505093 / january 24, 2012 - british columbia · 5.2.7. geology 19 5.2.8. hydrogeology 20 6. a...

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TABLE OF CONTENTSPage

1. INTRODUCTION 1

1.1. Limitations 1

2. BACKGROUND 2

2.1. The Issues 4 2.1.1. Administrative 4 2.1.2. Technical 5 2.1.3. Approach to Regulatory Issues 7 2.1.4. Approach to Technical Issues 7

3. CONCEPTUAL SITE MODEL (CSM) 9

4. STREAMLINING SITE ASSESSMENT FOR UPSTREAM OIL AND GAS SITES IN NORTHEAST BC 11

5. DEVELOPING THE STANDARD CSM SITE CONDITIONS 14

5.1. Upstream Oil and Gas Activities 14 5.2. Physiography of Northeast BC 15

5.2.1. Topography 15 5.2.2. Site drainage 15 5.2.3. Weather 16 5.2.4. Vegetation 17 5.2.5. Muskeg / Organic Soils 18 5.2.6. Land use 19 5.2.7. Geology 19 5.2.8. Hydrogeology 20

6. A SUMMARY OF THE SITE ASSESSMENT PROCESS 22

6.1. Stage 1 PSI 22 6.2. Stage 2 PSI 23 6.3. DSI 23

7. STAGE 1 PSI IMPLEMENTATION 24

7.1. Sources of Background and Historical Information 24 7.2. Typical APEC and PCOC at Upstream Oil and Gas Well Sites 25 7.3. Revisiting the CSMs 26

8. SOIL INVESTIGATION 27

8.1. Applicable standards 27 8.1.1. Applicable Land Use and Associated Soil Standards 27 8.1.2. Organic Soils and Muskeg 28 8.1.3. Soil Assessment Design 29 8.1.4. Electromagnetic (EM) Surveys 30 8.1.5. Inspection During Well Abandonment 31

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TABLE OF CONTENTS (Cont'd)Page

8.2. Subsurface Soil Assessment 32 8.2.1. Organic Soils and Muskeg 34

8.3. Recommended Soil Assessment Approach and Recommended Minimum Assessment Levels 34 8.3.1. Wellhead 35 8.3.2. Flaring Facilities 35 8.3.3. Drilling Waste Disposal Areas 36 8.3.4. Pipelines / Flowlines 37 8.3.5. Temporary USTs/ASTs 37 8.3.6. Other soil assessment 38

8.4. Detailed Site Investigation (Soil) 38 8.5. Recommended Techniques 38

8.5.1. Field Screening Techniques 38 8.6. Specific Issues Associated with Soil Assessment 40

8.6.1. Background Soils 40 8.6.2. Organic soil and Muskeg Sampling 40

9. HYDROGEOLOGIC INVESTIGATION 42

9.1. Background 42 9.2. Clay-rich Aquitards Conceptual Site Model – Aquitard Integrity 44 9.3. Designing the Hydrogeologic Investigation Program 47

9.3.1. Objectives 47 9.3.2. Defining the Conceptual Site Model - Scenario Testing 47 9.3.3. Scale 48 9.3.4. Phased Approach, Triggers and Weight of Evidence 48

9.4. Stage 1 PSI 48 9.5. Field Investigation (Stage 2 PSI and DSI) 49

9.5.1. Determining Potential Pathways and Receptors – Groundwater Uses 49 9.5.2. Determining the Lateral and Vertical Extent of the Clay-rich Aquitard 50 9.5.3. Determining Aquitard Integrity 51 9.5.4. Determining Hydrogeologic Properties 52 9.5.5. Determining Contaminant Concentrations 54

9.6. Further Investigation 54 9.6.1. Surface Water 56 9.6.2. Sediment 56 9.6.3. Vapour 57

10. SUMMARY AND CONCLUSIONS 58

10.1. Technical 58

11. REFERENCES 62

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TABLE OF CONTENTS (Cont'd)Page

IN-TEXT TABLEA: Applicable Site-Specific Standards for Upstream Oil and Gas Sites - NE BC 28

DRAWINGS

� Map 1 - Regional Map Northeast BC – Western Sedimentary Basin Oil and Gas Activity� Map 2 - Regional Map Northeast BC – Existing Water Supply Wells� Map 3 - Regional Map Northeast BC – Agricultural Land Reserve� Map 4 - Regional Map Northeast BC – Wetlands / Muskeg

CSM #1

� 505093-001 – CSM#1 (fine grained soil) Site Plan with APECs� 505093-001B – CSM#1 (fine grained soil) Cross Section� Air Photograph 1A Conceptual Model (fine grained soil)� Photograph 1B: Ground Level Photograph Fine Grained Soils

CSM #2

� 505093-002 – CSM#2 (Organic Soils) Site Plan with APECs� 505093-002B – CSM#2 (Organic Soils) Cross Section� Air Photograph 2A Conceptual Site Model (organic soil)� Photograph 2B: Ground Level Photograph Organic Soils� 505093-003 – Post Abandonment Wellhead Assessment

APPENDICESI Stage 1 PSI Background Data SourcesII List of Potential Contaminants of Concern (SNC in-house reference)III Depth Dependant Standards

P:\CP\OTHER\505093\WP\R124CHDA_ MOE UOG.DOCX

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1. INTRODUCTION

The British Columbia Ministry of Environment (MoE) has contracted SNC-Lavalin Inc., Environment Division (SLE) to develop advice regarding technical guidance for the characterization of contamination at upstream oil and gas sites in Northeast British Columbia.

This document will serve to advise MoE in developing guidance for the upstream oil and gas sector. This draft guidance will be subjected to the normal process of development and public

consultation prior to finalizing and issue by the MoE.

This document, while designed to be as free-standing as possible, should be used in the context

of existing regulatory guidance documents.

The technical guidance draws on our project team’s first hand experience in the characterization of contamination at upstream oil and gas sites in northeast BC; on our experience with Alberta’s regulatory process for these activities and on our strong knowledge and experience of existing policies and guidance for other types of contaminated sites in BC. SLE collaborated with Sue Gordon, Ph.D. P.Geol. of Gordon Groundwater Consultancy for this project. Dr. Gordon provided input on report organization and content focused primarily on other jurisdictions’ approaches for upstream oil and gas sites and advice on contaminant hydrogeology investigative techniques for use in assessing aquitards.

The primary purpose of this project is to catalogue and compare regulatory approaches used by MoE, British Columbia Oil and Gas Commission (OGC) and other jurisdictions to accomplish the same goal; to adequately and efficiently assess contamination at upstream oil and gas sites.This project has necessarily identified a number of issues that, until addressed, limit our ability to accomplish this. These issues are, however, outside our scope. As such, we have identified a

number of issues that need to be addressed.

1.1. Limitations

It is necessary that those using this document possess an appropriate combination of formal education, practical knowledge, skills and experience in conducting a technically sound and rational site assessment; are familiar with applicable federal, provincial and municipal legislation and published guidelines used to evaluate the presence of contamination as well as being familiar with upstream oil and gas operations. It is the use of adequately informed professional judgement based on a weight of evidence approach that will allow for streamlining of the

assessment of these sites.


2. BACKGROUND

The northeast region of British Columbia is experiencing increased activity in the oil and gas

exploration and production industry, collectively known as the “upstream oil and gas sector”.

This sector drills and develops oil and gas production wells and collects, transports and

processes the oil and gas through an array of different types of facilities. The sector currently

includes about 20,000 active and abandoned well sites accompanied by a network of oil and

gas distribution, processing, and storage infrastructure. A plan showing the areas of activity and

well locations is included as Map 1 in the Drawings Section. The regulation of any

contamination at these sites as well as the approximately 100 to 200 of these sites that are

permanently abandoned per year, is jointly undertaken by the OGC and the MoE. The sharing

of responsibilities is defined by the 2008 Memorandum of Understanding (MoU) between MoE

and OGC. The MoU outlines the roles and responsibilities and processes respecting the

assessment and cleanup of oil and gas sites in general as follows:

� The OGC is responsible for regulating remediation and reclamation of upstream oil and gas

sites through the Certificate of Restoration (CoR) process. This includes review of site profiles

to determine if site investigation is required under the Environmental Management Act1

(EMA) and the Contaminated Sites Regulation2

� The MoE will be responsible for the management of assessment and remediation of sites

deemed to be high risk according to the MoE risk classification system. MoE may remove the

high risk classification allowing further assessment under the OGC process and subsequent

CoR application.

(CSR). OGC also administers the priority site

classification process which determines whether a site is considered high priority. If a site is

not classified as high priority, OGC reviews assessment and remediation reports to determine

adequacy for granting of a CoR Part 1. OGC then reviews reclamation reports to determine

that the site has been adequately reclaimed before granting a CoR Part 2.

� CoR’s issued by OGC will have satisfied provincial requirements for site closure and the MoE

will consult the OGC before issuing remediation orders on any oil and gas site.

1 Environmental Management Act (EMA), S.B.C. 2003, c. 53, as am. by S.B.C. 2004, c. 18.2 Contaminated Sites Regulation (CSR), B.C. Reg. 375/96, including amendments up to B.C. Reg. 97/2011.


While OGC has primary responsibility for managing assessment, remediation and reclamation

of these sites, the applicable standards are those established by MoE under the EMA, the

Hazardous Waste Regulation3

OGC guidance is provided to industry to manage potentially contaminating activities during

construction, operation and abandonment of oil and gas sites. These regulations often guide

“activities” rather than regulating the resulting environmental quality (e.g., “Assessing Drilling

Waste Disposal Area” (ADWDA) document (OGC undated). Complying with OGC regulation

does not necessarily satisfy the assessment requirements of MoE regulations and guidance.

In assessing the level and adequacy of assessment and remediation completed on a site the

OGC accepts a higher level of professional judgement in characterizing contaminant sources,

pathways and resulting impact to potential receptors.

(HWR) and the CSR. Currently, the requirements for

contaminant characterization are prescriptive and are provided through a large number of MoE

protocols, procedures and guidance documents. MoE guidance has been developed to be

applicable to all areas of BC; all land uses, topography and weather conditions; all soil and

groundwater conditions; and all industries, associated contaminants, and to all levels of

contamination and sensitivities of receptors. As such, the guidance documents are extensive

and complex in order to cover a broad range of conditions. All parties recognize that application

of existing guidance in the upstream oil and gas sector may in many cases be resulting in over-

assessment (defined as requiring a higher level of assessment than is warranted by the

potential risks to human and ecological receptors).

OGC regulations, however, also use a second line of evidence in a weight of evidence or lines

of evidence approach by regulating site reclamation through the CoR Part 2 application. A CoR

is not granted until a CoR Part 1 is obtained demonstrating that contamination has been

appropriately addressed and a CoR Part 2 is obtained demonstrating that the site has been

appropriately restored to surrounding conditions and vegetation has been satisfactorily

re-established. As at most upstream oil and gas sites, vegetation is the primary receptor in

agricultural and wildlands settings, OGC has a second line of evidence in identifying

contaminant conditions that would impact site ecology.

3 Hazardous Waste Regulation (HWR), B.C. Reg. 63/88, including amendments up to B.C. Reg. 63/2009.


2.1. The Issues

As the guidance document that will ultimately result from this project is to be used by industry to

meet the requirements of OGC and MoE our approach has been to obtain input from these

stakeholder groups. Activities undertaken for this project include:

� review of existing guidance and development of a questionnaire to identify issues that

stakeholders want addressed;

� review guidance used in other relevant jurisdictions (Alberta, Saskatchewan);

� conduct first stakeholder’s meeting December 1, 2010;

� meet with Treaty 8 Tribal Association in Fort St. John on January 20, 2011;

� through these first meetings, identify key issues with existing regulatory guidance and

reconcile with upstream oil and gas activities and conditions in northeast BC;

� prepare draft outline for technical guidance as reading material for preparation of additional

stakeholder input;

� conduct second workshop February 23, 2011 to obtain comments on the technical guidance;

� incorporate feedback from the stakeholders into a draft report; and

� obtain review comments on draft report and finalize report.

Through our work in the upstream oil and gas sector and through our process of stakeholder

meetings we have identified a number of key issues. The issues can be divided into

“administrative” and “technical”.

2.1.1. Administrative

The objective of this report is to identify administrative differences between the OGC and the

MoE processes and provide approaches to unify the processes. Some of the differences reside

in the underlying acts and protocols which are not the subject of this project. As such, we have

identified a number of issues that could be addressed outside of this guidance document.

These issues are identified in the “Parking Lot” section.


2.1.2. Technical

A wide variety of site conditions and land uses are present in areas of northeast BC. The majority

of the area, however, can be characterized by a common set of conditions present over a large

portion of northeast BC. Many (but certainly not all) upstream oil and gas sites demonstrate low

levels of contamination. OGC and industry are seeking streamlined guidance, not to address all

sites, but to address those sites where it can be demonstrated that contamination is limited and

contaminant sources, pathways and receptors meet the defined common site conditions.

By understanding the contaminants and their distribution, the site conditions that control

contaminant migration and the potential receptors, source and pathway assessment can be

streamlined. This will be accomplished by developing several standardized Conceptual Site

Models (CSM). The concept of a CSM is presented in (Golder Associates, 2010) and is prominent

in Technical Guidance 8, Groundwater Investigation and Characterization4

Once the assumed site conditions of the CSM are demonstrated at a site by a qualified

professional the guidance will provide minimum levels of historical review, soil and groundwater

assessment considered adequate to assess the exposure risks. Comment is also provided on

surface water assessment and soil vapour assessment.

.

While the objective of the guidance is to address only sites that conform with the defined CSMs,

some aspects of the guidance may be usable on other sites where not all CSM conditions

are met.

Through the input received from MoE, OGC, Integrated Land Management Branch,

Contaminated Sites Approved Professionals (CSAP), and the upstream oil and gas industry

through the questionnaire and the first meeting, the key regulatory and technical issues

identified are as follows:

Regulatory Issue #1

The CoR instrument obtained through the OGC, which is enabled under the EMA, is not

perceived as having the same legal standing as a Certificate of Compliance (CoC) from MoE as

enabled under the EMA and CSR. While the liability of the responsible party is not extinguished

under either instrument, it is perceived that the potential for ongoing liability is lower with a CoC

than with a CoR; as such, guidance will address perceived differences towards developing a

common standard. 4 Technical Guidance Document 8: Groundwater Investigation and Characterization, BC MoE, July 2010.


Regulatory Issue #2

OGC and MoE guidance are different in a number of respects. Industry may meet OGC

guidance (i.e., Assessing Drilling Waste Disposal Areas, depth dependant standards, site

priority classification), but still have to do additional work to meet CoR Part 1 or CoC

requirements. The need for assessment of the waste disposal area to meet regulatory

standards is still required.

Technical Issue #1

Required information sources and resulting checklists used in completing an historical review

(CSR guidance 10 checklist) include information sources that are not relevant to the upstream

oil and gas sector and do not include other sources that are relevant and necessary to fully

understand areas of potential environmental concern (APECs) and potential contaminants of

concern (PCOCs).

Guidance needs to include information sources relevant to upstream oil and gas activities and

remove information sources that are not applicable to upstream oil and gas sites.

Technical issue #2

Activities on upstream oil and gas sites differ substantially from other industries but are

consistent between oil and gas sites; as such, it is reasonable to provide a standard list of

APECs and PCOCs to be investigated and standard analytical parameters for analysis.

Technical Issue #3

Applicability of land use and soil, groundwater, surface water, sediment, and soil vapour

standards are not clear for upstream oil and gas sites. Applicability of site-specific factors for

typical upstream oil and gas sites is also not well defined. Classification of organic soils and

muskeg and determination of appropriate standards is of particular interest.


Technical Issue #4

As stated above MoE guidance covers all types of industry, site conditions and land uses

throughout BC. Application of MoE guidance can result in perceived over-assessment of many

oil and gas sites where low levels of contamination as well as limited transport pathways and

low potential for exposure of human or ecological receptors lead to low potential for

environmental impact. The intensity of assessment should be commensurate with the level of

contamination and the resulting potential for significant environmental impact.

Technical Issue #5

Highly organic soils are present on or around many upstream oil and gas sites.

Current accepted analytical methodology developed for primarily mineral soils appears to be

overly conservative for soils high in organic material and moisture content. This results in

elevated reported contaminant concentrations which may not be representative of actual

environmental risk.

2.1.3. Approach to Regulatory Issues

The roots of the regulatory issues lie in the underlying regulations and their approaches to

meeting the same objectives. OGC manages activities while MoE regulates ultimate site

conditions. The two approaches cannot be merged. We can, however, make recommendations

for attempting to develop an equivalency between the results of managing activities with the

ultimate site conditions. An example would be to review and modify the ADWDA document to

more closely meet regulatory standards such that meeting ADWDA would be considered

equivalent to an assessment meeting MoE standards. These “review and modify” activities are

beyond the scope of this document and have been identified as “parking lot” items.

2.1.4. Approach to Technical Issues

Activities and conditions present on sites in the upstream oil and gas sector in northeast BC

have a number of commonalities that influence the potential environmental impacts.

These conditions can be demonstrated on a sector wide and area-wide basis and, with limited

on-site proof-of-concept, can be used in assessing compliance with applicable regulations.

We have developed CSM that represent several common sets of conditions that describe a

large proportion of sites. If the proponent can demonstrate that their site meets the set of

conditions (proof-of-concept), the defined assessment program can be applied.


The CSMs rely on the qualified professional having a good understanding of the contaminants,

the site conditions that control migration and the potential receptors. Our approach relies on

being able to apply regional understandings (e.g., type of site soils) to site-specific conditions

(e.g., hydraulic conductivity of soil). The better the understanding of these relationships on a

regional basis, the higher the confidence in applying them on a site-specific basis; as such,

regional studies of a number of these relationships are recommended. We have identified a

number of studies that can be completed to further the regional understanding of some site

conditions. These are identified in the “parking lot”. In the absence of these studies, a higher

level of site-specific assessment will be necessary to adequately assess a specific site and a

high level of professional judgement will also be required in order to ensure that the

relationships made and the resulting streamlining is technically supportable and is consistent

with the risks of unacceptable receptor exposure under the site-specific conditions.

This requires that those responsible for site assessment can demonstrate the appropriate level

of education and experience. A weight-of-evidence approach should be taken in evaluating

whether the level of assessment is appropriate for the identified level of contamination and the

potential exposure scenarios.

In this report we have provided “interim” approaches that may be modified or expanded through

further research. These include determination of hydraulic conductivity of the regional fine

grained soils, classification of “muskeg” (organic soil media or aquatic environment) and the

analysis of organic soils.

What sites aren’t covered

Sites within northeast BC will exhibit conditions that are not consistent with those defined for the

CSMs. Examples would be mountainous settings in the southwest and settings with granular

soils consisting of recent channel deposits or glacial outwash deposits. These sites do not fit the

assumed conditions and cannot be assessed under this standardized approach. These sites

would be assessed utilizing existing MoE guidance.


3. CONCEPTUAL SITE MODEL (CSM)

“A conceptual site model is a three-dimensional picture of site conditions that conveys what is

known or suspected about the sources, releases and release mechanisms, contaminant fate

and transport, exposure pathways, potential receptors, and risks. The conceptual site model is

based on the information available at any given point in time and will evolve as more information

becomes available.” – US EPA.

The risk to receptors is dependent on the nature of the source (contaminants, media and

concentrations), the potential concentrations at the receptor (based on contaminant fate and

transport through exposure pathways) and the nature of the receptor itself (sensitivity, media and

duration of exposure). The purpose of site assessment is to identify and quantify each of these.

The overall process for developing a CSM through site assessment is as follows:

1) evaluate site history and general setting Stage 1 (Preliminary Site Investigation [PSI] to

identify APECs and PCOCs and site topography and proximity to potential receptors);

2) develop CSM;

3) complete “coarse” assessment of the site;

a) first stage of field investigation (Stage 2 PSI) to determine if contamination is present at

APECs and to provide information on soils and groundwater conditions);

4) determine if CSM is applicable to the site and adjust CSM based on results;

5) address data gaps;

a) additional detailed investigations (Detailed Site Investigation [DSI] to delineate

contamination and fully evaluate pathways and receptors); and

6) CSM now complete with characterization and delineation of contamination, identification of

receptors and characterization of pathways.


CSMs consist, at a minimum, of a site plan and a cross section, generally aligned in the

direction of anticipated or measured groundwater flow. The CSM, when fully developed, defines

the contamination present at the site in all relevant environmental media, the potential human

and ecological receptors at and in the vicinity of the site and provides an evaluation of the

pathways between the two. If there is no contamination or no pathway between contamination

and receptor, there is no unacceptable environmental impact.

Once assessment is complete (i.e., all gaps in the CSM are addressed), then identified

unacceptable risks can be mitigated through remediation to numerical standards or to risk

based standards. Remediation and risk assessment are beyond the scope of this report but

comments are provided in the “parking lot” section.


4. STREAMLINING SITE ASSESSMENT FOR UPSTREAM OIL AND GAS SITES IN NORTHEAST BC

The purpose of streamlining site assessment is to minimize the extent of site-specific

assessment activity by identifying common conditions of sources, pathways and receptors

based on commonalities in site activities at upstream oil and gas sites, commonalities in site

settings and site conditions and commonalities in site usage and ecology. Site assessment can

be further streamlined if certain relationships can be drawn between easily measured site

parameters and conditions affecting risk to receptors (i.e., relating soil grain-size and thickness

to contaminant transport parameters). On the basis of the CSMs developed for the industry

specific and region-specific conditions, it is our intent that the process of eliminating potential

land and groundwater uses and eliminating certain site-specific factors can be standardized

based on professional judgement applied to regional data, as well as site inspection and limited

soil and groundwater data collected from the site itself.

As stated above, MoE guidance is based on the presence of a broad range of land uses and

site conditions. The majority of sites in the oil and gas sector in northeast BC, however, can be

characterized as follows:

� Sector-wide similarities in site configurations, contaminant sources and waste handling

practices;

� common APECs and PCOCs between sites.

� Western Canadian Sedimentary Basin physiography, geology and related ecosystems;

� primarily poorly drained relatively flat plateau lands with or without significant thickness

of surficial organic soils or muskeg;

� primarily substantial thickness of fine grained soils;

� sites frozen approximately half the year; and

� limited groundwater drinking water resource currently in use.


� Land Use.

� sparse human habitation;

� predominantly wild lands or agricultural land uses;

� majority of lands under Crown ownership, and First Nations traditional land use; and

� many remote locations with only limited and seasonal access.

Our approach assumes that:

� characterization of common conditions can be demonstrated on an area-wide basis;

� the presence of these common conditions can be incorporated into the CSM on a site-by-site

basis with limited site-specific assessment; and

� based on the assumptions in the CSMs, standardized assessment approaches can be

utilized that provide an adequate minimum level of assessment of the contamination,

pathways and receptor exposure.

For the purpose of this document we have defined two CSMs:

� CSM #1: assumes:

� fine grained soils to surface;

� common APECS and PCOCs associated with typical well drilling site;

� relatively flat poorly drained lands;

� sparse human habitation and wildlands or agricultural land use (no nearby buildings, no

livestock watering); and

� may be remote with limited access.


� CSM #2: assumes:

� a thickness of orgainic soils overlying fine grained soils;

� common APECS and PCOCs associated with typical well drilling site;

� relatively flat poorly drained lands with surficial organic soils that are seasonally

saturated and muskeg in area;

� sparse human habitation and wildlands land use (no nearby buildings, no livestock

watering); and

� likely remote with limited access (vehicular access in winter only if at all).

Plans and cross-sections depicting the two CSMs are included in the Drawings Section, along

with aerial photographs and site photographs of typical sites.


5. DEVELOPING THE STANDARD CSM SITE CONDITIONS

The following sections summarize the conditions present on many upstream oil and gas sites in

northeast BC.

These are the conditions that will be reviewed in order to justify aspects of this guidance.

5.1. Upstream Oil and Gas Activities

Upstream oil and gas refers to sites where oil and gas is being produced from the ground, and

the associated facilities to conduct the oil or gas to collection facilities. These sites include the

following (AENV, 2010).

� Prepared wellsite (not drilled) – This is a wellsite where soil salvage and preparation for

drilling is complete; but drilling at the site did not occur (no CSR Schedule 2 activities).

� Drilled and Abandoned (D&A) wellsite – Site which was drilled and abandoned (never put into

production). (Wellhead, sump/ Drilling Waste Disposal Area [DWDA], flare pit).

� Producing oil wellsite – Well which produces primarily liquid hydrocarbons from a pool or

portion of a pool (wellhead, sump/DWDA, pileline, flare facility, on-site tankage, leaks, spills).

� Producing gas wellsite – well producing natural gas (wellhead, sump/DWDA, flowline, flare

facility, leaks, spills).

� Battery site – system or arrangement of tanks or other surface equipment, together with

associated infrastructure, for receiving or holding the effluent of one or more wells

(pipeline, on-site tankage, leaks, spills).

Associated off-site disturbances (when present) may include:

� off-site drilling waste disposal areas (DWDA);

� temporary camp sites; and

� off-site spills/leaks associated with lease activity.


As pipelines which sometimes cross a well site in a right-of-way are administered under different regulations, they are not being considered on this project except to be considered as potential

off-site APECs.

These common site activities have common APECs and associated PCOCs which can be

assumed based on site activity.

5.2. Physiography of Northeast BC

The physiographic conditions of a region include topography, site drainage, weather, vegetation,and land use. The defined CSMs are based on the presence of typical topography and geology present northeast of the Rocky Mountains in the Western Canadian Sedimentary Basin. This guidance will not generally cover the mountainous areas to the southwest or other areas of the Province where upstream oil and gas activities occur. Some aspects of the guidance (common APECs and PCOCs) will be applicable to other areas of the Province. A map

indicating the general area of oil and gas activity in BC is included as Map 1.

5.2.1. Topography

Topography in the Western Sedimentary Basin is relatively flat except where drainage courses have incised relatively steep, narrow drainage channels. To the southwest the basin meets the Rocky Mountains. This is the southern extent of our study area. In the northern part of the

region, organic soils and wetlands / muskeg are prevalent as shown on Map 4.

5.2.2. Site drainage

Drainage on the topographically flat area of the Western Canadian Sedimentary Basin is generally poor with significant seasonal variation. Through late fall, winter and early spring (approximately six months) when temperatures are below freezing, no runoff occurs. During late spring when snow melts but the ground is still frozen, drainage is dominated by surface retention of meltwater in depressions and overland flow to localized seasonal water courses.These localized seasonal water courses ultimately lead to larger permanent streams and rivers.During summer, once the ground has thawed, some infiltration of surface water occurs.During late summer and early fall there is little runoff and the land dries through evapotranspiration; as such, it is unlikely that the seasonal water courses would be considered aquatic environment due to the seasonality of flow. Professional judgement will be required in assessing the presence of aquatic environment where it is not clear that water courses

are seasonal.


In the northern areas, many sites have organic soils or muskeg present on or near the site.

Muskeg is defined by MoE to mean:

� “boreal wetland bog, fen or permanent marsh as classified by the Canadian Wetland

Classification System and is characterized, without limitation, by a surface or near-surface

water table and a preponderant presence of peat, Sphagnum mosses and sedges.”

(MoE Procedure 8)

Under certain circumstances, organic soils could be considered terrestrial soils in that they are

only seasonally saturated and hence don’t fit the definition of muskeg . In these areas, surface

water flow during summer and early fall is through the organic soils or seasonal water courses.

For the purpose of this report, muskeg will not be considered an aquatic receiving environment

unless surface water is present for more than half of the frost-free season. Where surface water

on muskeg is present for more than half of the frost-free season, compare surface water and

peat chemistry to ambient Water Quality Guidelines (WQGs) and CSR sediment criteria,

respectively. Where surface water on muskeg is present for less than half of the frost-free

season, compare surface water and peat chemistry to CSR numerical groundwater standards

and soil standards, respectively.

A detailed study of when and whether a particular muskeg site is considered an aquatic vs. a

terrestrial receiving environment is beyond the scope of this report. Recommendations for

further assessment have been included in the “parking lot” section of this report. We understand

that MoE will ultimately develop muskeg and wetland use standards. In the interim, professional

judgment will be required in determining if a site or the surrounding area should be considered

terrestrial or aquatic environment.

5.2.3. Weather

As stated above, this region has average monthly temperatures below freezing for five months

to six months of the year. The area receives about 450 mm of precipitation through the year with

about 150 mm during months when the ground would be frozen. Winter precipitation (snow)

accumulates on site and melts in spring prior to the ground thawing. As such, snow melt is

drained through seasonal drainage courses resulting in limited infiltration to the subsurface.

In many areas vehicular access is not possible during breakup (when the ground is thawing in

spring/early summer). In muskeg areas vehicular access may only be possible in winter months

when the ground is frozen.


5.2.4. Vegetation

The northeast region of BC known commonly as the Peace River Region is part of an extensive

belt of boreal coniferous forest occurring across Canada. In BC, this zone is known as the

Boreal White and Black Spruce (BWBS) biogeoclimatic zone and it displays some unique

ecotypes which are not found anywhere else in BC.

We can generalize and describe the BWBS zone as an area where winters are long and cold

and the growing season short; the ground remains frozen for much of the year. Numerous past

fires have created extensive successional forests of aspen and lodgepole pine and where flat,

the landscape is typically a mosaic of black spruce bogs (muskeg) and white spruce and

trembling aspen stands.

We can further generalize when describing the dominant ecotypes in the Peace River Region.

The first ecotype can be described as an upland mesic ecotype dominated by heavy clay soil

with several tree species and an abundance of shrubs, herbs and mosses. The second

dominant ecotype can be described as a lowland one with very wet organic soils (muskeg) and

a substantially different vegetation complex commonly populated by one or two tree species,

mosses, herbs, and a very limited number of shrubs.

Upland Sites

Generally speaking, upland well-drained sites contain 40% to 70% tree cover made up of white

spruce, trembling aspen, lodgepole pine, and black cottonwood depending on aspect, slope

position, and soil composition.

This vegetation description is for silt and clay rich soils, generally formed on morainal,

glaciofluvial or lacustrine deposits.

Lowland Sites

Again, generally speaking, lowland sites are considered to be muskeg and generally contain

20% to 25% ground cover largely made up of black spruce with a minor component of

tamarack.


This vegetation description is for slope position ranges from level to depressional with very little

variation. Soils in these settings (muskeg) are generally classified as organic as they are

developed on organic parent materials.

Rooting

The typical tree species found in both upland and lowland settings in northeast BC are generally

characterized by shallow rooting systems (http://www.for.gov.bc.ca/hfp/silviculture/Compendium/).

However, there is a lack of scientific literature on the distribution of roots for these species in

northeastern BC. Many important limiting factors surrounding root system development are

present. These can include cool temperatures (especially in subsoils), soil physical condition

(elevated bulk density and soil strength in B and C horizons) and also wet or water logged

conditions. Based on our observations, these conditions together typically result in root

development in the upper 1 m of soil, and usually it is concentrated within the upper 30 cm in

association with LFH, A, or upper B horizons, or with organic soil horizons in peatland

environments.

However, very few fine and very fine roots may occasionally be observed in subsoil horizons

(B, BC or C horizons) and may extend to below a depth of 1 m. Little is known on the

distribution of these roots; however, they may play a role in accessing water during drought

conditions. Caution should be exercised in applying generalizations in areas that are not

underlain by clay and silt rich parent materials where root development may extend deeper in

the soil profile (i.e., well drained medium to coarse grained fluvial or glacio-fluvial deposits).

5.2.5. Muskeg / Organic Soils

As stated above for the purpose of this report, true muskeg will be treated as an “aquatic

receiving environments”. Muskeg where surface water is not present for half the frost-free

season will be treated as terrestrial habitat, and CSR soil and groundwater standards will be

applied.


5.2.6. Land use

Land use in the region is predominantly wildlands or agricultural land use. In some areas, sites

are in the agricultural land reserve (ALR). A map showing ALR areas in northeast BC is included

as Map 3 in the Drawings section. Habitation is sparse. For the purpose of the CSMs it is

assumed that there are no residential or commercial buildings proximate to the site and

groundwater is not used for drinking water supply. Irrigation of agricultural land from groundwater

sources is not common due to low groundwater yields. Livestock watering may occur in some

agricultural areas through excavation of dugouts; however, these largely collect surface runoff

rather than groundwater.

The majority of lands are Crown owned and subject to First Nations traditional land uses.

Many sites are remote with only limited seasonal access. This implies that for the majority of

sites, frequency and duration of human exposure to the site will be, at most, very limited.

5.2.7. Geology

The main surficial deposits in much of northeast BC consist of fine grained soils including tills

and glaciolacustrine deposits that overlie the Western Canadian Sedimentary Basin bedrock

(shale, siltstone, sandstone), with thicknesses of 0 m and up to 100 m or more. Typically silts

will have a hydraulic conductivity of 10-5 m/s to 10-8 m/s and clays will have a hydraulic

conductivity of 10-8 m/s to 10-12 m/s.

Near-surface fracturing of the fine grained soils may occur as a result of frost action and

seasonal soil desiccation. At some locations, localized sand layers are observed within the fine

grained soils.

Where incised drainage channels are present there can be fluvial deposits of sand and gravel.

The proposed CSMs in this report would not be applicable to sites in these soil conditions.

In the northern areas, many sites have organic soils or muskeg present on or near the site.

At many locations, low level metals exceedences have been identified in soil including, arsenic,

barium, boron, cadmium, selenium, sodium, and molybdenum. These may represent

background concentrations.


5.2.8. Hydrogeology

A highly generalized regional hydrogeologic setting in northeast BC consists of deep saline

aquifers in the Cretaceous Western Canadian Sedimentary Basin (WCSB), overlain by much

shallower potable aquifers in younger bedrock and glacial-fluvial overburden, which themselves

are covered by clay rich tills and glaciolucustrine deposits over a significant portion of the area.

The WCSB is a massive wedge of sedimentary rock that can reach up to six kilometres in

thickness, is approximately 1.4 million square kilometres in area and represents a time span of

over 600 million years. Subsurface geology in northeast BC can be quite complex; but

generally, there is a layer of recent unconsolidated glacially derived material (Quaternary

< 2.5 million years) lying on top of bedrock (> 60 million years). In some areas, the Pleistocene

clay-rich tills and glaciolacustrine sediments completely cover the glaciofluvial sands and

gravels. Oil and gas producing zones in the WCSB are typically found at depths of

approximately 800 m to 3,000 m. Depth to bedrock varies considerably over the region from

surface outcrop to greater than 500 m. However, it commonly ranges from 50 m to 150 m in

depth below the ground surface. Most potable groundwater sources are found in the shallowest

unconsolidated horizons lying at depths ranging from 0 m to 150 m (BC OGC, 2010; Levson et

al., 2005).

Groundwater is generally present at shallow depth (at least seasonally) at sites represented by

the CSMs. The groundwater is present in the thin organic or muskeg soils and sometimes in thin

sand lenses or in secondary permeability (fractures) in the fine grained soils. The ability of the

subsurface to act as an aquifer will be determined as defined in Technical Guidance 65

5 Technical Guidance Document 6: Water Use Determination, BC MoE, Version 2, July 2010 (effective

February 1, 2011).

(BC MoE, 2010a), based on hydraulic conductivity and yield. It is anticipated the limited shallow

groundwater flow is through the sand layers, fractures in fine grained soils or the shallow soils

including the organic soils. Where deeper groundwater is considered a resource that requires

protection, it will generally be below the fine grained soil in deeper unconsolidated material or

within the bedrock. The thickness of the protective layer (aquitard) will need to be determined if

a subsurface investigation is required.


For the purpose of this report the CSM has assumed minimal shallow groundwater flow.

Future work towards refinement of upstream oil and gas guidance should include compilation of

soil and groundwater data from existing sources in order to identify areas where groundwater is

considered a resource (parking lot). Discussed in Section 9.1, there is also a need to have a

regional geological understanding related to depositional environments and stratigraphy in order

to provide more certainty on the ability of the fine grained material to protect the groundwater

resources that may be under or adjacent to an upstream oil and gas site.

In groundwater, low level metals concentration exceedences are sometimes identified, including

iron, manganese, magnesium, cadmium, sulphate, and cobalt in groundwater.


6. A SUMMARY OF THE SITE ASSESSMENT PROCESS

The same principles for investigating contamination at other industrial sites apply to upstream oil

and gas sites; however, as described previously, the conditions in northeast BC can result in

some differences. Under the CSR, site investigation is required under several conditions,

including orders, spills, etc.; however, for the most part, site investigation will be triggered by

completion of a site profile. Under the OGC process the site profile is submitted with the CoR

Part 1 application.

This section describes the key elements in the investigation program with reference to existing

regulatory guidance and policy. These documents include investigation checklists

(Technical Guidance TG10 and TG116) as well as guidance for the characterization of site soil

(e.g., TG1, 2, 5, and 16 and Protocol 47), sediment (TG198), groundwater (TG6, 8, 13, and 15

and Protocol 99), and vapour (TG410

6.1. Stage 1 PSI

).

Based on the Site Profile checklist, it is probable that commercial or industrial activities as

described in CSR Schedule 2 have taken place at an upstream oil and gas site; therefore, a

Stage 1 PSI will likely be required.

6 Technical Guidance Document 10: Checklist for Reviewing a Preliminary Site Investigation (PSI), BC MoE,

revised October 2005.Technical Guidance Document 11: Checklist For Reviewing a Detailed Site Investigation, MoE, June 2005.

7 Technical Guidance Document 1: Site Characterization and Confirmation Testing, BC MoE, July 2009.Technical Guidance Document 2: Statistical Criteria for Characterizing a Volume of Contaminated Soil, BC MoE, January 2009.Technical Guidance Document 5: Sampling and Determining Soil pH at Soil Relocation Receiving Sites, BC MoE, October 2005.Technical Guidance Document 16: Soil Sampling Guide for Local Background Reference Sites, BC MoE, June 2005.Protocol 4; Protocol for Contaminated Sites - Determining Background Soil Quality, MoE, October 15, 1999.

8 Technical Guidance Document 19: Assessing and Managing Contaminated Sediments, MoE, August 2005.9 Technical Guidance Document 6: Water Use Determination, BC MoE, Version 2, July 2010 (effective

February 1, 2011).Technical Guidance Document 8: Groundwater Investigation and Characterization, BC MoE, July 2010.Technical Guidance: Groundwater Model (Version 2009), updated June 2009.Technical Guidance Document 15: Compliance Points for the Protection of Aquatic Receiving Environments(Version 1, Draft 5), BC MoE, August 2009.Protocol 9; Protocol for Contaminated Sites - Determining Background Groundwater Quality, MoE.

10 Technical Guidance Document 4: Vapour Investigation and Remediation, BC MoE, September 2010.


The objectives of a Stage 1 PSI are to identify the potential areas of contamination and the

potential contaminants of concern at a given site. Information is also collected to help determine

the likelihood of contamination and its distribution and fate in the environment. These objectives

can be achieved by:

� developing an understanding of current and historical land uses at the site and on

neighbouring properties; and

� forming a preliminary interpretation of the physical environment of the site.

A complete and adequate Stage 1 PSI should either provide assurance the CoR application is

complete without a Stage 2 PSI because contamination is unlikely, or provide information that

can direct a Stage 2 PSI at the site.

6.2. Stage 2 PSI

A Stage 2 PSI is intended to assess the presence / absence of contamination (PCOC) within

each APEC identified during the Stage 1 PSI, and compare the results to standards contained in

the HWR and the CSR (Schedules 4, 5, 6, 9 10 etc.). A Stage 2 PSI consists of sampling

relevant environmental media by intrusive or non-intrusive methods (i.e., drilling, water

sampling, electromagnetic conductivity surveys, etc.).

6.3. DSI

If the scope of the Stage 2 PSI is sufficient and no contamination is identified then a CoR Part 1

application can be made and a DSI is not required. If contamination of any media is identified

above applicable standards, a DSI is required to further characterize and delineate

contamination as well as identify potential receptors and assess potential pathways.


7. STAGE 1 PSI IMPLEMENTATION

7.1. Sources of Background and Historical Information

The sources of relevant background information for upstream oil and gas sites are different from

those listed in TG10 for urban industrial sites. Given that oil and gas sites are predominantly

located outside of urban centres, fire insurance maps and city (or reverse) directories are

generally not available.

A list summarizing the typical historical information sources that are considered applicable for

conducting the historical review portion of a Stage 1 PSI on an upstream oil and gas site is

included in Appendix I.

Background physiological data is key in forming an understanding of environmental risks at a

site and is the basis for developing a preliminary interpretation of site conditions for a CSM

identifying potential contaminant sources, pathways and receptors. A variety of data sources

related to site physiography exist. A list summarizing the typical sources of physiological data is

also included in Appendix I.

It is recognized that on older sites, where legislation was not in place for recording site activities,

the location of drilling waste disposal areas or flaring facilities may be unknown. The Stage 1

PSI is expected to exhaust all reasonable avenues to locate these APECs. It is the responsibility

of the assessor to determine if the historical information is adequate to determine the presence

of all APECs on the site.

The Stage 1 PSI should include:

� Review of client and relevant government files relating to the site;

� Aerial and Satellite Imagery Review;

� Site Reconnaissance; and

� Interviews.

Details on what these should include are included in Appendix I.


7.2. Typical APEC and PCOC at Upstream Oil and Gas Well Sites

Typical historical site APECs at upstream oil and gas sites include the well head, leakage from

the well casing, drilling waste disposal areas, flaring facilities, spills and ongoing leaks during

operation of the well, and leaks from storage facilities or piping.

An understanding of site operations and production status is key in determining the applicable

APEC at a given site. A summary of common APEC and their associated PCOC and regulated

analytical parameters at upstream oil and gas wellsites is provided in Appendix II.

Other possible APECs are described in subsequent sections.

Over the life of a producing well, various production related facilities (e.g., wellhead,

pipelines/flowlines, flare pit, buildings, etc.) may be abandoned or decommissioned.

These facilities typically constitute consideration as APECs in a Stage 1 PSI. However, if the

resource company is able to provide supporting documentation, a rationale may be formulated

to discount the location of a given former facility as an AEC after the Stage 1 PSI investigation.

Environmental observations and/or data collected during abandonment are examples of

supporting documentation that may be used to evaluate the risk associated with a particular

APEC. If a pipeline/flowline (related to site activity) is known to be present, it should be

considered an APEC, but may be discounted based on observations indicating no

environmental stresses and well head assessment, indicating no significant contamination

relating to the pipeline/flowline.

Often temporary camps were established on or near a well site during drilling. Due to the

temporary nature of these camps and the limited potential for contamination, they would not

normally be considered APECs. The camp site should be inspected during the site

reconnaissance but unless signs of contamination are identified no further assessment

is warranted.

Pipelines crossing the site in a right-of-way are managed separately and should be considered an

off-site APEC. As such, potential impacts should only be assessed as they could affect the site.

The result of a Stage 1 PSI is to define physiography, site activities, site use, and surrounding

land/water use, geology/hydrogeology and have determined soil, groundwater, surface water,

sediment, and soil vapour standards applicable to the site.


In relation to this guidance we have also determined that the site meets the defined conditions

of the CSM.

7.3. Revisiting the CSMs

Based on insertion of the observed site conditions into the CSM we have now defined APECs and

PCOCs and potential human and ecological receptors. We now design the intrusive investigation

to confirm these and to evaluate the potential pathways.


8. SOIL INVESTIGATION

8.1. Applicable standards

A list of applicable land uses is provided in Section 1 (Definitions) of the CSR and corresponding

soil standards are listed in Schedules 4 and 5. Based on Section 11 of the CSR, numeric

standards for urban park land use are considered to be applicable in wildlands settings.

Additional relevant information is found in Part 5 and 6 of the CSR and TG6.

8.1.1. Applicable Land Use and Associated Soil Standards

Applicable land use is determined by comparing uses of the site to the definitions in Section 1

(Definitions) of the CSR. Initially, the land use determination will be based on historical

information and expected future use of the site. This determination would be confirmed by direct

observation during the site inspection. Zoning and land use restrictions (i.e., Agricultural Land

Reserve or Range Tenure) should also be researched through the appropriate municipal and

provincial government agencies. On active well sites the applicable land use is typically

industrial. Where the site is to be abandoned and the lease terminated, typically the CSR

wildland (WL) or agricultural (AL) standards will apply. The land uses have corresponding

standards in schedules 4, 5 and 10 of the CSR.

In all cases, soil quality below a depth of 3 m is compared to commercial standards independent

of the land use at surface. MoE has depth dependant standards that can be applied in the

immediate vicinity of the well head. OGC has depth dependent standards that can be applied at

any distance from the well head.

These depth dependant standards differ somewhat between OGC and MoE and are illustrated

in Appendix III. The MoE depth dependent standards are defined in Part 6 Section 17 of the

CSR.

Matrix Numerical Site-Specific Factors

Once the applicable land use standards are determined, the appropriate site-specific factors

based on presence and proximity of local receptors (Schedule 5 CSR). Site-specific factors and

associated comments are listed in Table A.


TABLE A: Applicable Site-Specific Standards for Upstream Oil and Gas Sites - NE BCComments

Human Health Protection

� Intake of contaminated soil Mandatory at all sites

� Groundwater used for drinking water Applies until proven otherwise as per TG6

Environmental Protection

� Toxicity to soil invertebrates and plants Mandatory at all sites

� Livestock ingesting soil and fodder Applies only when AL applies (ALR, Range Tenure or active grazing). Note - even where livestock is currently not using the site it could not reasonably be discounted for future use if within the ALR.

� Major microbial functional impairment Applies only when AL applies

� Groundwater flow to surface water used by aquatic life – Fresh water

Applies until proven otherwise as per TG6

� Groundwater flow to surface water used by aquatic life – Marine

Not applicable in northeast BC

� Groundwater used for livestock watering Applies only when AL applies (ALR, Range Tenure or active grazing) until proven otherwise as per TG6. Only applies if groundwater is currently used for purpose.

� Groundwater used for irrigation watering Applies only when AL applies until proven otherwise as per TG6. Only applies if groundwater is currently used for purpose. While TG6 does not provide an exemption where groundwater yield is low, an exemption of this nature would be consistent with the drinking water exemption.

The most stringent of site-specific standards that apply are the appropriate standards for

comparison of soil quality. The presence of Hazardous Waste as defined by the HWR must also

be used for comparison.

It is noted in the case of groundwater use, the site investigation will determine applicable water

use standards. The assessment program should be planned with this objective in mind.

8.1.2. Organic Soils and Muskeg




peat chemistry to ambient WQGs and CSR sediment criteria, respectively. Where surface water

on muskeg is present for less than half of the frost-free season, compare surface water and

peat chemistry to CSR numerical groundwater standards and soil standards, respectively.


terrestrial receiving environment is beyond the scope of this report.


Clearly with the present state of knowledge, professional judgement will be important in

assessing the presence of muskeg.

8.1.3. Soil Assessment Design

At this stage the CSM is based only on published regional data, file review and observations

from the site inspection and is used to develop the assessment strategy for the Stage 2 PSI.

The CSM will illustrate:

� Site setting:

� topography and drainage based on airphotograph review and site inspection.

� Geology and hydrogeology:

� based on published data.

� APECs and PCOCs:

� based on file review, site inspection and interviews.

Potential receptors

This provides a preliminary understanding of potentially contaminated areas and contaminants,

potential migration pathways and potential receptors. Where technical decisions are required in

evaluating whether the site meets the conditions of the CSM, specialist input is recommended

from a qualified professional. This may include biologists to evaluate the presence of aquatic

environments or hydrogeologists to assess applicable groundwater use standards.

If no APECs were identified in the Stage 1 PSI (e.g., a site where the pad was built but a well

was not drilled and no indications of contamination were observed during the site inspection),

no further work is required and a CoR Part 1 application can proceed. This is consistent with

Alberta regulation.


Specific APEC may be discounted provided the documentation reviewed in the Stage 1 PSI is

sufficient to demonstrate that there is limited potential for contamination or that contamination

was adequately addressed prior to or during well abandonment. For instance, over the life of a

well, various on-site facilities (e.g., sump, wellhead, pipelines/flowlines, flare pit, buildings, etc.)

may have been abandoned or decommissioned. These facilities typically would be considered

as APECs in a Stage 1 PSI. However, if the historical review provides supporting

documentation, a rationale may be formulated to discount the APEC without further

assessment. Environmental observations and/or data collected during abandonment are

examples of supporting documentation that may be used to evaluate the potential risk

associated with a particular APEC.

The next step is to design an intrusive soil assessment. As a minimum the soil investigation will

identify or confirm the following:

� site geology and stratigraphy including any stratification that could affect bulk soil properties;

� characterization of soil for level of contamination at identified APECs for identified PCOCs;

� characterization of physical properties of soils with respect to assessing potential pathways;

and

� characterization of properties of secondary features such as rootlets and fractures with

respect to assessing potential pathways.

Depending on the completeness of the site data in the Stage 1 PSI, the location of APECs on a

site may not yet be known.

8.1.4. Electromagnetic (EM) Surveys

If the location of drilling waste disposal areas or flare pits are not known an electromagnetic

survey (EM) may be a useful tool to help identify APEC locations. EM surveys measure the

conductivity of the subsurface and results are typically mapped using GPS technology.

The resulting image presents a spatial conductivity distribution of the surveyed area and can

identify areas of potentially elevated conductivity. Areas of elevated conductivity may indicate

ionic contamination, such as salt, changes in stratigraphy or soil moisture, and/or buried metallic

or conductive debris.


Results can provide valuable information at the screening level to assist in identifying APECs

(i.e., flare pit or DWDAs). The EM survey is commonly used as a screening tool to identify

possible APEC through a lateral soil conductivity distribution. These APEC typically include

buried steel structures (pipelines, etc.) or soil conductivity anomalies caused by exposure to

chemicals or produced water. The survey also helps in identifying areas of the site which have

normal or background conductivity, and aid in the identification or confirmation of APEC

identified through other components of the Stage 1 PSI. Typically EM surveys are done

comparing variations in average conductivity at lesser and greater depths (EM38 – 0 m to

1.5 m, EM31 – 0 m to 8 m).

The CSM site plans in the Drawing section of this report show overlayed EM survey results.

An important limitation, particularly where sites are accessed in winter, is that snow cover will

reduce the effective depth of the survey, potentially muting the response. Depending on the

level of interpretation required for site assessment purposes, a registered professional

geophysicist may need to be consulted.

Results from EM surveys should be verified by laboratory analyses of soil samples collected in

the field at a frequency that is commensurate with the level of confidence required at the

particular phase of investigation (initial site screening versus closure sampling).

8.1.5. Inspection During Well Abandonment

During well abandonment activities, the abandonment crew cuts and caps the well head,

removes any associated pipelines or flow lines within the lease and removes other facilities that

may be on site. Valuable data can be obtained if environmental inspections and sampling can

be completed during abandonment. As a minimum, this could include inspection of soils around

the well head and inspection of removed pipelines and/or pipeline trenches. Sufficient data may

be collected to rule out APECs from further assessment.

On the basis of the results of the Stage 1 PSI, the EM survey (if completed) and any inspection

work completed prior to or during abandonment, a robust sampling plan is designed for the soil

assessment.


8.2. Subsurface Soil Assessment

Investigative techniques for the assessment of soil conditions are based on standard techniques

that are defined in a number of existing technical guidance documents (TG1, TG10).

Generally, the investigative techniques include collection of representative shallow and deeper

soil samples for field screening and subsequent laboratory analysis. Analysis of soil samples

provides information on the physical properties of the soil and the soil quality relative to the

applicable standards. There is a range of techniques from collection of shallow soil samples with

hand tools to collection of samples with excavators or drill rigs. While drilling has the advantage

of allowing assessment to greater depths, the depth that can be reached by an excavator is

often sufficient where soils are fine grained and vertical migration is expected to be limited.

While drilling produces minimal surface disruption and provides good quality discrete samples,

test pitting allows the assessor to observe the bulk characteristics of the soils in the test pit and

allows better interpretation of the nature and depth of soil fracturing and oxidation and other

potential secondary permeability features. At upstream oil and gas sites access may be

restricted, long and seasonal. It is often desirable to complete assessment with a single piece of

equipment in one site visit. Where assessment has to extend below about 5 m and only one

piece of equipment can be mobilized to the site, a drill rig is recommended.

There are also a number of in situ soil testing techniques including direct push technologies.

There are a number of references which address the pros and cons of these various

techniques, so we will only provide comment here as to specific advantages and disadvantages

with respect to assessment of upstream oil and gas sites. These more advanced techniques

would likely only be employed on complex sites where contamination is significant and migration

is significant.

A wealth of information exists on the design and execution of environmental site assessments.

In BC, TG1, TG10 and TG1211 provide guidance on the principles of contaminated site

characterization including important “how to” elements for carrying out site investigations and

related statistical calculations in the context of the CSR.

11 Technical Guidance Document 12: Statistics for Contaminated Sites, MoE, October 2005.


Selection of assessment locations is based on the results of the Stage 1 PSI and should take

into consideration identified gaps in the CSM with respect to contaminant source, horizontal and

vertical extent, migration pathway, and known or suspect receptors. The intensity of the

sampling program should be commensurate with the extent and complexity of the contaminant

distribution and the significance of the potential receptors based on available information.

The following table summarizes the various sampling approaches that are often used in

contaminated sites assessment.

Sampling Approach Description CommentsPreferential / Judgement

Investigator targets known APEC or evidence of contamination.

� Suitable for initial screening and characterization of hotspots.

� Can bias population estimates high, especially where field screening is used to select samples for analysis.

� Results not ideal for statistical purposes.Systematic Grid Typically used when investigator lacks

information on location of APEC or distribution of contamination is not well understood (not from a point source).

� Suitable for initial screening. � Spacing ranges from 5 m to 50 m

depending on type and mechanism of contamination.

� Frequency should also reflect certainty in location and inferred risk associated with APEC.

Random Sampling Used to characterize a single suspect or known population.

� Can be useful for obtaining statistical information on a known or suspect single population (i.e., DWDA).

The highest quality soil samples are generally obtained through hollow stem auger drilling or

geoprobe drilling techniques where discrete soil samples can be collected from specific depths.

Solid stem augering produces good quality samples at shallow depths. Discrete soil samples

are recommended. The collection of composite samples may be inappropriate for various

classes of contaminants (i.e., volatile) and can result in uncertainties regarding contaminant

distribution. There may be instances where composite sampling is appropriate and relevant

technical guidance can be found in TG1 and TG12.

As with fine grained soils anywhere, contaminant migration through the soil matrix is restricted due to the fine grained nature of the soil. Contamination can be present in thin permeable layers

or in secondary permeability features such as rootlets and fractures, if present.

Assessment techniques should therefore not only assess matrix soil quality but be designed to

identify the presence, extent and continuity of these features.


8.2.1. Organic Soils and Muskeg

As stated previously, organic and muskeg soils are soils with a high organic content and high

moisture content. As such, laboratory analysis of these soils using similar methodologies to

mineral soils results in several effects as follows:

� Naturally occurring organics in the soil tend to mask analytical results for petroleum

hydrocarbons. Some research recommends using silica gel cleanup on samples with high

organic content to remove naturally occurring polar organics. Other references recommend

collection of a background soil sample from an unaffected area for analysis. The naturally

occurring organics would then be subtracted to provide a more accurate hydrocarbon

concentration. This approach would require additional research prior to recommendation.

� Laboratory analysis of mineral soils is reported on a dry weight basis. In soils with high

moisture content (as high as 80%), this results in an exaggerated reported concentration

when weight of contaminant is compared to the dry weight of the “solid” portion of the sample.

Accepted laboratory methods report results on a dry weight basis consistent with MoE

accepted methodologies. An alternate approach would be for analytical results in organic

soils to be reported on a wet weight basis to provide a concentration more representative of

the concentration to which soil invertebrates would be exposed. This may not be an approach

that can be accepted as “standards based” assessment but can be considered on a

weight-of-evidence basis in Screening Level Risk Assessment. This proposed methodology

will require some further research to ensure it is scientifically supportable.

8.3. Recommended Soil Assessment Approach and Recommended Minimum Assessment Levels

The following provides guidance on the level of assessment considered adequate at the Stage 2

PSI assessment level to characterize soil quality at some common APEC on upstream oil and

gas sites. The proposed minimum assessment levels are consistent with current MoE guidance.

The APEC that are present on the majority of sites include the wellhead, flaring facilities, drilling

waste disposal area, pipelines or flowlines, and temporary tankage during well drilling.

The level of effort required to find the drilling waste disposal area, as well as environmental site

assessment requirements for other areas of the site will be site-specific.


Existing guidance is considered adequate for the other common oilfield APEC (i.e., tanks,

buildings, etc.), when present.

8.3.1. Wellhead

Characterizing the environmental quality of soil in the vicinity of the wellhead at the time of

abandonment is desirable. This allows inspection of soil conditions and sampling of soils and

backfill in the immediate area of the wellhead. If the wellhead has not been cut and capped at

the time of assessment or a post-abandonment assessment is to be completed, the objectives

should include the following:

� Characterization of shallow soil from the immediate vicinity of the wellhead (1 or 2 samples).

If characterizing backfill, the recommended sampling frequency is 1 sample per 30 m3

consistent with TG2. These samples should be collected manually consistent with ground

disturbance protocols.

� Completion of three investigative locations (borehole or test pit) to a minimum depth of 3 m

(depth of cut and cap) centred on, and at an approximate distance of 5 m from the wellhead.

The distance from the wellhead may vary depending on ground disturbance protocols.

� Collection of a sufficient number of samples from each investigative location to characterize

each stratigraphic unit encountered including backfill and underlying undisturbed soils.

A schematic showing recommended assessment locations is provided on Drawing 505093-003.

8.3.2. Flaring Facilities

Flare pits and stacks are always considered APEC unless sufficient documentation is available

to confirm they were never used. If a flare pit was built but not used, confirmatory sampling from

the flare pit area is not required. If flare tanks were used, confirmatory sampling is not required,

unless spillage was determined from the historical review.

Where the locations of these facilities remain unknown, professional judgement based on

conventions of site configuration and Stage 1 PSI information (e.g., interviews, site

reconnaissance observations) should be used in deciding on the frequency and location of

assessment and sampling locations. An increased level of effort should be made to locate

former flare pit locations given they often present significant risk to the environment. If the flare


location cannot be determined, an increased level of grid sampling should be undertaken with

any anomalous results further delineated.

Representative samples should be collected from the base of the flare pit on a 5 m to 7 m grid

consistent with TG1 with a minimum of two sample locations (test pit or borehole) to ensure

adequate characterization. Any sludge and underlying soils should be characterized at each

sampling location. A minimum of three samples should be collected to characterize perimeter

berms.

8.3.3. Drilling Waste Disposal Areas

The most common form of drilling waste disposal is mix-bury-cover and this guidance focuses

on it. OGC, Alberta and Saskatchewan have checklists for assessing drilling waste disposal

areas to determine compliance. Compliance is determined by completion of one of several

checklists. The checklist used is dependent on the type of drilling fluid and activities used during

drilling. In BC, even if the DWDA is compliant with the appropriate OGC checklist, direct

sampling to demonstrate compliance with the CSR is required. With further research, comparing

field screening results to laboratory analytical results, the checklist compliance approach may

be demonstrated to be consistent with CSR requirements. This is a “parking lot” issue.

Unless post-disposal confirmatory sampling demonstrates suitable environmental quality of the

drilling waste / soil mixture, the DWDA (mix-bury-cover or landspread wastes) will be considered

as an APEC. Drilling wastes disposed at surface can be characterized by employing a

systematic sampling grid over the DWDA.

The minimum sampling requirements below are for characterization of the drilling waste

disposal area after its location has been identified.

The following table provides the recommended minimum number of investigative locations to be

completed within a DWDA, and is based on the OGC’s ADWDA document.

Depth of Well or Combined Depth of Contributing Wells Minimum Number of Investigative Locations

<1,500 m 31,500 m to 2,500 m 4

>2,500 m 5


The investigative locations should be selected to provide representative coverage of the full

areal extent of the disposal area. Discrete representative samples should be collected from

each investigative location at approximate 1 m depth intervals and/or to characterize distinct

stratigraphic units. Collection of samples from overlying cap material and from underlying soils

may be desirable to evaluate the potential for contaminant migration.

TG2 may be useful in the interpretation of environmental quality data from DWDAs, particularly

where based on professional judgement, the material is determined to be homogeneous and

representative of a single population.

8.3.4. Pipelines / Flowlines

Pipelines within legally surveyed right-of-ways should be treated and assessed as off-site

APEC. In order to evaluate if subsurface impacts have resulted on the subject site as a result of

the operation of off-site pipelines, soil quality should be assessed (on site) at a depth similar to

that of the buried line or near surface, where valves or pigging stations are known to exist near

the site. Pipeline trenches may also act as preferential pathways and should be assessed if

these have the potential to affect conditions on site.

For producing well sites, on-site pipelines or flowlines should be assessed at a sampling

frequency of one sample per 10 m to 30 m of the on-site length. Assessment locations should

be biased towards the terminus and any joints along the pipe. If the pipeline/flowline has been

cut at the lease boundary a sample should be taken in this area. If pipeline inspections and

integrity testing were completed during operation and environmental observations and sampling

was completed during abandonment, an argument may be made for reduced sample density.

8.3.5. Temporary USTs/ASTs

Above ground storage tanks (ASTs) that contained hydrocarbons are considered APEC.

If surficial staining is present Stage 2 PSI assessment should be completed. If the tank stored

produced water a Stage 2 PSI is required.

If a consultant was present during the removal of an underground storage tank (UST) that

contained only hydrocarbons and there was no evidence of staining, this information should be

submitted in the CoR application as the basis for not requiring further assessment. If staining or

other indicators of a release were observed, a Stage 2 PSI is required in the tank area.


If the underground storage tank contained produced water, a Stage 2 PSI is required, even if a

consultant was present during the tank removal.

If an environmental consultant was not present when the underground storage tank was

removed, a Stage 2 PSI is required to determine if spills or releases occurred.

8.3.6. Other soil assessment

Systematic grid sampling of areas of a site should only be necessary when the locations of

APEC cannot be identified through historical records. Judgement sampling should be used to

assess any anomalies identified (from EM survey, depressions identified through site inspection

or areas of stressed vegetation or staining).

8.4. Detailed Site Investigation (Soil)

Following the Stage 2 PSI assessment the CSM is further populated with data and, if

contaminated areas, pathways and receptors require further assessment then a DSI is designed.

If a Stage 2 PSI identifies contaminant concentrations in excess of the applicable HWR or CSR

standards, a DSI is typically completed to further characterize the contamination, the vertical

and horizontal extent of the soil contamination, and to evaluate the potential migration of the

contamination to adjoining properties. For remote upstream oil and gas sites or where access is

particularly difficult, the DSI may be completed concurrently with the Stage 2 PSI, based on field

observations. This approach depends a great deal on observations and field screening without

supporting analytical data. This can result in the risk of assessing more than required or not

enough.

8.5. Recommended Techniques

8.5.1. Field Screening Techniques

A variety of technologies is available for field screening of soil samples for typical oilfield

contaminants. These technologies can be useful for decision making during field assessments

or remediation to support decisions for selection of samples for laboratory analysis.

Field screening will aid in identifying the most likely areas to analyze but each analysis plan will

depend on the standards to which you are comparing and the screening results achieved

(i.e., more stringent standards and low screening results will likely result in higher frequency of

sampling because correlations will be difficult to achieve).


The most common PCOC for which we screen are hydrocarbon based (crude oil, diesel and

condensate) and salt based (produced water, mud additives). The following are typical

screening approaches for each:

Hydrocarbons

Vapour measurements using PID’s, combustible gas meters etc., can measure relative

differences in vapours between one sample and another; but they are not typically effective with

heavy end hydrocarbons; have varied success with diesel (depending on how degraded it is);

and are relatively effective with condensate. In all these cases observations combined with

professional judgment (i.e., where will the contamination most likely be, at surface or at depth, is

the material disturbed, obvious odours, sandy material vs. fine grained, etc) are typically the

most effective method of screening samples for analysis.

We note there are other field screening techniques or field tests that can be used to detect mid

to heavy end hydrocarbons including turbidimetric test kits (i.e., Dexsil Corporation’s

PetroFLAG®), portable infrared detector test kits, UV fluorescence detection kits, and portable

colorimetric test kits. All of these have limitations that typically include interference from organic

matter, use of solvents to prepare tests and reliability in clay soils.

Produced Water

Saturated Paste, direct read soil salinity meters and Quantabs® are also methods that can be

effective ways to determine relative salt concentrations. The following is a brief description of

each:

Saturated Paste – an electrical conductivity meter is used to screen a sample of paste that is

prepared with a 1:1 ratio of soil and distilled water, shaken, left for approximately 10 minutes to

20 minutes (time must be consistent between samples to compare), and shaken prior to

measuring electrical conductivity from the paste.

Direct reading soil salinity meters – Typically a meter with a probe consisting of one to four tines

inserted into the soil a minimum of 1 cm depth, which is then recorded into the meters data

logger to compute soil conductivity in Siemens/meter or other comparable units. The meters

sometimes have different settings for soil types for more uniform results between samples.

Readings are usually near instantaneous. We note based on experience this method is quick

but is extremely sensitive to different soil types and moisture content and not effective in organic

soils or coarse grained soil.


Quantabs® – Are similar to pH strips and are used widely in the industry to test chloride

concentrations in water and waste water. They can be used with the saturated paste technique

as well. For water this method is effective but making a paste first presents challenges with time

and costs as compared to laboratory analysis.

All these methods can produce data that correlates well with concentrations of gross and

moderate salt contamination but are not typically useful for low levels of salt contamination that

still may be greater than standard (i.e., with low responses, the highest readings may not

correlate with the actual highest concentrations that could still exceed standards).

Regardless of screening technique used it is important to be as consistent as possible on how

the screening is done from one sample to the next in order to appropriately identify where the

anomalies are noted. Again visual observations (i.e., is the soil type the same, is the moisture

content affecting the results etc.) are also important in the screening process and it is imperative

to know the limitations of your screening techniques.

8.6. Specific Issues Associated with Soil Assessment

8.6.1. Background Soils

At many locations, low level metals exceedences have been identified in soil which may

represent background concentrations including, arsenic, barium, boron (regulated for AL only),

cadmium, selenium, sodium, and molybdenum

8.6.2. Organic soil and Muskeg Sampling












terrestrial receiving environment is beyond the scope of this report. Recommendations for

further assessment have been included in the “parking lot” section of this report. We understand

that MoE will ultimately develop muskeg and wetland use standards. In the interim, professional

judgement will be required in determining if a site or the surrounding area should be considered

terrestrial or aquatic environment.

Further investigation is required into analytical methods and reporting of analytical results of

organic soil samples. The issues to be resolved relate to masking of hydrocarbon results due to

the presence of naturally occurring organic material and the reporting of soil concentrations on a

dry weight basis. For the purpose of this document, we are proposing that silica gel cleanup be

used on organic soil samples to remove polar organics, and suggest that background organic

soil samples be collected from unaffected locations in the immediate area of the site and

analyzed using the same methodology as the site organic soil samples. In this way, the

influence of naturally occurring organics can be understood. It may be suitable to simply

subtract the “background” concentration from the site organic soil sample results.

With high moisture content soils, reporting of analytical results on a dry weight basis inflates the

results. While this is the approved analytical reporting format, reporting on a wet weight basis

may be more representative of actual concentrations to which receptors are exposed.

Seasonality

As stated previously, many sites are remote and may only be accessible on a seasonal basis.

This makes repeat sampling and sampling under specific seasonal conditions very difficult. It is

our opinion that the proponent should be able to provide an argument for limited seasonal

sampling based on professional judgement. This argument should take into consideration the

overall risk to potential receptors and should also take into consideration that the CoR Part 2

process provides a second line of evidence in a weight-of-evidence approach. If it cannot be

demonstrated that suitable vegetation can be re-established then a CoR will not be granted.


9. HYDROGEOLOGIC INVESTIGATION

9.1. Background

This section provides technical guidance on hydrogeologic investigations at upstream oil and gas

sites situated in the tills and glaciolacustrine deposits of northeast BC. Both stakeholder

workshops selected these settings as priorities because they are the most common sites and also

present the greatest investigative challenges for upstream oil and gas sites in northeast BC.

The key challenges identified are:

� appropriate level of investigative detail; primarily with uncertainties or inconsistencies in the

number of boreholes and monitoring wells and the appropriate techniques related to

adequate borehole seals, water level recovery times, representative groundwater elevations,

and samples;

� lack of information:

� on the fracture network in tills and glaciolacustrine deposits and as a corollary a lack of

knowledge and understanding of key contaminant transport and attenuation processes

in these tills and glaciolacustrine deposits;

� on the distribution, particularly the depth below the tills and glaciolacustrine deposits, of

any potable underlying aquifers;

� lack of publically available regional studies of the:

� hydrogeology of shallow aquitard/aquifer systems (e.g., less than 150 m) in northeast

BC; and

� background quality of shallow groundwater (e.g., less than 150 m) in northeast BC.

These challenges create uncertainties in the required level of subsurface investigation at

upstream oil and gas sites situated in these fine grained unconsolidated deposits.

More specifically, it is often difficult to determine a reasonable level of effort that can be

scientifically defended using professional judgement.


The tills and glaciolacustrine deposits in this conceptual model are assumed to be clay-rich

aquitards; the terminology used in this section instead of the more generic terms used in earlier

sections. Aquitards are considered here to be geologic deposits of sufficiently low hydraulic

conductivity, and sufficient areal extent, thickness and geometry, to impede groundwater flow

between or to aquifers. Aquitards with more than 10% to 15% by weight clay-sized particles

behave hydrogeologically as clayey units (e.g., extremely low matrix hydraulic conductivity that

does not increase appreciably with larger percentage of clay size particles). A subsurface

investigation in clay-rich aquitards focuses on the porous media properties and groundwater;

hence, this component encompasses the broader approach of a hydrogeologic investigation.

The hydrogeologic investigation will address the aquitard integrity which refers to the capability of

an aquitard to provide protection to an underlying aquifer (discussed further in Section 9.2).

The numerous references on conducting hydrogeological investigations (e.g., BC MoE, 2003;

BC MoE, 2010; BC MoE, 2010; CCME, 1994; EPA, 1993; Golders Associates Ltd., 2010) are

more applicable for the characterization of contamination at downstream sites and in particular, for

more permeable deposits. They do not provide the level of guidance needed to adequately

characterize contamination of tills and glaciolacustrine aquitards at upstream oil and gas sites in

northeast BC. Guidance provided here relies heavily on Cherry et al. (2006) and Bradbury et al.

(2006), who provide comprehensive and scientifically defensible information on the state of the

science and technical guidance on contaminant transport through aquitards, respectively.

USEPA Ohio (2009) provides high level regulatory guidance for the evaluation of aquitard integrity

which is a useful comparison for the range in scope compared to the level of detail in the two

previously mentioned references.

This information presented here is a guide not a manual. This technical guidance is written for

hydrogeological studies specific to aquitard integrity. The existing guidance on other assessments

and techniques not related to aquitard integrity (e.g., sampling protocols, field and laboratory

analytical procedures) should still be applicable. The guidance provided here reflects the balance

between the need to provide reliable interpretations of site conditions with that of funding

limitations and/or unquantifiable complexities in aquitard hydrogeologic systems. Therefore, this

guidance uses an information framework with a combination of quantitative results from minimum

standards which are supported by qualitative data. Acceptable gaps in knowledge should be

based on professional judgement. Depending on the certainty required, additional technique may

be required using the information provided here or more extensively in Cherry et al. (2006) and

Bradbury et al. (2006).


The assumption for the minimum requirements is a reliance of on-site information. When the

regional studies noted above become available, the level of uncertainty will be reduced and thus

more opportunity to be flexible with requirements beyond the minimum standard. The guidance

focuses on:

� technical challenges to investigate aquitard integrity;

� alignment with existing regulatory guidance; and

� reasonable phased investigation to provide the certainty required based on the consideration

of the risks.

9.2. Clay-rich Aquitards Conceptual Site Model – Aquitard Integrity

This section draws from the key aquitard references noted in Section 9.1. The additional

references quoted are from within these reports.

The role of aquitards in groundwater protection depends on the interrelationship of geology,

groundwater flow and contaminant type. Aquitards can decrease the susceptibility of underlying

ground water to contamination by increasing both time of travel and the flow path distance from

contamination. Three main factors that affect aquitard integrity are: geologic framework,

hydrogeologic characteristics and contaminant properties.

Geologic Framework

The geologic origin of the aquitard and the post-depositional history are more important indicators

of aquitard integrity than the thickness. The integrity of many clay-rich aquitards that were

exposed at ground surface during their geologic history, including deposition from glaciers in

northeast BC, can be affected by the resulting contraction fractures formed from wetting/drying or

freeze/thaw effects. The dominant fractures are vertical, but horizontal fractures can also be

present. The density of fractures and preferential pathways typically decreases with depth below

the oxidized zone, but can extend to 10 m to 15 m below the top of the oxidized zone and perhaps

deeper. If the aquitard is composed of different sedimentary units, fractures in deeper units may

have formed when these units were exposed at surface and then remained open after burial.

Evidence indicates the presence of deep, active fractures for many clay-rich aquitards.

The integrity of an aquitard generally increases with increasing thickness; however, even large

aquitard thickness (>50 m) should not be used without other lines of evidence to conclude that

there is absence of open, fully penetrating fractures.


Extensive diffusion-controlled aquitards tend to have a particular geologic origin such as lake or

marine deposition with minimal weathering or structural disturbance after deposition.

This suggests that the glaciolacustrine deposits may have a lower potential to be fractured than

the tills. Regional studies would be needed to confirm this. However, site studies cannot assume

that fractures do not exist without evaluating the aquitard integrity.

A laterally extensive aquitard can provide more or less protection of an underlying aquifer

depending on the part of the aquitard under consideration. Near the edge of an aquitard, for

example, an underlying aquifer may be semi-confined or unconfined because flow paths can

easily bypass the aquitard. As the aquitard thickens or deepens away from its periphery, an

underlying aquifer may be increasingly protected.

Hydrogeologic Characterization

Although geologic designation of an aquitard can be a useful starting point in an aquitard integrity

investigation, hydraulic profiles are needed to identify the zone contributing most strongly to the

integrity. Clay-rich aquitards are commonly designated as such based on geologic features, such

as grain size (e.g., clayey strata); however, field studies using vertical hydraulic head profiles

commonly show that only a small part of the geologically designated aquitard thickness provides

nearly all of the resistance to groundwater flow.

Hydrogeologic properties of aquitards often vary over a much larger range than for aquifers

because of fractures and preferential flow paths. Aquitards can be more anisotropic than aquifers;

hydraulic conductivity can be much higher in the horizontal than vertical direction due to

stratification, which has important implications to interpretation of slug test data from monitoring

wells. Conversely, vertical fractures may cause the vertical hydraulic conductivity component to

greatly exceed the horizontal component (Cherry et al., 2006). As well, the hydraulic conductivity

of the upper weathered and often fractured layers can result in significantly higher hydraulic

conductivities than the deeper unweathered zone. For example, tills in SW Ontario can be visibly

weathered to depths of 4 m to 6 m with hydraulic conductivities 2 to 3 orders of magnitude greater

in the weathered zone than in unweathered zone ((McKay et al., 1993).


Contaminant Properties

Diffusion dominated contaminant transport in clay-rich aquitards that have no preferential

pathways such as fractures, root holes or other discontinuities for groundwater flow and

contaminant migration results in travel time scales of hundreds or thousands of years.

Preferential pathways greatly diminish the integrity of many aquitards because the velocity of

contaminant migration in these pathways can be many orders of magnitude greater than in the

matrix material. Vertical fractures are the most common type of preferential pathway, and even

fractures with commo��

The propensity for a contaminant to migrate through an aquitard, particularly if the aquitard is

fractured, depends strongly on the contaminant type. Transport of dissolved contaminants in a

fractured clay-rich aquitards is expected to be controlled by (1) advection through the fractures;

(2) diffusion into the porous matrix; and (3) retardation processes such as sorption, precipitation

and degradation in both the fractures and the porous matrix. The migration front for dissolved

contaminants transported by groundwater flow in fractures will be slower due to diffusion-driven

chemical mass transfer from the fractures into the low permeability matrix. If the fractures are

not large, the matrix-driven retardation effect can be strong enough to allow fractured aquitards

to have considerable integrity with respect to dissolved contaminants. Hence, if the fractures are

very small (�� !�� nants.

If compounds are strongly sorbing, the combined effects of matrix diffusion and sorption, even

transport in larger fractures is insignificant.

Dense non-aqueous liquids (DNAPLs) have the strongest propensity to penetrate through

fractured aquitards. The driving force due to large density and the minimal viscosity of many

"#$%&� �!!�� !�� !!� �� . Because of the

buoyancy effect, light non-aqueous phase liquids (LNAPLs) have much less tendency than

DNAPLs to migrate downward through aquitards. However, in some circumstances, continued

release of LNAPL to the subsurface can cause sufficient thicknesses to exceed fracture entry

pressures and drive the free phase product downward into fractures below the water table.

Cherry et al. (2006) report on a study by Oliveira and Sitar (1985), where LNAPL was found far

below the water table in a clay-rich aquitard in California. It should be determined if any of the

waste with the salty produced water may be denser than water. If non-aqueous phase liquid

(NAPL) is present, diffusion into the porous matrix will act as a long term source of contamination.


9.3. Designing the Hydrogeologic Investigation Program

9.3.1. Objectives

This investigative component will use scientifically defensible techniques and professional

judgement to develop a CSM, assess its applicability to the Clay-rich Aquitard CSM, identify

APEC, PCOCs, relevant receptors triggers, and ensuing investigative requirements for a

particular upstream oil and gas site.

9.3.2. Defining the Conceptual Site Model - Scenario Testing

The CSM frames the decisions to acquire information and develop interpretations. The testing of

the applicability of the appropriate scenario requires knowledge of the clay-rich aquitard

(geologic framework, hydrogeology properties, and contaminant characteristics and distribution)

and on the identification of on-site and relevant off-site receptors. The CSM is adapted and

revised until the study objectives are met.

Two main CSM scenarios are expected to apply at upstream oil and gas sites situated in the

clay-rich aquitards in northeast BC. At a site where there is a relatively thick sequence of clay

rich glacial deposits (e.g., 20 m to 40 m or more), the primary concern may be the lateral

migration of groundwater and contaminants towards nearby wetlands and ditches. In this

situation, the focus will be on sand lenses at any depth and fractures in the shallower weathered

and oxidized zone. At a site, where the clay-rich deposits are relatively thin (<10 m), the main

concern will be downward flow and contaminant migration. In this case, the focus will be on

identifying the presence of deep, possibly widely spaced, fractures. A shallow flow system will

still need to be investigated at this type of site.

Ideally, testing of these CSM scenarios would benefit from regional geologic and hydrogeology

studies of aquitard/aquifer systems in the area. As discussed at the February 23, 2011

workshop, this is an important study to initiate because it would allow for an improved

representation of the CSM, and thus, a more efficient and productive field verification process

for both industry and regulators.


9.3.3. Scale

Scale issues address both temporal and spatial aspects of the hydrogeologic investigation in

order to ensure that adequate data is collected over time and across the site and off site, if

necessary. The well lease is typically approximately 120 m x 120 m. For investigation in

clay-rich aquitards, the appropriate number of samples and locations will be dependent on the

fracture network and the ability to reasonably monitor it and is discussed further in Section 9.5.

9.3.4. Phased Approach, Triggers and Weight of Evidence

The phased investigation approach and triggers for moving onto the next stage are the same as

other contaminated site investigation (TG8). Access constraints requiring winter field programs

may result in a condensed field program. Any limitations in using this approach must be

presented and justified that the results are representative and the investigation provides

adequate spatial and temporal coverage.

The weight of evidence approach is the recommended approach. Justification for the techniques

used and the level of effort will need to be provided by a qualified professional based on the

level of certainty required.

9.4. Stage 1 PSI

The Stage 1 PSI discussed in previous sections should include a preliminary determination of

the hydrogeologic setting based on existing information that would include the following:

� topography� geology and stratigraphy� thickness and distribution of

geological and fill materials

� distribution of potential aquifers� structural make-up of the

subsurface � precipitation and general climatic

records� surface drainage features

� drainage characteristics of soils� land use, surface vegetative cover

and surface water bodies � groundwater and surface use in the

area

This stage of the investigation is similar to that at other contaminated sites, although the

information gathered on APECs and PCOCs will be specific to upstream oil and gas sites as

discussed in earlier sections. If APECs are identified, the assembled information should be

evaluated to assess the potential for contamination of the environmental media, including the

aquitard. The preliminary CSM should be refined for a hydrogeologic focus on aquitard integrity.

It will also serve as a basis for planning the next phase of the field investigation, the Stage 2 PSI.


9.5. Field Investigation (Stage 2 PSI and DSI)

A subsurface field investigation program should be initiated if APECs have been identified from

the Stage 1. It is recommended that the intrusive field program focus on examining the integrity

of the aquitard and a preliminary evaluation of whether it may be contaminated.

Groundwater samples may not need to be collected if the aquifer integrity investigation confirms

that rate of groundwater flow is minimal such that contaminant concentrations will not exceed

the applicable criteria for any groundwater uses identified in the field investigation. The level of

effort is similar to a Stage 2 PSI described in TG8. However, there is a reduced emphasis on

flow through porous media in the vertical direction and more on fracture flow. In the shallow

zones, if the fracture network is extensive enough to be considered, it may need to be treated

as an equivalent porous media. If any further field investigation is required it will focus on the

characterization of groundwater contamination and will follow the regulatory guidance provided

in TG8 for a DSI, particularly if contamination along the shallow groundwater pathway is shown

to be of concern. If vertical migration is also an issue then aquifer integrity must be investigated

further using greater resolution and likely additional techniques.

9.5.1. Determining Potential Pathways and Receptors – Groundwater Uses

The CSM scenarios discussed in Section 1.5 provide the basis for determining pathways and

potential receptors as required in TG6, which requires that “groundwater at a site is suitable for

current and future uses and is of adequate quality to protect adjacent water uses”. Two main

potential migration pathways should be considered. The first is whether the integrity of the

clay-rich aquitard is such that vertical migration of any potential contaminant will not adversely

affect a groundwater use in an underlying aquifer. The other main potential pathway is lateral

migration of contamination through any shallow weathered zones to reach an aquatic receptor.

Consideration must also be given to whether a contaminated aquitard could serve as a long

term source of contamination even if there is minimal groundwater flow.

Evaluation of the existence of any vertical pathways is in consideration of three potential

groundwater uses: drinking water (DW), livestock water (LW) and irrigation water (IW).

Evaluation of any potential migration in a shallow flow system will need to address groundwater

concentrations related to aquatic life use (AW). TG6 and Schedules 6 and 10 of the CSR

provide the specific criteria (concentrations, distances, and properties of the media) to

determine whether any of these uses apply at the site. For the vertical pathways, the TG6


evaluation addresses aquitard thickness, bulk hydraulic conductivity, uniformity, presence of

fractures, continuity across the extent, and predicted migration pathway and contaminant

concentration with depth. There is good overlap with the previous discussion Section 9.2 on

critical factors affecting aquitard integrity. Hence, the evaluation of aquitard integrity will provide

answers to the questions required in TG6. However, the guidance provided here, based on the

references and practical experiences, recommends a deeper depth to investigate and outlines

the practical challenges in estimating vertical hydraulic conductivity, the presence of fractures

and distribution of the aquitard, and the contaminants within it. Finally, it is noted that not all

aquitards hydraulically confine aquifers beneath them, i.e., in those cases, the hydraulic head in

the underlying aquifer is not above the elevation of the base of the aquitard. Of particular

relevance to this guidance, is that a large confining head (i.e., a hydraulic head in the underlying

aquifer is significantly above the base of the aquitard indicating upward vertical flow) does not

imply strong aquitard integrity (Cherry et al., 2006).

9.5.2. Determining the Lateral and Vertical Extent of the Clay-rich Aquitard

Given that clay-rich aquitards can have variable laterally continuity and thickness, the following

should be undertaken as a minimum requirement.

1) Building on the background regional geology information collected in Stage 1, and any other

existing geological and geophysical interpretation, mapping, determine as best as possible,

how the depositional environment is likely to have created the potential for the formation of

fractures and review the stratigraphy for indications of thickness, grain size, and

discontinuities. Bradbury et al. (2006) provide an overview of the applicability of various

regional techniques.

2) An intrusive program with test pits and boreholes is recommended. Intrusive drilling programs

in clay-rich aquitards typically use hollow or solid stem augers, direct push, and sonic and

rotary drilling techniques. Bradbury et al. (2006) provide detailed comparison of these drilling

methods that would be applicable to clay-rich aquitards. Cross-contamination techniques and

cautionary drilling in sources zones particularly for NAPL, as noted in standard manuals, apply

here. At the site level, a minimum of three boreholes should be installed if significant soil

contamination is identified. The literature suggests that at least one borehole should be

installed to depths greater than 10 m to prove a minimum thickness for aquitard integrity.

This should be installed outside any APEC. The locations of the other boreholes will need to


be based on site conditions and should supplement the existing information. Both these

techniques will also need to address the homogeneity of the aquitards properties and

uniformity of thickness.

9.5.3. Determining Aquitard Integrity

Determining the degree of protection that aquitards provide to underlying aquifers is a

challenging task. Characterizations based on primary porosity will often provide erroneous

conclusions if the secondary porosity is controlling groundwater flow due to fractures, joints and

other macropores. Therefore, site investigations should use methods that are designed to

determine the local stratigraphy and to check for the presence and extent of fracturing on a

site-specific basis. Knowledge of the stratigraphy including depositional and post-depositional

history can also greatly aid in predicting the hydraulic properties of a site, as demonstrated by

Melvin and others (1992) and Simpkins and Bradbury (1992 [Christy et. al., 2000]) (From Cherry

et al., 2006).

Geologic information on its own is rarely, if ever, adequate, and should always be supplemented

with other types of data. The literature describes many methods for investigating aquitards.

Information on hydrogeologic setting (Belitz and Bredehoeft, 1990, Neuman and Neretnieks,

1990, Simpkins et al., 1996), hydraulic head (Eaton, 2002, Eaton and Bradbury, 2003, Rophe et

al., 1992), aquifer pumping tests with piezometers in the aquitard (Grisak and Cherry, 1975,

Neuman and Witherspoon, 1972, Rowe and Nadarajah, 1993), hydraulic conductivity

(Shaw and Hendry, 1998, Williams and Farvolden, 1967, van der Kamp, 2001), and

hydrochemistry and isotopes (Hendry, 1988; Hendry, Wassenaar, and Kotzer, 2000; Nativ et al.,

1995; Nativ and Nissim, 1992; Pucci, 1998; Pucci, 1999; Remenda, van der Kamp, and Cherry,

1996; Stimson et al., 2001), is typically necessary to establish a high degree of certainty about

aquitard integrity (from Cherry et al., 2006).

Of the approaches outlined above the following is recommended as the minimum level for site

investigation:

1) Mapping of any nearby natural exposures such as stream cuts or pre-existing excavations

such as road cuts and quarries.


2) A test pit program to investigate fractures. However, specific techniques related to removal of

smeared surfaces from the earthmoving equipment are required to allow the fractures to be

uncovered and measured. Christy et al. (2000) provide the background and a method that

can be followed. They note that the number of pits and the extensiveness of the mapping

effort will be dependent upon the overall goals of the investigation and available resources.

3) Coring and logging of the boreholes (previous section) is required to provide useful data for

interpreting stratigraphy and visual observation of fractures. Bradbury et al. (2006) provide

examples of other more sophisticated down-hole techniques if greater certainty is required.

4) If the site is particularly sensitive to vertical hydraulic conductivity, piezometers could be

installed in these boreholes to evaluate pressure (water level) changes, e.g., to monitor

response to rainfall or snowmelt, which can indicate presence or absence of fractures and for

use in measuring hydraulic conductivity (next section). Pressure transducers could be utilized

depending on the certainty required.

It is noted that the proximity of the piezometers in the aquitard to the fractures will influence the

ability to detect vertical pathways. A professional opinion must be provided on how the design of

the investigation will provide favourable probability for discerning the presence of fractures that

may be widely spaced and visually indistinct in cores and excavations.

9.5.4. Determining Hydrogeologic Properties

Measurements of aquitard hydraulic conductivity along with hydraulic head measurements

provide the basis for calculating groundwater flux through aquitards. However, obtaining a

representative and accurate measurement of K in clay-rich aquitards, and the ability to confirm

secondary permeability from fractures, are often both very difficult procedures. For example,

hydraulic conductivity of an aquitard (KV – vertical component) is a fundamental parameter to

determine; however, it can be extremely difficult to measure. Basic hydrogeologic techniques

designed for aquifers, such as pumping and slug tests, commonly need modification to be

appropriate for assessment of clay-rich aquitards (Novakowski and Bickerton, 1997,

Shapiro and Greene, 1995, van der Kamp, 2001) (from Cherry et al., 2006).

Conventional hydraulic conductivity tests (e.g., rising-, falling- and constant-head tests;

Hvorslev, 1951; and many others) primarily provide information concerning horizontal hydraulic

conductivity (KH - horizontal component) instead of KV. In addition, as most monitoring wells are

installed vertical, they only sample a small section of horizontally deposited aquitards. As well,


the response time for water levels to equilibrate is very long (days to weeks or longer) and often

measurements are taken before hand. Small heterogeneities (such as fractures) can greatly

influence the bulk K measurement, but are difficult to determine with a monitoring well. As a

consequence, where feasible, the bulk vertical hydraulic conductivity of the aquitard is often

assessed using results obtained from a pumping test on an adjacent aquifer (e.g., Grisak and

Cherry, 1975; Rodrigues, 1983; Keller et al., 1986).(McKay et al., 1993).

Both Cherry et al. (2006) and Bradbury et al. (2006) each devote a chapter to the estimation of

hydraulic conductivity. Recommendations include the use of multiple approaches starting with

regional estimates based on pumping tests of aquifers that are confined by the aquitard of

interest. Regional groundwater flow models are also recommended for estimating KV. Slug test

results can be compared with results from laboratory tests on core samples for estimates of KH.

Slug test results that are significantly higher than those from analysis of cores suggest that there

may be fractures present.

Bradbury et al. (2006) provides recommendations of four types of borehole instrumentation:

traditional piezometers (or nests), horizontal nests, multi-level monitoring systems, and buried

transducers. The degree of sophistication in the system selected would need to be determined

by the level of certainty required. For the “Stage 2 PSI” investigations, the minimum requirement

is for three piezometers to be installed (devices that enable the measurement of hydraulic

head). The minimum recommendation for hydraulic conductivity estimates is difficult to

determine given the discussion presented in Cherry et al., 2006 and Bradbury et al., (2006).

Professional judgement and justification will need to be relied upon in this matter. It is noted that

estimates based on water levels may not yield representative results because of the long times

to equilibrate. However, if pressure transducers are installed this should improve estimates of

hydraulic conductivity (KH).

Multilevel monitoring systems which consist of isolated “depth-discrete” ports should be

considered for sites needing greater certainty to obtain profile of water levels and groundwater

chemistry. TG8 lists examples of these systems. Hydraulic gradient profiles can be estimated

from these types of piezometer installations. They can also be approximated from the borehole

installations noting from above, the challenges about recovery times and adequate borehole

seals. For a surficial aquitard, the steady state hydraulic gradient across the aquitard is

determined by a comparison of the water-table elevation and the head in the aquifer below

the aquitard.


Surface geophysical (Crattie 1991; EddyDilek et al., 1997; Oatfield and Czarnecki, 1991;

Owen, Park, and Lee 1991; Young and Sun, 1995) and geostatistical methods (Desbarats et al.,

2001; James and Freeze, 1993; Ritzi, Dominic, and Kausch, 1996), have been applied to field

data to assess the extent and continuity of aquitards, particularly in the case of shallow

unlithified clay aquitards (from Cherry et al., 2006).

9.5.5. Determining Contaminant Concentrations

The results of the previous evaluations will determine the level of effort required in the

evaluation of contaminants in clay-rich aquitards at upstream oil and gas sites for the “Stage 2

PSI”. In particular, the level of effort required will be tied to the results of the soil sampling, the

confidence in the interpretation of aquitard integrity and in the determination of groundwater

fluxes and the identified groundwater uses.

Data on contaminant concentration in the subsurface will need to be determined. Professional

judgement must be relied upon to determine the number of samples and the frequency.

Initially, only indicators of the PCOCs should be measured. Environmental isotope tracers

Tritium, Oxygen-18/Deuterium and Carbon-14 could also be analyzed to provide information on

recharge rates and travel times. Field screening techniques described in TG8 are also

applicable here. Porewater samples could be obtained from the cores collected during the

drilling of the boreholes (Cherry et al., 2006). The piezometers installed in the boreholes should

be constructed in such a manner that they can also serve as monitoring wells. Monitoring well

construction details can be taken from TG8 as well as Cherry et al., 2006 and Bradbury et al.,

2006. Extra effort must be taken to ensure an adequate seal in the clay-rich aquitards to ensure

that surface runoff does not enter the annulus from ground surface.

9.6. Further Investigation

As noted in Section 9.5, the previous component of the field investigation will have focused on

the evaluation of aquitard integrity and a preliminary assessment of the extent of any

contaminant migration to deeper zones through a fracture network and/or more laterally through

a shallower groundwater flow system. If required, groundwater will have been sampled,

analyzed and concentrations compared against the relevant CSR standards. Depending on the

results of both types of evaluations, additional field investigation may be required. If that is the

case, Cherry et al. (2006) and Bradbury et al. (2006) should be consulted for further details on

appropriate additional techniques that have been mentioned in previous subsections.


The level of effort for any further investigation will be similar to a DSI described in TG8,

i.e., typically completed to delineate the degree of contamination (vertical and horizontal) and to

evaluate the migration of the contamination to adjoining properties. TG8 requirements related to

temporal sampling should be applied here: A sufficient number of samples are collected to

establish the magnitude of temporal concentration variations including seasonal variations or to

allow predictions to be made with reasonable certainty. If the detailed field investigation follows

immediately after the previous one (i.e., “Stage 2 – PSI”), without supporting analytical data and

possibly before adequately recovery of the piezometers/monitoring wells, this detailed

investigation will run the risk of assessing more than required or not enough. For the later

scenario, additional field investigation would likely be needed at a later date.

Issues

The hydrogeologic assessment program presented identifies that a number of regional studies

could result in a better understanding of a number of the hydrogeologic factors that influence the

risks associated with groundwater contamination at a particular site. In the absence of these

studies, assessment carried out on each individual site takes on a higher level of complexity in

an effort to assess hydrogeologic conditions on a site-specific basis. The level of assumed risk

is inversely related to the level of site-specific assessment completed. It is our opinion that a

reasonable level of site-specific assessment combined with professional judgement based on

training and experience, in working in the upstream sector in northeast BC, will result in an

acceptable level of risk.











terrestrial receiving environment is beyond the scope of this report.


9.6.1. Surface Water

On active sites, runoff is managed under the Oil and Gas Activities Act. Following abandonment, if

surface water is present on a site in a natural water body (which could be considered an aquatic

environment), water quality should be compared to BC Approved Water Quality Guidelines12

If the surface water is in a borrow pit or maintained ditch which is solely for conducting storm

water from the site then the water body should not be considered an aquatic environment unless

an aquatic environment has been allowed to develop. The services of an aquatic biologist may be

required to determine if the water body constitutes an aquatic environment. If surface water

discharges through a ditch drainage system which ultimately reaches an aquatic environment,

quality should be compared to CSR AW which assumes a 10 fold dilution prior to reaching the

aquatic environment. We would propose that overland flow resulting from snowmelt and runoff

from a site should also be compared to AW as the surface water should not be considered an

aquatic environment due to the seasonal nature of the flow.

(BCAWQG) for aquatic environments.

9.6.2. Sediment

Typically sediment has not been considered during assessment of oil and gas sites unless there is

a stream, river or lake within the lease boundaries or within the plume of off-site contaminant

migration. Where surface water on muskeg is present for more than half of the frost-free season,

compare surface water and peat chemistry to ambient WQGs and CSR sediment criteria,

respectively.

While there may be issues with regards to cumulative effects on streams and rivers across BC

this issue is not discussed in this guidance. Where assessment of sediment is required,

Technical Guidance 19 “Assessing and Managing Contaminated Sediments” would be

considered the most appropriate at this time and there are standards for sediment included in

CSR Schedule 9. Sediment assessment will not be discussed further in this guidance.

12 Water, Air and Climate Change Branch, MoE, British Columbia Approved Water Quality Guidelines (Criteria),

2006 Edition (BCAWQG).


9.6.3. Vapour

Based on Technical Guidance 4, if an upstream oil and gas site is classified as wildlands,

characterization of soil vapour is not required.

If an upstream oil and gas site is not classified as wildlands and there are no buildings nearby

(i.e., within 30 m of the plume), then only the outdoor vapour pathway has to be assessed.

Vapour concentrations can be determined through modelling based on soil and groundwater

concentration data (i.e., it will not likely be necessary to collect vapour samples at the majority of

upstream oil and gas sites); as such, this guidance does not address soil vapour sampling.

If soil vapour sampling is required please refer to TG4.


10. SUMMARY AND CONCLUSIONS

SLE thanks the MoE for the opportunity to work on this project. The issues we have addressed

are issues that we have been dealing with in our work in the upstream oil and gas sector.

This report primarily defines these issues and proposes some solutions and some approaches

to coming to solutions.

Administratively there are fundamental differences between MoE and OGC approaches to

attaining the same end point. Some differences are seated in the fundamental approach and

underlying regulations and some are seated in process.

By addressing the technical differences it is our opinion that the perceived differences between

the CoC and the CoR can be reduced, resulting in the acceptance of the equivalency of the

processes.

10.1. Technical

A number of technical issues associated with applying provincial standards specifically to the

upstream oil and gas sector in northeast BC have been identified and solutions/approaches

proposed.

The key issue is that we are dealing with a large number of remote sites, many of which have a

low level of impact from short duration, low intensity, site activities. The challenge is to provide a

level of assessment that provides a level of risk that is acceptable to all stakeholders while still

respecting the challenges of completing assessment work under the prevailing conditions.

The proposed solution is to gain an understanding of the regional conditions that can be applied

to individual sites such that the “big picture” risk associated with a site can be understood in

order to inform the design of site-specific assessment. If specific pathways and receptors can be

shown to not be at risk, assessment is focused on the remaining at-risk pathways.

The approach requires qualified professionals and the latitude for those professionals to use

their judgment based on an overall understanding of regional conditions and a limited data set

of site-specific assessment data.

The following comments address the original issues identified through the stakeholder’s

questionnaire and workshops.


Regulatory Issue #1

The proposed guidance will serve to bring the OGC and MoE processes closer together.

As such, the guidance moves toward a common standard and the instruments should be

perceived as equivalent.

Regulatory Issue #2

OGC and MoE guidance are different in a number of respects. By making some changes to the

sampling aspects of OGC guidance the two approaches can be brought closer together.

While results may not be directly applicable to the standards-based MoE approach, they can be

brought in at the screening level risk assessment (SLRA) stage. It is our opinion that the best

opportunity for incorporating a number of the streamlining steps is in the SLRA. The process will

need some changes to be applicable to the upstream oil and gas sector in northeast BC. SLRA

(risk assessment in general) is considered remediation and is beyond the scope of this project.

Technical Issue #1

Information sources appropriate to upstream oil and gas sector have been presented. Checklists

10 and 11 will require modification to reflect addition and deletion of information sources.

Technical issue #2

In the upstream oil and gas sector, APECs are quite standard based on the site activities that

have occurred. A list of APECs linked to site activities is provided. A list of PCOCs associated

with standard APECs is provided.

Technical Issue #3

Arguments for the applicability of standards in the sector have been provided.

� argument for discounting DW (aquitard of 5 m of fine grained soil is protective of potential

deeper aquifers provided no significant secondary permeability features are observed);

� argument that, under some site conditions, organic soils and associated groundwater at many

sites should not be assessed as aquatic environment;

� guidance for applicability of IW and LW; and

� guidance for applicability of soil vapour standards.


Technical Issue #4

With completion of regional studies of soil type and groundwater usage the applicable guidance

can be refined. With the application of the results of these studies and professional judgement,

assessment of the pathways and receptors can be standardized. With addition of the second

line of evidence of the CoR Part 2 assessment, a robust weight-of-evidence, argument can be

made without over-assessment of the specific site where assessment demonstrates there are

low levels of contamination, as well as low potential for receptor exposure.

Technical Issue #5

Alternate assessment and results presentation approaches are proposed for organic soils.

These may not be applicable at the standards-based level but could be incorporated at the

SLRA level.

We have defined two CSMs that represent two sets of common conditions in upstream oil and

gas in northeast BC. For each of these CSMs we have defined guidance for assessment of soil,

groundwater, surface water, sediment and soil vapour. We have defined the steps necessary to

conclude if a particular site meets the CSM pre-conditions. Once that is proven then we have

defined the standards that apply and the level of assessment that will be considered sufficient to

demonstrate compliance.

The validity of this steamlining approach requires that a number of relationships between

regional conditions (e.g., presence of fine grained soils) and site-specific conditions

(e.g., hydraulic conductivity <10-7) can be applied. The assumed conditions are as follows:

Assumption of Site Condition based on Regional Condition Site-specific Assessment Required Resulting Applicable StandardAPEC and PCOC are based on site activity.

Determine site activity in Stage 1 PSI (provided no contradictory information).

Based on site activity define APEC and PCOC for site assessment.

Fine grained soils over large part of region with limited secondary permeability features.

Analyze soil samples for grain size to 5 m below depth of contamination.Excavate test pits to assess secondary permeability by observing fracturing.Install monitoring wells in three boreholes and complete falling head tests. If necessary conduct a yield test in shallow monitoring well.

Discount DW for shallow groundwater (DW doesn’t apply in muskeg either) and confirm protection of any potential deeper aquifer.

Prevalence of background metals in soil.

Compare metals results to established regional background metals standards.

If meet regional background then not contaminated.

Estimation of local groundwater flow direction based on ground slope.

Identify ground surface slope and direction.

Refine investigation of potential receptors based on estimatedgroundwater flow direction.


Assumption of Site Condition based on Regional Condition Site-specific Assessment Required Resulting Applicable StandardOrganic soil is compared to soil standards.

Determine that muskeg is only seasonally saturated (rather than a bog or fen). If in doubt then assessment by biologist.

Compare analytical results to soil standards and groundwater samples to applicable groundwater use standard.

Nature of organic soils affects analytical results.

Analyze background organic soilsamples for naturally occurring organicsReport organic soil results on a wet weight basis.

Subtract background concentrations when comparing to standards.Compare wet weight basis results to standards.

Seasonal surface water does not constitute an aquatic environment.

Determine surface water is seasonal through inspection. If in doubt then assessment by biologist.Sample surface water.

Compare analytical results to AW rather than BCAWQG.

Soil vapour standards are not applicable at wildlands sites.On non-WL sites only outdoor air has to be assessed if no buildings within 30 m.

Through Stage 1 PSI determine if site is WL or AL land use. Confirm through site inspection that there are no buildings within 30 m.

For wildland no vapour assessment is required.For agricultural land with no buildings within 30 m only assessment for outdoor air is required. Should be able to complete by modeling from soil and groundwater results if havefull list of parameters.

On Agricultural land IW/LW would only apply if there is currently irrigation or livestock watering occurring.

Through Stage 1 PSI and site inspection determine if there is current irrigation or livestock watering near the site.If you can’t discount then assess travel time argument to be used in an SLRA.

If no current use then IW/LW don’t apply.If you can’t discount then make travel time argument to discount.

Limited occupancy. Determine potential for occupancy from Stage 1 PSI and site inspection.

If little potential for human habitation then you can discount human health in a SLRA.

Parking Lot Issues

Parking Lot issue Suggestions for Who could conduct studyComparing results currently obtained during OGC DWDA activities(EC, SRA, salinity) to laboratory analytical methodologies for CSR parameters (chloride, sodium). Either determine equivalency or propose analytical changes to bring closer to CSR.

CAPP and OGC

Evaluate effect of naturally occurring organics and moisture content on analytical results in organic soils.

CAPP members provide data to be assessed by consulting laboratory.

Investigate background metals concentrations in soil and groundwater on a regional basis (compile data from recent and future site assessments).

CAPP members provide data to be compiled and assessed by consultant.

Compile data on locations of existing wells and hydrogeology conducive to water supply development from existing sources.

Consulting hydrogeologist

Investigate relationship of grain size and secondary permeability (fracturing and rootlets) to hydraulic conductivity in fine grained soils in northeast BC.


Investigate parameters of the falling head test to determine the minimum duration of the test to determine that hydraulic conductivity meets CSR TG6 requirement for an aquitard.


While a number of the streamlining items may not be applicable to standards based assessment, they may be valuable in a Screening Level Risk Assessment. Review SLRA and modify with respect to upstream oil and gas in northeast BC.

CSAP


11. REFERENCES

BC Ministry of Environment, 2003. British Columbia Field Sampling Manual, Part E Water and

Wastewater Sampling, Groundwater Pollution Monitoring.

http://www.elp.gov.bc.ca/epd/wamr/labsys/field_man_pdfs/grnd_poll_mon.pdf . .

BC Ministry of Environment, 2010a. Technical Guidance 6. Water Use Determination. Version 2

(July 2010). 8 pg.

BC Ministry of Environment, 2010b. Technical Guidance 8. Groundwater Investigation and

Characterization. Version 1 (July 2010). 16 pg.

BC MoE, 2010. Technical Guidance 8. Groundwater Investigation and Characterization.

BC Oil and Gas Commission, 2010. Oil and Gas Water Use in British Columbia. 30 p.

Bradbury, K.R. et al., 2006. Contaminant Transport Through Aquitards: Technical Guidance for

Aquitard Assessment. Sponsored by Awwa Research Fund. 176 p.

CCME, 1994. Subsurface Assessment Handbook for Contaminated Sites. CCME EPC-NCSRP-

48E. 293 p.

Cherry, J.A. et al., 2006. Role of Aquitards in the Protection of Aquifers from Contamination: A

State of the Science Review. Sponsored by the Awwa Research Foundation. 152 p. .

Christy, A.D., McFarland, L.A. and Carey, D., 2000. The Use of Test Pits to Investigate

Subsurface Fracturing and Glacial Stratigraphy in Tills and Other Unconsolidated

Materials. OHIO J SCI 100 (3/4):100-106.

EPA, 1993. Subsurface Characterization and Monitoring Techniques (EPA 625-R-93-003).

Golders Associates Ltd., 2010. Groundwater Investigation In Site Assessment. 2nd Edition. 63 p.

Levson, V., Ferbey, T. and Hickin, A. 2005. Surficial Geology and Aggregate Studies in the

Boreal Plains of Northeast British Columbia in Summary of Activities 2005, BC Ministry

of Energy and Mines, pages 42-50.

http://www.empr.gov.bc.ca/OG/oilandgas/aggregates/Documents/Levson_et_al.pdf


McKay, L., Cherry, J.A. and Gillham, R.W., 1993. Field Experiments in a Fractured Clay Till 1.

Hydraulic Conductivity and Fracture Aperture. Water Resources Research

29(4):1149-1162.

US EPA (Ohio), 2009. Assessment of an Aquitard during a Ground Water Contamination

Investigation. 9 p. http://www.epa.ohio.gov/portals/28/documents/TGM-Supp1.pdf.

DRAWINGS

� Map 1 - Regional Map Northeast BC – Western Sedimentary Basin Oil and Gas Activity� Map 2 - Regional Map Northeast BC – Existing Water Supply Wells� Map 3 - Regional Map Northeast BC – Agricultural Land Reserve� Map 4 - Regional Map Northeast BC – Wetlands / Muskeg

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0 8,100 16,200 24,300 32,4004,050Meters

REGIONAL MAP NORTHEAST BCEXISTING WATER SUPPLY WELLS

MINISTRY OF ENVIRONMENT

505093-004B01:500,000

NORTHEAST BC

MGM

CHD

2011-06-13

NAD 1983 UTM Zone 10N

Bing Maps and MapPoint Web Service - Copyright (c) 2010 Microsoft Corporation.BCGOV ILMB Crown Registry and Geographic Base Branch (CRGB) - data accessed through www.GeoBC.gov.bc.ca

1. Original in colour.2. Numerical scale reflects full-size print. Print scaling will distort this scale, however scale bar will remain accurate.3. Intended for illustration purposes, accuracy has not been verified for construction or navigation purposes.

P:\Current Projects\Other Projects\5050xx\505093\Cartography\505093-004B_WaterWells.pdf

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# Surface Water Points of Diversion

Groundwater Well

Groundwater Aquifers

REFERENCES

NOTES

LEGEND

CLIENT NAME: PROJECT LOCATION:

BY:

CHK'D:

SCALE: DATE: REF No: REV:

PROJ COORD SYS:

0 8,100 16,200 24,300 32,4004,050Meters

REGIONAL MAP NORTHEAST BCAGRICULTURAL LAND RESERVE


505093-004C01:500,000

NORTHEAST BC

MGM

CHD

2011-06-13




P:\Current Projects\Other Projects\5050xx\505093\Cartography\505093-004C_ALR.pdf

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BC Groundwater Aquifers

Agricultural Land Reserve

REFERENCES

NOTES

LEGEND


BY:

CHK'D:


PROJ COORD SYS:

093I/11

093I/08093I/07

093I/06093I/05

093I/09093I/10

093I/12

093I/16093I/15

093I/14093I/13

093J/11

093J/08093J/05 093J/06 093J/07

093J/09093J/12 093J/10

093J/16093J/13 093J/14 093J/15

094I/11

094I/01094I/02094I/03094I/04

094I/08094I/07094I/06094I/05

093K/08

094I/09094I/10

094I/12

093K/09

094I/16094I/15094I/14094I/13

093P/11

093K/16

093P/01093P/02

093P/03093P/04

093P/08093P/07093P/06093P/05

093P/09093P/10

093P/12

093N/01

094A/11

093P/16

094B/11

093P/15093P/14093P/13

093N/08

093O/11

094A/01094A/02094A/03094A/04094B/01094B/04 094B/03 094B/02

094J/11

093N/09

093O/01093O/04 093O/03 093O/02

094A/08094A/07094A/06094A/05094B/08094B/05 094B/06 094B/07

094J/04 094J/01094J/03 094J/02

093N/16

093O/08093O/05 093O/06 093O/07

094F/01

094A/09094A/10

094A/12094B/09094B/12 094B/10

094C/01

094J/08094J/05 094J/06 094J/07

093O/12 093O/09093O/10

094F/08

094A/16094A/15094A/14094A/13094B/13 094B/16094B/14 094B/15

094C/08

094J/09094J/12 094J/10

093O/13 093O/16093O/14 093O/15

094F/09

094C/09

094J/13 094J/16094J/14 094J/15

094F/16

094C/16

094H/11

094H/01094H/02094H/03094H/04

094H/08094H/07094H/06094H/05

094G/11

094K/01

094H/09094H/10

094H/12

094G/04 094G/01094G/02094G/06

094K/08

094H/16094H/15094H/14094H/13

094G/08094G/05 094G/06 094G/07

094K/09

094G/09094G/12 094G/10

094K/16

094G/13 094G/16094G/15094G/14

094P/11

094P/01094P/02094P/03094P/04

094P/08094P/07094P/06094P/05

094P/09094P/10

094P/12

094N/01

094P/16094P/15094P/14

094N/08

094P/13

094O/11094N/09

094O/01094O/04 094O/03 094O/02

094O/08094O/05 094O/06 094O/07

094N/16

094O/12 094O/09094O/10

094O/13 094O/16094O/15094O/14094N/15

094N/10

094N/07

094N/02

094K/15

094K/10

094K/07

094K/02

093I/01

094F/15

094F/10

093I/02

094F/07

094F/02

093I/03

094C/15

094C/10

093I/04

094C/07

093K/01 093J/04 093J/01

094C/02

093J/03 093J/02

093N/15

093N/10

093N/07

093N/02

093K/15

093K/10

093K/07

093K/02

0 8,100 16,200 24,300 32,4004,050Meters

REGIONAL MAP NORTHEAST BCMUSKEG


505093-004D01:500,000

NORTHEAST BC

MGM

CHD

2011-06-13




P:\Current Projects\Other Projects\5050xx\505093\Cartography\505093-004D_Muskeg.pdf

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Freshwater Atlas - Wetlands

NTS 50k Grid

REFERENCES

NOTES

LEGEND


BY:

CHK'D:


PROJ COORD SYS:

"

"

"

"

"

"

"

"

"

"

"

"

"

Trutch

Chetwynd

Mackenzie

Bear Lake

Fort Nelson

Dawson Creek

Nelson Forks

Manson Creek

Tumbler Ridge

Hudson's Hope

Fort St. John

Pink Mountain

Fort St. James

093I/11

093I/08093I/07

093I/06093I/05

093I/09093I/10

093I/12

093I/16093I/15

093I/14093I/13

093J/11

093J/08093J/05 093J/06 093J/07

093J/09093J/12 093J/10

093J/16093J/13 093J/14 093J/15

094I/11

094I/01094I/02094I/03094I/04

094I/08094I/07094I/06094I/05

093K/08

094I/09094I/10

094I/12

093K/09

094I/16094I/15094I/14094I/13

093P/11

093K/16

093P/01093P/02

093P/03093P/04

093P/08093P/07093P/06093P/05

093P/09093P/10

093P/12

093N/01

094A/11

093P/16

094B/11

093P/15093P/14093P/13

093N/08

093O/11

094A/01094A/02094A/03094A/04094B/01094B/04 094B/03 094B/02

094J/11

093N/09

093O/01093O/04 093O/03 093O/02

094A/08094A/07094A/06094A/05094B/08094B/05 094B/06 094B/07

094J/04 094J/01094J/03 094J/02

093N/16

093O/08093O/05 093O/06 093O/07

094F/01

094A/09094A/10

094A/12094B/09094B/12 094B/10

094C/01

094J/08094J/05 094J/06 094J/07

093O/12 093O/09093O/10

094F/08

094A/16094A/15094A/14094A/13094B/13 094B/16094B/14 094B/15

094C/08

094J/09094J/12 094J/10

093O/13 093O/16093O/14 093O/15

094F/09

094C/09

094J/13 094J/16094J/14 094J/15

094F/16

094C/16

094H/11

094H/01094H/02094H/03094H/04

094H/08094H/07094H/06094H/05

094G/11

094K/01

094H/09094H/10

094H/12

094G/04 094G/01094G/02094G/06

094K/08

094H/16094H/15094H/14094H/13

094G/08094G/05 094G/06 094G/07

094K/09

094G/09094G/12 094G/10

094K/16

094G/13 094G/16094G/15094G/14

094P/11

094P/01094P/02094P/03094P/04

094P/08094P/07094P/06094P/05

094P/09094P/10

094P/12

094N/01

094P/16094P/15094P/14

094N/08

094P/13

094O/11094N/09

094O/01094O/04 094O/03 094O/02

094O/08094O/05 094O/06 094O/07

094N/16

094O/12 094O/09094O/10

094O/13 094O/16094O/15094O/14094N/15

094N/10

094N/07

094N/02

094K/15

094K/10

094K/07

094K/02

093I/01

094F/15

094F/10

093I/02

094F/07

094F/02

093I/03

094C/15

094C/10

093I/04

094C/07

093K/01 093J/04 093J/01

094C/02

093J/03 093J/02

093N/15

093N/10

093N/07

093N/02

093K/15

093K/10

093K/07

093K/02

HELMET

RING

DAHL

OJAY

EKWAN

NOEL

DRAKE

RIGEL

KELLY

INGA

SHEKILIE

GUNNELL CREEK

BUICK CREEK

PICKELL

SIERRA

TOMMY LAKES

SILVER

ALTARES

BEG

ELLEH

SUKUNKA

MAXHAMISH LAKE

GROUNDBIRCH

MONIAS

SUNDOWN

KLUA

DOE

GUTAH

MARTIN

TOWN

KAHNTAH RIVER

OAK

VELMA

DESAN

GRAHAM

NIG CREEK

BIVOUAC

PEEJAY

MILO

HIDING CREEK

ADSETT

BULLMOOSE

KOBES

JEDNEY

LADYFERN

MURRAY

CLARKE LAKE

FIREWEED

BOUNDARY LAKE

CUTBANK

WARGEN

ESKAI

GWILLIM

SUNRISE

LAPRISE CREEK

SIKANNI

ELM

THETLAANDOA

YOYO

TSEA

EAGLE

CHINCHAGA RIVER

BIRCH

ZAREMBA

JUNIOR

BOUGIE

BRASSEY

OSPREY

STODDART WEST

CYPRESS

STODDART

BLACK CREEK

CABIN

WEASEL

BLUEBERRY

CONROY CREEK

KOTCHO LAKE

BUBBLES NORTH

HOSSITL

WILDER

SWAN LAKE

MICA

CARIBOU

SIPHON

FORT ST JOHN

SAHTANEH

COMMOTION

PARKLAND

CACHE CREEK

PRESPATOU

BRAZION

BEAVERTAIL

DOIG RAPIDS

JACKPINE

BUICK CREEK NORTH

GREEN CREEK

MOOSE

BIRLEY CREEK

LAPP

TWO RIVERS

BUBBLES

UMBACH

OSBORN

FIREBIRD

FEDERAL

CURRANT

FLATROCK

HAY RIVER

BOUNDARY LAKE NORTH

EAGLE WEST

SEPTIMUS

SEXTET

LILY LAKE

SATURN

BEG WEST

MONTNEY

GRIZZLY SOUTH

MEL

WILDMINT

POCKETKNIFE

RIGEL EAST

TUPPER CREEKBOULDER

EVIE BANK

WOLVERINE

BUTLER

NIG CREEK NORTH

KYKLO

HOFFARD

MUSKRAT

FLATROCK WEST

TOWER LAKE

HIGHHAT MOUNTAIN

CECIL LAKE

SOJER

MERCURY

KOTCHO LAKE EAST

AIRPORT

OOTLA

DAIBER

BERNADET

CHOWADE

BLAIR

LOUISE

OWL

GOTE

ATTACHIE

TOOGA

WOLF

KOMIE

MIKE

PETITOT RIVER

BUICK CREEK WEST

BULLMOOSE WEST

WILLOW

GUNDY CREEK

TATTOO

SQUIRREL

SUNSET PRAIRIE

PARADISE

MILLIGAN CREEK

INGA NORTH

BEAR FLAT

DILLY

PORTAGE

HALFWAY

GRIZZLY NORTH

SIPHON EAST

BURNT RIVER

JULIENNE CREEK

PEEJAY WEST

BLUEBERRY WEST

WOODRUSH

AITKEN CREEK

HUNTER

CURRANT WEST

RED CREEK NORTH

BUCKINGHORSE

GOOSE

DAWSON CREEK

LAGARDE

BRIAR RIDGE

BEAVER RIVER

SILVERBERRY

MILLIGAN CREEK WEST

STONE CREEK

BEATTON RIVERBEATTON RIVER WEST

RED CREEK

RED DEER

GUNDY CREEK WEST

REDEYE

PLUTO

TOWNSEND

NORTH PINE

BOUDREAU

AITKEN CREEK NORTH

CRUSH

BULRUSH

ELBOW CREEK

BEAVERDAM

FORT ST JOHN SOUTHEAST

WINDFLOWER

BULLDOG

STODDART SOUTH

ROGER

GRASSY

LAPRISE CREEK WEST

JULIENNE CREEK NORTH

CROW RIVER

FARRELL CREEK WEST

ALCES

TRUTCH

GOPHER

REDWILLOW RIVER

WEASEL WEST

JULIENNE CREEK SOUTH

BLUEBERRY EAST

THETLAANDOA NORTH

JEDNEY WEST

THUNDER MOUNTAIN

MOBERLY LAKE

NIG CREEK WEST

ELLEH NORTH

PINTAIL

KOBES WEST

INGA SOUTH

0 8,100 16,200 24,300 32,4004,050Meters

REGIONAL MAP NORTHEAST BCOIL AND GAS


505093-004E01:500,000

NORTHEAST BC

MGM

CHD

2011-06-28




P:\Current Projects\Other Projects\5050xx\505093\Cartography\505093-004E_OilGas.pdf

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" BC Communities

Gas Field

Oil Field

Oil/Gas Field

} OGC Facilities

* OGC Wellsites

NTS 50k Grid

REFERENCES

NOTES

LEGEND


BY:

CHK'D:


PROJ COORD SYS:

CSM #1

� 505093-001 – CSM#1 (fine grained soil) Site Plan with APECs� 505093-001B – CSM#1 (fine grained soil) Cross Section� Air Photograph 1A Conceptual Model (fine grained soil)� Photograph 1B: Ground Level Photograph Fine Grained Soils

505093

Air Photograph 1A: Conceptual Model (fine grained soil).

505093

Photograph 1B: Ground Level Photograph (fine grained soils).

CSM #2

� 505093-002 – CSM#2 (Organic Soils) Site Plan with APECs� 505093-002B – CSM#2 (Organic Soils) Cross Section� Air Photograph 2A Conceptual Site Model (organic soil)� Photograph 2B: Ground Level Photograph Organic Soils� 505093-003 – Post Abandonment Wellhead Assessment

505093

Air Photograph 2A: Conceptual Model (organic soils).

505093

Photograph 2B: Ground Level Photograph (organic soils).

APPENDIX I

Stage 1 PSI Background Data Sources


APPENDIX I: Stage 1 PSI Background Data Sources

The first component of a Stage 1 Preliminary Site Investigation (PSI) is review of relevant client

and government files relating to the site. A summary of the site information is as follows:

� Resource company records:

� Site survey plans with notations;

� Drilling, workover, well servicing, and completion reports;

� Mud additives lists;

� Drilling waste handling and disposal documentation;

� Operation and maintenance records;

� Facilities / pipeline abandonment or decommissioning reports; and

� Previous environmental investigation reports.

� Legal titles;

� Provincial and/or municipal government agencies

� zoning; and

� land use restrictions (i.e., Agricultural Land Reserve).

� Ministry of Environment databases;

� Spills;

� Contaminated Site Registry; and

� SWIS, WASTE, COORS (do not typically provide information of use).

� Oil and Gas Commission (or Ministry of Energy Mines and Petroleum Resources Archives);

� Rig, wellsite and reclamation inspection reports;


� Drilling reports;

- Well authorization documentation;

- Flaring authorizations; and

� Production records.

� Physiological Data Sources;

� Geology, surficial geology and soil surveys;

� Orthophotography, satellite imagery;

� If imagery of the wellsite does not capture the associated facility, a separate image of

the associated facility must be provided (e.g., aerial, satellite, etc. and site

photographs);

� Topographic maps;

� Nearby groundwater well logs; information on aquifers or groundwater supplies;

� Site construction records (Pre-site or Schedule A assessments); and

� Drilling waste sump suitability.

Following completion of the file review a review of aerial and satellite imagery is completed.

Review of aerial or satellite imagery can provide a visual chronological history of activities that

occurred at a site when viewed at an appropriate scale. Imagery can provide valuable information

about a site, especially when the company documentation is not available or incomplete.

Information about the site such as location of facilities and features, sumps and flare pits, spills

and clean up can be obtained. If the results of the Stage 1 PSI indicate contamination is likely,

imagery can be used to develop a soil sampling plan. Submissions of aerial photographs or

satellite photographs that provide sufficient detail are required with the CoR Part 1 application.

Ensure all information is provided with the application, including the date the imagery was

reviewed, the name of the reviewer, photograph identification, year, scale, and observations.

A site reconnaissance is then carried out.


A site reconnaissance is conducted to confirm site operations and environmental conditions that

may not have been apparent through the historical review. A site reconnaissance is of increased

importance where historical records are incomplete and the location of APEC, either confirmed

or inferred based on historical activities, remain unknown. Common examples of these include

drilling waste disposal areas (DWDA), former flaring facilities and decommissioned pipelines or

production facilities.

Often intrusive assessments must be completed under winter access conditions; however, effort

should be made to complete the site reconnaissance during snow free conditions

(and preferably during the growing season) to ensure meaningful observations of surficial

conditions including the condition of vegetation on site and on surrounding land. Consideration

should be given to locating suitable background sampling locations during the reconnaissance.

A summary of the types of observations considered necessary to develop a sound

understanding of site conditions and to develop a CSM is included below

Where abandonment or decommissioning of a facility (i.e., flare pit, pipelines, drilling waste,

disposal areas) has occurred, depressions may be the only remaining visible evidence regarding

its location. These should be documented and considered in conjunction with other corroborative

evidence in establishing the most likely locations of unconfirmed APEC at a site. Photographs

should also be taken to record the general site condition, land use and each APEC.

In low-lying wet environments or where unsuitable substrate was identified for on-site drilling

waste disposal, a remote upland site may have been identified for the remote disposal of drilling

wastes. These should be inspected as part of the site reconnaissance.

Other ancillary facilities that can be associated with a given well site (tied to lease) include

temporary camps and access road. Based on the inferred temporary land use typical at these

types of facilities, impacts to soil and groundwater would not be anticipated. However, these

facilities should be inspected during the site reconnaissance to confirm or refute the presence of

evidence of contamination.


Documentation of a site reconnaissance should include the following:

� Date (d/m/y): The date on which the site reconnaissance was conducted.

� Assessor: The person who conducted the site visit and their employer’s name.

� Surrounding land use: State the land use surrounding the site in all four directions.

� Topography: Describe the topography across the site. Include any topographical changes

that may occur and the relation to off lease areas.

� Vegetation: List the type of vegetation and plant species on the site and the surrounding area.

� Proximity to neighbouring features: Features such as residences, water wells, surface

waterbodies (ponds, streams, rivers) must be listed with distances from the lease provided.

� Visual indicators: Document the type of facility present, its size and location.

On-site equipment or tanks, along with visual signs of former facilities, or open or buried

earthen pits may indicate potential contamination sources.

� Evidence of past spills: Provide information on any visual indicators of contamination.

Indicators may include staining, presence of crusted soils (indicating salt spills), changes in

soil characteristics, slumping, depression areas, etc.

� Adjacent land affected by operations on the site: Any operational off lease impacts

originating from the site must be noted. This may include spills that extended off lease, off

lease vegetation impacts, rutting, and water ponding. Detailed information should be recorded

during the site visit identifying the type of impact, the potential cause, area affected, etc.

� Vegetation stress: Provide the location of any stressed vegetation and size of the impacted

area. Visual indicators of vegetation stress include bare soil or indicator plant species such as

kochia or fox tail barley, which are typically associated with saline soils.

Site construction technique (pad, cut and fill, strip to side) is important from a stratigraphic

perspective as well as understanding the reclamation status of the site. The interpretation of the

working grade of the site during drilling and operations requires an understanding of the

reclamation status of the site. For instance, the assessor should be aware if there has been

restoration of cut and fill slopes or redistribution of surface soils.


Interviews

Interviews with knowledgeable persons may improve the understanding of environmental

conditions and historical operations at a site. Only interviews of people with first-hand

knowledge of a site are useful. Interviews are primarily completed to identify environmental

concerns at a site (e.g., spills, etc.) and to confirm APEC and PCOC at a site. Interviews can be

useful in providing additional and corroborating evidence where incomplete or partial information

was obtained from other sources during the Stage 1 PSI. Interviewees should include

landowner (or occupant[s]) and resource company representatives. The investigator should

confirm with the interviewees that they are not aware of other individuals with more complete

knowledge that might be better suited to participating in the interview process.

APPENDIX II

List of Potential Contaminants of Concern (SNC in-house reference)


APPENDIX II: List of Potential Contaminants of Concern (SNC in-house reference)

Based on the results of the Stage 1 Preliminary Site Investigation (PSI), the list of potential

contaminants of concern (PCOCs) and regulated parameters would be refined based on the

known activities on the site.

Area of Potential Environmental Concern (APEC)

Potential Contaminant of Concern (PCOC)

Regulated Parameters of Concern

Wellhead and Surrounding Area(includes ASTs)

Diesel, crude oil, natural gas, condensate, drilling fluids and additives, drill cuttings, produced water, workover

fluids, well production / treatment chemicals, herbicides / sterilants

Metals, BTEX, VPH, LEPH, HEPH, PAH, Chloride, Sodium

Flare Pit Hydrocarbons and produced water Metals, BTEX, VPH, LEPH, HEPH, PAH, Chloride, Sodium

Flare Stack Natural gas, condensate, produced water

Metals, BTEX, VPH, LEPH, HEPH, PAH, Chloride, Sodium

Drilling Waste Disposal Areas (including mix-bury-cover and

landspreading)

Crude oil, condensate, drilling fluids and additives, drill cuttings, produced water,

treatment chemicals

Metals, BTEX, VPH, LEPH, HEPH, PAH, Chloride, Sodium,

other parameters associated with specific treatment chemicals

General Screening / Spills (including unconfirmed former above ground storage tank [AST] / underground

storage tank [UST] locations)

Gasoline, diesel, condensate, natural gas, drilling fluids and additives, work over

fluids, produced water, treatment chemicals


other parameters associated with specific treatment chemicals

Stains, Stressed, Vegetation, etc. Gasoline, diesel, condensate, natural gas, drilling fluids and additives, work over fluids, produced water, treatment

chemicals

Metals, BTEX, VPH, LEPH, HEPH, PAH, Chloride, Sodium, other parameters associated with specific treatment chemicals

Above Ground and Underground Storage Tanks

Gasoline, diesel, condensate, natural gas, drilling fluids and additives, work over fluids, produced water, treatment

chemicals

Metals, BTEX, VPH, LEPH, HEPH, PAH, Chloride, Sodium other parameters associated with specific treatment chemicals

Above Ground and Underground Lines

Gasoline, diesel, condensate, natural gas, drilling fluids and additives, work over fluids, produced water, treatment

chemicals


Dehydrators Natural gas, crude oil, produced water, glycols, methanol


Methanol, GlycolsSeparators Natural gas, crude oil, produced water Metals, BTEX, VPH, LEPH,

HEPH, PAH, Chloride, SodiumCamp Site Gasoline, diesel, Metals, BTEX VPH, LEPH,

HEPH, PAHPigging Stations Natural gas, crude oil, produced water Metals, BTEX, VPH, LEPH,

HEPH, PAH, Chloride, SodiumMetering Equipment Mercury Metals

Buildings and Other Production Facilities Gasoline, diesel, condensate, natural

gas, produced water, process and treatment chemicals


BTEX – benzene, toluene, ethylbenzene, and xylenes PAH – polycyclic aromatic hydrocarbonsHEPH – heavy extractable petroleum hydrocarbon VPH – volatile petroleum hydrocarbonsLEPH – light extractable petroleum hydrocarbons in water


Other treatment and/or process chemicals that may have been used during drilling and/or

production should be considered as PCOC based on site- or process-specific knowledge.

Example chemicals include glycols and methanol. These, and other regulated substances,

should be considered as PCOC and be appropriately assessed. Where the use of solvents in

the operation and/or maintenance of equipment has been noted in the Stage 1 PSI, associated

volatile organic compounds may require assessment.

There are other activities that may generate contaminants which may need to be addressed in

some capacity:

� Herbicides and Soil Sterilants.

� Imported Soil.

� Naturally Occurring Radioactive Materials - Naturally occurring radioactive materials may

concentrate inside oil and gas processing equipment, particularly within certain oil and gas

fields.

� Proprietary Substances - drilling additives or process chemicals in which all specific chemical

constituents may not be reported for proprietary reasons.

APPENDIX III

Depth-Dependant Standards


APPENDIX III: Depth Dependant Standards

The British Columbia Oil and Gas Commission (OGC) and Ministry of Environment (MoE)

Contaminated Sites Regulation1

OGC depth dependent standards are as follows:

(CSR) each define depth dependent standards, the standards

applicable based on depth below ground surface. The depth dependant standards defined in the

CSR (Part 6, Section 17), allow application of commercial land use (CL) standards below 2 m

depth within 15 m of the well head and below 3 m depth beyond 15 m from the well head.

� for agricultural land (AL) use, AL standards are applicable to a depth of 1m. Urban

parkland (PL) standards can be applied below 1 m depth, to 2 m depth. Below 2 m depth CL

standards can be applied. The site-specific factor of “Toxicity to soil invertebrates and

plants” does not have to be applied below a depth of 1 m; and

� for wildland (WL) use, PL standards are applicable to a depth of 1 m. CL standards can be

applied below 1 m depth. The site-specific factor of “Toxicity to soil invertebrates and plants”

does not have to be applied below a depth of 1 m.

The two standards are illustrated in the attached figures.

� 505093 – Figure 1 – Comparison of Depth dependent standards (Agricultural Land Use);

and

� 505093 – Figure 2 – Comparison of depth dependent standards (Wildland Use).

The OGC depth dependent standards (not applying “toxicity to soil invertebrates and plants”

below a depth of 1 m) recognize that rooting depth is limited in fine grained soils and hence

contaminants below 1 m depth are less bio-available to plants and invertebrates.

As can be seen, the depth dependent standards applied differ between MoE and OGC. The two

approaches could be reconciled by considering soil type and rooting depth in a screening level

risk assessment step. This screening level risk assessment would however have to be less

rigorous and allow qualitative characteristics such as soil type to be incorporated without

rigorous assessment of soil type and extent (e.g., if soil is demonstrated to be fine grained and

in a geoclimatic zone where rooting depths are shallow then OGC depth dependent standards

could be applied. 1 Contaminated Sites Regulation (CSR), B.C. Reg. 375/96, including amendments up to B.C. Reg. 97/2011.