in the winter can become softer in the heat of the summer. This

means that a feature can be classed as a wet oil lake in the summer but becomes dry in

the winter. This need to be considered when classifying the features.

Laboratory results show the Wet and Dry Oil Lake Layer 1 material Total Petroleum

Hydrocarbons – hexane extraction (TPH (HEM)) ranges between 7 – 17 % TPH (where

1% equals 10,000 mg/kg). The TPH - Saturates Aromatics Resins Asphaltines (SARA)

typical range between 10 – 40 % TPH. The TPH - Criteria Working Group (CWG) shows

that the majority of the TPH are the higher carbon chain lengths EC35 to EC90.

The discrepancy between the TPH HEM and SARA results is likely due to the two

different extraction methods used by the laboratory. The HEM method is not as efficient

in extracting the longer carbon chain lengths which the TPH CWG confirm are present.



Layer 2: This layer comprised oil contaminated sand that is visibly stained. Generally it

was found that the darker brown/black the colour the higher the TPH concentrations.

Laboratory results show the Wet and Dry Oil Lake Layer 2 material TPH (HEM) ranges

between 0.2 – 9 % TPH. The TPH (SARA) typical range between 0.4 – 13 % TPH. The

TPH (CWG) shows that the majority of the TPH are the higher carbon chain lengths

EC35 to EC90.

Layer 3: This layer comprised sands with no visual evidence of contamination. The trial

pits dug for the LSSC show that there is a sharp visual boundary between Layer 2 and 3.

There is a high correlation between lack of visual staining and low (<0.5%) hydrocarbon

concentrations.

Laboratory results show the Layer 3 material TPH (HEM) ranges between 0.01 – 0.5 %

TPH. The TPH (SARA) typical range between 0.01 – 0.33 % TPH. The TPH (CWG)

shows that the majority of the TPH are the higher carbon chain lengths EC35 to EC90.

A comparison of the TPH (HEM) analytical results from the CIC and LSSC investigations

suggest that the TPH values are comparable, with samples taken in the same vicinity

(and layer) being of the same order of magnitude. Differences in the results from the two

investigations is likely to be from the inherent variability of contaminated sites. It should

also be noted the CIC investigation’s analysis of Layer 2 was just TPH – HEM which, as

stated above, under reports the higher carbon chain lengths.

It is important to note that areas designated in the CIC report as Dry Oil Lakes, upon

investigation under the LSSC were Tarcrete. This demonstrates the innate variance in

ground conditions across the oilfield and supports the requirement for further more

detailed characterization.

Zoning

Based on the analytical data and thickness of the Layer 2 materials (identified for

remediation under Phase 1) from the LSSC and CIC investigations, 7 zones were

defined to assist in identifying areas suitable for different remediation strategies.

Zone Approximate Area (m²)

Estimated Volume of Wet

Oil Lake Layer 2(m³)

Estimated Volume of Dry

Oil Lake Layer 2(m³)

Range of TPH (HEM) Layer 2

(%)

Zone 1 950,000 67,620 290,250 0.8 – 7.0Zone 2 312,000 0 116,760 0.9 – 3.2Zone 3 750,000 73,500 176,940 0.3 – 7.4Zone 4 585,000 3,920 157,950 0.1 – 3.8

Zone 5a 155,000 31,850 355,570 0.2 – 6.7



Zone 5b 505,000 8,820 106,900Zone 6 345,000 39,890 251,100 0.2 – 6.7Zone 7 680,000 67,620 290,250 0.3 – 7.9

Zones 2 and 7 were identified as areas suitable for remediation as part of phase 1.

Zone 2 has been identified as suitable for Phase 1 remediation due to the ease of

access of Layer 2 materials. Across the vast majority of Zone 2, the Layer 1 (crust)

ranges from a few millimetres to a few centimetres in thickness. The crust is a hardened

but friable dry oil lake crust. The contamination identified in Layer 2 is typically in the

range of 2.0-2.5% TPH of 0.3m thickness. This area is estimated to generate in the

region of 100,000 m³ of material suitable for remediation.

By contrast, Zone 7 forms a large expanse in a topographic depression of dry oil lake

intermingled with occasional small (<1000m2) and medium (>10,000m2) shallow wet oil

lake features. The crust can therefore vary between a thin hardened crust through to a

moist heavy sludge. However, the underlying Layer 2 contaminated sands range in

thickness from 0.2 m to greater than 1.2 m, providing a substantial volume of material for

remediation, in the region of 250,000 m3. This Layer 2 material typically has a

concentration in the range of 1.5 to 2% TPH.



1 INTRODUCTION

This report presents the activities and findings of the Limited Scope Site

Characterization (LSSC) carried out on behalf of the Kuwait Oil Company (KOC) by

Amec Foster Wheeler (AFW or PMC). As part of the Kuwait Environmental

Remediation Project (KERP), KOC is undertaking remedial activities on the legacy of oil

contamination generated as a result of the Gulf War. The remedial strategy incorporates

five main components, including risk based analysis, bioremediation, other treatment

technologies, recovery/reuse and landfilling. This work was performed under Other

Direct Costs (ODCs) 016 (for UXO support) and 017 (for environmental analytical

laboratory services).

The aim of the remedial strategy is to reduce the number of landfills by developing

appropriate alternatives to treat, recover or reuse contaminated materials. The purpose

of the LSSC was to gather updated oil contaminated soil data to further inform the

overarching remedial strategy. A limited scope site characterization (ground

investigation) was designed following completion of a data gap analysis. A designated

area, at South and East Kuwait Greater Burgan Oilfield (SEK), herein referred to as the

Investigation Area, was targeted due to the extent of differing types of oil contamination

present. The Investigation Area within the Greater Burgan Oilfield is shown in Figure 1

(Appendix A).

Site characterization was carried out according to the LSSC Sampling and Analysis Plan

(SAP) in the period of 16th November 2014 to 3rd December 2014 by PMC with UXO

support provided by Horizon Assignments (India). Laboratory analysis of soil samples

was performed by SGS Jubail Environmental.

1.1 Objectives

The objectives for the LSSC were to:

Update understanding of contamination profile and comparative assessment with historical data;

Confirmation of presence and boundaries of dry oil lake features;

Undertake specific testing suitable to inform risk assessment to support the Risk Based Approach (RBA); and



Characterize soils suitable for remediation treatment and identify areas and indicative volumes within South and East Greater Burgan oilfield suitable for SEK Remediation Phase 1.

1.2 Scope of Work

The scope of work for the LSSC work involved the following:

1. UXO anomaly avoidance survey to ensure safe pedestrian access from oilfield gatch roads to sampling locations;

2. UXO anomaly avoidance support during sampling activities;

3. Excavation of soil sampling trial pits;

4. Logging the ground conditions encountered at all trial pits, including photographic record;

5. Collection of soil samples and where available, sludge samples, from the planned locations, with applicable chain of custody as per the laboratory QA/QC procedures; and

6. Analysis of samples for physical and chemical determinants to inform remedial options.

This report details the factual element of work completed and provides commentary on

the findings of the LSSC work, namely contamination presence and type and indicative

volumes of material for remediation.

1.3 Report Structure

This report is presented in the following sections along with the appendices. A brief

description of each section is presented below:

Introduction This section provides the project objectives, scope summary and organization of this document.

Project Background Provides background information relevant to the development of the LSSC Report and presents the site contamination history.

Site Characterization Design and Scope

This section describes the overview of the scope, health and safety, UXO anomaly avoidance and sample collection.

Health, Safety and Environment

This section describes procedures in place to conduct the work safely with no risk to the



environment.

Discussion of Findings This section describes the observations made during the investigation, zones identified as possible areas for phase 1 remediation and reviewed the data. This section also looks at the comparison with historic data and the volumes of contaminated material in the above mention zones.

Conclusions Conclusions outlining the findings of the site investigations.

The following appendices are provided:

Appendix A: Figures and Drawings

Appendix B: Trial Pit Logs

Appendix C: Laboratory Analytical Data

Appendix D: UXO Avoidance Report



2 PROJECT BACKGROUND

This section provides an overview of the general characteristics of the site,

historical/current contamination and geological setting. During 1990 and 1991, severe

environmental damage was sustained in Kuwait as a direct result of Iraq’s invasion and

occupation of the country. Iraq destroyed a large number of Kuwait’s oil wells and other

oil field infrastructure, causing large oil field fires and releases of oil to the terrestrial

environment.

2.1 Site Contamination History

Numerous oil wells and other oilfield infrastructure was damaged or destroyed at the end

of the Gulf War. This resulted in numerous oil well fires and broken oil pipelines.

Differing types of contamination features were derived from either airborne deposition of

crude oil, overland flow or earth moving activities used to mitigate crude oil migration, as

described below.

2.1.1 Wet Oil Lake Features

Crude oil flow from damaged oil wells and pipelines accumulated in shallow

topographical depressions and drainage channels resulting in what is referred to as wet

oil lakes. The wet oil lakes largely comprise:

1. Sludge (which may or may not have a thin bituminous crust) with high sediment loading (known as Layer 1), which in turn overlies;

2. Visually stained sand with varying concentrations of oil contamination (Layer 2), overlying;

3. Visually non-contaminated sands (Layer 3).

There are instances in the oilfield where wet oil lakes were purposefully formed for the

recovery of crude oil. One instance of this is located within the LSSC investigation area.

2.1.2 Dry Oil Lake Features

The dry oil lakes are generally found in very shallow depressions and flat areas,

frequently forming fringe areas around wet oil lakes. Dry oil lakes cover a much larger

surface area than wet oil lakes. The dry oil lakes comprise:

1. A variable thickness, black, moderately hard to hard, tar-like dry surface layer (Layer 1), overlying;



2. Visually stained sand with varying concentrations of oil contamination (Layer 2), overlying;

3. Visually non-contaminated sands (Layer 3).

2.1.3 Tarcrete

Tarcrete is the most widely dispersed form of oil contamination. This is a function of its

airborne formation from crude oil ejected from damaged oil wells, whether ignited or not.

Tarcrete forms a very thin hard crust typically beyond the extent of wet and dry oil lakes

and is a distinct material type. The crust varies in thickness and composition and can

form either a continuous surface covering or a broken granular like bed. Tarcrete is

characterized by an absence of oil contaminated sand beneath the crust.

2.1.4 Oil Contaminated Piles

Oil-contaminated piles are man-made mounds of soil that are contaminated with crude

oil. These are located where earth-moving equipment was used to consolidate oil-

contaminated soil and/or liquid oil. These piles were made in an effort to stop the spread

of oil flows caused by the destruction of oil wells, or to clear areas of oil contamination as

necessary to facilitate fire-fighting or subsequent KOC field operations.

2.2 Geology

The description of the geology for the south-eastern area of Kuwait has been acquired

through reference to the CIC reports for Burgan dated 2002. Kuwait’s shallow geology

primarily comprises sedimentary strata from the Tertiary age which results in a surface

topography of sandy plains. The Dibdiba formation overlies Fars and Ghar formations.

The Dibdiba formation comprises fluviatile sequence of ungraded cross bedded sands

and gravels, sandy clays, sandstones, conglomerate and siltstones. Fars and Ghar

formations comprise ungraded cross bedded calcareous sandstone sands and gravel

with sandy limestone and unconsolidated clay and sand.

The underlying geology directly influences the soil which in the Burgan area can extend

to around 2 m depth. The soils whilst predominantly sand also have a high percentage of

silt, ranging between 15% and 35%. Also typically present are fine gravels up to 15%.

Due to the calcareous nature of the soils the surface is often found to comprise a thin

cemented layer or crust, described as Lag deposits. A hardpan calcareous layer (locally

called gatch) is found throughout the Kuwaiti desert at various depths. It is a

consolidated calcareous sandy matrix with high silica content, which is slightly

gypsiferous.



3 SITE CHARACTERIZATION DESIGN AND SCOPE

3.1 Site Characterization Design

The LSSC was designed to supplement characterization data obtained in 2002 by the

Consortium of International Consultants (CIC). The CIC data was collected to inform

compensation claims to the United Nations and as such, had a different scope.

However, the data gathered from CIC provides a broad baseline of ground conditions

from 2002.

The locations for the Limited Scope Soil Characterization were defined following review

of CIC data. Where there were significant data gaps between the CIC data points,

additional characterization locations were planned. Due to the lack of unexploded

ordnance (UXO) clearance certificates for wet oil lake features, the vast majority of the

sampling was conducted across dry oil lake features and from what have been defined

as ‘transition areas’, i,e. those areas between wet oil lake and dry oil lake features. In

addition to the dry and wet oil lake features, background samples were also taken in

areas where no visual contamination was present or had historically been recorded as

present.

A range of chemical and physical suites of analysis were defined to inform remedial

design, whether for risk assessment, bioremediation or mechanical remediation

processes.

3.2 Overview of Scope

The site investigation field program was conducted in the South and East Kuwait Greater

Burgan Oilfield (SEK) from 16th November 2014 to 3rd December 2014.

The Site investigation involved the following scope of work:

UXO anomaly avoidance for foot access to, and excavation of, hand dug trial pits;

Hand dug trial pit excavation;

Soil sampling and consignment of samples to the nominated laboratory; and

Topographic survey of each sampling location.

3.2.1 UXO Support

Due to the historical legacy of unexploded ordnance (UXO) associated with the Gulf

War, UXO had the potential to be present within the area of inspection. Although UXO

clearance certificates are available across the dry oil lake features, because of the depth



of excavation, further UXO anomaly avoidance was considered necessary, in line with

KERP protocols.

Horizon Assignments (India) Pvt Ltd. (Horizon) provided UXO anomaly avoidance

support during the Limited Scope Site Characterization in SEK. Horizon provided

personnel and detection equipment for two soil sampling teams. The Horizon report

(AMEC/ODC-016/FR/001) which covers activities undertaken during the LSSC is

included in Appendix D.

3.2.1.1 UXO Anomaly Avoidance for Access to Trial Pits

The UXO team conducted a UXO anomaly avoidance survey of all access routes and

sampling locations within areas that held UXO clearance certificates. Equipment used

comprised all metal large Loop Metal Detector (LLMD) / Hand Held Metal Detector

(HHMD) capable of detecting the smallest known or anticipated military munitions to a

depth of approximately 0.3 meters. If any anomalies were detected, the area was

prominently marked with a red flag for avoidance during the sampling activities.

Vehicles were parked as close as possible to the sample locations using established

roads, wellhead pads, or other features that have been constructed in the past 20 years.

An approximate 2-meter wide path from the vehicle parking area to the sample location

was established and marked with stakes. After the proposed trial pit location was

reached, a safe working area around the trial pit location was established and marked

with stakes.

3.2.1.2 UXO Anomaly Avoidance for Trial Pit Excavations

Each trial pit location was first surveyed at surface by Horizon. Where no anomalies

were detected, the trial pit was excavated to the maximum depth of detection. The trial

pits were excavated incrementally to their full depth utilising continued application of

anomaly avoidance.

3.2.2 Trial Pit Excavation

Trial pit excavations were completed using, where necessary, a pick to break the

hardened surface and a standard hand shovel to excavate the underlying sand. The test

pits were excavated from a minimum 0.2 m to a maximum depth of 1.2 m below ground

level (m bgl). Typically, trial pits were approximately 0.5 m long by 0.5 m wide by 0.5 m

deep. A total of 218 trial pits (referenced TP-1 to TP-222) were excavated at the

locations shown on Figure 2 (Appendix A). Figure 3a/b show the trial pit locations with



the short reference. The presence of utilities or access limitations prevented four trial

pits from being completed (TP-111, TP 189, TP- 198 and TP-204).

Excavated trial pits were backfilled immediately following logging of ground conditions

and sampling of soils. The trial pit was backfilled using the stockpiled arisings from

excavation in the reverse order that the trial pit was excavated (i.e. the deepest soil was

replaced in the bottom of the excavation).

3.2.2.1 Trial Pit Logging

The lithologic descriptions for unconsolidated materials (soils or deposits) were logged in

accordance with British Standard BS 5930:1999 +A2:2010 using the name of the

predominant particle size (e.g., silt, fine sand, coarse sand). The dimensions of the

predominant and secondary sizes were recorded using the metric system. The grain

size and name of the deposit were accompanied by the predominant mineral content,

accessory minerals, colour, particle angularity, and any other characteristics. The colour

descriptions were designated by the Munsell Color System.

Trial pit logs which summarize the conditions encountered at each location such as total

depth of excavation, thickness of different contaminated layers together with visual and

olfactory evidence are provided in Appendix B.

The following table summarises, in chronological order, the trial pitting locations

completed for each day of field activity.

DateTest Pit Excavation Activities Performed

Dry Oil Lakes Wet Oil Lakes* Background

16-Nov-14 TP 35, TP 36

17-Nov-14 TP 26, TP 34, TP205, TP186, TP24, TP28, TP 195

18-Nov-14 TP 23, TP 32, TP 160, TP 25, TP 31, TP 34, TP 159, TP 21, TP 22,

TP 33, TP 185, TP 105,

19-Nov-14 TP 1, TP 2, TP 106, TP 107, TP 108, TP 196

TP 110, TP 109, TP112, TP161, TP 196

20-Nov-14 TP37, TP38, TP39, TP40, TP114, TP115, TP125,TP127, TP165, TP41, TP162,

22-Nov-14 TP8, TP124, TP128, TP139, TP166, TP167 TP9, TP 199

23-Nov-14 TP12, TP13,TP19,TP20,TP54, TP55, TP56, TP76, TP77, TP78, TP138, TP174,TP178 TP 202



DateTest Pit Excavation Activities Performed

Dry Oil Lakes Wet Oil Lakes* Background

24-Nov-14TP 85, TP 86, TP 87, TP 88, TP 146, TP 157, TP 158, TP 180, TP 183, TP 184, TP 204

TP 193, TP 89, TP 204

25-Nov-14 TP 75, TP 94, TP 101, TP 102, TP 103, TP 104, TP 155, TP 156, TP 194 TP 203

26-Nov-14

TP 9, TP 82, TP 83, TP 90, TP 91, TP 92, TP 95, TP 96, TP 97, TP 99, TP 100, TP 151, TP 152, TP 153, TP 154, TP 154, TP 182

TP 93, TP 98,

27-Nov-14TP 149, TP 81, TP 80, TP 79, TP 148TP 147, TP 84, TP 181, TP 150, TP 18TP 14, TP 192, TP 15

TP 179

29-Nov-14 TP 16, TP 17, TP 58, TP 63, TP 65TP 66, TP 68, TP 139, TP 140, TP 141, TP 175, TP 176, TP 200

TP 64, TP 200

30-Nov-14 TP 51, TP 52, TP 53, TP 57, TP 59, TP 60TP 62, TP 67, TP 133, TP 134, TP 135, TP 136, TP 137, TP 168, TP 169, TP 203

TP 188,

1-Dec-14 TP 42, TP 45, TP 47, TP 48, TP 50TP 120, TP 121, TP 122, TP 123, TP 130TP 131, TP 132, TP 163, TP 171

TP 61, TP 164, TP 187, TP 197, TP 46

2-Dec-14

TP 10, TP 11, TP 69, TP 70, TP 71, TP 72 TP 73, TP 126, TP 142, TP 143, TP 144, TP 145, TP 170, TP 172, TP 173, TP 177, TP 190, TP 191,

TP 43,

3-Dec-14 TP 3, TP 4, TP 5, TP 7, TP 29, TP 30, TP 116, TP 117, TP 118, TP 119, TP206 –TP222

TP 27,

Total 184 26 9

* Wet oil lakes includes the transition area adjacent to the wet oil lakes that have a profile more akin with wet oil lakes than dry.

3.3 Sampling

Soil sampling was undertaken at approximately 205 locations as shown on Figures 2

and 3a/b (Appendix A). The sampling locations and number of samples were based on

filling in data gaps in reference to the CIC data. Approximately 310 samples were

collected from the intrusive locations with 251 of these undergoing laboratory analysis.

The remaining 59 samples collected were either oversampling or from ground conditions

already characterized at other locations. The sample depth ranged from ground surface

to a maximum of 1.2 m below ground level (bgl). This allowed characterization across

the investigation area of the three differing layers comprising:

Layer 1: Oily crust/thick sludge/oil/water (wet oil lake feature) or crust (dry oil lake feature);



Layer 2: Oil contaminated sand (of various stained colours); and

Layer 3: Visually and olfactory no evidence of contamination.

A total of 301 samples were taken from contaminated feature locations from one of the

layers identified above. A further nine samples were taken to characterize background

conditions. The sampling intervals for these layers were visually field-determined.

As part of the wet oil lake sampling/transition zone, 10 sludge or crust samples were

collected and analysed to provide data to support the market research study for re-use /

disposal of these materials.

Soil samples were collected from cleared faces of trial pits, ensuring no debris from

excavation. The primary focus of the LSSC was collection of data from Layer 2 and

therefore the majority of soil samples were collected from Layer 2. Samples were

collected using a clean stainless steel trowel. All of the samples were collected as

discrete samples. Sampling equipment that was in contact with soils was

decontaminated between sampling exercises. Care was exercised during excavation of

test pits to prevent material from falling into the pit from upper intervals and potentially

cross-contaminating the sample.

Soil samples were placed in 250ml clear glass jars provided by the laboratory and

sealed with a septum and plastic lid. Sufficient volume of soil was collected, as

determined by the laboratory for the required analysis. Each sample was given a unique

reference. In addition to the trial pit reference, e.g. TP133, known as the Short ID, an

additional reference was provided using the following example sample ID (known as the

Long ID). The Long ID was used for incorporation of the data within the overarching

KERP database, whilst the Short ID has been used in reporting for ease of reference.

Example Sample ID:


Sample ID SuffixSample ID Main PartSample ID Prefix

BG27829116-1

782782 East 3209116 North


The Sample ID suffix consists of a two character value starting with “-1” for the

uppermost sample. The combination of the Short and Long ID ensured samples were

not mixed at the laboratory.

A pre-printed sample label was affixed to the outside of the sample bottles and key

information comprising date of sampling, time of sampling, unique sample identification

(ID) number and the sample depth range was recorded on the label of the sample

bottles.

Digital photographs were taken to document the conditions after sampling. Photographs

were taken at each sampling area and test pit excavation. Where possible, the

photographs illustrate the soil layers down to the layer from which the sample is

collected. The photographs will serve to verify information entered in the field

notebooks. For each photograph taken, the time, date, sample location number, and

direction (for sampling area photos) was written in the field notebook. Photographs of

each trial pit are included in the field logs in Appendix B.

A unique reference Chain of Custody documentation was completed and enclosed with

each batch of samples. The samples were placed directly into cool boxes (coolers) with

frozen ice packs, to maintain low temperatures, and dispatched on the same day as

collection.

Samples were picked up at the end of each day at the PMC office by the analytical

laboratory. The chain of custody documentation was completed and signed by the

laboratory’s representative / courier. The analytical laboratory was responsible for

transporting the sample coolers to their facility in Saudi Arabia in a timely manner to

ensure the internal temperature of the coolers does not rise above 4°C.

3.4 Equipment Decontamination

All equipment that was directly or indirectly in contact with samples were

decontaminated before proceeding to the next sampling location. Cross contamination

during sample collection was minimized by the use of disposable gloves which were

replaced for each soil contamination layer (i.e., Layer 1, Layer 2 and Layer 3) sampled.

All non-disposable field equipment were decontaminated before each use to avoid

cross-contamination between layers. Sampling equipment was decontaminated using a

solution of anionic (non-phosphate) soap (Alconox Liquinox®) and potable water

followed by a “clean” rinse using potable water. To ensure that sampling equipment was

free of contamination, an equipment blank was collected.



3.5 Sample Analysis Summary

Soil samples were collected based on visual observations of the soil layers identified at

any given sample location. The analytical tests which were performed (Analytical Test

Group [ATG] plus any miscellaneous tests) for each soil layer are intended to support

the anticipated remedial alternative(s) for that layers. The sample analysis summary is

discussed in Section 5 below.

Laboratory analysis was performed on selected soil samples obtained from test pits

samples. The laboratory analytical certificates are provided in Appendix C.

3.6 Quality Assurance

The quality assurance (QA) and quality control (QC) requirements ensured that the

samples were collected and analysed in accordance with the SAP. A senior

environmental professional experienced with contaminated land investigations lead the

sampling team and was in charge of QA/QC.

Sample-handling procedures included field documentation, COC documentation, sample

shipment, and laboratory sample tracking. The possession and handling of samples

were documented from the time of collection to delivery to the laboratory. Field

personnel maintained custody of all samples until they were relinquished to the

laboratory courier. Samples were packaged and transported in a manner that maintained

the integrity of the sample(s) and permitted the analysis to be performed within the

prescribed holding time. Samples were transported on the same day to the laboratory.

Field-sampling precision and data quality were evaluated through the use of sample

duplicates and blanks as per BS 10175:2011+A1:2013 as discussed below.

Sample Duplicates - Sample duplicates provided precision information regarding

homogeneity, handling, transportation, storage, and analysis. Duplicates were collected

at an approximate rate of 1 per 25 samples for a total of 9 duplicates. Each duplicate

pair were collected from the same location using the same procedure. The samples

submitted as duplicates were blind duplicates, i.e. were referenced in such a manner so

as to prevent the laboratory from identifying their location. Where analysed, each

duplicate pair was analysed for the same parameters.

Ambient Blanks - Ambient blanks (field blank) were used to assess the potential

introduction of contaminants from ambient sources (e.g., wind-blown, venting wells,

internal combustion motors in operation) to the samples during sample collection. The

ambient blanks were handled like an environmental sample and transported to the



laboratory for analysis. Ambient blanks were only analyzed for VOCs. Over the

investigation area one ambient blank was collected and analysed.

Equipment Blanks - Equipment blanks were prepared to assess the effectiveness of

equipment decontamination procedures on sampling equipment (hand trowels).

Equipment blanks consist of ASTM Type II reagent grade water poured over a sampling

device, collected in a sample container, and transported to the laboratory. Equipment

blanks were collected immediately after the equipment had been decontaminated.

Given the relatively low density of soils, most of the samples were collected from the

face of excavations by the engineer using clean nitrile gloves. However, where heavily

contaminated soils were encountered, sampling devices were employed. During the site

investigation one equipment blank was collected.

Trip Blanks - Trip blanks were used with VOCs only, to ensure that containers,

transportation, storage, and/or the preservation of the samples did not introduce

contamination. Trip blanks were collected at a rate of 1 per 40 for a total of 5 trip blanks.

The laboratory was responsible for ensuring that the laboratory’s data precision and

accuracy are maintained in accordance with their specifications. Internal laboratory

duplicates and calibration checks were performed on one in every 20 samples submitted

for analysis. Other internal laboratory QA/QC was performed according to the laboratory

standard operating procedures (SOP) in accordance with ISO 17025.

3.7 Surveying

The location of each sampling location was initially measured and recorded using a

hand-held Global Positioning System (GPS) unit prior to surveying. Sampling locations

and elevations were surveyed using the Universal Transverse Mercator (UTM) projection

World Geodetic System 1984 (WGS 84) reference coordinate system. The zone for

Kuwait is 38N; some areas in the east of Kuwait are within zone 39N. All elevation

data was referenced to the Mina Ahmadi Construction Datum (MACD).The surveying

was carried out by PMC’s dedicated surveying team.

3.8 Waste Handling

No solid waste arisings were generated during the execution of the site characterization

works. Wash and rinse water generated during decontamination procedures were

disposed of on the ground surface. Disposable gloves, used during sampling, and non-

investigative waste such as non-contaminated refuse was removed from site and



transported to a municipal waste collection bin. Waste was managed as per the KOC

Waste Management Procedure KOC.EV.008.



4 HEALTH, SAFETY, AND ENVIRONMENT

In order to ensure that HSE issues were addressed at the earliest stage of the project,

the process started with the planning stage hazard identification and risk assessment

process, which also included the development of a project risk map. Potential hazards

associated with the scope of work, specifically UXO anomaly avoidance & soil/sludge

sample collection, were identified and risk mitigation measures agreed to ensure the

risks to our employees and subcontractors were reduced to ALARP.

All personnel required to work in the field were given a Project specific Safety Induction,

where they were made aware of the safety requirements specified in the Health, Safety,

and Environment Plan (HSE Plan), as per KOC.GE.048

Toolbox talk meetings were held at the site on a daily basis to reaffirm the HSE

requirements prior to works commencing for the day.

The works were controlled under the KOC Permit to Work System which was

implemented in accordance with KOC.SA.004 Permit to Work. AFW acted in the roles of

Permit Applicant and Worksite Supervisor and KOC operations personnel acted as

Permit issuer.

To ensure HSE support and advice was available throughout the life of the field works,

an HSE professional was assigned fulltime to the field team.

Since the field works were considered site based, all personnel were required to wear

appropriate Personnel Protective Equipment (PPE) for the tasks carried out as per

Procedure for Personal Protective Equipment (KOC.SA.010). The following PPE items

were considered as mandatory during work on this project:

Hard hat

Coveralls

Safety boots

Safety glasses

Emergency Planning was undertaken and the arrangements formalised within the HSE

Plan.

Prior to works commencing, an Emergency information sheet was completed detailing

first aiders, the assigned ERC for the shift and the GPS coordinates for the particular

area being sampled. This was posted in the assigned emergency vehicle prior to works

commencing.



The emergency vehicle contained the necessary first aid equipment and fire

extinguishers to allow the ERC to respond to an emergency situation.

The project was completed without injury or damage to property or the environment.



5 DISCUSSION OF FINDINGS

5.1 Introduction

The limited scope soil characterization was carried out between 16 th November and 3rd

December 2014.

This section reviews:

The observations made during the ground characterization;

The dividing of the CIC and LSSC data into Zones (based on observed Layer 2 thicknesses) to facilitate remediation options appraisal;

A review of the data;

A comparison of the TPH (hexane extraction – or HEM) data from the CIC and LSSC site investigations;

The estimated volumes of Layer 2 materials (oil impacted sands), by zones; and,

A summary of the field investigations findings.

Figure 2 and 3a/b (Appendix A) show the location of the trial pits excavated as part of

the LSSC investigation.

5.2 Overview of Visual Observations

The CIC investigation identified three distinct layers based on the level on contamination

of the natural sand.

Layer 1 – Oil and sludge

Layer 2 – Oil contaminated sand

Layer 3 – Sand which has No Visual and Olfactory evidence of Contamination

These layers were also identified during the current investigation in the wet and dry oil

lakes. Separate to the oil lakes, tarcrete was encountered as a crust of contaminated

material on Layer 3 type material. The photos below shows photos from wet and dry oil

lakes with Layers 1, 2 and 3 labeled up.



From left: Examples of Wet (TP179) and Dry Oil (TP157) Lake Trial Pit Excavations

5.2.1 Layer 1

Generally Layer 1 can be split in two distinct categories; hard, dry and brittle; and soft,

wet and plastic/rubbery. The harder Layer 1 often shows signs of burning from when the

oil lakes were on fire. The softer layer includes pockets and areas of free phase. In

general, dry oil lakes primarily appeared to have a harder Layer 1 but some dry oil lakes

the Layer 1 is more plastic/rubbery. Wet oil lakes always had a soft/sludge Layer 1.

From the recent sampling programme Layer 1 tends to be less than 0.1 m thick with

occasional deep areas up to 0.7 m. However there is a sampling bias to these depths as

the wet oil lakes were not sampled as part of the scope of this work. It is expected that

the Layer 1 will be thicker in the wet oil lakes.

It should be noted that the properties of the surface are sessional/temperature

dependent. Areas that are hard during the winter can be soft when heated up during the

summer.

5.2.2 Layer 2

Layer 2 generally comprised of dark brown sands and silty sands. The layer has visible

contamination with a strong hydrocarbon odour. The dark colour is likely to be due to

hydrocarbon staining. Generally (but not always) with depth the colour becomes lighter

to medium brown signifying a reduction in contamination.

5.2.3 Layer 3

Layer 3 comprised light brown sands and silty sands. Layer 3 show no visual and

olfactory evidence of contaminated or only a slight hydrocarbon odour.

Where hard layers were encountered or Layer 2 was deeper than 1.2 m, Layer 3 was

not always reached.

5.2.4 Background Conditions

Background samples were taken where oil contamination was not expected and where

there was no visual or olfactory evidence of contamination at surface. These samples

were in appearance very similar to Layer 3 soils and have a similar contaminant profile

to Layer 3 soils..



5.2.5 Tarcrete

Tarcrete is associated with airborne oil emitting from gushing or burning wells. As such

the tarcrete tends to be hard and thickest around the oil wells. With distance from the

wells the tarcrete becomes thinner eventually becoming loose bound and friable.

5.3 Zoning

Based on data collected during the CIC and LSSC site investigations, seven zones were

identified. These zones were delineated based on the thickness of the Layer 2 material,

and were designed to assist in identify areas suitable for different remediation strategies

(i.e. Excavation and Transport to landfill, potential recycling or re-use, bioremediation,

soil washing etc.). Figures 4a/b (Appendix A) show the locations of the zones with the

TPH (HEM) results from all the Layer 2 samples. The below table sets out the zone

areas and the samples taken within each zone (it should be noted that the LSSC

sampling targeted all the dry oil lake features in the investigation area not just the dry oil

lakes in the 7 zones).

Zone Approximate Area (m²) No. of CIC locations No. of LSSC locations

Zone 1 950,000 8 15Zone 2 305,000 5 8Zone 3 750,000 16 15Zone 4 585,000 8 10

Zone 5a 155,000 5 4Zone 5b 505,000 8 5Zone 6 345,000 6 9Zone 7 680,000 7 12

All Zones 4,190,000 61 75There were a further 147 LSSC and 111 CIC locations which were in the investigation area but did not form part of the 7 zones identified as suitable for remediation

5.3.1 Zone 1

Zone 1 is located in the north of the investigation area. The zone is elongated running

east-west along a topographic low. The zone contains two oil wells, one in the east of

the zone and one in the west. Both oil wells have oil contaminated piles on three sides of

the gatch pad, these will have been used during the firefighting. There is a large wet oil

lake (102,000 m²) in the west of the zone, adjacent to the western oil well. There are a

number of small pockets of wet oil lake features in the centre zone west of the eastern

oil well. There are also two medium sized wet oil lakes (10,000 and 3,500 m²) in the

south eastern corner of zone 1. The approximate areas of the contaminated features in

Zone 1 are:



Dry oil lakes 775,000 m²

Wet oil lakes 140,000 m²

Oil contaminated piles 35,000 m²

Figure 5 (Appendix A) shows zone 1 with the contaminated features marked, along with

the CIC and LSSC trial pit locations.

5.3.2 Zone 2

Zone 2 is located to the east of the investigation area. It consists of two dry oil lakes one

is located just north of an oil well the other is located between the same oil well to the

north and a large wet oil lake to the south. Zone 2 consists of a channel running between

the oil well and the wet oil lake with a large shallow area to the east. Zone 2 just consists

of two dry oil lake features, with no wet oil lake or oil contaminated piles. The

approximate area of the contaminated features in Zone 2 is:

Dry Oil Lake: 305,000 m²

Figure 6 (Appendix A) shows zone 2 with the contaminated features marked, along with


5.3.3 Zone 3

Zone 3 is located in the south east of the investigation area. Zone 3 is between a triangle

of three oil wells, one in the north and two in the south, with a spur to the south east.

The oil wells have oil contaminated piles around the gatch pad, these will have been

used during the firefighting. There are two large wet oil lake features in zone 3 both in

topographic lows, one in the centre of the zone 86,000 m² and one on the spur to the

south east of the zone 50,000 m². The area between the central wet oil lake feature and

the oil well to the south east of the zone is classed as a dry oil lake feature, however the

data suggests that this area has a significate Layer 1. The approximate areas of the

contaminated features in Zone 3 are:




Figure 7 (Appendix A) shows zone 3 with the contaminated feature marked, along with




5.3.4 Zone 4

Zone 4 is located in the south of the investigation area. Zone 4 connects three oil wells

with linear dry oil lake features. Two oil wells in the north and one in the south. The oil

wells have oil contaminated piles around the gatch pad, these will have been used

during the firefighting. There are only some small wet oil lake features in zone 4. The

approximate areas of the contaminated features in Zone 4 are:






5.3.5 Zone 5

Zone 5 is located in the south west of the investigation area. This zone has been split

into two 5a and 5b. Zone 5a is a wet and dry oil lake associated with a single oil well.

The approximate areas of the contaminated features in Zone 5a is:



Zone 5b is part of a bigger area classified by CIC as a dry oil lake feature associated

with a number of oil wells. Zone 5b showed a greater thickness of Layer 2 material. The

data suggests that the rest of the feature may have been misclassified and may be

Tarcrete. Zone 5b has a number of oil contaminated piles associated with the oil wells.

In the south and middle of the zone there are occasional medium sized wet oil lakes. In

the north there are number of long thin wet oil lakes which trend WNW – ESE. The

approximate areas of the contaminated features in Zone 5b are:




Figure 9 (Appendix A) shows zone 5a&b with the contaminated feature marked, along

with the CIC and LSSC trial pit locations.



5.3.6 Zone 6

Zone 6 is located just south of the centre of the investigation area. Zone 6 is part of a

bigger area classified by CIC as a dry oil lake feature associated with a number of oil

wells. Zone 6 is just south of a large wet oil lake 175,000 m². There are two oil wells in

the north of the zone and one to the south, these have oil contaminated piles around the

gatch pad, these would have been used during the firefighting. There are a number of

wet oil lakes in the southern half of the zone which trend north east – south west. There

are also some wet oil lakes around the most northerly of the oil wells. The approximate

areas of the contaminated features in Zone 6 are:






5.3.7 Zone 7

Zone 7 is located in the west of the investigation area, located just west of GC-07. Zone

7 is also part of the same bigger area classified by CIC as a dry oil lake feature which

Zone 6 is part of. Zone 6 is in the south east of the area where Zone 7 is in the north-

west. Zone 7 has 8 oil wells along its western and northern edge these each have oil

contaminated piles associated with them. The middle section of the zone has five

medium sized wet oil lakes (between 4,000 – 17,000 m²) surrounded by a number of

smaller wet oil lake features. The northern section of the zone has some linear wet oil

lake features trending north east – south west. There aren’t any recorded wet oil lake

features in the south of the zone. The approximate areas of the contaminated features in

Zone 7 are:








5.4 Review and Assessment of Data

This section of the report describes in detail the findings from the limited scope site

investigation in relation to the different feature types, i.e. wet oil lakes, dry oil lakes and

background samples, together with their respective layering. Layers 1, 2, and 3 are the

different layers used to describe the lake features as illustrated in Figure 11.

For each feature type and layer there is a broad summary discussion of the findings

before a greater focus on the various hydrocarbon analyses. There are four main types

of total petroleum hydrocarbon (TPH) analysis as follows:

TPH (Hexane Extractable Matter - HEM); USEPA 9071B – This analysis used a

hexane extraction and is analyzed to provide a single total hydrocarbon result. This

analysis is designed for “oil and greases” and is not suited for defining volatile

hydrocarbons that can be lost during the extraction process. Indeed, results for

hydrocarbons up to EC16 have the potential to be compromised due to the

extraction process. Additionally, it is recognized that some elements of crude oils

may not be fully extracted, i.e. are not soluble within hexane. However, this

methodology was used in assessing soil contamination in 2003 by the CIC and,

therefore, provides some comparability.

TPH Criteria Working Group (CWG) Perf Methodology 8015B/8260 – This analysis

used dichloromethane as the solvent for extraction allowing a greater proportion of

hydrocarbons to be extracted and subsequently analyzed. The volatile fractions are

assessed by headspace analysis to minimize loss. The methodology speciates and

bands hydrocarbons into the following:

o Aliphatics: EC5-EC6, EC6-EC8, EC8-EC10, EC10-EC12, EC12-EC16, EC16-

EC21, EC21-EC35

o Aromatics: EC5-EC6, EC6-EC8, EC8-EC10, EC10-EC12, EC12-EC16, EC16-

EC21, EC21-EC35

In addition, EC35-EC90 results have been provided by the laboratory.

TPH Saturates Aromatics Resins Asphaltines (SARA); IP469 – Following a

dichloromethane extraction process, this analysis fractioned the hydrocarbons into0:

o Saturates: non-aromatic cyclic and acyclic hydrocarbons (naphthenes and

paraffins);

0 Definitions taken directly from IP169/01 (2006): Determination of saturated, aromatic and polar compounds in petroleum products by thin layer chromatography and flame ionization detection.



o Aromatics: hydrocarbons containing one or more aromatic ring including some

sulfur containing hydrocarbons of the thiophene or sulphide type. Some low

content nitrogen-containing compounds, e.g. benzocarbazoles and oxygen-

containing compounds, e.g. benzofurans, may also be present;

o Polar (I) compounds: not well defined lower molecular mass polar compounds

containing nitrogen, sulfur and oxygen, e.g. benzoquinolines, carboxylic acides,

phenols and metalloporphyrins; and

o Polar (II) compounds: not well defined higher molecular mass and polyfunctional

polar compounds. This compound class is similar, but not identical, to heptane-

insoluble asphaltenes.

TPH Fractionated; 8015B and 8260B – This analysis grouped the hydrocarbons into

gasoline range organics (GRO) comprising EC5-EC10, analyzed by headspace,

diesel range organics (DRO) comprising EC10-EC34 using a hexane extraction and

residual range organics (RRO) comprising >EC35 using a toluene extraction.

5.4.1 Wet Oil Lakes

Wet Oil Lake Layer 1 – Summary Overview

A total of 16 soil samples were collected from Layer 1 of wet oil lake features across the

LSSC investigation area. The sample locations generally correlate with areas identified

by CIC as being wet oil lake features. However, there are a small number of sample

locations that have been considered as wet oil lakes that were previously identified as

dry oil lakes. These locations are in areas of lower elevation.

The Layer 1 samples were taken from large single wet oil lake features and their

immediate surroundings or from areas where there are numerous small wet oil lake

features grouped together. The wet oil lake locations are provided on Figure 3a/b

(Appendix A).

Analysis of Layer 1 materials comprised some or all of the following:

Total (HEM) Electrical Conductivity

Gross Calorific Value

PSD

TPH CWG Moisture Salt

TPH SARA pH BS&W

TPH Fractionated Sodium absorption ratio



Despite the widespread geographic distribution of Layer 1 samples, within the

contaminant profile, there are similarities. The hydrocarbon composition is dominated by

the heavier end >EC35 compounds together with polar (I) compounds, i.e. lower

molecular mass polar compounds containing nitrogen, sulphur and oxygen. From the

samples collected there was no positive identification of volatile compounds in the EC5-

EC10 range. Overall, the TPH concentrations are identified as greater than 10% TPH.

Further more detailed assessment is provided below.

The basic sediment and water analysis (BS&W) from eight samples shows an

approximate 30-45% proportion of the wet oil Layer 1 as sediment. The particle size

analysis indicates that the sediment mainly comprises medium to fine sands and

silt/clays. The silt/clays can be significant with one sample containing nearly 55%

silt/clays. The water content of the Layer 1 material is typically between 10% and 20%,

occasionally containing up to 40%.

The gross calorific values are typically between 20 and 40 Mj/kg at wet oil features,

reducing to <10 Mj/kg in areas adjacent to wet oil lake features. Salt content ranges from

10 pounds per thousand barrels (PTB) to 18,000 PTB. The locations with the higher salt

content are in areas of marginally lower elevation compared to surroundings, i.e. in

shallow depressions. The pH ranges from slightly alkaline at 7.25 to alkaline at pH 9.70.

TPH Assessment

Three main types of TPH analysis were undertaken on the Layer 1 materials. These

comprised:

TPH (HEM) – 7 samples,

TPH SARA – 13 samples, and

TPH Fractionated – 7 samples.

Only one sample was assessed for TPH CWG.

TPH (HEM)

The analytical results for the TPH (HEM) for wet oil lakes are amongst the highest TPH

concentrations recorded from the Limited Scope investigation. The concentrations range

from 94,835 mg/kg (9.48% TPH) to 166,171 mg/kg (16.62% TPH). The geometric and

arithmetic mean are similar at 133,373 mg/kg (13.34% TPH) and 135,557 mg/kg

(13.55% TPH) respectively, suggesting consistent concentrations for this material type.



TPH SARA

The TPH SARA provides further definition on the TPH composition for the Layer 1

materials. The summation of the four components: saturates, aromatics, polar (I) and

polar (II) compounds gives a total TPH SARA ranging from a minimum of 96,231 mg/kg

(9.62% TPH) through to 355,944 mg/kg (35.59% TPH). The geometric and arithmetic

means of 166,617 mg/kg (16.66% TPH) and 177,438 mg/kg (17.74% TPH) respectively,

are higher than that for TPH (HEM), a function of the efficiency of the extraction

methodology across a wider carbon range. Where samples have been scheduled for

both TPH SARA and TPH (HEM), TPH SARA results are typically between 30 to 40%

greater than TPH HEM.

The TPH SARA analysis shows that the composition of the extractable hydrocarbons is

dominated by Polar (I) compounds, typically comprising approximately 60% of the total

composition, saturates and aromatics comprising approximately 20% and 17%

respectively with the remaining 3% composition comprising Polar (II) compounds.

TPH SARA (IP 469/01 2006)Material Type /

Analysis

Number of Samples

Maximum (mg/kg)

Minimum (mg/kg)

Geometric Mean

(mg/kg)

Arithmetic Mean

(mg/kg)

Standard Deviation (mg/kg)

Wet Oil LakeLayer 1

Saturates 12 66,549 13,499 30,405 34,036 26,580Aromatics 12 77,133 5,242 25,729 32,775 1,020

Polar I 12 207,042 45,846 92,269 103,000 5,423Polar II 12 26,580 1,020 5,423 49,483 7,627

TPH Fractionated

The fractionated TPH supports the findings from the TPH SARA, indicating the heavier

residual range organics (RRO) are dominant. From the seven samples collected, there

was no detection of gasoline range organics (GRO) in the range of EC5-EC10 above the

laboratory limit of detection (LOD) of 20 mg/kg. Given the likely weathering at and near

surface of the material, this result is not unexpected.

Hydrocarbons in the EC10 to EC34 diesel range organics (DRO) are present in the

range of 4,338 mg/kg to 29,188 mg/kg, with the geometric and arithmetic means broadly

around 10,000 mg/kg (1% DRO). In comparison, the RRO concentrations comprising

>EC35 range from 101,567 mg/kg to 260,825 mg/kg with the geometric and arithmetic



means broadly around 159,000 mg/kg (15.90% RRO). The RRO concentrations are

between 13 and 16 times greater than the DRO.

TPH CWG

Only one sample was analyzed for TPH CWG. However, the results from the CWG

further support the findings of other TPH analyses by identifying an absence of light end

EC5-EC10 hydrocarbons and, compared to the total TPH present, relatively low EC10-

EC34 aliphatic and aromatic compounds, totaling 17,813 mg/kg (1.7%). The reported

EC35-EC90 for this sample was reported as 338,131 mg/kg (33.81%).


A total of 24 samples were analyzed from wet oil lake Layer 2 materials. Analysis of

Layer 2 materials comprised some or all of the following:

Total (HEM) Electrical Conductivity

Metals (Cr (III) and (VI), Ni, Cd, V, Pb, As, Methyl-Hg)

Gross calorific value

PSD

TPH CWG Moisture Alkalinity as CaCO3

Salt

TPH SARA pH Chloride BS&W

TPH Fractionated

Sodium absorption ratio

Nitrate, nitrite, phosphorus and potassium

PAH Phenols TKN

VOC Sulphate, Sulphur

As noted for the WOL Layer 1 materials, hydrocarbon analysis indicates a dominance by

the heavier end >EC35 hydrocarbons. However, the concentrations are not as high as

that for Layer 1. The hydrocarbon concentration distribution can be broadly divided into

two main concentration groupings:

the first grouping ranging from approximately 10,000 mg/kg to 50,000 mg/kg; and

the second grouping ranging from approximately 60,000 mg/kg to 100,000 mg/kg.

The second grouping of concentrations from Layer 2 were located in the north of the

investigation area along a wet oil lake feature that had sludge/oily Layer 1 materials

evident at surface. One other higher hydrocarbon concentration was observed in the



south-west, again in an area that had sludge/oil at surface. Whatever the hydrocarbon

concentrations recorded, the Polar (I) compounds contributed over 50% by composition,

saturates and aromatics broadly 20% and 25% respectively and Polar (II) compounds

between 1 and 2%.

VOC and PAH analysis was undertaken on one sample (TP186) from within a wet oil

feature. No volatile or PAH compounds were detected above the laboratory limits of

detection (LOD). Phenols were also assessed on eight samples with no detection above

the laboratory LOD.

Two shallow Layer 2 samples were analyzed for Gross Calorific Value with results of

2.33 and 8.92 Mj/kg. Salt content, by ASTM-3230, was recorded at 10 PTB in the one

sample (TP109) analyzed by this technique. BS&W was also analyzed on TP109 that

identified approximately 87% sediment, 7% oil and the remaining 6% water. PSD

analysis indicates the Layer 2 soils generally comprise medium to fine sands with

variable composition of silts/clays (<0.063 mm) ranging anywhere between 5% and

22%.

In addition, one sample was analyzed from the interface between the Layer 1 and Layer

2 materials at TP27. The gross calorific value was recorded at a higher concentration

than the two other Layer 2 samples at 21.79 Mj/kg. This higher calorific value is

explained by the BS&W analysis that shows a profile more akin to Layer 1 materials with

approximately 30% sediments, 30% oil and 40% water. These results indicate the

variance in the contaminant profile over a short vertical interval and the high sediment

(87%) recorded indicative of oil contaminated sands compared to oils with sediments.

One sample was analyzed for metals. Chromium (III), vanadium and barium were the

only metal species identified above their laboratory LOD, with barium the most dominant

at 125 mg/kg. All other identified species were less than 25 mg/kg.

Alkalinity ranged from 268 mg/kg to 5,500 mg/kg. Chloride concentrations were analyzed

in eight samples ranging from 60 mg/kg to a maximum 32,756 mg/kg, though generally

less than 1,000 mg/kg. Although the majority of the samples fell within the range of

background chloride concentrations, the average chloride results from Layer 2 were up

to five times higher than background soils.

Electrical conductivity was analyzed in 23 samples with results ranging from 854 µS/cm

to a maximum 61,300 µS/cm, though generally the conductivity was below 3,000 µS/cm.

This is approximately two to three times higher than that observed in background

samples. The moisture content ranged from 0.4% to 15.9%, though on average between 1 Jun 15 Page 36 of 78


4-5 %. The highest moisture content related to TP162, where water seepage was

identified within the soil profile beneath the crust at 0.15m bgl. pH ranged from a neutral

pH 7.0 through to an alkaline pH 9.1.

Eight samples were analyzed for parameters to inform biodegradation. Generally, nitrate

concentrations were not above the laboratory limits of detection with the exception of two

samples of 1.13 mg/kg and 9.44 mg/kg. Nitrites were not identified. Phosphorous was

present from concentrations ranging from 68 mg/kg to 142 mg/kg which is in line with

background concentrations. Potassium was also present at background concentrations

ranging from 19 mg/kg to 102 mg/kg. Nitrogen (as TKN) was likewise comparable with

background concentrations at approximately 1 mg/kg. Sulphate concentrations in Layer

2 soils were, however, markedly higher than background with an approximate eight

times increase. The sodium absorption ratio appeared to be within the tolerances of

background conditions.

TPH Assessment

All four types of TPH analysis were undertaken on Layer 2 samples as summarized

below:

TPH (HEM) – 16 samples

TPH CWG – 6 samples

TPH SARA – 19 samples

TPH Fractionated – 20 samples

TPH (HEM)

The TPH (HEM) analysis recorded a minimum concentration of 11,585 mg/kg (1.16%)

through to a maximum recorded concentration of 87,450 mg/kg (8.74%). The geometric

and arithmetic mean are broadly aligned at 32,847 mg/kg (3.28%) to 39,749 mg/kg

(3.97%), indicating a degree of consistency across the areas sampled. At three locations

in the north of the investigation area (trial pits TP033, TP161 and TP185), multiple

samples were analyzed from varying depths of the Layer 2 materials. No distinct pattern

is observed across these samples. In TP033, the TPH concentrations within Layer 2

decrease rapidly from 70,253 mg/kg (7.03%) to 26,415 mg/kg (2.64%) within 0.1-0.2m.

However, in TP161, the TPH concentrations remain broadly similar across 0.4m at

5.75%. In contrast, concentrations of TPH in TP185 increased from 39,540 mg/kg

(3.95%) to 60,106 mg/kg (6.01%) over a 0.1m interval and then decreased to



23,056 mg/kg (2.31%) over a 0.5m interval. Of interest, the latter variation in TPH

concentration correlates with the visual observations within the trial pit.

TPH CWG

Of the six samples analyzed for TPH CWG, no detects were identified above the

laboratory LOD of 20 mg/kg for aliphatic or aromatic compounds in the EC5-EC10

range. Generally, relatively low concentrations of both aliphatic and aromatic compounds

were detected in the range of EC10-EC35 (broadly <3,500 mg/kg) compared to the total

fraction of EC35-EC90 which ranged from 14,162 mg/kg (1.42%) to 100,109 mg/kg

(10.01%). There was one exception to this at TP061, where EC21-EC35 aliphatic were

present at 23,077 mg/kg (2.31%). This sample location also recorded the highest EC35-

EC90 at 100,109 mg/kg. On the whole, the dominant fraction relates to the EC35-EC90

range organics from Layer 2 materials.

TPH SARA

The TPH SARA results display a similar pattern to that observed for WOL Layer 1

materials, whereby the highest contribution to the composition of the oil contaminated

sand is from Polar (I) compounds (approximately 50-55%), followed by saturates and

aromatics, both being broadly of similar contribution (each between ~20-25%), and the

remaining smaller contribution from Polar (II) compounds (1-2%).

As anticipated, the TPH results from the SARA analysis are higher than those identified

from the TPH (HEM). The table below provides a summary of the TPH SARA data.

TPH SARA (IP 469/01 2006)Analysis Number of

SamplesMaximum

(mg/kg)Minimum (mg/kg)

Geometric Mean

(mg/kg)

Arithmetic Mean

(mg/kg)


Wet oil Lake Layer 2Saturates 19 40,261 1,550 7,496 11,087 10,226

Aromatics 19 50,985 3,080 10,391 14,221 12,252Polar I 19 74,849 7,576 23,712 29,423 19,831

Polar II 19 6,270 <LD 630 988 1,433

TPH Fractionated

The fractionated TPH did not record any GRO above the laboratory LOD of 20 mg/kg.

The DRO ranged from 175 mg/kg to 9,882 mg/kg with the dominant hydrocarbon range

identified in the RRO, ranging from 8,316 mg/kg through to 95,933 mg/kg. The geometric

and arithmetic means show the same profile with the RRO being approximately ten

times that of the DRO.1 Jun 15 Page 38 of 78



Three samples were analyzed from soils below WOL features. These samples were

analyzed for:

Total (HEM) Electrical Conductivity Alkalinity as CaCO3 Nitrate, Nitrite

TPH CWG Moisture Chloride Total Phosphorous

TPH SARA pH Phenols Potassium

TPH Fractionated PSD Sodium absorption ratio

Nitrogen (TKN)

Sulphate, sulphur

In comparison to other WOL layers, Layer 3 displays significantly lower hydrocarbon

concentrations with the maximum recorded as 2,947 mg/kg for EC35-EC90. As for the

other WOL layers, there is an absence of volatile components with the dominant fraction

being >EC35. The TPH SARA analysis shows Polar (I) compounds as dominant within

the hydrocarbon make-up at approximately 54% composition, aromatics at 27% and

saturates at 19%, with an absence of Polar (II) compounds.

The three samples of Layer 3 WOL were scheduled for phenols. None were detected

above the laboratory LOD of 0.5 mg/kg.

Only one sample, from TP110, was analyzed for alkalinity as CaCO3 and which reported

4,300 mg/kg. Similarly, the same sample was analyzed for chloride and reported

205.9 mg/kg. These results are within the bounds of background conditions. Electrical

conductivity ranged from 2,220 µS/cm to 5,950 µS/cm, again within the bounds of

background conditions.

Moisture content ranged from 3.0% to 5.7% and pH were recorded as alkaline from pH

8.09 to 8.83. For biodegradation parameters, nitrate and nitrite was not detected in the

one sample TP110, though concentrations of phosphorous, potassium, nitrogen and

sulphate were detected at concentrations comparable with background conditions.

Particle size distribution indicates medium and fine sands form the majority of the soils

composition with 16% to 25% silts/clays.

TPH Assessment


below:







TPH (HEM)

From the two samples analyzed, concentrations recorded were 174 mg/kg and 1,833

mg/kg. Compared to Layer 1 and Layer 2 materials, these concentrations are

significantly lower.

TPH CWG

The TPH CWG analysis shows an absence of hydrocarbons in the EC5-EC10 range

above the laboratory limits of detection of 10 mg/kg (aliphatics) and 0.5 mg/kg

(aromatics). Additionally, for the EC10-EC16 aliphatics, there are no detects above the

LOD of 5 mg/kg. For the remaining aliphatic and aromatic hydrocarbons to EC35,

concentrations range from 6 mg/kg to 223 mg/kg. As noted for the TPH (HEM), these

are significantly lower concentrations compared to the Layer 1 and Layer 2 WOL

materials.

The larger hydrocarbon contamination relates to the EC35-EC90 with concentrations of

2,751 mg/kg to 2,947 mg/kg.

TPH SARA

Three samples were analyzed for TPH SARA. The same pattern of contribution to the

hydrocarbon concentration was identified as for Layer 1 and Layer 2 WOL despite the

overall concentrations being much lower. The table below summarizes the findings for

the three samples.

TPH SARA (IP 469/01 2006)Material Type /

Analysis

Number of Samples

Maximum (mg/kg)

Minimum (mg/kg)

Geometric Mean

(mg/kg)

Arithmetic Mean

(mg/kg)


Wet Oil Lake Layer 3Saturates 3 737 <LD 637 429 383

Aromatics 3 922 <LD 920 614 531Polar I 3 1,843 166 797 1,221 919

Polar II 3 <LD - N/A N/A N/A



TPH Fractionated

The three samples analyzed for Fractionated TPH are similar in pattern to that for Layer

1 and Layer 2 WOL. There is an absence of GRO above the laboratory limit of 20 mg/kg.

Only two detects were recorded of DRO with concentrations of 368 mg/kg and 568

mg/kg. The major contributor remains RRO with concentrations recorded at 1,703 mg/kg

and 1,748 mg/kg. One sample recorded RRO as low as 202 mg/kg.

5.4.2 Dry Oil Lakes

The most abundant data relates to dry oil lake (DOL) features.

Dry Oil Lake Layer 1 – Summary Overview

A total of 6 samples were analyzed from dry oil lake Layer 1 materials. Analysis of Layer

1 materials comprised some or all of the following:

Total (HEM) Metals Nitrate, nitrite

TPH CWG Electrical Conductivity Total Phosphorous

TPH SARA Moisture Nitrogen (TKN)

TPH Fractionated pH Sulphate, sulphur

PAH Redox potential Phenols

VOC Sodium absorption ratio PSD

From the six samples analyzed of dry oil lakes (DOL) Layer 1, a general picture of the

contaminant profile can be observed, though it should be noted that due to the small

dataset it is likely that there will be greater variances observed in DOL Layer 1 materials

in the field.

Hydrocarbon analysis shows a range of concentrations dependent upon the extraction

process and analytical technique employed. The minimum hydrocarbon concentration,

from TPH (HEM), is 71,538 mg/kg (7.15% TPH) with a maximum total TPH identified

from TPH SARA at 398,136 mg/kg (39.81%), though this latter result appears much

higher than the typical total hydrocarbon concentration of approximately 80,000 mg/kg

(8% TPH) to 150,000 mg/kg (15% TPH). In comparison to WOL Layer 1, the total

hydrocarbon concentration for DOL Layer 1 is marginally lower. However, there are also

similarities in the composition of the WOL and DOL Layer 1 materials. As anticipated,

the dominant banding is >EC35 with an absence of EC5-EC10 compounds. The

composition of the DOL Layer 1 crust shows Polar (I) compounds at approximately 62%



contribution, aromatics and saturates at approximately 16% each and Polar (II)

compounds contributing the remaining 6%. Where analyzed, phenols, VOCs and PAHs

were not detected above the laboratory LOD of 0.5 mg/kg.

Two samples were analyzed for metals. Metals detected above their laboratory LOD

were chromium (III) (maximum 9.55 mg/kg), nickel (maximum 25.5 mg/kg), vanadium

(47.5 mg/kg) and barium (53.7 mg/kg). As WOL Layer 1 was not analyzed for metals, no

direct comparison can be made between the WOL and DOL material types.

Five of the six samples were analyzed for pH, moisture content and electrical

conductivity. The pH ranged from near neutral at pH 6.82 through to slightly alkaline at

pH 8.45. The moisture content was generally low ranging from 0.3% to 4.7% but with a

geometric and arithmetic mean of 0.8% and 1.7% respectively. These moisture values

are lower than those observed for the wet oil lake samples. Electrical conductivity

ranged from 560 µS/cm to 17,980 µS/cm, though typically around three times greater

than that in background soils.

Alkalinity as CaCO3 was analyzed in one sample (TP83) with a result of 438 mg/kg. The

same location recorded a chloride concentration of 10,189 mg/kg, significantly higher

than background samples of typical concentration 150 mg/kg. In contrast, a second

sample analyzed for chloride recorded a concentration of 7.5 mg/kg.

Two samples were analyzed for biodegradation suite of determinants. Nitrate and nitrite

were not identified above the laboratory LOD of 0.02 mg/kg. Phosphorous was identified

at similar concentrations of 86 mg/kg and 123 mg/kg, whilst potassium was recorded as

20 mg/kg and 218 mg/kg. Nitrogen (TKN) was recorded consistently at 0.7 mg/kg in both

samples. Sulfate concentrations were 392 mg/kg and 1693 mg/kg suggesting potential

wider variance across DOL Layer 1 materials. In the same way, the sodium absorption

ratio (SAR) was recorded as 0.542 mg/kg in one sample and 6.594 mg/kg in the second,

showing potential wider variance.

Particle size distribution shows the DOL Layer 1 materials to contain a high proportion of

fine sands, with medium sands and silts/clays comprising the remaining fractions. The

analysis shows between 7% and 13% of Layer 1 comprising silt/clays.

TPH Assessment


below:







TPH (HEM)

Of the four samples analyzed, three samples were in the range of 71,538 mg/kg to 76,

798 mg/kg (i.e. 7.15%-7.68%). These sample locations had relatively thin crusts of

0.01 m to 0.05 m forming Layer 1, typical of many locations. The fourth sample location

taken from Layer 1 and analyzed for TPH (HEM) reported a higher concentration of

106,209 mg/kg (10.62%). This sample location recorded the greatest thickness of crust

from the four samples at 0.25 m.

TPH CWG

The three samples analyzed for TPH CWG did not identify hydrocarbons in the EC5-

EC10 aliphatic and aromatic range above the laboratory LOD of 20 mg/kg (aliphatic) and

0.5 mg/kg (aromatic). Relatively low concentrations of hydrocarbons in the EC10-EC21

were identified both for aliphatic and aromatic species, ranging from 11 mg/kg to 282

mg/kg. The EC21-EC35 banded hydrocarbons for both aliphatic and aromatic

hydrocarbons were recorded at slightly higher ranges from 329 mg/kg to 1,785 mg/kg.

The dominant hydrocarbon range reported was from EC35-EC90 ranging from

71,014 mg/kg (7.10% TPH) to 396,063 mg/kg (39.60% TPH).

TPH SARA

The TPH SARA analysis, undertaken on 5 samples of Layer 1 DOL, shows a consistent

hydrocarbon composition of the crust encountered. The major contribution is derived

from polar (I) compounds, ranging from 63%-67% by composition, with saturates and

aromatic hydrocarbon compounds being broadly equal, each between 16%-19% by

composition, with the remaining polar (II) compounds comprising approximately 1%.

Summation of the SARA fractions shows typical total concentrations ranging from

118,272 mg/kg (11.83% TPH) to 398,136 mg/kg (39.81% TPH). The table below shows

summary statistics for the individual components of the SARA analysis.


SamplesMaximum


Geometric Mean

(mg/kg)

Arithmetic Mean

(mg/kg)


Dry Oil Lake Layer 1Saturates 5 54,291 17,034 26,178 28,831 15,352

Aromatics 5 36,194 26,642 31,151 31,358 4,034




SamplesMaximum


Geometric Mean

(mg/kg)

Arithmetic Mean

(mg/kg)


Polar I 5 307,651 70,378 102,191 124,172 103,171Polar II 5 2,171 <LD 1,776 1,446 876

TPH Fractionated

A similar profile to the TPH CWG is shown by the Fractionated TPH. GROs are absent

above the laboratory LOD of 20 mg/kg. DROs are present ranging from 521 mg/kg to

5,036 mg/kg. But RRO continues as the dominant fraction with concentrations ranging

from 71,892 mg/kg (7.12% RRO) to 247,490 mg/kg (24.75% RRO) with the geometric

and arithmetic mean of 113, 832 mg/kg (11.38% RRO) and 126,001 mg/kg (12.60%

RRO) respectively.


A total of 137 samples were analyzed from dry oil lake Layer 2 soils. Analysis of Layer 2

soils comprised some or all of the following:

Total (HEM) Metals Nitrate, nitrite

TPH CWG Electrical Conductivity Total phosphorous PSD

TPH SARA Moisture Nitrogen (TKN)

TPH Fractionated pH Sulphate

VOC Sodium absorption ratio Phenols

PAH Redox potential Carbonate

Hydrocarbons were analyzed through different extraction methods and by a number of

analytical techniques. However, there are good correlations between the various TPH

datasets that show a range of concentrations from <1000 mg/kg through to

approximately 100,000 mg/kg (10% TPH). Detailed assessment of the TPH data

indicates 90% of the contamination is within the 5,000 mg/kg (0.5% TPH) to

50,000 mg/kg (5% TPH) range with the most abundant concentrations within the

15,000 mg/kg (1.5% TPH) to 30,000 mg/kg (3% TPH) range. The highest recorded

concentrations are from samples taken directly beneath a Layer 1 crust, frequently in

close proximity to the periphery of wet oil lake features. There is an absence of

hydrocarbons in the EC5-EC10 range which is typical of the wider contamination and is

supported by the lack of volatiles from VOC analysis. Both TPH CWG and Fractionated 1 Jun 15 Page 44 of 78


TPH show a relatively small contribution from EC10-EC34 hydrocarbon compounds with

the dominant fraction being >EC35. The TPH SARA analysis identifies the composition

being very similar to DOL Layer 1 mainly comprising Polar (I) compounds (approximately

60%) but with a lower contribution from Polar (II) compounds. PAH analysis on 22

samples only identified target compounds (16-USEPA) occasionally on two samples,

TP130 and TP53. However, the concentrations are relatively low with the maximum

concentration for an individual species identified for naphthalene at 24 mg/kg. Both

samples where PAH’s were detected are from locations associated with the periphery of

wet oil features.

Of the metals, analysis for six species were present above the laboratory LOD

comprising chromium (III), nickel, vanadium, lead and barium. Of these, the most

abundant species was barium with a maximum concentration of 136.2 mg/kg,

approximately double that of background samples. The remaining metal species are of

concentrations on a par with background concentrations.

Alkalinity as CaCO3 ranges from 47 mg/kg to 853 mg/kg with geometric and arithmetic

mean of 245 mg/kg and 295 mg/kg. These values are within those identified in

background samples. One sample recorded alkalinity at 4,700 mg/kg. However, review

of the photographic log indicates this sample location was in an area of shallow calcrite

deposits and the high concentration is likely to be a function of this attribute.

Chloride concentrations range from 3 mg/kg to 7,800 mg/kg, though on the whole

concentrations are <1,000 mg/kg in line with background conditions. Electrical

conductivity ranges from 238 µS/cm to 13,550 µS/cm. Comparison between chloride

concentration and electrical conductivity does not show a strong correlation.

Moisture content ranges from <0.1% to 25.5% with typical moisture content in the 2-4%

range, twice that of background samples and the overlying DOL Layer 1 materials. The

pH ranges from slightly acidic at pH 6.3 through to slightly alkaline at pH 8.0. Only one

sample was analyzed for oxidation-reduction potential and recorded 11.5 mV.

Samples for the biodegradation suite identified nitrate, potassium, nitrogen and sulfate

as present above the laboratory limits of detection. Sulfate was the most abundant with

concentrations ranging from 69 mg/kg through to 4,288 mg/kg, though generally around

1,000 mg/kg, typical of background conditions. Phosphorous and nitrogen were likewise

typical of background concentrations while nitrate and potassium were lower than

background concentrations.



Particle size analysis shows the composition of the Layer 2 soils to be predominantly

fine sands with medium sands and silt/clays also present. The silt/clays can have a

significant contribution, at times as much as 60%, though this is rare. On average,

silt/clays have 10% contribution to the soil make-up, though this does not take into

consideration the potential for higher fines content where fine sands can comprise

weakly cemented silts.

TPH Assessment


below:





TPH (HEM)

A total of 65 samples of Layer 2 DOL were analyzed for TPH (HEM). Concentrations

ranged from 2,257 mg/kg (0.23% TPH) to 66,878 mg/kg (6.69% TPH). The geometric

and arithmetic mean were calculated as 17,202 mg/kg and 21,613 mg/kg respectively,

suggesting the contaminant concentrations are broadly similar across the soil profile.

Further assessment of the data shows that the majority (65%) of TPH contamination lies

within the 10,000 mg/kg (1% TPH) to 30,000 mg/kg (3% TPH) range. A further 20% of

the contamination is recorded within the 30,000 mg/kg (3% TPH) to 50,000 mg/kg (5%

TPH) range with occasional concentrations greater than this.

TPH CWG

There were no detects of hydrocarbons in the EC5-EC10 range above the laboratory

LOD for both aliphatic (LOD of 20 mg/kg) and aromatics (LOD of 0.5 mg/kg) from Layer

2 DOL samples. Relatively low concentrations of EC10-EC12, EC12-EC16, EC16-EC21

and EC21-EC35 for both aliphatic and aromatic hydrocarbons were detected ranging

from the LOD through to a maximum 16,802 mg/kg, though generally concentrations

were recorded as <1,000 mg/kg. The greatest hydrocarbon concentrations relate to the

EC35-EC90 range (non-speciated) with concentrations ranging from 603 mg/kg to

98,892 mg/kg, though the geometric and arithmetic means are 18,475 mg/kg and 25,816



mg/kg respectively. Nearly 90% of the EC35-EC90 concentrations are within the range

of >5,000 mg/kg to <50,000 mg/kg.

TPH SARA

The summation of the TPH SARA fractions range from 603 mg/kg (0.06% TPH) through

to 109,047 mg/kg (10.9% TPH). The composition of the oil within Layer 2 sands is

dominated by the polar (I) compounds with a contribution of approximately 60%.

Saturates and aromatic compounds are broadly similar in percent contribution at 16.5%

and 22.5% respectively, a slight higher contribution identified from aromatic compounds.

Polar (II) compounds contribute the remaining 1%.

Analysis of the summation of the SARA fractions indicates that nearly 80% of the results

fall within the 10,000 mg/kg (1% TPH) to 40,000 mg/kg (4% TPH) range. The remaining

20% comprise more sporadic higher concentrations mainly falling within >40,000 to

<75,000 mg/kg (7.5%).

Table – TPH SARA (IP 469/01 2006)Material Number of

SamplesMaximum


Geometric Mean

(mg/kg)

Arithmetic Mean

(mg/kg)


Dry Oil Lake Layer 2Saturates 99 18,093 98 3,929 5,026 3,388

Aromatics 99 29,046 130 5,264 6,823 4,719Polar I 99 69,864 359 14,360 18,061 12,941

Polar II 99 3,200 <LD 235 368 455

TPH Fractionated

The Fractionated TPH provides a similar profile to the TPH CWG. Results show that only

two from the 130 samples analyzed identified GROs above the laboratory LOD of

20 mg/kg. The two samples were from one location (TP130) both at shallow depth (0.2-

0.4 m bgl) and at greater depth (1.1-1.2 m bgl that had concentrations of 57 mg/kg and

52 mg/kg respectively. This same location also displayed one of the few identifications of

PAHs, notably naphthalene at 23.6 mg/kg. It is unclear as to why this one sample

displays any volatile compounds. DROs were identified above the laboratory LOD of 5

mg/kg in all but six of the 130 samples, ranging to a maximum 7,147 mg/kg (0.72%

DRO). RROs were identified in all samples from a minimum 419 mg/kg (0.04% RRO) to

75,017 mg/kg (7.50% RRO). On the whole, RRO concentrations are in the order of 13-

15 times greater than GRO and DRO, clearly being the dominant fraction.



Further assessment shows that nearly 90% of the RRO contamination lies within the

>5,000 mg/kg to <40,000 mg/kg range, the remaining 10% relating to occasional much

higher RRO concentrations associated with samples collected at the interface between

Layer 1 and Layer 2 materials.


A total of 47 samples were analyzed from dry oil lake Layer 3 soils. Analysis of Layer 3

soils comprised some or all of the following:

Total (HEM) Metals Nitrate / nitrite PSD

TPH CWG Electrical Conductivity Phosphorous

TPH SARA Moisture Potassium

TPH Fractionated pH Nitrogen

VOC Sodium Absorption Ratio

Sulphate

PAH Alkalinity as CaCO3 Phenols

The various hydrocarbon analyses provide broad ranges of TPH concentrations. These

are on average typically <1,000 mg/kg though occasional concentrations have been

recorded greater than this. One sample location, TP91, recorded a concentration in the

region of 7,500 mg/kg. This appears to be from a sample taken directly beneath Layer 1

where there was an absence of Layer 2. On the whole, there appears to be a good

correlation between what was considered Layer 3 from visual and olfactory evidence

and relatively low hydrocarbon concentrations. As identified from other layers of

hydrocarbon contamination, there is an absence of EC5-EC10 hydrocarbons, confirmed

by the VOC analysis. The dominant fraction remains >EC35 with the familiar

composition profile of Polar (I) dominance, saturates and aromatics followed by Polar (II)

compounds. PAHs and phenols were not identified above their respective laboratory

LOD.

Nine samples were analyzed for metals. Metals identified above their respective

laboratory LOD were chromium (III), nickel, vanadium, lead and barium, with barium the

most abundant species at a maximum of 67.9 mg/kg. All identified metal concentrations

were comparable and within background concentrations.

The pH of Layer 3 soils ranged from neutral at pH 7.0 through to alkaline pH 9.5.

Moisture content ranged from 0.2% through to 10.8% but, on the whole, averaged



around 2%, approximately twice that of background samples. Electrical conductivity,

chloride and alkalinity were all comparable with, and slightly lower than, background

concentrations.

For the biodegradation parameters (nitrogen, nitrate, phosphorous, nitrogen and

sulphate), all parameters were comparable with background concentrations, the only

notable variance being a marginally higher average total phosphorous concentration of

118 mg/kg compared to background of 106 mg/kg.

Particle size distribution shows the highest proportion of the Layer 3 soil to be a fine

sand, with medium sand and silt/clays also present. The silt/clays can, at times, form a

significant part of the soil composition with up to 43% recorded from one sample, though

typically this is around 10%.

TPH Assessment


below:





TPH (HEM)

The range of hydrocarbon identified in Layer 3 DOL ranged from 103 mg/kg to

4,616 mg/kg with the geometric and arithmetic mean of 523 mg/kg and 647 mg/kg

respectively. These results are significantly lower than Layer 1 and 2 DOL and correlate

with the visual observations recorded during trial pitting.

TPH CWG

From the 36 samples analyzed for TPH CWG, hydrocarbons in the range of EC5-EC16

were not detected. Only 6 samples identified concentrations above the laboratory LOD

whether aromatic or aliphatic compounds above EC16 with the maximum concentration

of 69 mg/kg for EC21-EC35 aromatics.

From the EC35-EC90 band, 35 of the 36 samples identified hydrocarbons above the

laboratory LOD. Concentrations ranged from 316 mg/kg to 3,110 mg/kg with the



exception of one sample, TP91, where a concentration of 7,561 mg/kg was recorded.

This one sample appears as an outlier to the main dataset for Layer 3 samples.

The geometric and arithmetic mean can be calculated for the EC35-EC90 where there

are sufficient samples. The results show a geometric mean of 910 mg/kg and a similar

arithmetic mean of 1,024 mg/kg. This suggests a good correlation between visual

observations in the field of materials that have no visual and olfactory evidence of

contamination and low concentrations of hydrocarbons, i.e. <0.5% TPH.

TPH SARA

The total (summation of saturates, aromatics, polar (I) and polar (II) compounds) for the

TPH SARA compounds are similar to the TPH CWG with concentrations ranging from

165 mg/kg to 3,385 mg/kg with one outlier sample (TP91) having a concentration of

7,616 mg/kg. The percentage composition of the contamination within Layer 3 comprises

between 59% and 66% polar (I) compounds, 27-28% aromatic compounds, 19%-20%

saturate compounds and 1% as polar (II) compounds, the same composition pattern

observed throughout the DOL contaminant profile.

Table– TPH SARA (IP 469/01 2006)Analysis Number of

SamplesMaximum


Geometric Mean

(mg/kg)

Arithmetic Mean

(mg/kg)


Dry Oil Lake Layer 3Saturates 36 569 <LD 175 182 109

Aromatics 36 971 <LD 250 272 195Polar I 36 2,956 165 512 627 520

Polar II 36 40 <LD 11 10 11

As can be seen from table, above, the geometric and arithmetic mean for the individual

components are <1,000 mg/kg. The geometric mean for the summation of the SARA

parts gives 920 mg/kg and the arithmetic mean gives 1,091 mg/kg. This again, indicates

a good visual correlation between field records of no visual or olfactory evidence of

contamination and low hydrocarbon concentrations of, broadly, <1,000 mg/kg.

TPH Fractionated

Confirming the TPH CWG, no GROs were observed above the laboratory LOD of

20 mg/kg. Only six of 47 samples identified DROs above the laboratory LOD of 5 mg/kg

with a maximum concentration of 134 mg/kg recorded. In comparison, the RROs range



from 114 mg/kg to 2,223 mg/kg. One sample was identified as an outlier from TP91 with

a concentration of 5,585 mg/kg.

5.4.3 Background

Nine samples were taken from background locations where there was a visual absence

of contamination both at surface and sub-surface. These samples were analyzed for

some or all of the following determinants:

Total Organic Carbon Nitrate, Nitrite and Sulphate

Total Sulphur Chemical Oxidation Demand

Electrical Conductivity Chloride Calcium Oxidation/Reduction Potential

Moisture Content Total Alkalinity as Calcium Carbonate

Phenols Sodium Absorption Ratio

pH Carbonate Metals

Metal species that were present above their respective laboratory limits of detection

comprise chromium (III), nickel, vanadium and barium, the latter forming the most

abundant species at 63.8 mg/kg and on average, 30-35 mg/kg. The other identified

species present were all on average approximately 10 mg/kg.

The following table provides a summary of the background conditions encountered.

pH, Moisture Content, Electrical Conductivity, ORP, Chloride, Alkalinity, Carbonate, Calcium (Background)

Analysis Number of Samples

Maximum (units as stated)

Minimum (units as stated)

Geometric Mean (units as stated)

Arithmetic Mean (units as stated)

Standard Deviation (units as stated)

Background SamplespH 9 9.2 7.5 8.5 8.5 0.6Moisture Content (%)

9 3.4 0.1 0.5 1.0 1.3

Electrical Conductivity (µS/cm)

9 5,930 96 976 1,788 1,997

Oxidation / Reduction Potential (mV)

9 282 92 118 126 60

Chloride (mg/kg)

9 5,114.2 14.9 161.8 757.6 1651.9

Alkalinity as CaCO3 (mg/kg)

7 5,065 107 363 936 1,822



Carbonate (mg/kg)

9 53,500 5,065 18,410 24,887 17,777

Calcium (mg/kg)

8 25,857 11,250 16,524 17,154 5,113

Nutrients (Background)Analysis Number

of Samples

Maximum (units as stated)

Minimum (units as stated)

Geometric Mean (units as stated)

Arithmetic Mean (units as stated)

Standard Deviation (units as stated)

Background SamplesNitrate (mg/l)

9 194 <0.02 3.66 21.9 64.5

Nitrite (mg/l)

9 0.5 <0.02 0.44 0.1 0.2

Total Phosphorus (mg/kg)

9 133 80 105 107 17

Potassium (mg/kg)

9 895 23 250 506 364

Total Kjeldahl Nitrogen (mg/l)

9 1.1 0.4 0.8 0.8 0.2

Miscellaneous (Background)Analysis Number of

SamplesMaximum (mg/kg)

Minimum (mg/kg)

Geometric Mean (mg/kg)

Arithmetic Mean (mg/kg)


Background SamplesChemical Oxygen Demand

9 11,235 544 2,490 4,285 4,146

Organic Matter

9 5,521 222 1,038 1,845 1,896

Total Organic Carbon

9 3,210 129 600 1,071 1,103

Inorganic Carbon

6 5,800 299 1,483 2,614 2,325

Sodium Absorption Ratio

8 21.7 <0.25 1.45 2.94 7.57

Phenols 9 <0.5 <0.5 <0.5 <0.5 <0.5Sulphate 9 3,427 65.3 484 1,022 1,176Sulphur 9 1,524 25.6 174 387 495



5.5 Comparison of data

This section of the report factually describes the comparison of the TPH data collected

during the LSSC and the data collected as part of the CIC investigation (27th August

2003). Further comparative analysis and interpretation is provided in Section 5.7.2,

below. The CIC primarily analyzed for TPH using the same 9071B methodology as used

under the LSSC. It should be noted that the LSSC has a much wider TPH scope that

provides greater detail into the TPH characterization, as described in Section 5.4 above.

5.5.1 Layer 1

Because the primary focus of the LSSC was data collection from Layer 2 soils, only 12

samples were taken in Layer 1 material and so comparison with CIC data is limited.

Wet Oil Lake TPH Comparison for LSSC Analytical Data with CIC Analytical Data

Descriptions LSSC TPH Results (mg/kg)

CIC TPH Results (mg/kg)

Geometric Mean 133,557 Not reported

Arithmetic Mean 135,557 224,326

Minimum 94,835 20,800

Maximum 166,171 647,000

Dry Oil Lake TPH Comparison for LSSC Analytical Data with CIC Analytical Data

Descriptions LSSC TPH Results (mg/kg)


Geometric Mean 80,510 Not reported

Arithmetic Mean 81,637 89,767

Minimum 17,538 556*

Maximum 106,209 694,000

* = Reported in CIC as Layer 1, however value suggest this is a background sample



5.5.2 Layer 2

Presented below are the summaries of the analytical results for the Layer 2 sampling

locations within each of the 7 Zones. The summary tables in the sections below for each

zone provide:

TPH concentration;

The depth range of Layer 2;

Sample depth range (LSSC data only); and

Physical appearance from observation made of site trial pit excavations during the

field survey (for LSSC data only).

For each zone, the LSSC and CIC geometric mean, arithmetic mean, minimum, and

maximum analytical results are presented both as separate data sets and as one

combined data set.

5.5.2.1 Zone 1In Zone 1 fifteen samples were analyzed for TPH HEM during the LSSC and these

analytical results where compared with CIC data from eight locations. The tables below

show the Layer 2 data for the LSSC and the CIC for Zone 1.

Zone 1: LSSC Analytical Data

Si. No. Sampling Location

TPH HEM (mg/kg)

Layer description

Sample Range (m bgl)

Layer 2 Range (m bgl)

Wet Oil Lake1

3370,253 DBS 0.13-0.23

0.01 - >0.752 26,415 DBS 0.2-0.53 109 18,230* DBS 0.4-0.5 0.08-0.734 112 17,590 DBS 0.15-0.3 0.005-0.35

18539,540 DBS 0.08-0.18

0.08-0.96 60,106 DBS 0.21-0.307 23,056 DBS 0.8-0.9

Dry Oil Lake8 1 36,152 DBS 0.04-0.08 0.01-0.119 2 52,020* DBS 0.03-0.06 0.015-0.18

10 32 18,322 DBS 0.1-0.23 0.015-0.311 106 21,815 DBS 0.17-0.21 0.03-0.4112

10739,066 DBS 0.1-0.15

0.07-0.513 10,305 DBS 0.35-0.4514

10822,564 DBS 0.1-0.2

0.01-0.5515 19,125 DBS 0.2-0.3

Geometric Mean 27,666




TPH HEM (mg/kg)

Layer description



Arithmetic Mean 31,367Minimum 10,305Maximum 70,253DBS = Dark Brown Sand, * = Sample analyzed using TPH SARA

As seen from the table above the LSSC TPH concentrations range between 10,305 and

70,253 mg/kg as recorded at sample locations TP 107 and TP 33 respectively. The layer

thickness ranges from between 0.1 to 0.81 m and the contaminated base ranges from

0.11 to 0.9 m bgl with the contamination depth range varying at each sampling location.

At TP 33 the soil in the base of the trial pit showed signs of contamination at 0.75 m bgl.

The Layer 2 soil was all recorded as Dark Brown Sand (DBS). The dark color is likely

due to hydrocarbon staining of impacted sand which is shown with high concentration of

TPH level.

Zone 1: CIC Analytical Data

Si. No.

Sampling Location TPH (mg/kg) Layer Layer 2 Range

(m bgl)1 40456 14,600 Layer 2 0.15-0.852 58544 8,220 Layer 2 0.005-0.2753 78021 15,200 Layer 2 0.03-0.14 78040 11,200 Layer 2 0.03-0.295 78139 33,900 Layer 2 0.03-0.086 80407 11,200 Layer 2 0.01-0.267 80430 13,900 Layer 2 0.07-0.278 70349 48,600 Layer 2 0.04-0.13

Geometric Mean 16,403Arithmetic Mean 19,603Minimum 8,220Maximum 48,600

As seen from the table above the CIC TPH concentrations range between 8,220 and

48,600 mg/kg as recorded at sample locations 58544 and 70349 respectively. The layer





Zone 1: TPH Comparison for LSSC Analytical Data with CIC Analytical Data

Descriptions LSSC TPH HEM Results (mg/kg)


Combined data (mg/kg)

Geometric Mean 27,666 16,403 23,066

Arithmetic Mean 31,637 19,603 27,451

Minimum 10,305 8,220 8,220

Maximum 70,253 48,600 70,253

The LSSC analytical results for dry & wet oil lake contamination show mean

concentrations of around 28,000 to 32,000 mg/kg TPH in the soil of Layer 2. In

comparison the CIC data shows the mean concentrations of around 16,000 to 20,000

mg/kg TPH in similar Layer 2 soil.

5.5.2.2 Zone 2In Zone 2 eight samples were analyzed for TPH HEM during the LSSC and these

analytical results where compared with CIC data from five locations. The tables below

show the Layer 2 data for the LSSC and the CIC for Zone 2.



TPH HEM (mg/kg)

Layer description



1. TP 128 28,890 DBS 0.05-0.15 0.15 – 0.52. TP 129 31,083 DBS 0.03-0.06 0.02 – 0.353. TP 9 27,272 DBS 0.04-0.08 0.05 - 0.184. TP 8 32,499 DBS 0.15-0.25 0.1 - 0.415. TP 167 12,952 MBS 0.10-0.20 0.05 – 0.46. TP 40 11,051 MBS 0.1-0.2 0.01-0.857. TP 41 17,285* DBS 0.3-0.4 0.015-0.678. TP127 19,875 DBS 0.07-0.1 0.01-0.8


Arithmetic Mean 22,613

Minimum 11,051

Maximum 32,499DBS = Dark Brown Sand, MBS = Medium Brown Sand* = Sample analyzed using TPH SARA



As seen from the table above the TPH concentrations range between 12,952 and

32,499 mg/kg as recorded at sample locations TP 40 and TP 8 respectively. The layer



It is observed that the sampling locations are recorded as Dark Brown Sand (DBS) in all

but two sample with two location recorded as Medium Brown Sand (MBS) in Zone 2.

The dark color is likely due to hydrocarbon staining of impacted sand which is shown

with higher concentration of TPH level, whereas the Medium Brown Sand (MBS) shows

the minimum value of TPH level recorded in this zone.


Si. No. Sampling Location TPH (mg/kg)

Layer descriptio

nLayer 2 Range

(m bgl)

1. 78141 15,900 0.03-0.1

2. 80908 21,100 0.03-0.45

3. 78331 9,070 0.02-0.26

4. 80530 16,300 0.02-0.51

5. 80542 15,700 0.05-0.5



Minimum 9,070

Maximum 21,100

As seen from the table above the TPH concentrations range between 9,070 and 15,357

mg/kg at recorded at sample locations 78,331 and 80,908 respectively. The layer







Geometric Mean 21,090 15,076 18,535



Arithmetic Mean 22,613 15,614 19,921

Minimum 11,051 9,070 9,070

Maximum 32,499 21,100 32,449


concentrations of around 22,000 mg/kg TPH in the soil of Layer 2. Whereas the CIC

data shows the mean concentrations of around 15,500 mg/kg TPH in similar Layer 2

material.

5.5.2.3 Zone 3In Zone 3 fifteen sampling where tested during the LSSC and these analytical results

where compared with existing CIC data (16 locations). The tables below show the Layer

2 data for the LSSC and the CIC for Zone 3.



TPH HEM (mg/kg)

Layer description



Wet Oil Lake

1. 193 14,222 DBS-MBS 0.06-0.1 0.02-0.12

Dry Oil Lake

2. 144 6,202 MBS 0.05-0.1 0.01-0.14

3. 88 14,756* DBS-MBS 0.06-0.1 0.02-0.12

4. 180 46,738 DBS 0.01-0.07 0.01-0.07

5. 145 5,567 MBS 0.05-0.1 0.01-0.23

6. 146 32,264 DBS-MBS 0.0-0.2 0.2-0.6

7. 87 43,936 DBS-MBS 0.28-0.45 0.28-0.64

8. 73 22,186 DBS 0.05-0.1 0.02-0.13

9. 85 11,607 DBS-MBS 0.3-0.35 0.3-0.65

10. 86 17,519 DBS-MBS 0.32-0.65 0.32-0.85

11. 177 5,049 MBS 0.05-0.15 0.05-0.15




TPH HEM (mg/kg)

Layer description



12. 190 3,372 MBS-LBS 0.15-0.3 0.02-0.3

13. 191 13,173 MBS 0.05-0.1 0.05-0.3

14. 71 3,571 MBS 0.1-0.2 0.02-0.4

15. 143 5,602 MBS 0.1-0.2 0.02-0.2



Minimum 3,372

Maximum 46,936

DBS = Dark Brown Sand, MBS = Medium Brown Sand, LBS = Light Brown Sand * = Sample analyzed using TPH SARA


mg/kg at sample locations TP 190 and TP 180, respectively. The layer thickness ranges

from between 0.06 to 0.53 m and the contaminated base ranges from 0.07 to 0.85 m bgl

with the contamination depth range varying at each sampling location.

It is observed that the Dark Brown Sand (DBS) is seen in half of the sampling location

with a one location recorded as Light Brown Sand (LBS) in Zone 3. The dark color is

likely due to hydrocarbon staining of impacted sand which is shown with higher

concentration of TPH level, whereas the Light Brown Sand (LBS) shows the minimum

value of TPH level recorded in this zone.


Si. No. Sampling Location TPH (mg/kg) Layer Layer 2 Range

(m bgl)

1 77032 62,200 Layer 2 0.29-1.31

2 78150 48,600 Layer 2 0.02-0.08

3 78384 28,200 Layer 2 0.03-0.07

4 57027 8,600 Layer 2 0.2-0.3

5 70611 8,270 Layer 2 0.01-0.18




(m bgl)

6 82004 8,350 Layer 2 0.03-0.35

7 40452 20,600 Layer 2 0.02-0.55

8 82003 73,900 Layer 2 0.09-0.59

9 70428 7,840 Layer 2 0.15-0.275

10 88350 63,300 Layer 2 0.22-0.67

11 78044 57,100 Layer 2 0.03-0.24

12 78289 56,600 Layer 2 0.08-0.54

13 88183 50,200 Layer 2 0.25-0.72

14 37031 64,800 Layer 2 0.2-0.56

15 50473 11,000 Layer 2 0.03-0.49

16 80482 40,300 Layer 2 0.08-0.62



Minimum 7,840

Maximum 73,900


mg/kg at sample locations 70428 and 82003, respectively. The layer thickness ranges







Geometric Mean 11,637 28,391 18,440

Arithmetic Mean 16,384 38,116 27,601

Minimum 3,372 7,840 3,372



Maximum 46,936 73,900 73,900


concentrations of around 12,000 to 16,000 mg/kg TPH in the soil of Layer 2. Whereas

the CIC data shows the mean concentrations of around 28,000 to 38,000 mg/kg TPH in

similar Layer 2 material.

5.5.2.4 Zone 4In Zone 4 ten sampling where tested during the LSSC and these analytical results where

compared with existing CIC data (8 locations). The tables below show the Layer 2 data

for the LSSC and the CIC for Zone 4



TPH HEM (mg/kg)

Layer description



1 183 38,040 DBS 0.06-0.1 0.01-0.15

2 184 16,448DBS

0.04-0.1 0.01-0.27

3 158 14,762DBS

0.15-0.2 0.01-0.51

4 157 14,987DBS

0.15-0.25 0.01-0.34

5 156 7,817DBS

0.1-0.2 0.01-0.27

6 103 8,930DBS

0.1-0.2 0.015-0.22

7 102 17,235 DBS 0.03-0.05 0.01-0.06

8 101 10,865DBS

0.02-0.04 0.015-0.04

9104

24,237 DBS 0.06-0.120.02-0.3

10 10,033 LBS 0.22-0.26



Minimum 7,817




TPH HEM (mg/kg)

Layer description



Maximum 38,040

DBS = Dark Brown Sand, LBS = Light Brown Sand


mg/kg at sample locations TP 156 and TP 183, respectively. The layer thickness ranges



It is observed that the Dark Brown Sand (DBS) account for almost of all of the sampling

location with one location recorded as Light Brown Sand (LBS) in Zone 4. The dark color

is likely due to hydrocarbon staining of impacted sand which is shown with higher

concentration of TPH level.



(m bgl)

1 80481 7,480 Layer 2 0.03-0.45

2 80909 15,600 Layer 2 0.02-0.56

3 50921 17,300 Layer 2 0.01-0.17

4 88025 12,000 Layer 2 0.01-0.53

5 88280 1,330 Layer 2 0.03-0.4

6 80403 16,100 Layer 2 0.03-0.52

7 88344 8,210 Layer 2 0.01-0.13

8 80394 9,410 Layer 2 0.01-0.1



Minimum 1,330

Maximum 17,300




mg/kg at recorded at sample locations 88280 and 50921 respectively. The layer







Geometric Mean 14,600 8,920 11,728

Arithmetic Mean 16,335 10,929 13,932

Minimum 7,817 1,330 1,330

Maximum 38,040 17,300 38,040





5.5.2.5 Zone 5In Zone 5 fourteen sampling where tested during the LSSC and these analytical results

where compared with existing CIC data (9 locations). The tables below show the Layer 2

data for the LSSC and the CIC for Zone 5.



TPH HEM (mg/kg)

Layer description



Wet Oil Lake1 98 20,099* DBS 0.3-0.4 0.2 - >0.92 179 26,816 DBS 0.7-0.8 0.7 - >1.23 194 66,878 DBS 0.14-0.4 0.014-0.84

Dry Oil Lake4

7945,240 DBS 0.06-0.5

0.06 - >0.65 3,317 MBS 0.3-0.56 80 47,576 DBS 0.05-0.2 0.05-0.57 94 53,422 DBS/MBS 0.04-0.18 0.04-0.398

15024,042 DBS 0.10-0.20

0.03-0.629 9,422 DBS 0.5-0.6

10 181 28,370 DBS 0.04-0.08 0.02-0.8




TPH HEM (mg/kg)

Layer description



11 16,662 DBS 0.4-0.5Geometric Mean 23,928Arithmetic Mean 31,077Minimum 3,317Maximum 66,878DBS = Dark Brown Sand, MBS = Medium Brown Sand* = Sample analyzed using TPH SARA


mg/kg at recorded at sample locations TP 150 and TP 194 respectively. The layer



At TP 79, TP 98 and TP 179 the soil in the base of the trial pit showed signs of

contamination at 0.6, 0.9 and 1.2 m bgl respectively.

It is observed that the material Layer 2 is was recorded as Dark Brown Sand (DBS) in all

but one locations, with a one location recorded as Light Brown Sand (LBS). The dark

color is likely due to hydrocarbon staining of impacted sand which is shown with higher

concentration of TPH level, whereas the Light Brown Sand (LBS) shows the minimum

value of TPH level recorded in this zone.



TPH (mg/kg) Layer Layer 2 Range

(m bgl)1 70270 26,300 Layer 2 0.07-0.472 70365 24,900 Layer 2 0.05-0.553 77033 30,300 Layer 2 0.19-0.554 77034 26,800 Layer 2 0.16-0.815 78153 7,410 Layer 2 0.03-0.846 78368 59,100 Layer 2 0.6-1.067 80268 15,600 Layer 2 0.03-1.78 80344 2,540 Layer 2 0.4-0.139 88048 14,300 Layer 2 0.05-1.15

Geometric Mean 17,202Arithmetic Mean 23,028Minimum 2,540Maximum 59,100


mg/kg at recorded at sample locations 80344 and 78368 respectively. The layer

thickness ranges from between 0.09 to 0.1.67 m and the contaminated base ranges



from 0.13 to 1.7 m bgl with the contamination depth range varying at each sampling

location.


Descriptions LSSC HEM TPH Results (mg/kg)



Geometric Mean 23,928 17,202 20,626

Arithmetic Mean 31,077 23,028 27,455

Minimum 3,317 2,540 2,540

Maximum 66,878 59,100 66,878





5.5.2.6 Zone 6In Zone 6 seven samples where tested during the LSSC and these analytical results





TPH HEM (mg/kg)

Layer description



Wet Oil Lake

161a

66,672 DBS 0.3-0.40.15 - >1.2

2 18,899 DBS 1.0-2.0

Dry Oil Lake

3 62 2,462 DBS 0.04-0.08 0.05-0.17

466

25,763 DBS 0.05-0.80.03-0.5

5 15,999 DBS 0.2-0.3

6 65 17,982 DBS 0.2-0.3 0.05-0.45

7 218 No sample taken DBS 0.3-0.4 0.04 - >0.64




TPH HEM (mg/kg)

Layer description





Minimum 2,462

Maximum 66,672

DBS = Dark Brown Sand


mg/kg as recorded at sample locations TP 62 and TP 61a respectively. The layer

thickness ranges from between 0.12 to over 1.2 m and the contaminated base ranges

from 0.17 to over 1.2 m bgl with the contamination depth range varying at each sampling

location. At both locations TP 61a and TP 218 the soil in the base of the trial pit showed

signs of contamination at 1.2 and 0.64 m bgl respectively.

It is observed that the material Layer 2 is was all recorded as Dark Brown Sand (DBS).

The dark color is likely due to hydrocarbon staining of impacted sand which is shown

with high concentration of TPH level.


Si. No. Sampling Location TPH (mg/kg) Layer Range (m bgl)

1. 70357 24,600 Layer 2 0.03-0.05

2. 70356 12,800 Layer 2 0.01-0.2

3. 78158 20,900 Layer 2 0.01-0.12

4. 57025 9,040 Layer 2 0.2-0.8

5. 57026 61,600 Layer 2 0.28-1.08

6. 88115 42,100 Layer 2 0.03-0.05



Minimum 9,040




Maximum 61,600


mg/kg as recorded at sample locations 57025 and 57026 respectively. The layer







Geometric Mean 16,863 23,159 19,761

Arithmetic Mean 24,630 28,507 26,568

Minimum 2,462 9,040 2,462

Maximum 66,672 61,600 66,672





5.5.2.7 Zone 7In Zone 7 twelve samples where tested during the LSSC and these analytical results





TPH HEM (mg/kg)

Layer description



Wet Oil Lake

1 164 17,298 DBS/MBS 0.7-0.8 0.35 - >0.9

2 187 9,824 DBS/MBS 0.2-0.3 0.06 - >1.2




TPH HEM (mg/kg)

Layer description



Dry Oil Lake

3130

19,323 DBS 0.2-0.40.2 - >1.2

4 18,919 DBS 1.1-1.2

5 45 21,242 DBS 0.04-0.08 0.05-0.31

6134

14,195 DBS 0.03-0.180.03-0.35

7 14,182 LBS 0.2-0.3

8 206 - DBS/MBS - 0.1-0.22

9 208 - DBS/MBS - 0.03-0.75

10 209 - DBS - 0.05-0.4

11 210 - DBS/MBS - 0.01-0.25

12 211 - DBS - 0.05-0.42



Minimum 9,824

Maximum 21,242

DBS = Dark Brown Sand, MBS = Medium Brown Sand, LBS = Light Brown Sand


mg/kg as recorded at sample locations TP 187 and TP 45 respectively. The layer



At TP 130, TP 164 and TP 187 the soil in the base of the trial pit showed signs of

contamination at 1.2, 0.9 and 1.2 m bgl respectively

It is observed that all bar one of the samples are Dark Brown Sand (DBS), around half of

the sample lighten with depth to a Medium Brown Sand (MBS) there is one location

recorded as Light Brown Sand (LBS) in Zone 7. The dark color is likely due to

hydrocarbon staining of impacted sand which is shown with higher concentration of TPH

level.





1. 70331 29,000 Layer 2 0.015-0.345

2. 70316 27,300 Layer 2 0.02-0.16

3. 70314 11,900 Layer 2 0.01-0.14

4. 78167 7,360 Layer 2 0.02-0.97

5. 40315 3,120 Layer 2 0.3-1.3

6. 57024 79,300 Layer 2 0.2 - >2.2

7. 78361 10,300 Layer 2 0.03-0.28



Minimum 3,120

Maximum 79,300


mg/kg at sample locations 40315 and 57024, respectively. The layer thickness ranges

from between 0.13 to >2 m and the contaminated base ranges from 0.14 to >2.2 m bgl

with the contamination depth range varying at each sampling location. At location 57024

the soil in the base of the trial pit showed signs of contamination at 2.2 m bgl.





Geometric Mean 15,976 15,027 15,518

Arithmetic Mean 16,426 24,040 19,747

Minimum 9,824 3,120 3,120

Maximum 21,242 79,300 79,300









5.6 Estimated Volume of Layer 2 material

Following the work carried out for the PMC contract and using both the LSSC and CIC

data the dry oil lake portion of Zones 1 through 7 were subdivided into 3 to 5 subzones

each based on the depth of the Layer 2 contamination (Figures 4 -10 in Appendix A).

Using these subzones and the thickness of Layer 2 derived from the CIC and LSSC

investigations, the estimated volume of material in Layer 2 was calculated.

Zone 1 estimated volumes of DOL Layer 2 materialSub-zone 1 2 3 4

Area, m² 77,000 126,000 277,000 276,000

Layer 2 thickness, m 0.38 0.14 0.47 0.41

Volume of Layer 2, m³ 29,260 17,640 130,190 113,160

Estimated Total volume zone 1, m³ 290,250

Zone 2 estimated volumes of DOL Layer 2 materialSub-zone 1 2 3 4 5Area, m² 63,000 100,000 25,000 39,000 85,000

Layer 2 thickness from LSSC, m 0.35 0.35 0.13 0.31 0.52

Volume of Layer 2, m³ 22,050 35,000 3,250 12,090 44,370


Zone 3 estimated volumes of DOL Layer 2 materialSub-zone 1 2 3 4

Area, m² 153,000 146,000 115,000 149,000

Layer 2 thickness, m 0.18 0.3 0.4 0.4

Volume of Layer 2, m³ 27,540 438,000 46,000 59,000


Zone 4 estimated volumes of DOL Layer 2 materialSub-zone 1 2 3 4 5

Area, m² 97,000 196,000 98,000 64,000 89,000

Layer 2 thickness, m 0.37 0.35 0.33 0.055 0.2

Volume of Layer 2, m³ 35,890 68,600 32,340 3,520 17,800




Zone 5 estimated volumes of DOL Layer 2 materialSub-zone 1 2 3

Area, m² 48,000 56,000 431,000

Layer 2 thickness, m 0.09 0.5 0.75

Volume of Layer 2, m³ 4,320 28,000 323,250



Area, m² 96,000 78,000 95,500


Volume of Layer 2, m³ 24,000 46,800 36,100



Area, m² 195,000 154,000 180,500


Volume of Layer 2, m³ 39,000 161,700 50,400


Estimated volumes of DOL Layer 2 materialZone 1 2 3 4 5 6 7

Area, m² 756,000 312,000 563,000 543,000 535,000 269,500 529,500

Layer 2 Volume,

m³290,250 116,760 176,940 157,950 355,570 106,900 251,100

Estimated Total volume zone, m³ 1,455,470

The WOLs were outside of the scope of the LSSC investigation and so the estimated

volumes of the WOL layer 2 were calculated using the average thicknesses from the

limited data available from the CIC investigation. The CIC reported the base of layer 1 at

0.15 m and the base of layer 2 at 0.64 m giving a thickness of 0.49 m.



Estimated volumes of WOL Layer 2 materialZone 1 2 3 4 5 6 7

Area, m² 138,000 0 15,000 8,000 65,000 18,000 61,000

Layer 2 thickness,

m0.49 0.49 0.49 0.49 0.49 0.49 0.49

Volume of Layer 2,

m³67,620 0 73,500 3,920 31,850 8,820 39,890

Estimated Total volume zone, m³ 215,600

It should be noted that these volumes are based on very limited data averaged over a

large area and as such the volumes are only approximations. Because of the large areas

involved the volume of material is very sensitive to the thickness of the contamination

with a small change in thickness resulting in a large change in the volume of material.

From the data collected the thickness of Layer 1 in this zone is very thin (from ground

surface to the top of Layer 2 (tables above)). When Layer 1 is removed as part of the

remediation it is likely that part of Layer 2 will also be removed, this will reduce the

volume of the Layer 2 material.

5.7 Summary of Findings

This section pulls together the different aspects of the field work results.

5.7.1 Layering

From observations made during the LSSC field work the CIC designation of the wet and

dry oil lakes may need revising. As discussed in section 5.2.1 the properties of Layer 1

are dependent on the seasons and temperature. As such a feature that was classified as

a dry oil lake in winter may be designated as a wet oil lake in the hotter summer. It is

proposed to use the layer definitions where Layer 1 is a surface or, in the case of areas

subject to subsequent wind deposited sands, near surface material that comprises a

crust or oil/sludge that is not dominated by sand, Layer 2 is oil contaminated sand and

Layer 3 is classed as material with no visual or olfactory evidence of contamination.

The equivalence would be:

Significant Layer 1 = Wet oil lake

Thin Layer 1 crust with Layer 2 = Dry oil lake 1 Jun 15 Page 73 of 78


No Layer 2 = Tarcrete.

This designation would also pick up transitions between the wet and dry oil lake

features.

From the surface it can be difficult to distinguish between the drier, more brittle Layer 1

and the presence of tarcrete, however vegetation seems to be able to grow through

tarcrete (unless it is very think) whereas there does not tend to be vegetation in the oil

lake features. The presence of vegetation is one way to make a first pass nonintrusive

method of distinguishing between tarcrete and Layer 1 oil lake material.

The colour profile through the Layer 2 material can be used as a first guide to the level of

contamination. The natural colour of the uncontaminated material is a light brown/cream

colour. The colour profile of Layer 2 tends to be: Dark brown/black at the top (below

Layer 1), and the soil colour generally becomes a lighter brown with depth. From the

observations made in the field, there is a sharp transition between the colour of the

Layer 2 material into the light brown/cream colour of the Layer 3 material.

The analytical data also suggests that there is a reduction in TPH concentration with

depth that correaltes with the change in colour.

Samples collected in the Layer 3 material, which was recorded in the field as having no

visual or olfactory evidence of contamination, recorded TPH (SARA) levels ranging from

165 mg/kg (0.02 % TPH) to 3,385 mg/kg (0.3% TPH) with the geometric mean at

888 mg/kg and the arithmetic mean as 1,030 mg/kg.

5.7.2 Comparison of CIC and LSSC TPH HEM Data

As identified in sections 5.5.2.1 – 5.5.2.7 there is a difference between the TPH HEM

concentrations from the CIC analysis and the LSSC analysis. This difference between

the two data sets can be attributed to:

Samples were taken at different locations within the oil lake features;

There is variation in the contamination profile within the feature; and

There is significant variation of contamination with depth, material at the top of

Layer 2 near the boundary with Layer 1 will have a higher TPH concentration

than the material lower in Layer 2.

However across the investigation area the data of the LSSC and the CIC show a

reasonable correlation given the heterogeneity of the material.



Figures 12a and 12b (Appendix A) show the CIC designated features with the

classification from the LSSC trial pit locations (points). The figures shows that at a

number of areas that were designated as Dry Oil Lakes are, in numerous places.

tarcrete. This demonstrates the difficulty in designating features from surface and aerial

photography and further emphasises the importance of combining surface visual

inspections with trial pits.

5.7.3 Phase 1 Remediation Areas

Site reconnaissance combined with review of the field logs and chemical data has

identified two zones deemed suitable for the short term Phase 1 remediation. Aspects

that were considered when reviewing each zone comprised:

Continuous presence of Layer 2 contaminated materials;

Thickness of Layer 2 contaminated materials;

Contamination profile, particularly TPH, of Layer 2 materials;

Estimated volume of Layer 2 materials generated from each zone;

Thickness and consistency of Layer 1 materials, i.e. level of effort required to access Layer 2 materials;

Proximity and limitations of oilfield infrastructure; and

Presence of metallic debris at surface.

The two zones identified as suitable candidates for Phase 1 remediation comprise Zone

2, located in the east of the LSSC investigation area and Zone 7, located in the central

west of the investigation area.

Zone 2 has been identified as suitable for Phase 1 remediation due to the ease of

access of Layer 2 materials. Across the vast majority of Zone 2, the Layer 1 (crust)

ranges from a few millimetres to a few centimetres in thickness. The crust is a hardened

but friable dry oil lake crust. The contamination identified in Layer 2 is typically in the

range of 2.0-2.5% TPH of 0.3m thickness. This area is estimated to generate in the

region of 100,000 m³ of material suitable for remediation.

By contrast, Zone 7 forms a large expanse in a topographic depression of dry oil lake

intermingled with occasional small (<1000m2) and medium (>10,000m2) shallow wet oil

lake features. The crust can therefore vary between a thin hardened crust through to a

moist heavy sludge. However, the underlying Layer 2 contaminated sands range in

thickness from 0.2 m to greater than 1.2 m, providing a substantial volume of material for



remediation, in the region of 250,000 m3. This Layer 2 material typically has a

concentration in the range of 1.5 to 2% TPH.

The remaining zones may also provide additional volumes of material for subsequent

remediation. However, they have been rejected from this current recommendation for a

number of reasons:

Zone 1 in the north of the investigation area is likely to be remediated under the SEK

E&T Contract, especially given the large wet oil lake feature and frequent small and

medium wet oil lake features present;

Zone 3 in the central south of the investigation area was identified as having a

substantial hardened crust akin to the adjacent large wet oil lake feature. The level of

effort required to access the underlying Layer 2 material was considered too high

compared to other zones;

Zone 4 was identified as having intermittent dry oil lake and tarcrete intermingled and

is likely to require additional investigation to resolve more accurately the presence

and volume of dry oil lake;

Zone 5A and Zone 5B, in the south-west of the investigation area, like Zone 4, have

frequent areas of tarcrete. This is likely a function of the way in which the oil

contamination was formed, from broken and ruptured pipework rather than from oil

wells. Adjacent to Zone 5A and 5B is the area where the former Gathering Centre

GC12, was located. The destruction of this piece of oilfield infrastructure has left

frequent metallic debris across a wide area, including potential EODs.

Zone 6 in the centre of the investigation area, adjacent to the south of a large wet oil

lake feature (ID 4423), may provide further volumes of material for remediation.

There are, however, areas where tarcrete is present, and further resolution of dry oil

lake presence, and subsequent more accurate volumes, is recommended.

6 CONCLUSIONS AND RECOMMENDATIONS

The LSSC was designed to complement the CIC investigation from 2002, and to update

the understanding of contamination profile. The investigation also compared the current

assessment data with the CIC data.

Contamination Profile

The LSSC confirms the CIC classification of three layers;



o Layer 1 – Oil and sludge

o Layer 2 – Oil contaminated Sand

o Layer 3 - Sand which has No Visual and Olfactory evidence of Contamination

There is a general reduction of contamination with depth, this is evident from the

colour getting lighter with depth.

There is a sharp colour change between the Layer 2 and Layer 3.

Visual observation proves a good first guide for identification of contaminated soil.

Where Layer 3 material was recorded as NVOC concentrations were generally

below 0.1 % TPH, however there were occasional concentrations up to 0.5%.

Comparison of historical data

Layer 1 – based on limited LSSC sampling data (11 samples) the TPH HEM gives results from CIC and the LSSC investigation in the same order of magnitude;

o Wet oil lake, mean TPH. CIC 224,326 mg/kg – LSSC 135,557 mg/kg

o Dry oil lake, mean TPH. CIC 89,767 mg/kg – LSSC 81,637 mg/kg

Layer 2 – The results for Layer 2 compare well between the CIC and LSSC data. The variation between the LSSC and CIC data is likely to be due to inherent variability within ground conditions.

Zone LSSC TPH (HEM) Geomean (mg/kg)

CIC TPH (HEM) Geomean (mg/kg)

Zone 1 27,666 16,403

Zone 2 21,090 15,075

Zone 3 11,637 28,391

Zone 4 15,221 8,920

Zone 5 23,928 17,202

Zone 6 16,863 23,159

Zone 7 15,976 15,027

As a result of a higher density of sampling to fill the identified data gaps in the CIC data, areas that were designated as Dry Oil Lakes in the CIC report were identified as tarcrete from the LSSC data.

Phase 1 remediation

From the data gathered in the LSSC investigation and using the CIC data Zone 2 and 7

have been identified as potential areas for Phase 1 remediation



Zone 2

Thin Layer 1 crust;

Hard but friable crust;

2.0 – 2.5 % TPH in Layer 2;

0.3 m think Layer 2; and

Estimated 100,000 m³ of material suitable for remediation.

Zone 7

Varying Layer 1 thickness;

Occasional small to medium, shallow wet oil lakes

Layer 1 varies between thin and hard and moist heavy sludge;

1.5 – 2.0 % TPH in Layer 2;

0.2 m to greater than 1.2 think Layer 2; and

Estimated 250,000 m³ of material suitable for remediation

The remaining zones may also provide additional volumes of material for subsequent

remediation. However, they have not been put forward for this phase of remediation.


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