Mercury in Crude Oil Refined in Canada

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Mercury in Crude Oil Refined in Canada

Prepared by:

B.P. Hollebone Emergencies Science and Technology Division

Science and Technology Branch Environment Canada

335 River Road Ottawa, Ontario K1A 0H3

and

C.X. Yang

Environmental Protection Operation Division – Ontario Environmental Stewardship Branch

Environment Canada 4905 Dufferin Street

Toronto, Ontario M3H 5T4 October, 2007

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This report may be cited as: Hollebone, B.P. and C.X. Yang, “Mercury in Crude Oil Refined in Canada”, Environment Canada, Ottawa, ON, 2007.

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This report contains technical and scientific information from a joint project conducted by Environment Canada and the Canadian Petroleum Products Institute to study the amount of mercury in various types of crude oils. The report is intended to make information available that is of interest to a limited audience. The demand for such technical reports is usually confined to participants in the project and specialists in the fields concerned. These reports are therefore produced in small quantities. Copies are available from the address below. The recommended citation is provided on the back of the title page. This report is available in Environment Canada libraries and is listed in the catalogue of the National Library of Canada. It is printed in the official language chosen by the author to meet the language preference of the likely audience, with an abstract in the second official language. To determine whether there is significant demand for making this report available in the second official language, Environment Canada invites users to specify their official language preference. Copies of this report are available from: Environmental Protection Operations Division - Ontario Region Environment Canada 4905 Dufferin Street, Second Floor Toronto, Ontario, Canada M3H 5T4 © Minister of Public Works and Government Services Canada 2007 Catalogue No. ISBN

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Acknowledgements We would like to thank the Canadian refineries who participated in this study. Sampling for work reported here was done by personnel at these refineries. The refineries are listed here in alphabetical order. Chevron Canada Ltd. NOVA Chemicals (Canada) Ltd. Consumers' Co-op Refinery Ltd. Petro-Canada Ltd. Husky Energy Inc. Shell Canada Products Imperial Oil Ltd. Suncor Energy Products Incorporated North Atlantic Refinery Ultramar Ltée Thanks are also extended to the following individuals who were members of the review committee and their organizations which provided advice and financial support for this project. Canadian Petroleum Products Institute Jack Belletrutti Environment Canada

Atlantic Region Michael Hingston Emissions Inventory Reporting and Outreach David Niemi National Mercury Program Tonya Bender and Lorrie Hayes Oil, Gas and Energy Division Bruce McEwen, Elizabeth Escorihuela,

Lynne Patenaude, Andrew Snider, Francine Beaudet, Shannon Castellarin, Carl Chenier, and Saviz Mortazavi

Ontario Region Shawn Michajluk Pacific and Yukon Region Stan Liu Prairie and Northern Region Maureen Brown

Ottawa University David Lean and Ogo Nwobu

Department of Biology Shell Canada Gerry Ertel

Shell Canada Products Thanks to Lisa Graham of the Emissions Measurement and Research Division of Environment Canada for her initial proposal on this project, Dr. Yi-Fan Li of Environment Canada for generating digital maps, and Feng Hou of Statistics Canada for his advice on sampling design. Thanks are also due to our American counterparts, Mark Wilhelm of Mercury Technology Services and David Kirchgessner of the U.S. E.P.A., for their advice throughout the project. Finally, we would like to commend all involved for the spirit of cooperation that characterized this work. This project required wide-ranging collaboration between government, industry, and academia. With mutual interests in environmental issues, all stakeholders worked together to achieve these results.

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List of Acronyms AA Atomic absorption (spectrometry) AFS Atomic fluorescence spectrometry API American Petroleum Institute ASTM Originally the American Society of Testing and Materials, now the

organization is simply known as ASTM International. CA CEBAM Analytical Laboratories CEPA Canadian Environmental Protection Act CPPI Canadian Petroleum Products Institute CVAA Cold vapour atomic absorption CVAFS Cold vapour atomic emission spectrometry DQO Data quality objective EC Environment Canada ESTD Emergencies Science and Technology Division (Environment

Canada) ICP-AES Inductively-coupled plasma-atomic emission spectrometry ICP/MS Inductively-coupled plasma/mass spectrometry MDL Method detection limit NIC Nippon Instrument Corporation NIST National Institute of Standards and Technology (U.S.) NPRA National Petrochemical and Refiners Association (U.S.) NPRI National Pollutant Release Inventory (Environment Canada) NVLAP NationalVoluntary Laboratory Accreditation Program, run by

NIST (U.S.) OU Ottawa University laboratory Ppb Parts per billion by weight (ng/g oil) or by volume (µg/L oil) Ppbw Parts per billion by weight (ng/g oil) Ppm Parts per million: by weight (µg/g oil) or by volume (mg/L oil) Ppmw Parts per million by weight (µg/g oil) PSA PS Analytical PTFE Poly-TetraFluoroEthylene QA Quality assurance QC Quality control RPD Relative percent difference RSD Relative standard deviation SD Standard deviation [THg] Total mercury concentration (in crude oil) U.S. EPA United States Environmental Protection Agency

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Executive Summary A quantitative assessment of the amount of mercury processed by the petroleum sector is necessary for many programs and initiatives. Mercury is identified as a priority toxic substance in the Canadian Environmental Protection Act, 1999. Despite this, mercury emissions from the petroleum-refining sector are not well quantified. For the past three decades, researchers in both Canada and the United States have attempted to quantify the concentration of mercury in crude oil and to estimate potential releases of mercury from petroleum sources. It has been difficult to estimate emissions based on these past studies, however, due to problems with sample selection and handling and the variety of analytical methods used. To obtain an inventory of mercury in the petroleum-refining sector, Environment Canada, in collaboration with the Canadian Petroleum Products Institute (CPPI) and most Canadian refineries (including both CPPI members and independents), have measured the mercury concentrations in 32 types of crude oil used in Canadian refineries. The goal of this study is to determine the average concentration of total mercury present in crude oils refined in Canada and the total amount of mercury in all the crude oil refined in Canada in a single year. The study was conducted from November 2003 to June 2006. The project was a collaboration between the federal government, the petroleum-refining industry, and academia. Environment Canada provided overall project coordination, technical management, and sample analysis. The Canadian Petroleum Products Institute ensured sample confidentiality and liaised between the industry and the government. Processing data for the year 2002 was used for sampling design. The participating refineries conducted sampling throughout 2004 and 2005, ensuring that the samples taken were representative of the processing of crude oil in 2002. Sample management and analysis were carried out by the University of Ottawa. Duplicate sample analysis was performed by CEBAM Analytical of Seattle, Washington. The volume-weighted average of total mercury concentration from refineries has been computed from the total mercury concentration for each type of oil. This was used to estimate the total amount of mercury in all crude oils refined in Canada, as well as the maximum potential for mercury releases from refineries. The most significant release pathway for mercury in petroleum products is through emission to the atmosphere by combustion of refined fuels. Refineries, however, can also release mercury to water and land as well as to air. More than 100 types of crude oil were processed by the participating refineries in the year 2002. Approximately half were produced in Canada. Imported oils originated in Europe (17%), Africa (6%), the Middle East (6%), the U.S. (9%), South America (9%), Mexico (5%), and Asia (1%). A set of 32 oil types was chosen to be sampled, representing 72% by refined volume of all crude oils refined in Canada in 2002. A total of 109 grab-samples was collected at the entry point to the refineries. The total mercury concentration in each sample was measured by two different laboratories using cold vapour atomic absorption (CVAA) and cold vapour atomic fluorescence spectrometry (CVAFS). The oil density and total sulphur content were also determined. Strict quality control was observed for all measurements.

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Findings The average total mercury concentration in crude oil was 2.6 ± 0.5 ng of mercury/g of oil, weighted by the volume refined in Canada in 2002. This corresponds to a total of 227 ± 30 kg of mercury contained in all crude oil processed in Canada in 2002. This value agrees well with the mean value of 2.1 ng/g for Canadian oils reported by the U.S. EPA and the American Petroleum Institute (API) in a parallel survey of crude oils processed in the U.S. from 2003 to 2007. Average volume-weighted mercury concentrations in oil were calculated for the geographical source of the crude oils: 1.1 ± 0.2 ng/g from eastern Canada (including the Maritimes and Ontario); 1.6 ± 0.3 ng/g from western Canada (Alberta, British Columbia, and Saskatchewan); and 4.5 ± 0.8 ng/g for oils produced outside of Canada. The average volume-weighted mercury concentration in synthetic crude oils, included in the western average concentration, produced from the Alberta tar sand was estimated to be 2.2 ± 0.4 ng/g. Average volume-weighted mercury concentrations in oil were calculated by refinery location: 1.4 ± 0.3 ng/g for western Canada (British Columbia, Alberta, and Saskatchewan); 2.1 ± 0.4 ng/g for Ontario; and 4.5 ± 0.8 ng/g for Quebec and Atlantic provinces (Quebec, New Brunswick, Nova Scotia, and Newfoundland). Additional significant findings include the following.

o The range of mercury concentrations in crude oil was observed to be 0.1 to 50 ng/g. o The average concentration and the range measured are significantly lower than those

reported in the literature. o No strong correlations were found between the total mercury concentration in crude oil

and either total sulphur content or density of the oil. o Canadian oils have lower concentrations of total mercury than oils from foreign sources.

Refineries on the east coast of Canada handle crude oils with higher levels of mercury than those in Ontario or western Canada. This is almost entirely due to their use of higher levels of foreign crude oils.

Recommendations 1. The refined volume-weighted average of total mercury concentration in Canadian crude

oil is 2.6 ± 0.5 ng of mercury/g of oil (ppbw). From this average mercury concentration, the total amount of mercury in crude oil processed in Canada is estimated to be 227 kg in 2002, 231 kg in 2003, 240 kg in 2004, and 233 kg in 2005. This is based on the total amount of crude oil refined in Canada in those years.

2. The processing pattern for crude oil reported here was that for 2002. In 2002, eight types

of crude oil accounted for 30% of the Canadian processing volume but contained more than 80% of all the mercury in crude oil processed in Canada. These eight crude oils originated from western Canada, Europe, and Africa. However, the processing pattern for crude oil in Canada has changed slightly each year. If crude oil use deviates significantly in the future from the usage pattern evaluated in this work, the results of this study will need to be re-evaluated.

3. The total amount of mercury in all crude oil processed in Canada in 2002 (227 ± 30 kg)

can be used as an estimate of the upper limit of potential mercury emissions from the refining sector. This includes potential mercury emissions from all refined petroleum products and all the potential mercury releases from refineries. This study targeted only

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the crude oil received by the refinery at the feedstock. Actual emissions from refineries were not measured. In addition, mercury released from upstream oil and gas extraction, handling, and transport to refineries should not be included in this estimate. Mercury from other refinery inputs, such as natural gas, may also affect this estimate.

4. The value for the total amount of mercury in crude oil refinery inputs can also be used as

an estimate of the upper limit of mercury in refined fuels. Emissions of mercury into the atmosphere from the exhaust of on-road motor vehicles as a result of combustion of refined petroleum products can be estimated to be no more than 227 ± 30 kg/yr. Using this worst-case estimate, the maximum potential anthropogenic atmospheric emissions of mercury from combustion of refined fuel would be 3.6% of the Canadian total (6,340 kg of mercury) in 2002. Note that the actual disposition of mercury in each stream of the petroleum products used to power on-road motor vehicles, including gasoline and diesel fuels, was not measured in the present study.

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Sommaire-recommandations De nombreux programmes et initiatives ont besoin d’une évaluation quantitative de la quantité de mercure traitée par le secteur pétrolier. Par exemple, le mercure est désigné comme substance toxique d’intérêt prioritaire dans la Loi canadienne sur la protection de l’environnement de 1999. Les émissions de mercure des raffineries de pétrole sont mal quantifiées. Pendant les trois dernières décennies, des chercheurs canadiens et états-uniens ont tenté de chiffrer la concentration de mercure dans le pétrole brut et d’estimer les rejets potentiels de cet élément par le secteur pétrolier. La sélection et la manutention des échantillons ainsi que la diversité des méthodes d’analyse ont rendu difficile l’estimation des émissions d’après ces études antérieures. Pour obtenir un inventaire du mercure dans le secteur du raffinage, Environnement Canada (EC) a mesuré, en collaboration avec l’Institut canadien des produits pétroliers (ICPP) et la plupart des raffineries canadiennes (membres de l’ICPP et indépendants), la teneur en mercure de 32 types de bruts raffinés au Canada. L’objet de l’étude était de déterminer la teneur moyenne en mercure total des bruts raffinés au Canada et la quantité totale de mercure présent dans tout le brut raffiné en une année au Canada. L’étude a été effectuée de novembre 2003 à juin 2006. Le projet était une collaboration entre l’administration fédérale, l’industrie du raffinage et des universités. Environnement Canada a assuré la coordination globale du projet, sa gestion technique et l’analyse des échantillons. L’ICPP a assuré la confidentialité des échantillons et servi de trait d’union entre l’industrie et l’administration fédérale. Les résultats du traitement des données de l’année 2002 ont servi à l’élaboration du plan d’échantillonnage. Les raffineries participantes ont effectué les prélèvements d’échantillons en 2004 et en 2005, en s’assurant qu’ils étaient représentatifs du traitement effectué en 2002. La gestion et l’analyse des échantillons ont été confiées à l’Université d’Ottawa. CEBAM Analytical, de Seattle (Washington) a effectué l’analyse des échantillons en double. On a calculé la concentration moyenne de mercure total, pondérée en fonction du volume, qui provient des raffineries à partir de la concentration de mercure total dans chaque type de brut. On s’en est ensuite servi pour estimer la quantité totale de mercure dans tous les bruts raffinés au Canada ainsi que le tonnage potentiel maximal des rejets de mercure par les raffineries. La principale voie de rejet du mercure des produits pétroliers passe par l’émission de l’élément dans l’atmosphère suite à la combustion des carburants raffinés. Les raffineries, cependant, peuvent également rejeter du mercure dans l’eau et le sol ainsi que dans l’atmosphère. En 2002, les raffineries participantes ont traité plus de 100 types de bruts. La moitié de ces bruts étaient canadiens. Les bruts importés provenaient d’Europe (17 %), d’Afrique (6 %), du Moyen-Orient (6 %), des États-Unis (9 %), d’Amérique du Sud (9 %), du Mexique (5 %) et d’Asie (1 %). Pour l’échantillonnage, on a choisi un ensemble de 32 types de brut, qui représentaient 72 % du volume raffiné de tous les bruts raffinés au Canada en 2002. On a prélevé en tout 109 échantillons au hasard, au point d’entrée dans les raffineries. On a dosé le mercure total de chaque échantillon dans deux laboratoires, par spectrométrie d’absorption atomique en vapeur froide (CVAA) et spectrométrie de fluorescence atomique en vapeur froide (CVAFS). On a également mesuré la densité du pétrole et dosé son soufre total. Dans toutes les analyses et mesures, on s’est rigoureusement conformé aux normes de contrôle de qualité.

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Constatations La concentration moyenne de mercure total (Hg) dans le brut était de 2,6 ± 0,5 ng/g, pondérée en fonction du volume raffiné au Canada en 2002. Cela correspond à un total de 227 ± 30 kg de mercure se trouvant dans tout le brut raffiné au Canada en 2002. Cette valeur correspond bien à la valeur moyenne de 2,1 ng/g dans les bruts canadiens signalée par l’Agence de protection de l’environnement des États-Unis (USEPA) et l’American Petroleum Institute (API), dans une étude parallèle de bruts raffinés aux États-Unis, de 2003 à 2007. On a calculé, en tenant compte de l’origine géographique des bruts, leur teneur moyenne en mercure, pondérée en fonction du volume : dans les bruts de l’est du Canada (y compris des Maritimes et de l’Ontario), elle était de 1,1 ± 0,2 ng/g ; dans ceux de l’Ouest et du Nord du Canada (Alberta, Colombie-Britannique, Saskatchewan), elle était de 1,6 ± 0,3 ng/g ; tandis que dans les bruts importés, elle était de 4,5 ± 0,8 ng/g. En ce qui concerne les bruts de synthèse produits à partir des sables bitumineux albertains, leur teneur moyenne en mercure, pondérée en fonction du volume, est estimée à 2,2 ± 0,4 ng/g. On a calculé, selon l’emplacement des raffineries, les teneurs moyennes en mercure, pondérées en fonction du volume : dans l’Ouest du Canada (C.-B., Alb., Sask.), elle était de 1,4 ± 0,3 ng/g ; en Ontario, elle était de 2,1 ± 0,4 ng/g ; tandis que dans l’Est (Qc, N.-B., N.-É., T.-N.), elle était de 4,5 ± 0,8 ng/g. Voici notamment d’autres constatations faites à la faveur de cette étude :

o Les concentrations de mercure observées dans le brut allaient de 0,1 à 50 ng/g. o La concentration moyenne et l’intervalle mesurés sont sensiblement plus bas que ceux

que l’on trouve dans les publications. o On n’a trouvé aucune corrélation étroite entre la teneur en mercure total dans le brut

d’une part et la teneur en soufre total ou la densité du brut d’autre part. o Les pétroles canadiens renferment moins de mercure total que ceux de l’étranger. o Les raffineries de la côte est du Canada manutentionnent des concentrations de mercure

supérieures à celles que l’on observe en Ontario ou dans l’Ouest. Cela est presque entièrement attribuable à l’emploi de plus grandes quantités de bruts étrangers.

Recommandations 1. La teneur moyenne du brut canadien en mercure total, pondérée en fonction du volume

raffiné, est de 2,6 ± 0,5 ng/g (milliardièmes) de brut. À partir de cette concentration moyenne, on estime la quantité totale de mercure dans le brut raffiné au Canada à 227 kg en 2002, 231 en 2003, 240 en 2004 et 233 en 2005. Ces chiffres se fondent sur la quantité totale de brut raffiné au Canada au cours de ces années.

2. Les types de bruts raffinés dont il est question concernaient l’année 2002. En 2002, huit

types de brut, qui ne constituaient que 30 % du volume total raffiné au Canada, renfermaient plus de 80 % de tout le mercure présent dans le brut raffiné au Canada. Ces huit bruts provenaient de l’Ouest du Canada, d’Europe et d’Afrique. Cependant, la liste des bruts raffinés au Canada a légèrement changé d’une année à l’autre. Si les types de bruts raffinés dans les prochaines années s’écartent sensiblement des types évalués dans l’étude, les résultats de cette dernière devront être réévalués.

3. La quantité totale de mercure se trouvant dans la totalité des bruts raffinés au Canada en

2002 (227 ± 30 kg) peut servir d’estimateur de la limite supérieure des émissions potentielles de mercure par le secteur du raffinage. Cela comprend les émissions

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potentielles de mercure par tous les produits raffinés du pétrole et la totalité des rejets potentiels de mercure par les raffineries. L’étude ne s’est intéressée qu’au brut reçu par la raffinerie en tant que matière première. On n’a pas mesuré les émissions réelles des raffineries. En outre, le mercure libéré en amont, lors de l’extraction pétrolière et gazière, du traitement et du transport de ces matières vers les raffineries ne devrait pas être inclus dans cette estimation. Le mercure d’autres intrants des raffineries tels que le gaz naturel peut également modifier cette estimation.

4. On peut également utiliser, comme estimation de la limite supérieure de la quantité de

mercure dans des carburants raffinés, la valeur de la quantité totale de mercure dans les intrants des raffineries de brut. Les émissions atmosphériques annuelles de mercure dans les gaz d’échappement des véhicules automobiles routiers, du fait de la combustion des produits pétroliers raffinés, peuvent s’estimer à 227 ± 30 kg au maximum. D’après cette estimation la plus pessimiste, les émissions potentielles maximales de mercure anthropique dans l’atmosphère par la combustion des carburants raffinés constitueraient 3,6 % du total canadien (6 340 kg de Hg) en 2002. À noter que, dans cette étude, on n’a pas mesuré le devenir réel du mercure présent dans chaque produit pétrolier utilisé comme carburant des véhicules automobiles routiers, y compris dans l’essence et les carburants Diesel.

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Table of Contents Acknowledgements ........................................................................................................................v List of Acronyms ........................................................................................................................vi Executive Summary ........................................................................................................................vii Sommaire-recommandations ..........................................................................................................xi 1 Introduction ........................................................................................................................1 1.1 Background................................................................................................................1 1.2 Project and Research Team........................................................................................2 1.3 US EPA/API/NPRI Study..........................................................................................2 1.4 Scope of Work ...........................................................................................................2 2 Mercury in Crude Oil ..........................................................................................................2 3 Sampling Design...................................................................................................................5 3.1 Refining in Canada ....................................................................................................5 3.2 Selection of Oils for Sample List...............................................................................6 3.2.1 Refined Volume.............................................................................................7 3.2.2 Geographic Origin .........................................................................................7 3.2.3 Type of Input Oil ...........................................................................................7 3.2.4 Location of Refinery ......................................................................................9 3.2.5 Availability ....................................................................................................10 3.2.6 U.S. EPA/API/NPRI Parallel Study...............................................................10 3.2.7 Sample Variability .........................................................................................11 3.3 Sample List Selection ................................................................................................11 3.4 Sampling Schedule.....................................................................................................12 4 Sample Collection Process...................................................................................................12 4.1 Sampling Protocol......................................................................................................12 4.2 Sample Custody and Information Management. .......................................................14 5 Laboratory Measurement ...................................................................................................16 5.1 Ottawa University: Cold Vapour Atomic Absorption ...............................................16 5.1.1 Method Summary...........................................................................................16 5.1.2 Quality Control ..............................................................................................17 5.2 CEBAM Analytical: Cold Vapour Atomic Fluorescence Spectrometry ...................17 5.2.1 Method Summary...........................................................................................17 5.2.2 Quality Control ..............................................................................................18 5.3 Environment Canada: Density and Sulphur Content .................................................18 5.3.1 Method for Determining Density and API Gravity .......................................19 5.3.2 Method for Determining Sulphur Content.....................................................19 5.4 PS Analytical: Confirmation Laboratory Testing ......................................................19 5.4.1 Method Summary...........................................................................................19

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6 Quality Assurance and Quality Management ...................................................................20 6.1 Analysis Requirements ..............................................................................................20 6.2 Quality Assurance for Ottawa University Laboratory ...............................................21 6.2.1 Internal Quality Control.................................................................................21 6.2.2 Challenge Samples.........................................................................................22 6.2.3 Results of Pooled Replicates..........................................................................22 6.2.4 Estimated Uncertainties in the Results from Ottawa University Laboratory .......................................................................25 6.3 Quality Assurance for CEBAM Analytical ...............................................................25 6.3.1 Internal Quality Control.................................................................................25 6.3.2 Challenge Samples.........................................................................................25 6.3.3 Results of Pooled Replicates..........................................................................27 6.3.4 Estimated Uncertainty in CEBAM Analytical Results..................................28 6.4 Inter-laboratory Differences: Ottawa University and CEBAM Analytical ...............28 6.5 Inter-laboratory Differences: PS Analytical ..............................................................30 7 Total Mercury Concentrations ...........................................................................................32 7.1 Sample Data ...............................................................................................................32 7.2 Correlation of Density and Sulphur Content with Mercury Concentration...............35 7.3 Averaged Crude Oil Data...........................................................................................35 7.4 Mean and Median Total Mercury Concentration.......................................................37 8 Data Analysis ........................................................................................................................39 8.1 Volume-weighted Averages of Total Mercury .........................................................39 8.2 Total Mass of Mercury in Crude Oil Refined in Canada...........................................43 8.3 Total Mercury in Crude Oil in the Context of Canadian Emissions..........................44 9 Conclusions and Recommendations ...................................................................................46 9.1 Main Findings ............................................................................................................48 9.2 Recommendations......................................................................................................49 10 References ........................................................................................................................50 Appendices A Crude Oils and Refined Volumes Processed by Reporting Refineries in 2002.....................54 B Sampling Protocol..................................................................................................................58 C Sampling Kits, Packing Materials, and Documentation ........................................................60 D Chain of Custody Forms ........................................................................................................62 List of Tables 1 Refineries and Refinery Districts in Canada in 2002.............................................................6 2 Geographic Origins of Crude Oils and Locations of Reporting Refineries...........................8 3 Sample List ........................................................................................................................13 4 Results of Challenge Samples for Ottawa University Laboratory.........................................24 5 Results of Challenge Samples for CEBAM Analytical .........................................................26 6 Results for Ottawa University, CEBAM Analytical, and PS Analytical...............................30 7 Sample Data ........................................................................................................................32 8 Averaged Crude Oil Data.......................................................................................................37 9 Arithmetic Mean and Median Total Mercury in Oil Concentrations ....................................38

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10 Volume-weighted Averages of Total Mercury Concentrations.............................................37 11 Mass of Mercury in Canadian Crude Oil...............................................................................43 12 Total Mercury Emissions in 2002 Compared to Mercury in Processed Crude Oils..............44 13 Mercury in Crude Oil Processed in Canada from 2002 to 2005............................................46 List of Figures 1 Values from Literature for Concentrations of Mercury in Crude Oil....................................4 2 Canadian Refineries Reporting to NPRI in 2002...................................................................5 3 Volumes of Crude Oils Refined in Canada by Geographic Origin .......................................8 4 Geographic Origin of Crude Oils Refined in Canada in 2002...............................................9 5 Volume of Crude Oil Processed in Canadian Refinery Districts in 2002..............................10 6 Sampling Schedule.................................................................................................................14 7 Sample Management and Documentation .............................................................................15 8 Absolute Standard Deviation Plotted against Measured Mercury Concentration

for the Ottawa University Laboratory (top) and Absolute Difference Plotted against Mercury Concentration for CEBAM Analytical (bottom).....................................................23

9 Measured Concentration of Total Mercury Plotted against Nominal Values for Ottawa University Laboratory Challenge Samples..........................................................24 10 Measured Concentration of Total Mercury Plotted against Nominal Values for CEBAM Analytical Challenge Samples ..........................................................................27 11 Measured Total Mercury Concentration for 109 Samples of Crude Oil, Ottawa University Plotted against CEBAM Analytical. ....................................................................29 12 Results from Ottawa University (top) and CEBAM Analytical (bottom) Plotted against

PS Analytical Results (bottom)..............................................................................................31 13 Total Mercury Concentration [THg] and Density of Oil .......................................................36 14 Total Mercury Concentration [THg] and Sulphur Content of Oil .........................................36 15 Distribution of Total Mercury Concentration by Type of Oil ...............................................38 16 Comparison of Volume-Weighted Average Total Mercury Concentrations [THg] in Crude Oil ........................................................................................................................40 17 Measured Total Mercury Concentration [THg] Compared to Historical Ranges of Mercury.................................................................................................................41 18 Total Canadian Mercury Emissions in 2002 Compared to Mercury in Refined Crude Oils ............................................................................................................45

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1 Introduction 1.1 Background

The concentration of mercury (Hg) in crude oils and other naturally occurring hydrocarbons has come under increasing scrutiny in recent years, due not only to environmental concerns, but also to industrial and regulatory needs. In collaboration with the Canadian Petroleum Products Institute (CPPI) and most Canadian refineries, including CPPI members and independents, Environment Canada initiated the present study to determine the total amount of mercury that could be accounted for in the processing of crude oil. This effort was motivated by the facts that mercury is an inhibitor to many refining processes (Wilhelm and Bloom, 2000) and is difficult to remove from the refinery outputs (Wilhelm, 1999, Spiric, 2001). It was also influenced by the requirements of the Canadian Environmental Protection Act (CEPA, 1999) that both government and industry monitor mercury emissions. Of particular recent interest is the potential for mercury emissions to the air as a result of petroleum combustion. Sunderland and Chmura (2000) estimated mercury emissions from petroleum sources in Maritime Canada. Environment Canada commissioned a preliminary study of mercury emissions from the transportation sector, focusing on diesel fuels (Levelton Engineering, 2000). The United States Environmental Protection Agency (U.S. EPA) has made several estimates of mercury emissions from crude oil combustion, starting with the report on mercury pollution to Congress (U.S. EPA, 1997) and with later refinements reported by Wilhelm, 2001b. Wilhelm (2001a) is the most comprehensive estimate to date, based on data from 1970 to 2000 and more than 20 separate studies. Estimates of the average total mercury concentrations in crude oil have ranged widely from 10 ng/g of oil (Wilhelm, 2001a) to 3,500 ng/g of oil (U.S. EPA, 1997). Wilhelm based his estimate on about 20 studies, but stated that a proper statistical analysis was not possible due to the limitations of the report data and the wide variety of experimental procedures used. In its report to Congress, the U.S. EPA based its estimate on mass-balances calculated from oil-burner smokestack emissions (U.S. EPA, 1997). Mercury concentrations in crude oil have been reported from as low as 0.1 ng/g of oil to as high as 50,000 ng/g of oil (Wilhelm and Bloom, 2000). With this enormous range, it has been difficult to estimate the contributions of the petroleum sector to the total budget of mercury emissions. This has had significant implications for both industry and government. An estimate of 10 ng/g of oil (Wilhelm, 2001a) implies that there is approximately 900 kg of mercury in the crude oil processed in Canada each year. This is based on 2002 production volumes. Using the U.S. EPA (1997) estimate of 3,600 ng of mercury/g of oil implies that over 300,000 kg of mercury is processed by petroleum refineries each year in Canada. In 2000, atmospheric mercury emissions from all major sources ranged from 100 kg to 2,000 kg per sector, with the total anthropogenic atmospheric emissions of mercury in Canada being 8,000 kg (NPRI, 2000). According to the Pollution Data Division of Environment Canada, the most recent measurement of atmospheric emissions of mercury from all anthropogenic sources in Canada is approximately 6,340 kg in 2002. A better estimate is required because of the wide range of historical data and the CEPA 1999 requirements for reporting releases from transporting of crude oils and their refined products. Ideally, estimates should be based on the actual crude oil used and weighted according to the amount of each oil used by industry.

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1.2 Project and Research Team Many industrial, academic, and government organizations contributed to the study

described in this report. Ten Canadian refineries participated in this study and sampling was done by personnel at these refineries. These refineries, along with members of the review committee and their organizations which contributed financial and material support to the project are listed in the Acknowledgments section of this report.

1.3 U.S. EPA/API/NPRA Study

In 2003, the U.S. EPA, the American Petroleum Institute (API), and the National Petrochemical and Refiners Association (NPRA) began a comprehensive survey of mercury in crude oils refined in the United States (Wilhelm and Kirchgessner, 2003). The joint U.S. EPA/API/NPRI project consisted of three phases: a comprehensive examination of methods for measuring mercury in crude oil, including round-robin testing of several laboratories; an investigation of sampling and measurement procedures, including sample storage, handling and manipulation; and a measurement phase of more than 300 oil samples. The survey of mercury in crude oils refined in Canada is designed to be comparable to that conducted by the U.S. EPA/API/NPRA. This will allow a composite estimate of mercury concentrations between the two countries to be calculated, while still providing a stand-alone, definitive estimate for Canadian stakeholders. 1.4 Scope of Work

The study presented in this report was designed to measure the concentration of mercury in crude oil as it enters a refinery before processing. A mean value of the mercury concentration is to be determined, weighted by the refinery processing volumes of the types of crude oil. From this mean value, a total amount of mercury in all crude oil processed in Canada is to be determined and used as the estimate of the potential upper limit of the total mercury in all refined products. This estimate can then be used as the upper limit of mercury concentrations in petroleum products or to quantify the potential for maximum mercury concentrations in the exhaust emissions of motor vehicles. 2 Mercury in Crude Oil

Mercury concentrations in crude oil have been reported from as low as sub-parts-per billion (Kelly, 2003) to as high as 50,000 ng/g of oil (Wilhelm and Bloom, 2000). Historically, the U.S. EPA based its estimates on data compiled by Brooks (1989). Brooks relied primarily on concentrations measured by neutron activation reported by Shah et al. (1970) and Filby et al. (1975). Of these oils, which were mostly American, several Californian oils were found to have very high mercury contents. These estimates resulted in the U.S. EPA estimating very high values of mercury in crude oil for many years. In 1977, the U.S. EPA estimated mercury emissions in crude oil to be 3.5 ppmw (3,500 ppbw) (U.S. EPA, 1977). Other researchers, however, reported much lower ranges of total mercury concentration than the U.S. EPA estimate. Hitchon and Filby (1983) found that in 86 Alberta crude oils and two tar sands bitumens, approximately half the samples had values below their detection limit of 2 ppbw. Their mean concentration was 50 ppbw with a maximum of 399 ppbw. Using microwave-digested inductively-coupled plasma-atomic emission spectrometry (ICP-AES), Cao found that all 24 crude oils tested had an average total mercury concentration below his detection limit of 15 ppbw (Cao, 1992). In 1995, using neutron activation analysis, Musa et al. (1995) reported an average total mercury concentration of 3.1 ppbw in 6 Libyan oils.

3

More recent reports have also suggested lower values for mercury concentrations. Tao et al. (1998) reported an average total mercury concentration of 40 ppbw for 7 condensate oils of Asian origin using gas chromatography/inductively-coupled plasma-mass spectrometry (GC/ICP-MS). Using a cold-vapour atomic fluorescence spectrometry technique, Shafawi et al. (1999) reported a similar range of values for Asian condensates. Using cold vapour atomic absorption (CVAA), Magaw and co-workers reported an average of 65 ppbw for 26 oils from refineries on the west coast of the U.S., ranging from 10 to 1,560 ppbw (Magaw et al., 1999). Liang and co-workers reported an average value of 7.2 ppbw in 11 oils using cold-vapour atomic fluorescence (Liang et al., 2000). Levelton Engineering reported on 8 crude oils refined in Canada, accounting for approximately half of the refined volume at that time (Levelton Engineering, 2000). Using an acid digestion/CVAA technique, they found that all oils had total mercury concentrations less than 9 ppbw and an average value of 1.5 ppbw. Additional data for 17 oils provided by private communication from an independent refiner confirmed their main findings (Levelton Engineering, 2000). In a large survey of 76 types of oil, Bloom found that total mercury concentrations covered a wide range of values, from less than his detection limit of 0.1 to more than 1,500 ppbw (Bloom, 2000). Many of his samples with the highest concentration came from a low-volume oil field in South American or were Asian condensates. In 2000, Morris reported that the mean amount of mercury in crude oil imported to refineries on the U.S. east coast was less than 5 ppb (Morris, 2000). The ranges, and recommended or mean values reported by these studies are summarized in Figure 1. While more than 20 studies have been conducted over the last 30 years, the limitations and unique nature of each study severely restrict the use of the combined dataset (Wilhelm and Bloom, 2000; Wilhelm, 2001b). The wide variety of measurement techniques, ranging from neutron activation to many types of digestion systems with detectors as diverse as mass spectrometers, ICP/MS, atomic absorption, and AFS, have poorly known correlations and are very difficult to compare. More important, however, is the lack of information on sampling conditions, handling of samples, and the age of the samples at the time of analysis. Both the condition of the oil during sampling and the subsequent handling of the samples must be controlled to quantify mercury in crude oil. Mercury in crude oil can take many chemical forms, including forms that dissolve in oil and mercury compounds that precipitate from oil-forming suspensions. While speciation of the mercury compounds has been attempted (Corns, 2004; Tao, 1998), in this work only the total mercury concentration in crude oil is measured. Because of these various forms of mercury in crude oil, homogeneity of the samples is a significant concern. Stratification of the various mercury compounds and suspended particles in a pipeline or tank may significantly affect sampling.

4

Shah et al. 1970

Filby and Shah.1975

Hitchon and Filby 1983

Cao 1992

Musa et al. 1995

Olsen et al. 1997

Tao et al. 1998

Tao et al. 1998

Magaw

et al. 1999

Shafawi et al. 1999

Bloom

2000

Levelton 2000

Liang et al. 2000

Morris 2000

Schmit (Levelton 2000)

Schmit (Levelton 2000)

Schmit (Levelton 2000)

Wilhelm

2001

[TH

g] (p

pb)

0.1

1

10

100

1000

10000

100000

Figure 1 Values from Literature for Concentrations of Mercury in Crude Oil

(range shown by vertical; average, or recommended value indicated by circle) The handling of samples can also significantly affect the measured results. A recent study found that the number of times a sample bottle had been opened could significantly affect the measured value (U.S. EPA, 2003). The effects of light, temperature, and sample-holding time on mercury concentrations in oil are largely unknown. These factors of crude oil variability and sample management combined with the lack of knowledge of the oils’ origins and their refinery usage volumes make a meaningful statistical analysis of the existing data sets unfeasible. The enormous range of estimates in the literature, which vary by a factor of 100 or more as shown in Figure 1, have made it difficult to estimate the contributions of the petroleum and refining sectors to the total budget of anthropogenic mercury emissions. Despite the large number of studies reporting total mercury concentrations in crude oil, because of the complications of sampling, sample handling and variability in measurement technique, several reviews have stated that a good estimate of total mercury concentrations in crude oil is only possible if a comprehensive study is done of a wide variety of crude oil types using well defined sampling, handling, and measurement techniques (Wilhelm 2001; Wilhelm and Bloom,

5

2000). Fuelled by the requirements of both regulatory agencies and private industrial stakeholders, this was the impetus for conducting the present study. 3 Sampling Design 3.1 Refining in Canada

2002 was chosen as the baseline year for all refinery volume usage in this study, as this was the most recent year for which complete usage data was available. In 2002, data for 19 refineries in Canada was reported to the National Pollutant Release Inventory of Environment Canada. These 19 refineries processed a total volume of 104,719,128 m3 of crude oils, upgraded bitumens, “synthetic crudes”, and natural gas condensates. Refineries in western Canada, Ontario, and the Quebec and Atlantic regions processed about 28%, 28%, and 44% of the Canadian total respectively. This is shown in Figure 2. The geographical distribution of active refineries in Canada in 2002 is shown in Table 1.

Figure 2 Canadian Refineries Reporting to NPRI in 2002 Participating refineries reported their crude oil usage for the present study. Note that the production data available covers only 32% of crude oils processed in Quebec and Atlantic regions. These refineries processed 91,884,390 m3 of 103 types of crude oil (crude oil, bitumen/oil sands, and natural gas condensates) in 2002, which was 88% of the Canadian total for that year. In Appendix A, the total refined volume is shown for each type of crude oil used by the reporting refineries, broken down by volume refined in each region and the percentage of the Canadian total volume for 2002. These oils came from both domestic and foreign sources. In 2002, no single crude oil was processed in a volume of more than 10% of the Canadian total. There were 26 crude oils with a volume percentage over 1%. For the purposes of this study, all

6

oils refined in volumes greater than 1% of the national total in 2002 are classified as major crude oils. Those less than 1% are considered minor crude oils. Table 1 Refineries and Refinery Districts in Canada in 2002*

Location Province Company Refinery Name City NPRI ID 1 British Columbia Chevron Canada

Ltd. Chevron-Burnaby Refinery

Burnaby 2776

2 British Columbia Husky Energy Inc.

Husky-Prince George Prince George 405

3 British Columbia Petro-Canada PC-Port Moody Port Moody 3905 4 Alberta Husky Energy

Inc. Husky-Lloydminster Refinery

Lloydminster 403

5 Alberta Petro-Canada PC-Edmonton Refinery

Edmonton 3903

6 Alberta Shell Canada Products

Shell-Scotford Refinery

Fort Saskatchewan

2960

Western Canada

7 Saskatchewan Consumers' Co-op Refinery Ltd.

Consumers' Co-op-Regina Refinery

Regina 4048

8 Ontario Imperial Oil Ltd. Imperial-Sarnia Refinery

Sarnia 3704

9 Ontario Imperial Oil Ltd. Imperial-Nanticoke Refinery

Nanticoke 3701

10 Ontario Nova Chemicals Canada Ltd.

Nova Chemicals-Corunna Site

Corunna 1776

11 Ontario Petro-Canada PC-Oakville Refinery Oakville 3901 12 Ontario Shell Canada

Products Shell-Sarnia Refinery Sarnia 3962

Ontario

13 Ontario Suncor Energy Products Inc.

Suncor-Sarnia Refinery

Sarnia 3071

14 Quebec Petro-Canada PC-Raffinerie de Montréal

Montreal 3897

15 Quebec Shell Canada Products

Shell-Raffinerie de Montréal

Montreal 3127

16 Quebec Ultramar Ltee Ultramar-Raffinerie Jean-Gaulin

St-Romuald 3928

17 Nova Scotia Imperial Oil Ltd. Imperial-Dartmouth Refinery

Dartmouth 3698

18 Newfoundland and Labrador

North Atlantic Refining Ltd.

North Atlantic-North Atlantic Refinery

Come By Chance

4316

Quebec and Atlantic

19 New Brunswick Irving Oil Ltd. Irving Oil-Saint John Refinery

Saint John 4101

* Only refineries reporting to NPRI are included in this table. 3.2 Selection of Oils for Sample List

Many factors were considered when choosing oils for use in this survey. These included the annual processed volumes of a type of oil, its geographical origin, the types of crude oil (crude oils, condensates, and oil sands products), and the location of the refineries. Practical considerations also included whether oils used in 2002 were available for sampling in 2004 and 2005, which crude oils were available for sampling in these years, compatibility with the U.S. EPA/API/NPRA project, and sample variability.

7

The types of crude oil were chosen to be reasonably representative of crude oils used by Canadian refineries as a whole. The origin and type of the oil as well as the location of the refinery were well represented in the sample list. The factors considered in choosing this sample list are discussed individually in this section. 3.2.1 Refined Volume

The 103 types of crude oil processed by the participating refineries in Canada are listed in Appendix A in descending order of refined volume. These volumes range from 8.4% of the total volume of crude oils refined domestically in 2002 to just over zero. The 26 major crude oils (volume > 1%) are listed first, followed by the 77 minor types of crude oil (volume < 1%). Because of their volume of usage, the 26 major crude oils have the highest potential for mercury emissions of all 103 types of oil. The 77 minor crude oils are potentially less significant to the overall mercury budget. As many of the major crude oils as possible were included in the sample list because of their potential significance. The remainder of the analytical effort focused on minor types of oil. As shown in Appendix A, 24 of the 26 major types of crude oil (those with production volumes > 1%) were analyzed in this study. Two types were no longer being used in Canada when the sampling took place. 3.2.2 Geographic Origin

Approximately half of the crude oil processed in Canada in 2002 was produced from Canadian wells. For the purpose of this study, the Canadian domestic crude oils were split into two groups: Canada West and Canada East. Canada West includes all types of oil from British Columbia, Alberta, Saskatchewan, and Manitoba. The types of oil from Canada East originate from Ontario, Quebec, Nova Scotia, Newfoundland and Labrador, New Brunswick, and Prince Edward Island.

The remaining half of crude oils processed in 2002 came from foreign sources, including

Europe, the U.S., South America, the Middle East, Africa, Mexico, and Asia. All oils from non-Canadian sources were designated as Foreign. The number of oils from each source is shown in Figure 3. The volumes from each source of origin are summarized in Table 2. A number of “minor” crude oils, those with total processed volumes of less than 1%, were chosen at random from each group to ensure that crude oils from each major geographical region were sampled. The regions from which Canada imported significant amounts of crude oil processed in 2002 are shown in Figure 4.

3.2.3 Type of Input Oil

Several commercially important refinery input streams are not typical crude oils. Natural gas condensates and “synthetic” crude oils are significant components of the Canadian crude oil market. Several crude oils of each type were included in the sampling program. The highest processed volumes of each type were included to make the sampling program representative. For example, as shown in Appendix A, samples CCAF45 and CCCN36 are natural gas condensates. Samples CCCN66, and CCCN67 are “synthetic” crude oils created by upgrading bitumen from the Alberta oil sands. CCCN 43 is a bitumen produced from oil sands that has not been upgraded upstream of the refinery

8

Figure 3 Volumes of Crude Oils Refined in Canada by Geographic Origin (2002,

reporting refineries only) Table 2 Geographic Origins of Crude Oils and Locations of Reporting Refineries

Crude Oil Geographic

Origins

Volume Processed in 2002 (m3/y)

Fraction of Canadian Total (%) Location of Refinery

Canada West 45,545,029 43.5 Western Canada and Ontario Canada East 6,049,216 5.8 Ontario, and Quebec and Atlantic Africa 8,220,795 7.9 Ontario, and Quebec and Atlantic Asia 52,365 0.05 Ontario Europe 20,602,634 19.7 Ontario, and Quebec and Atlantic Mexico 1,271,672 1.2 Quebec and Atlantic Middle East 5,471,951 5.2 Quebec and Atlantic South America 2,147,459 2.1 Quebec and Atlantic U.S. 2,523,269 2.4 Ontario, Quebec and Atlantic Study Total 91,884,390 88

Canada West

Canada East

AsiaMexico

South America

U.S.A.

Middle East

Africa

Europe

Foreign

9

Figure 4 Geographic Origin of Crude Oils Refined in Canada in 2002

3.2.4 Location of Refinery

To better understand the effects of refinery usage patterns, the geographic region of the processing refineries was also included in the study design. The processing refineries were categorized into three geographical districts: • Western Canada (British Columbia, Alberta, and Saskatchewan); • Ontario; and • Quebec and the Atlantic Provinces (Quebec, Newfoundland and Labrador, Nova Scotia, and

New Brunswick). Note that there is not a refinery in every province in Canada (See Table 1). This grouping identifies processing patterns in the refinery district while still protecting commercial confidentiality. The volume distribution according to the geographic location of the refineries is shown in Table 2, Figure 4, and Figure 5. Refer to Appendix A for detailed information on the types of oil used in each location. Each region was approximately equally well represented on the sampling list.

10

Figure 5 Volume of Crude Oil Processed in Canadian Refinery Districts in 2002 3.2.5 Availability

While some Canadian refineries handle crude oils and other inputs from the same set of suppliers or fields over a long period of time, others are active participants in the world spot markets for oil, buying crude oils based on best price and other commercial factors. This is particularly true for refineries in the Quebec and Atlantic region. The major effect of this activity for the present study is that some refinery inputs processed in 2002 were no longer available for sampling in 2004 and 2005. All major and minor types of crude oils reported for 2002 are listed in Appendix A. Of the 26 major types of crude oils, CCME57 and CCAF46 were no longer used in Canada during the sampling period. Several of the minor oil types were also unavailable. It was decided not to seek replacements or substitutes for the unavailable types. In addition, several oils were only available to be sampled once. These oils are noted as such in Table 3. 3.2.6 U.S. EPA/API/NPRA Parallel Study

As discussed in Section 1.3, this study was developed in parallel with and to compliment an ongoing study by the U.S. EPA/API/NPRA of mercury in crude oils refined in the United States (Wilhelm and Kirchgessner, 2003). Many types of crude oil are processed in both countries. About 45 of the 103 types of Canadian crude oil are also processed in the U.S. To make the best use of available resources, the sample list presented here and the U.S. sample lists were designed to overlap as little as possible.

For the 26 major types of crude oil processed in Canada in 2002, those with refined volumes greater than 1%, 21 types were included in the U.S. study.

There were 77 types of oil with refined volumes of less than 1% in Canada in 2002. Of these “minor” crude types, 22 were included in the U.S. study. There were 55 minor types that were only refined in Canada in that year.

Quebec & Atlantic32% by volume

Ontario28% by volume

Western Canada28% by volume

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3.2.7 Sample Variability Preliminary work by the U.S. EPA has shown that mercury concentrations in crude oils

can vary significantly over time (Wilhelm and Kirchgessner, 2003). The mercury concentration of one batch of oil may be significantly different from that of the nominally identical crude oil available at a later date. In order to capture this variability in the study, multiple samples (at least three) of each type of oil were taken from different batches of oil. For the purposes of this study, a batch is considered to be a discrete tanker shipment or individual pipeline transfer, as appropriate for each refinery. 3.3 Sample List Selection

It was budgeted for a maximum of 35 types of crude oil to be sampled. The oils were divided into 26 major types of oil with refined volumes of more than 1%, of which only 24 were available, and 77 minor types of oil with refined volumes of less than 1% in 2002. For all sample selection strategies, the following two constraints were present: to include all the 24 major crude oil types available and the remainder of samples were to be chosen from the 55 minor crude oils not included in the US EPA/API/NPRA study to maximize the coverage of oil types. Based on the factors discussed in Section 3.2, the following sampling strategies were considered for the study sample list: 1. Choose 11 types of minor crude oil with the highest refined volume.

Pro: This provides the highest volume coverage. Con: This is not necessarily representative of the types of oil with smaller refined volume.

2. Choose 11 types of minor crude oil at random.

Pro: This provides average volume coverage. Con: This covers the whole sample population, but may not be representative of each geographical region.

3. Randomly choose 6 types of minor crude oil with refined volumes of more than 0.1% and

5 types of minor crude with refined volumes of less than 0.1%. Pro: Average volume coverage is higher than that provided by strategy #2. Con: This covers the whole sample population, but may not be representative of each geographical region.

4. Choose the 6 types of minor crude oil with refined volumes of more than 0.1% and the

5 types of minor crude oil with refined volumes of less than 0.1% volume. Pro: Average volume coverage is higher than that provided by strategy #2. Con: As in strategy #1, this covers the whole sample population, but is not necessarily representative of the types of oil used in smaller volume.

5. Divide minor types of crude oil with refined volumes of more than 0.1% volume into

9 regions based on geographic origin (see section 3.2.2) and randomly select one or more from each region. Pro: This provides the highest volume coverage and is representative of all oils. Con: This is similar to strategy #1, but is more representative of minor types of oil.

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After some consideration, strategy #5 was adopted for this survey. One or a few crude oils were randomly selected from each region to ensure that all oils and regions were well represented. A total of 11 crude oils were randomly selected to make up a list of 35 crude oils. With help from the participating refineries, all the major types of crude oil from Canada West and Canada East were included as well as natural gas condensates, oil sands products, and synthetic crude oils. After eliminating a few unavailable types, a final sample list of 32 types of crude oil was developed. This list is provided in Table 3. These 32 types of oil make up 71% of the total volume of crude oils used by Canadian refineries in 2002. The list includes representative samples from seven of the nine geographical regions from which crude oil originated for Canadian refineries in 2002. The two regions not included are Mexico due to the discontinuation of the crude oils and Asia due to a negligible process volume in 2002. 3.4 Sampling Schedule

Crude oils were sampled by personnel at the refineries for 18 months from May 2004 to November 2005. The number of samples collected each month is shown in Figure 6. At least three samples of each crude oil were collected at different times of the year to minimize seasonal variations. 4 Sample Collection Process 4.1 Sampling Protocol

Sampling techniques can significantly affect the mercury concentrations measured in crude oil. If samples are handled in a haphazard manner, the mercury content of the crude oil can be much lower than its true value. To minimize losses of mercury during sampling, a standard sampling protocol and sampling kit were developed for this work. These are provided in Appendix B and C. A standardized sampling procedure is critical to the success of any survey project. One of the major concerns that has arisen out of the comprehensive reviews of previous surveys of total mercury in crude oil (Wilhelm and Bloom, 2000; Wilhelm, 2001) has been inconsistent and/or unreported sampling and sample-handling procedures. The sampling procedure followed in the present study was designed to be compatible with that of the ongoing U.S. EPA/API/NPRA parallel study. A major complication for sampling is that mercury is present in naturally occurring hydrocarbons in many chemical forms (Corns, 2004; Bloom, 2000). Elemental mercury and organo-mercury compounds, such as methyl- and dimethyl-mercury, are very volatile and can easily be lost to the atmosphere. Some inorganic mercury species, such as mercury sulphide and chlorides, can be formed by oxidative exposure. Inorganic mercury compounds are generally poorly soluble in oils and can settle out of oil. Many mercury species will concentrate on the walls of bottles or on metal surfaces. Glass vials were used for sampling. All oils were sampled into precleaned, certified, 40-mL amber PTFE-septa vials (I-Chem, U.S.) meeting U.S. EPA specifications for contaminant-free containers (U.S. EPA, 1992).

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Table 3 Sample List

Code Origin of Crude Oil Refinery Location(s) Volume Processed

in 2002 (m3/year)

Fraction of 2002 Total

Refined Volume (%)

Notes

CCCN67 Canada West Ontario & Western Canada 8,760,725 8.37% Synthetic crude CCEP30 Foreign (Europe) Ontario & QC/Atlantic 6,095,688 5.82% CCCN65 Canada West Western Canada 5,819,171 5.56% CCAF43 Foreign (Africa) Ontario & QC/Atlantic 5,645,287 5.39% CCEP33 Foreign (Europe) QC/Atlantic 4,297,500 4.10% CCCN32 Canada East Ontario & QC/Atlantic 3,738,838 3.57% CCCN64 Canada West Western Canada 3,346,093 3.20% CCCN51 Canada West Ontario 3,331,872 3.18% CCCN43 Canada West Ontario & Western Canada 2,806,402 2.68% Oil Sands Bitumen CCCN38 Canada West Western Canada 2,586,216 2.47% CCCN62 Canada West Western Canada 2,494,699 2.38% CCEP29 Foreign (Europe) QC/Atlantic 2,194,478 2.10% CCEP32 Foreign (Europe) Ontario & QC/Atlantic 2,171,157 2.07% CCCN42 Canada West Ontario 2,068,005 1.97% CCCN66 Canada West Western Canada 2,050,758 1.96% Synthetic crude CCEP22 Foreign (Europe) Ontario & QC/Atlantic 1,894,392 1.81% One sample CCCN53 Canada West Ontario 1,862,063 1.78% CCUS105 Foreign (US) Ontario & QC/Atlantic 1,618,401 1.55% One sample CCME56 Foreign (Middle East) QC/Atlantic 1,416,160 1.35% CCCN60 Canada West Ontario 1,371,238 1.31% CCEP24 Foreign (Europe) QC/Atlantic 1,209,664 1.16% CCCN71 Canada West Ontario 1,170,900 1.12% CCCN37 Canada East Ontario & QC/Atlantic 1,142,046 1.09% CCCN50 Canada West Western Canada 1,083,517 1.03% One sample CCCN30 Canada West Western Canada 798,232 0.76% CCCN49 Canada West Ontario 611,571 0.58% CCSA38 Foreign (S. America) QC/Atlantic 538,738 0.51% One sample CCCN36 Canada East Ontario 536,416 0.51% Gas Condensate CCAF45 Foreign (Africa) Ontario 511,017 0.49% Gas Condensate CCCN39 Canada West Ontario 458,998 0.44% CCCN40 Canada West Western Canada 313,560 0.30% One sample CCCN33 Canada East Ontario 175,542 0.17% Study Total 75,382,939 71.00%

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Figure 6 Sampling Schedule Crude oil samples were taken as close as practical to the point of entry into a refinery. When sampling from a pipeline or a tanker, samples were taken from a fresh batch or shipment. The oil was thoroughly mixed and sampled directly into the supplied vial either by autosampler or by dip sampling, to minimize the use of intermediate vessels. Contact with metal surfaces was avoided and contact time with air was minimized. The headspace in the vials was kept as small as possible and the vials were capped as soon as possible. Vials were stored at room temperature away from light sources. Samples were stored for their entire lifetimes in the amber headspace vials. At no time were any of the vials opened before measurement. Only samples with seals intact were measured and those that showed signs of leakage were discarded. The lifetime of samples from sampling to laboratory analysis was kept as short as possible, with an average lifetime of 45 to 50 days. The document that accompanied each sampling kit and the detailed sampling protocol is included in Appendix B. Typical sample kits and packaging are shown in Appendix C. 4.2 Sample Custody and Information Management

Great care was taken to ensure the integrity of the samples. All samples were documented with full chains of custody at all points in their life cycle. Initial chains of custody were generated by the refinery personnel who collected the samples. The samples were sealed with a custody sticker (see Appendix C) and sent to an intermediary laboratory at Ottawa University. To protect the commercial information about the refinery, the intermediary stripped off any identifying information except the sampling data and preassigned crude oil code (shown in Table 3), repackaged the samples, and initiated a new “ID-blind” chain of custody form. The form from the refineries was archived by the sample manager at Ottawa University and one sample was retained for analysis. See Section 5.1 for a description of the method.

0

5

10

15

20

25

May

-04

Jun-

04

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4

Aug

-04

Sep-

04

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-04

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-04

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05

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5

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-05

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05

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-05

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-05

Sampling Date

Num

ber

of S

ampl

es

15

The “ID-blind” samples were then transferred to Environment Canada with the hand-off documented on the new chain of custody form started by the intermediary at Ottawa University. Environment Canada retained three vials (if all were unbroken) for archival purposes and for measuring density and sulphur content as described in Section 5.3. The final two vials were shipped to CEBAM Analytical for analysis under seal of custody as outlined in Section 5.2. A flowchart of sample management is shown in Figure 7.

Refiner

OttawaUniversity

EnvironmentCanada

CEBAMAnalytical

6 VialsOriginal Chain of Custody

5 VialsId-Blinded Chain of Custody

2 VialsId-Blinded Chain of Custody

[THg](CVAA)

1 vial

Density &Sulphur

Archive

[THg](CVAFS)

Archive

1 vial

2 vials

1 vial

1 vial

Figure 7 Sample Management and Documentation Environment Canada also provided coded samples to both Ottawa University and CEBAM Analytical Laboratories. These consisted of blind challenge samples for both labs. An “ID-Blind” chain of custody record was started by Environment Canada and sent out to accompany the challenge samples. Examples of the refineries’ Chain of Custody Record and the ID-Blind form are provided in Appendix D.

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5. Laboratory Measurement Samples were sent to two laboratories, one at Ottawa University in Ottawa, Ontario

Canada, to be measured using cold-vapour atomic absorption and the other to CEBAM Analytical Laboratories of Seattle, Washington in the U.S. This laboratory was also used for primary analysis in the parallel U.S. EPA/API/NPRA study. 5.1 Ottawa University: Cold Vapour Atomic Absorption

The method for analyzing total mercury concentrations in crude oil and other petroleum hydrocarbons was developed by Ottawa University for the present study. It is based on the SP-3D, a high-temperature combustion analyzer from Nippon Instrument Corporation (NIC). The analytical method used is a modification of the standard method provided in the NIC operating manual. The method used here is similar to U.S. EPA Method 7473 (U.S. EPA, 1998), but was adapted for a hydrocarbon matrix. 5.1.1 Method Summary

Samples were ultrasonicated in the original sample vials for 30 minutes to ensure homogeneity. An aliquot of approximately 100 μL of oil was weighed out into a sample boat. Samples were combusted in the sample boat along with appropriate additives. Additive M consists of equal amounts of calcium hydroxide and sodium carbonate and was used to control halides that might interfere with the instrument and the reading. Additive B is made of aluminum oxide which absorbs the combustion gas and slowly releases it for decomposition. To ensure that the additives were mercury-free, crucibles of each additive were retained in a muffle furnace maintained at a constant 700°C. During the course of the analysis, the additives were interchanged between each sample run and allowed to cool down for 15 minutes before use. Samples were analyzed sequentially with the two additives in the order B-S-B-M with B standing for additive B, S for sample, and M for additive M. Combustion and sample decomposition took place using the manufacturer’s recommended mode for heavy naphtha, crude oil, lubricating oil, and other viscous oils. In this mode, the sample was first combusted at 350°C for 10 minutes in the combustion tube followed by decomposition of the produced gas for 6 minutes at 700°C in the decomposition furnace. Sample decomposition took place in a high-temperature combustion tube. A catalyst was used to accelerate the process. The gaseous decomposition product was scrubbed in a pH-7 phosphate buffer to remove acid gases and moisture. The sample was then cooled and dehumidified. The mercury gas sample was collected into a gold trap. Other gaseous products exited through the exhaust filter and carbon trap. Mercury on this first gold trap was desorbed and collected on a second gold trap to provide a cleaner sample with less interference. The second gold trap was then heated and the released mercury transported in a carrier gas to the detector using cold vapour atomic absorption (CVAA).

17

5.1.2 Quality Control Calibration standards were prepared from 1000 ppm of mercurous chloride (Hg2Cl2)

stock solution obtained from the instrument manufacturer (Nippon Instrument Corporation, Japan). A working standard solution of 50 ppb was serially diluted from the stock solution, with 0.001% L-cysteine added to minimize loss to the container walls or volatilization of the mercury. A calibration curve was obtained by dispensing 100, 200, 300, and 400 μL of working standard onto clean, ceramic boats used specifically for standards and analyzing to check recoveries. The instrument was calibrated using a machine blank reading and concentrations of 4 standard mercury solutions in the range of the samples to be measured were run at the start of each day. It was required that the coefficient of variation (r2) exceed 0.999 to obtain an acceptable calibration curve. Blanks were analyzed both before and after each sample. Blank values were consistently below 0.01 ng of mercury. A certified standard reference material (Conostan Division, ConocoPhillips Specialty Products Inc., U.S.) was run at least once a day. Acceptable recoveries were at least 95% of the standard value. Check standards and blanks were run every 5 samples. Samples spiked with a standard mercury material were also run on a regular basis to determine matrix recoveries. Samples were analyzed in triplicate and reported as means and standard deviations. 5.2 CEBAM Analytical: Cold Vapour Atomic Fluorescence Spectrometry

This method was performed at CEBAM Analytical Inc. of Seattle, Washington. It is based on combustion/trap/cold vapour-atomic fluorescence spectroscopy (CVAFS) and has been evolving since the early 1990s. This method was most recently published in Liang et al., (2003). It consists of a unique, purpose-built mercury cold vapour trap, followed by analysis on a commercial atomic fluorescence spectrometer. 5.2.1 Method Summary

Samples were homogenized by immersion in an ultrasonic bath for 1 hour. The temperature of the bath was controlled so as not to exceed 30°C, with cold water added as needed. For oil samples with a lower viscosity, aliquots were pipetted directly into the combustion tube. For more viscous samples, 0.5 to 0.8 mL of the oil was removed from the sample vial through the septum by syringe (without opening the vial), diluted to approximately 3 volumes with dichloromethane, and capped tightly. The diluted samples were then homogenized again and treated exactly the same as the less viscous samples. After homogenization, an aliquot of oil (or viscous oil solution) was removed through the vial septum with a pre-conditioned metal needle. The oil was then immediately introduced into the sample introduction segment of the combustion column. The carrier gas, ultra-high purity air at 320 L/min, was then connected to the sample port of the combustion column. The combustion/trap system is composed of a combustion column, a scrub bottle, and a soda lime trap (Liang et al., 1996). The combustion column is a quartz tube, 30 cm long, 6 mm ID, and 8 mm OD, packed with glass wool. The tube is divided into two independent heating zones,

18

one for sample introduction and the other for combustion. The sample introduction segment is about 4 cm long and was heated from room temperature to 800°C after the sample was introduced, then allowed to cool after sample decomposition for 1 to 2 minutes. The combustion segment was maintained at 800°C during the analysis. After combustion, vapour was blown through a scrub bottle containing distilled, deionized water and a pair of soda lime traps and finally collected on a custom-made, gold-coated sand trap (25 mm long, 4.0 mm ID, and quartz). The carrier gas was allowed to sweep the sample into the gold-coated sand trap for 4 to 5 minutes from sample injection. The trap was then removed for analysis on a Brooks Rand Model III atomic fluorescence spectrometer (Brooks Rand Trace Metals Analysis and Products, U.S.) as described in Liang et al. (1993). 5.2.2 Quality Control

Calibration standards of methyl mercury (MeHg) were prepared by serial dilution with dichloromethane from a stock solution of methylmercury (CH3HgCl) (Johnson Matthey, U.S.) in isopropanol. Initial calibration aliquots typically contained 50, 100, 150, and 200 pg of mercury, with a nominal 0-pg blank also included. Calibration verification standards, run with each set of samples, were the mid-level calibration standard and a method blank. Calibration repeatabilities were required to be less than 25%. Calibration standards were prepared often to ensure accurate concentrations. Before any analysis, the system was blanked for 5 minutes with only the pure carrier gas, i.e., no sample was introduced into the injection port. It was required that the baseline mercury level of the system be less than 2 pg. Before analyzing each set of samples, a reference oil of known concentration (developed at CEBAM) was run before and after sample analysis in duplicate to ensure that instrument recoveries were within acceptable limits. Three method blank samples consisting of pure dichloromethane were run before and after sample analysis. Method blanks were required to have total mercury contents less than 0.1 ng of mercury/mL of dichloromethane. For each set of 10 samples (or less), duplicate matrix spikes were also analyzed using one sample chosen at random. Matrix spike recovery was required to be 75% to 125%, with the duplicates having a relative percent difference (RPD) of less than 25%. All samples were analyzed in duplicate. All duplicates were required to have RPDs of less than 25%. Results were reported as duplicate values, means, and RPDs. 5.3 Environment Canada: Density and Sulphur Content

Environment Canada’s Oil Research Laboratory at the Environmental Science and Technology Centre in Ottawa, Ontario measured the density and sulphur content of each crude oil in the study. The analytical procedures were based on ASTM standard methods and were required to meet the reproducibility and repeatability of the appropriate method.

19

5.3.1 Method for Determining Density and API Gravity The density of an oil sample, in g/mL, was measured using an Anton Paar DMA 48

digital density meter (Anton Paar, U.S.A.) following ASTM Method D5002 (ASTM, 1999a). Measurements were performed at 20.0°C. The instrument is calibrated using air and distilled, deionized water at 0.0°C and 20.0°C. Method and operator performance is monitored by periodic measurement of a check standard of p-xylene at 15.0°C. A method control chart is kept of these measurements. Densities are corrected for sample viscosity, as specified by the instrument manufacturer. Measurements are repeated in triplicate and the mean reported as the density. 5.3.2 Method for Determining Sulphur Content

The mass fraction of total sulphur in oil is determined using X-ray fluorescence, closely following ASTM Method D4294 (ASTM, 1999b). The X-ray fluorescence spectrometer is calibrated using a duplicate series of 6 sulphur-in-oil standards (National Institute of Standards and Technology, U.S.A.). A calibration chart is prepared from the 12 standard measurements. Single-element standards are used to calibrate and remove chlorine interference in the sulphur signal. Instrument and operator performance is monitored by a triplicate measurement of a check standard consisting of a well characterized historical standard of crude oil. Check standard measurements are tracked on a quality control chart and used to estimate the uncertainty in measurement. Approximately 3 mL (+/- 0.1 mL) of oil was measured out into 31-mm HDPE XRF cells and sealed with 0.25 mm thick mylar film. The sealed cells are measured on a Spectro Titan XRF spectrometer (SPECTRO Analytical Instruments, Germany). 5.4 PS Analytical: Confirmation Laboratory Testing

PS Analytical of Kent in the United Kingdom was used as a confirmation laboratory for a select number of samples. 5.4.1 Method Summary

In order to obtain a representative homogeneous sample aliquot, the samples were placed in an ultrasonic bath for 15 minutes before aliquots were removed for preparation. The samples were prepared by heating in aqua regia at 120°C for 2 hours. Once cooled, an aliquot of the aqueous phase was removed, diluted, and analyzed using vapour generation atomic fluorescence spectrometry. All the samples were prepared in duplicate on two consecutive days and each solution was then analyzed in duplicate, i.e., n=4. Expanded uncertainties were reported for all measurements. Blank solutions were prepared and analyzed along with the samples, as were samples of Conostan mercury in base oil (prepared at 20 ng g-1), which were used to validate the measurements.

20

6 Quality Assurance and Quality Management The data quality objective for the present work is to provide a defensible and statistically

reasonable estimate of the volume-weighted mean and standard deviations of mercury concentrations in crude oils refined in Canada. Several steps were taken during the sampling design and measurement phases of this project to support this goal. 6.1 Analysis Requirements

The laboratories were required to meet several objectives in order for their results to be considered appropriate for use in the present work. In addition, several parameters related to the study design and the sample list had to be judged acceptable to ensure general applicability of the results. Method detection limits (MDLs) were required to be below those of the range of measured concentrations. Detection limits were determined for both techniques by analyzing element-blank oil samples provided by Conostan Division, ConocoPhillips Specialty Products Inc., U.S. For both laboratories, method blank measurements were below 0.1 ng of mercury/g of oil. Accuracies were required to be 100% ± 15%, i.e., standard recoveries should average between 85% and 115%. Accuracies were determined by performing internal quality controls on check standard and spike recoveries, but also by presenting blind challenge samples to each laboratory. Challenge samples were prepared in the following ways: a certified mercury standard (Conostan, U.S.) was spiked into an element-blank oil; the certified standard was also spiked into a crude oil (Alberta sweet mixed blend); and standard-addition recoveries were calculated. See Sections 6.2.2 and 6.3.2 for results. Precision was monitored for each measurement by analyzing each sample in duplicate (CEBAM Analytical) or triplicate (University of Ottawa). The relative percent difference (RPD) between measurements was not to exceed 20%. Pooled replicate analysis was also used to determine the relative standard deviation of all measurements. See Sections 6.2.3 and 6.3.3. Reproducibility between laboratories was not to exceed 15% on average. See Section 6.4 for additional information. As discussed in Section 3, the samples taken were considered to be representative of the Canadian oil market in 2002, based on coverage of 71% of the total oil refined in Canada by volume. The samples were representative in terms of the origin of each major oil, each refinery region, and of each type of refinery input. This was deemed broad enough to easily approximate the volume of Canadian refined oil. Practical considerations of availability and logistics did not significantly affect the coverage of the sample list. Most oil types were sampled three times (some types were only available to be sampled once -see Table 3). Absolute variances were calculated for each oil type. To minimize the absolute variances, the following procedure was used to calculate the number of resamples necessary for each oil type. The average concentration of total mercury in all types of crude oil is computed as:

∑∑= iiiVol VVTHgTHg ][][ (1) where [THg]i is the mean concentration of total mercury in crude type I, and

21

Vi is the volume of refinery usage in 2002. For each type of oil, [THg]i is initially estimated by three measurements. From these measurements, the average triplicate-measured concentration [THg(3)]i and the variance, σ(3)i

2, are computed. The average concentration of all the types of crude oil (for three measurements), ( )[ ]3THg is computed. The total number of samples to be taken in the study, n, is decided. In this study, n = 109. To minimize the variance in the weighted-average concentration, [ ]VolTHg , the number of samples per type of crude i is then computed as:

[ ][ ]( )∑ ∑∑=

j jjj

iiii VV

VVnn

)3()3(

σσ

(2)

Thus, to minimize the overall study variance, a further ni-3 samples should be taken for each type of crude oil (where ni-3 > 0). Note that this criterion was used only as a guide to further sampling, not as a rule. Practical considerations such as sample availability and time limitations required some reductions in the number and selection of samples taken over the course of the study. Both laboratories were required to be accredited by a recognized standards body. The Ottawa University Laboratory participates in the Canadian Association of Environmental and Analytical Laboratories (CAEAL) round-robin proficiency testing and is accredited for mercury analysis in coal by that body. CEBAM Analytical participates in mercury proficiency testing administered by the National Institute of Standards and Technology/National Voluntary Laboratory Accreditation Program (NIST/NVLAP) and the U.S. EPA and maintains good standing under both programs. Certifications for both laboratories were deemed to be acceptable. 6.2 Quality Assurance for Ottawa University Laboratory 6.2.1 Internal Quality Control

As described in Section 5.1., the Ottawa University laboratory’s control parameters consisted of running blanks every five samples and preparing control standards in a mineral oil base from a known standard, both supplied by Conostan. In all cases, the reported blank values were below the stated detection limits and the reported recoveries of their control standards exceeded 90% but were less than 110%. Both these parameters met the study objectives for internal quality control. Increasing standard deviation with measurement can be a problem if the standard deviation increases more than a linear increase in the measurement. To test if this was a concern, the relative standard deviation was plotted against concentration. This test at the Ottawa University laboratory is presented in the top graph in Figure 8. While the absolute standard deviation in measured mercury concentration may increase with increasing concentration, it is apparent that it is considerably less than linear. Measurements carried out at the Ottawa University laboratory have smaller RSDs on average at higher concentrations than near the detection limit. This is considered an acceptable result for this laboratory.

22

Note also that no results were reported below the method detection limit of 0.1 ng/g of oil. Blanks were checked regularly to ensure that low values were properly determined. 6.2.2 Challenge Samples

The analytical results for Ottawa University’s challenge samples are shown in Figure 9 and Table 4. These results include recoveries from a certified pure mineral oil base (Conostan, U.S.) and spike-addition recoveries in an Environment Canada reference oil (Alberta Sweet Mixed Blend, Reference Pour #4), a light, sweet crude oil similar to the more common Federated crude oil. The total mercury concentration of this oil was determined in advance by the Ottawa University laboratory. All samples were considered in aggregate when estimating the recovery, bias, and expanded uncertainty. The sample “Heavy Oil #5-01” prepared by CEBAM Analytical is routinely used by this lab as a check standard in their regular measurements. Recoveries show a bias of -14% and a relative standard deviation in recoveries of 7%. The bias value is close to the target maximum of 15% (absolute), but both values satisfy the objectives for each parameter. The linear correlation between the measured and the nominal values for the Ottawa University laboratory can be seen in Figure 9. For clarity, the value for Heavy Oil #5-01 is not shown in the figure. The error bars plotted for the measured values are the reported standard deviations listed in Table 4. As seen in the figure, there is a very strong linear relationship between the method results and nominal values, as shown by both the slope of the graph being very close to 1 and the coefficient of correlation, r2, also being very close to unity. The evidence of bias is also clear, however, with the intercept of the linear fit being displaced down to almost -2. While very linear and producing a 1:1 response, the Ottawa University laboratory values appear to slightly over-report the measured value of mercury. 6.2.3 Results of Pooled Replicates

As an alternative method for determining the relative variance in the data, rather than relying on a relatively small number of challenge samples, the pooled relative standard deviation of all replicates for all samples measured by Ottawa University (measured in triplicate) was calculated. The Ottawa University laboratory reported 117 triplicate measurements of total mercury concentration [THg]. Assuming that the relative variances are all similar, the pooled relative standard deviation can be computed for the entire dataset using the equation:

( )[ ] 2/122, )1(][)1( −−= ∑∑

−

iiiipr nTHgsns (3)

where: sr,p is the pooled relative standard deviation, ni is the number of points in each data set (3 in this case), si is the standard deviation of data set i, and [ ]THg i is its mean.

The pooled relative standard deviation (n = 343) for the Ottawa University data set is 0.077 or 7.7%. Using a coverage factor of k = 2, the expanded uncertainty for the pooled RSD is 15%.

23

Figure 8 Absolute Standard Deviation Plotted against Measured Mercury

Concentration for the Ottawa University Laboratory (top) and Absolute Difference Plotted against Mercury Concentration for CEBAM Analytical (bottom)

Ottawa University [Hg] (ng/g)

0 10 20 30 40 50

σ [H

g] (n

g/g

oil)

(n=3

)

0.0

0.5

1.0

1.5

2.0

2.5

3.0

Cebam Analytical [Hg] (ng/mL)

0 2 4 6 8

RPD

*[H

g] (n

g/m

L) n

=2

0.0

0.2

0.4

0.6

0.8

1.0

1.2

24

Figure 9 Measured Concentration of Total Mercury Plotted against Nominal Values

for Ottawa University Laboratory Challenge Samples Table 4 Results of Challenge Samples for Ottawa University Laboratory

Sample Matrix Nominal Value (ng/g oil)

Ottawa U Mean (n = 3) (ng/g oil)

Ottawa U SD (n = 3) (ng/g oil)

Recovery

Mineral Oil 5.577 4.88 0.23 87.5% Mineral Oil 11.058 9.77 0.25 88.4% Mineral Oil 11.268 9.82 0.08 87.1% HEAVY OIL # 5-01 275.000 273.72 13.59 99.5% ASMB#4 13.000 10.69 0.46 82.2% ASMB#4 13.023 10.48 0.25 80.5% ASMB#4 8.109 6.53 0.22 80.5% ASMB#4 8.597 6.90 0.18 80.3% Mean 85.8% Bias -14.2% Standard Deviation 7% Observations 8 Coverage Factor (n = 7, 95.45%) 2.43 Expanded Uncertainty 16%

Nominal [Hg] (ng/g)

0 2 4 6 8 10 12 14

Otta

wa

Uni

vers

ity M

easu

red

[Hg]

(ng/

g oi

l)

0

2

4

6

8

10

12

14

Meas= 1.002 Nom -1.901r ²=0.9999

25

6.2.4 Estimated Uncertainties in the Results from Ottawa University Laboratory The two estimates of expanded uncertainty agree remarkably well considering the large

differences in size of the datasets. From both results, the relative uncertainty of measurement in the results from the Ottawa University laboratory is estimated to be 15%. 6.3 Quality Assurance for CEBAM Analytical 6.3.1 Internal Quality Control

As described for the Ottawa University laboratory in Section 6.2.3, CEBAM Analytical used three types of quality control. A reference check was run before each set of standards, method blanks were run before and after each sample analysis, and a duplicate matrix spike was analyzed using one of the samples chosen at random. It was required that all recoveries be between 75% and 125%. As with the results from the Ottawa University laboratory, it is useful to determine whether the variation in repeat measurement increases as the value of mercury concentration increases. Since CEBAM Analytical was contracted to provide duplicate rather than triplicate measurements, the absolute differences (RPD×[THg]) are plotted against the measured mercury concentrations. From Figure 8, it can be seen that the absolute difference values do not greatly increase with increasing mercury concentration. As with the Ottawa University laboratory, CEBAM Analytical reported no results below their method detection limit of 0.1 ng/mL of oil. They also checked blanks regularly to ensure that low values were determined properly. 6.3.2 Challenge Samples

The analytical results for the challenge samples at CEBAM Analytical are shown in Table 5. The calculated values include both recoveries from a certified pure mineral oil base (Conostan, U.S.) and standard addition recoveries in the Environment Canada reference oil (Alberta Sweet Mixed Blend #4). The sample “MeHgCl” was prepared by the Ottawa University laboratory by mass from a Conostan U.S. mercury standard in an aqueous medium. It is immediately apparent from Table 5 that there was a systematic difference between the recoveries in the mineral oil, aqueous, and ASMB #4 matrices. This difference is probably due to uncertainty in the concentration of the ASMB #4 reference oil. This concentration was determined by duplicate measurements of four samples spaced months apart in the sampling schedule. The same procedure was used for the Ottawa University ASMB #4 measurements. The ASMB #4 matrix recoveries thus include measurement uncertainties both in the reference oil and in the spiked samples. Because of the differences between the two sets of samples, they have been considered separately for the purposes of bias and uncertainty estimations. Recoveries show biases of -14% for the mineral oil matrix and +15% for the crude oil matrix. These are within the objectives for both, although the span high and low is 30%. Relative standard deviations for both matrices are within the sampling design objectives.

26

Table 5 Results of Challenge Samples for CEBAM Analytical

Sample Matrix

Nominal Value (ng/g oil)

CEBAM Mean (n = 2) (ng/mL oil)

CEBAM RPD (%)

CEBAM (ng/g oil)

Recovery

Mineral Oil 4.143 3.13 -6.7 3.60 87.0%Mineral Oil 5.944 4.28 0.2 4.92 82.8%Mineral Oil 5.728 4.36 -2.3 5.02 87.6%Mineral Oil 57.794 43.90 0.1 50.55 87.5%Mineral Oil 59.091 44.64 -3.8 51.40 87.0%

Mean 86.4% Bias -13.6% Standard Deviation 2% Observations 5 Coverage Factor (n = 4, 95.45%) 2.87 Expanded Uncertainty 6%

MeHgCl 50.000 50.33 -3.7 50.33 100.7%

ASMB #4 10.065 7.03 3.7 8.35 83.0%ASMB #4 9.975 8.68 -1.8 10.31 103.4%ASMB #4 10.237 9.23 -6.1 10.97 107.2%ASMB #4 10.063 9.41 0.5 11.18 111.1%ASMB #4 10.783 10.67 3.7 12.68 117.6%ASMB #4 10.124 9.85 -3.6 11.70 115.6%ASMB #4 13.023 13.57 -3.0 16.13 123.8%ASMB #4 7.697 8.03 -0.4 9.54 124.0%

Mean 114.7% Bias 14.7% Standard Deviation 8% Observations 7 Coverage Factor (n = 6, 95.45%) 2.52 Expanded Uncertainty 20%

The nominal and reported values for the CEBAM Analytical challenge samples are compared in Figure 10. For the mineral oil matrix samples, CEBAM Analytical reported results almost identical to those of Ottawa University except that the slope is somewhat smaller. Response does appear to be very linear over the measurement range for the mineral oil matrix samples. The spike recoveries from the reference crude oil cover a narrower range and thus the fit equation is not as certain as that for the mineral oil matrix samples. The spike recoveries are linear over the range examined and very consistently reproduce the same recoveries. It is apparent from Figure 10 that the ASMB #4 samples are displaced vertically from the mineral oil matrix line, supporting the hypothesis that the difference between the two data sets is an uncertainty in the total mercury concentration of the base ASMB crude oil.

27

Figure 10 Measured Concentration of Total Mercury Plotted against Nominal Values

for CEBAM Analytical Challenge Samples Even if the absolute recoveries are in question, the repeatability of both data sets is well within the study design objectives of 15% for standard deviations of repeat measurements. Expanded uncertainties were found to be 6% for the mineral oil data set and 20% for the ASMB crude oil matrix set. 6.3.3 Results of Pooled Replicates

The duplicate measurements for each sample were used to compute a pooled relative standard deviation. The general equation for multiple replicates is shown in equation 3, Section 6.2.3. For duplicate measurements, equation 3 simplifies to:

( )[ ] [ ] 2/122/12

, 22][/ nRPDnTHgbas pr ∑∑ =−= (4)

where a and b are the duplicate measurements, [ ]THg is their average, n is the number of pairs, and RPD is the relative percent difference (as a fraction).

Nominal [Hg] (ng/g)

0 10 20 30 40 50 60

CEB

AM

Ana

lytic

al M

easu

red

[Hg]

(ng/

g oi

l)

0

10

20

30

40

50

60

Mineral Oil MatrixMeas=0.87Nom-0.09R2=1.00ASMB#4 Matrix

Meas=1.28Nom-1.41R2=0.87

MeHgCl(Aqueous)

28

For the CEBAM Analytical pool of duplicates (n = 260), the pooled, relative standard deviation is 5.2%. Again, assuming a coverage factor of 2, the relative expanded uncertainty for the CEBAM Analytical results is approximately 10%. 6.3.4 Estimated Uncertainty in CEBAM Analytical Results

The relative expanded uncertainties of measurement for the CEBAM Analytical data sets are 6% from the mineral oil, 20% from the ASMB #4 spike recovery data, and 10% from the pooled replicate data. While the mineral oil recovery data set agrees very well with the pooled replicate estimate, the ASMB #4 spike recovery data set does have a larger uncertainty estimate. Given the small size of the two recovery data sets (n = 5 for the mineral oil and n = 7 for the ASMB #4) and the large size of the pooled replicate data set (n = 260), it seems reasonable, however, to use the larger pooled replicate value. For the individual measurements reported by CEBAM Analytical, it was assumed that the relative uncertainty is approximately 10%. 6.4 Inter-laboratory Differences: Ottawa University and CEBAM Analytical

The relationship between the measurements performed at Ottawa University and CEBAM Analytical for each oil sample is shown in Figure 11. The horizontal ranges represent the RSD reported by Ottawa University for each sample type; the vertical ranges show the RPD reported by CEBAM Analytical. The graph at the top of the figure shows the entire data set and the graph at the bottom shows those ranging from 0 to 20 ppbw. A strong linear relationship can be observed between the two sets of measurements, although there is scatter between both measurements. The 0.89 value of the coefficient of correlation reflects this observation. The slope of the correlation shows that Ottawa University reported values approximately 15% higher than those of CEBAM Analytical. This is consistent with the challenge sample results discussed in Sections 6.2.2 and 6.3.2. Ottawa University reported values almost equal to the nominal values, while CEBAM Analytical showed a trend of under-reporting. At no more than approximately 15%, however, these differences appear to be relatively minor. This is within the range of the uncertainties calculated earlier. Another way of examining the relationships of the datasets is to compute the double-tailed Student’s t-values for the two data sets. Assuming a hypothesis of zero difference between the datasets, i.e., that they are identical and an alpha of 0.05, that is at 95% confidence, the Student’s t-test gives a statistic of -0.63, a P(T<=t) (two-tail) of 0.53, and a t-critical (two-tail) of 1.97. The mean of the Ottawa University data set is higher than that of the CEBAM Analytical dataset, but the t-statistic falls well below the critical t-value for a significant difference. Based on this calculation, it is more than 95% likely that the two data sets are statistically similar.

29

Figure 11 Measured Total Mercury Concentration for 109 Samples of Crude Oil,

Ottawa University Plotted against CEBAM Analytical - Top shows entire data set, bottom shows range from 0 to 20 ppbw.

Ottawa University [Hg] (ng/g oil)

0 10 20 30 40 50

CEB

AM

Ana

lytic

al [H

g] (n

g/g

oil)

0

10

20

30

40

50CA = 1.1623 OU - 0.0076r2 = 0.8900

Ottawa University [Hg] (ng/g oil)

0 5 10 15 20

CEB

AM

Ana

lytic

al [H

g] (n

g/g

oil)

0

5

10

15

20

30

6.5 Inter-laboratory Differences: PS Analytical As an additional check on the analyses conducted by both CEBAM Analytical and

Ottawa University, approximately 10% of the sample set was sent to PS Analytical in Kent, UK. The results for all three labs are shown in Table 6. An attempt was made to choose samples with a wide range of values that covered the full range of concentrations seen in the study. Table 6 Results for Ottawa University, CEBAM Analytical, and PS Analytical

Sample ID Sample Date Ottawa U (ng/g oil)

CEBAM (ng/g oil)

PS Analytical (ng/g oil)

PS Analytical Uncertainty

CCCN43 23-Jun-04 6.50 6.26 3.64 0.79 CCEP24 10-Jun-04 1.03 0.91 < 0.30 CCCN43 12-Jul-04 7.57 5.02 2.47 0.1 CCCN51 4-Jul-04 0.73 0.55 < 0.30 CCCN65 26-Jul-04 0.19 0.25 < 0.30 CCCN36 12-Aug-04 0.94 3.00 1.26 0.02 CCEP30 24-Jul-04 2.53 2.57 0.95 0.08 CCCN38 23-Sep-04 0.57 1.22 <0.30 CCAF43 9-Dec-04 16.45 12.44 14.7 1.3 CCCN66 13-Dec-04 0.23 0.78 < 0.30 CCCN67 29-Nov-04 38.24 43.60 47.68 4.28 CCEP32 3-Dec-04 13.38 18.80 20.25 2.19 CCEP33 4-Dec-04 3.53 4.33 1.99 0.08

The results from Ottawa University and CEBAM Analytical are plotted against the corresponding results from PS Analytical (PSA) in Figure 12. In both cases, 0.15 ppbw or one half the method detection limit was estimated for the below-detection-limit values reported by PS Analytical. Both graphs show a strong linear relationship between the data from PSA and the data from the other two laboratories. The slopes for both graphs are more than 1, indicating that the PSA measurements for total mercury concentration may be consistently less than those of the other two laboratories. Double-tailed Student’s t-tests were computed for both the Ottawa University-PSA and CEBAM Analytical-PSA pairs of data. Assuming differences of 0 and with 24 degrees of freedom, the t-statistics were found to be -0.028 for OU-PSA and 0.092 for CA-PSA. For a 95% probability of being identical, the t-statistics should be in the range -2.06 to +2.06. There does not appear to be any significant difference between the PSA data and that of either of the other two laboratories.

31

Figure 12 Results from Ottawa University (top) and CEBAM Analytical

(bottom) Plotted against PS Analytical Results

Ottawa University [Hg] (ng/g oil)

0 10 20 30 40 50

PSA

[Hg]

(ng/

g oi

l)

0

10

20

30

40

50

PSA = 1.24 OU - 1.61r2 = 0.96

CEBAM Analytical [Hg] (ng/g oil)

0 10 20 30 40 50

PSA

[Hg]

(ng/

g oi

l)

0

10

20

30

40

50

PSA = 1.13 CA - 1.46r2 = 0.992

32

7 Total Mercury Concentrations 7.1 Sample Data

The data for each sample taken over the course of the study are given in Table 7, listed according to sample code and date. Measurements for each sample are: density (±0.0005), sulphur content by weight (±0.05%), mean result of mercury concentrations (n = 3) from Ottawa University (OU [THg]), the relative standard deviation (RSD) of the three Ottawa University measurements, the CEBAM Analytical mean result of mercury concentrations (n = 2), (CA[THg]), and the relative percent difference (RPD) between the two measured values for CEBAM Analytical. As CEBAM Analytical reported their results in ng/mL of oil, in this table their results have been converted from mass/(unit volume oil) units to mass/(unit mass oil) units by the corresponding average densities measured by Environment Canada.

)/()/]([)/]([ mLgmLngTHggngTHg ρ= (5) A result from CEBAM Analytical is not available for one sample, CCCN36 sampled on 12-Jul-04. This is indicated by NM in Table 7. This sample was damaged in transit and a replacement or archive sample was not available. As CCCN36 was found to have very low values for total mercury concentration, a fourth replacement sample was deemed unnecessary. Table 7 Sample Data Sample ID

Sampling Date

Density (g/mL)

Sulphur (%w/w)

OU [THg] ng/g oil

OU RSD (%)

CA [THg] ng/g oil

CA RPD (%)

CCAF43 9-Dec-04 0.7940 0.12 16.5 12.4 2.4 CCAF43 17-Dec-04 0.7940 0.12 16.4 1.8% 19.7 -0.4 CCAF43 25-Dec-04 0.7948 0.12 11.8 3.4% 16.0 -1.3 CCAF43 31-May-05 0.7943 0.11 7.6 1.5% 14.4 -1.4 CCAF43 8-Jun-05 0.7943 0.10 4.5 5.6% 9.8 -9.9 CCAF43 20-Jun-05 0.7948 0.11 5.1 2.0% 10.3 -6.1 CCAF45 12-Jul-04 0.8044 0.31 2.8 3.3% 2.4 3.2 CCAF45 11-Aug-04 0.7341 0.20 1.3 8.9% 2.2 7.2 CCAF45 4-Aug-04 0.7315 0.16 1.3 2.2% 0.9 -9.2 CCCN30 13-Jan-05 0.8155 0.5621 1.2 0.9% 1.4 8.9 CCCN30 14-Jan-05 0.8160 0.5635 0.6 1.6% 1.2 0.6 CCCN30 13-Jan-05 0.8160 0.4707 1.2 5.8% 1.4 -7.6 CCCN30 14-Jan-05 0.8161 0.5522 0.9 7.5% 1.1 -4.6 CCCN32 5-May-04 0.8425 0.3809 1.1 10.7% 1.0 7.3 CCCN32 29-Jun-04 0.8414 0.5754 1.3 12.9% 0.9 0.8 CCCN32 22-Jul-04 0.8448 0.4606 0.9 8.8% 0.6 -4.9 CCCN33 25-Jun-04 0.8183 0.255 0.6 1.9% 1.1 5.9 CCCN33 29-Jun-04 0.8184 0.244 0.7 10.7% 1.2 7.0 CCCN33 1-Jul-04 0.8196 0.2175 0.7 7.6% 1.6 -10.0 CCCN36 12-Jul-04 0.7530 0.1 1.2 3.9% NM CCCN36 10-Aug-04 0.6804 0.4 0.8 7.6% 1.6 5.1 CCCN36 11-Aug-04 0.6797 0.1 1.1 2.8% 1.1 -4.4 CCCN36 12-Aug-04 0.6805 0.2 0.9 7.4% 3.0 -4.9

33

Sample ID

Sampling Date

Density (g/mL)

Sulphur (%w/w)

OU [THg] ng/g oil

OU RSD (%)

CA [THg] ng/g oil

CA RPD (%)

CCCN37 22-Jun-04 0.8468 0.8 1.6 5.7% 1.6 7.0 CCCN37 25-Jun-04 0.8472 0.8 1.6 4.5% 0.8 5.7 CCCN37 13-Jul-04 0.8415 0.6 1.2 3.5% 0.9 0.0 CCCN38 16-Jun-04 0.8323 0.6 0.8 10.2% 0.6 -5.4 CCCN38 13-Jul-04 0.8199 0.3 0.5 5.9% 0.5 3.2 CCCN38 23-Sep-04 0.8264 0.6 0.6 12.3% 1.2 13.9 CCCN39 1-Aug-04 0.8413 0.5 1.6 2.7% 1.9 8.6 CCCN39 25-Sep-04 0.8310 0.5 1.9 9.7% 2.0 -3.8 CCCN39 12-Oct-04 0.8295 0.5 1.6 7.5% 1.9 3.4 CCCN40 18-Jun-04 0.8208 0.6 0.8 3.7% 0.5 2.6 CCCN42 18-Jul-04 0.9258 3.0 1.6 1.8% 1.6 9.2 CCCN42 30-Aug-04 0.9349 3.2 2.4 5.9% 1.7 9.1 CCCN42 1-Oct-04 0.9277 3.1 2.0 5.5% 1.5 9.2 CCCN43 23-Jun-04 0.9216 3.4 6.5 9.1% 6.3 7.0 CCCN43 30-Jun-04 0.8348 0.8 1.5 6.7% 1.0 5.2 CCCN43 12-Jul-04 0.9250 3.6 7.6 8.0% 5.0 19.5 CCCN43 17-Nov-04 0.9232 3.7 8.9 2.1% 9.8 -2.4 CCCN43 6-Jan-05 0.9206 3.6 7.0 1.3% 8.2 -3.9 CCCN43 15-Feb-05 0.9180 3.7 8.3 3.3% 10.7 -3.0 CCCN49 25-Nov-04 0.8500 0.2 0.4 4.3% 0.6 6.5 CCCN49 21-Feb-05 0.8567 0.2 0.3 19.4% 0.4 -8.0 CCCN49 3-Mar-05 0.8570 0.2 0.6 4.0% 0.3 -3.5 CCCN50 29-Nov-04 0.8604 1.0 0.5 2.0% 0.7 8.1 CCCN50 6-Dec-04 0.8584 0.9 0.4 5.9% 0.9 -2.4 CCCN50 13-Dec-04 0.8593 1.0 0.4 2.8% 0.6 0.0 CCCN51 23-Jun-04 0.8487 1.3 0.8 9.7% 0.6 11.3 CCCN51 28-Jun-04 0.8469 1.3 1.2 11.9% 0.3 -6.9 CCCN51 4-Jul-04 0.8476 1.3 0.7 11.5% 0.6 21.3 CCCN53 17-Jun-04 0.9283 3.1 1.1 4.7% 0.9 -2.3 CCCN53 21-Jul-04 0.9323 3.0 1.1 2.8% 0.7 18.2 CCCN53 26-Aug-04 0.9277 3.2 1.4 4.3% 1.9 8.7 CCCN60 21-Jun-04 0.8273 0.5 2.9 5.5% 1.8 -11.8 CCCN60 26-Jun-04 0.8292 0.5 3.1 4.6% 1.1 9.4 CCCN60 9-Jul-04 0.8290 0.5 2.2 7.2% 1.1 -7.5 CCCN62 17-Jun-04 0.8225 0.5 6.3 6.0% 1.6 5.8 CCCN62 13-Jul-04 0.8218 0.5 2.9 8.8% 2.1 -11.8 CCCN62 28-Sep-04 0.8209 0.5 1.8 2.9% 1.2 -4.9 CCCN62 30-May-05 0.8217 0.5 2.8 19.5% 3.6 7.1 CCCN62 2-Jun-05 0.8217 0.5 1.3 7.9% 6.6 -0.4 CCCN62 8-Jun-05 0.8217 0.6 3.6 4.2% 7.6 -0.5 CCCN64 16-Jun-04 0.8302 0.4 3.0 3.8% 1.0 9.9 CCCN64 13-Jul-04 0.8295 0.4 2.3 8.0% 2.0 11.5 CCCN64 23-Sep-04 0.8304 0.5 4.0 9.9% 1.7 -11.5 CCCN65 22-Jun-04 0.8272 0.4 0.6 8.5% 0.4 0.0 CCCN65 14-Jul-04 0.8283 0.5 0.3 13.0% 0.5 0.0

34

Sample ID

Sampling Date

Density (g/mL)

Sulphur (%w/w)

OU [THg] ng/g oil

OU RSD (%)

CA [THg] ng/g oil

CA RPD (%)

CCCN65 26-Jul-04 0.8268 0.4 0.2 15.8% 0.3 18.2 CCCN66 29-Nov-04 0.8559 0.2 0.4 10.3% 0.5 11.1 CCCN66 6-Dec-04 0.8559 0.2 0.2 12.4% 0.4 2.9 CCCN66 13-Dec-04 0.8559 0.2 0.2 14.2% 0.8 13.3 CCCN67 29-Nov-04 0.8691 0.1 38.2 4.2% 43.6 2.3 CCCN67 6-Dec-04 0.8690 0.1 0.1 4.0% 1.6 15.1 CCCN67 16-Jul-05 0.8691 0.1 1.4 7.2% 1.6 0.0 CCCN67 26-Jul-05 0.8690 0.1 0.1 4.0% 0.6 -5.1 CCCN67 27-Jun-05 0.8661 0.1 2.4 3.7% 1.0 0.0 CCCN67 4-Jul-05 0.8665 0.2 1.0 2.1% 1.0 3.4 CCCN67 11-Jul-05 0.8667 0.1 1.3 27.2% 0.9 -3.7 CCCN71 3-Mar-05 0.8596 0.4 0.8 4.7% 0.3 0.0 CCCN71 11-Mar-05 0.8769 0.3 1.6 6.4% 0.4 -5.8 CCCN71 20-Mar-05 0.8628 0.3 1.5 8.5% 1.4 3.6 CCEP22 7-Jun-04 0.8546 0.4 1.7 7.8% 1.1 -1.4 CCEP24 10-Jun-04 0.8502 1.1 1.0 11.2% 0.9 12.2 CCEP24 23-Apr-05 0.8502 1.0 1.2 6.4% 0.7 2.0 CCEP24 23-Apr-05 0.8502 1.1 1.1 9.0% 0.8 -8.5 CCEP29 26-May-04 0.8781 0.3 1.7 3.3% 0.9 -14.3 CCEP29 17-Jun-04 0.8765 0.3 1.1 15.0% 0.8 7.0 CCEP29 14-Jul-04 0.8715 0.3 0.7 10.6% 0.5 3.1 CCEP30 31-May-04 0.8284 0.4 3.4 2.4% 2.3 6.6 CCEP30 5-Jul-04 0.8291 0.4 1.8 6.6% 1.5 10.2 CCEP30 24-Jul-04 0.8280 0.4 2.5 7.5% 2.6 0.1 CCEP30 21-Nov-05 0.8288 0.4 1.8 5.7% 2.0 -3.6 CCEP30 21-Nov-05 0.8290 0.4 1.5 0.6% 2.1 0.0 CCEP30 21-Nov-05 0.8293 0.4 1.9 3.2% 2.3 3.9 CCEP32 3-Dec-04 0.7961 0.2 13.4 6.4% 18.8 1.1 CCEP32 29-Mar-05 0.7961 0.2 5.3 2.5% 11.4 -7.1 CCEP32 2-Apr-05 0.7961 0.2 6.4 11.8% 14.7 2.3 CCEP32 5-Jun-05 0.7961 0.2 6.5 37.6% 11.8 -4.0 CCEP33 4-Dec-04 0.9064 0.6 3.5 7.0% 4.3 2.0 CCEP33 11-Dec-04 0.9068 0.6 0.7 4.8% 1.6 8.3 CCEP33 21-Dec-04 0.8991 NM. 1.6 9.0% 1.6 4.3 CCME56 10-May-04 0.8656 2.5 0.7 15.4% 0.5 10.2 CCME56 2-Aug-04 0.8713 2.8 0.5 8.7% 1.2 -0.5 CCME56 1-Oct-04 0.8646 2.6 0.6 7.3% 0.5 -6.2 CCSA38 20-Jul-04 0.8750 0.5 1.6 7.7% 1.3 11.0 CCSA38 20-Jul-04 0.8749 1.0 1.8 3.9% 1.3 -9.7 CCSA38 20-Jul-04 0.8749 1.2 1.9 8.7% 2.0 3.4 CCUS105 24-Sep-04 0.8265 0.6 2.0 2.4% 1.5 3.8

35

One hundred and nine (109) samples were measured over the course of the study. The samples show considerable variability, ranging from 0.1 to 38.2 ng of mercury/g of oil for the Ottawa University measurements and 0.2 to 43.6 ng of mercury/g of oil for the CEBAM Analytical results. While Ottawa University reported one measurement at the method detection limit (for a CCCN67 sample), no samples were reported below the detection limit for either laboratory. A detection limit of 0.1 ng of mercury/g of oil was sufficient to provide quantitative results for every measurement for all the types of oil measured in the study. 7.2 Correlation of Density and Sulphur Content with Mercury Concentration

The possible relationships of total mercury concentration in crude oil to both density and total sulphur content (by weight) are shown in Figures 13 and 14 respectively. As can be seen from Figure 13, there does not appear to be a simple or dominant relationship between the oil density and the total mercury concentration. A wide range of oils is represented, from light condensates (density 0.68) to heavy crude types (density 0.94). The vertical distribution of concentrations at a density of 0.78 to 0.79 is composed of measurements of two light crudes from Africa: CCAF43 and CCAF45 (see data in Table 7). With the exception of these two oils, the densities are distributed almost equally for the entire range of measurements of total mercury concentration. The density of crude oil does not appear to have a strong correlation with its total mercury content. As seen in Figure 14, any relationship between sulphur content and total mercury concentration is likewise small and does not dominate the mercury chemistry in this set of crude oils. The measured oils consist of sweet crudes, with less than approximately 1% sulphur and sour crudes, with more than 2% sulphur. For the 28 sweet crude oils, the highest total mercury concentrations were measured for the oils with the lowest sulphur content (<0.2% sulphur). For the 4 sour crude oils, CCCN42, CCCN43, CCCN53, and CCME56, there may be a positive correlation between increasing sulphur and mercury levels, but there are too few data points in the present study to draw definitive conclusions. These two features are suggestive of several possible mercury chemistries in crude oil: a sweet-crude configuration when the mercury compounds do not contain sulphur and a sour-crude chemistry with a possible sulphur-mercury association. 7.3 Averaged Crude Oil Data

The mean density, sulphur content, and total mercury concentration for both the Ottawa University (OU) and CEBAM Analytical (CA) laboratories for each sample type are given in Table 8. Note that the RSD values given for each total mercury concentration are those calculated from the variances of the values for each oil code in Table 7, i.e., they reflect the standard deviation between the individual measurements for each type of oil only. In Table 9, one set of values has been removed from the averages. The values for CCCN67 sampled on 29-Nov-04 (given in Table 8) have been omitted from the calculation due to the wide variation between the sampling on this date and all other samples of this crude oil. The outlier is well beyond the mean +3σ level considering all other samples of this type. An investigation of the sampling details on the chain of custody records indicated nothing unusual for this oil and the high value appears to be a true high concentration based on testing at three laboratories. Nevertheless, it is reasonable to believe that the statistical rejection of this data point is valid and that the average of the remaining values is the best representation of the average value for crude

36

oil type CCCN67. With 109 individual samples taken, it is not unreasonable to find one sample outside the 99%/3σ limit of average measurement. All other sample values shown in Table 8 were used to compute the averages shown in Table 9.

0

5

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15

20

25

30

35

40

45

50

0.6500 0.7000 0.7500 0.8000 0.8500 0.9000 0.9500

Density (g/mL) at 20C

[TH

g] (n

g/g

oil)

Ottawa UCEBAM

Figure 13 Total Mercury Concentration [THg] and Density of Oil

0

5

10

15

20

25

30

35

40

45

50

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0

% Sulphur (w/w)

[TH

g] (n

g/g

oil)

Ottawa UCEBAM

Figure 14 Total Mercury Concentration [THg] and Sulphur Content of Oil

37

Table 8 Averaged Crude Oil Data Sample ID Density

(g/mL) Sulphur (%w/w)

OU [THg] (ng/g)

OU RSD (%)

CA [THg] (ng/g)

CA RPD (%)

CCAF43 0.7944 0.1 10.3 5.4 13.8 3.8 CCAF45 0.7567 0.2 1.8 0.8 1.8 0.8 CCCN30 0.8159 0.5 1.0 0.3 1.3 0.2 CCCN32 0.8429 0.5 1.1 0.2 0.8 0.2 CCCN33 0.8188 0.2 0.7 0.1 1.3 0.3 CCCN36 0.6984 0.2 1.0 0.2 1.9 1.0 CCCN37 0.8452 0.7 1.5 0.3 1.1 0.4 CCCN38 0.8262 0.5 0.6 0.1 0.8 0.4 CCCN39 0.8339 0.5 1.7 0.1 1.9 0.1 CCCN40 0.8208 0.6 0.8 * 0.5 * CCCN42 0.9295 3.1 2.0 0.4 1.6 0.1 CCCN43 0.9072 3.1 6.6 2.7 6.8 3.6 CCCN49 0.8546 0.2 0.4 0.2 0.4 0.1 CCCN50 0.8594 1.0 0.4 0.1 0.7 0.1 CCCN51 0.8477 1.3 0.9 0.3 0.5 0.1 CCCN53 0.9294 3.1 1.2 0.2 1.2 0.6 CCCN60 0.8285 0.5 2.7 0.5 1.3 0.4 CCCN62 0.8217 0.5 3.1 1.8 3.8 2.7 CCCN64 0.8300 0.5 3.1 0.9 1.6 0.5 CCCN65 0.8274 0.4 0.4 0.2 0.4 0.1 CCCN66 0.8559 0.2 0.3 0.1 0.6 0.2 CCCN67 0.8679 0.1 1.1 0.9 1.1 0.4 CCCN71 0.8664 0.3 1.4 0.4 0.7 0.6 CCEP22 0.8546 0.4 1.7 * 1.1 * CCEP24 0.8502 1.1 1.1 0.1 0.8 0.1 CCEP29 0.8754 0.3 1.2 0.5 0.7 0.2 CCEP30 0.8288 0.4 2.2 0.7 2.1 0.4 CCEP32 0.7961 0.2 7.9 0.2 14.2 3.4 CCEP33 0.9041 0.6 1.9 1.5 2.5 1.6 CCME56 0.8672 2.6 0.6 0.1 0.7 0.4 CCSA38 0.8749 0.9 1.8 0.2* 1.5 0.4* CCUS105 0.8265 0.6 2.0 * 1.5 *

* Only one sample of this oil was available. 7.4 Mean and Median Total Mercury Concentration

Several simple statistics computed from the data in Table 8 are shown in Table 9. There is very good agreement between the laboratories for both the arithmetic means and medians, well within the measurement uncertainties calculated in Section 6.

38

Table 9 Arithmetic Mean and Median Total Mercury in Oil Concentrations Ottawa University

(ng/g oil) CEBAM Analytical (ng/g oil)

Lab Average (ng/g oil)

Arithmetic Mean ( [ ]THg )

2.0 2.2 2.1

Median 1.2 1.2 1.2 Minimum 0.3 0.4 Maximum 10.3 12.2 Standard Deviation 2.3 3.4

The distribution of total mercury concentrations in each type of crude oil for both laboratories from Table 8 is plotted in roughly ascending order in Figure 15. The black bars show the lab-average arithmetic mean and median, which can be found in the right-hand column of Table 9. It can be seen from Figure 15 that the different “average” values that can be computed for total mercury concentration in crude oil vary significantly. This is due to the extremely non-uniform range of concentrations of mercury in oil. The total mercury concentrations in most types of oil measured in this study is below 2.1 ppbw (25 of 32 for Ottawa University, and 26 of 32 for CEBAM Analytical) and a few oils have a concentration above 5 ppbw (3 for both laboratories). Based on these results, a simple arithmetic mean is not a good measure of the “average” value of crude oil processed in Canada for the types of oil measured in the present work, as it is distorted by a very few types of oil with concentrations much higher than the mean.

Figure 15 Distribution of Total Mercury Concentration by Type of Oil

02468

10121416

[TH

g] (n

g/g

oil)

CEBAM Analytical

Ottawa UniversityMedian [THg] (1.2 ppb)

Mean [Thg] (2.1 ppb)

39

8 Data Analysis 8.1 Volume-weighted Averages of Total Mercury Concentrations To simulate an “average” concentration of total mercury in oil that best reflects the refinery usage Canada, production volume-weighted averages have been computed using Equation 1 in Section 6.1. Weighted averages have been calculated for both the Ottawa University (OU) results and the CEBAM Analytical (CA) results, which are shown in Table 10. As well as a national average for all crude oil used in the country for all oil origins, weighted averages have also been computed for oil origin (East, West and Foreign) and refinery location (Quebec and Atlantic, Ontario, and Western Canada). Finally, volume-weighted averages have also been calculated for synthetic crude oils derived from Alberta oil sands production using the data for oil types CCCN43, CCCN66, and CCCN67. The production volumes as well as the oil origins, refinery locations and the samples included in the averages can be found in Table 3. Measured mercury concentrations were taken from Table 8. All averages, for both laboratories are shown in Table 10. These weighted averages are compared in figure 16. It can be seen that the two labs are in agreement in every case within the estimated 95% uncertainty limits. Both laboratories give statistically indistinguishable results results, the averages of the two sets of data will result in a more representative estimate of the mercury levels in the crude oils. The average total mercury concentrations are shown in Table 10 with estimated uncertainties. Note that the relative uncertainty for the combined laboratory average concentration is approximately 20% in all cases. Table 10 Weighted Total Mercury Concentrations 2002

Production Volume (m3/yr)

% PV Canada

2002

OU

VolTHg][(ng/g oil)

CA

VolTHg][ (ng/g oil)

Average Mercury

Concentration in Oil

(ng/g oil) In Study 74,714,601 71.3% 2.5 ± 0.4 2.8 ± 0.3 2.6 ± 0.5

Crude Oil Origin Canada East 5,592,842 5.3% 1.2 ± 0.2 1.0 ± 0.1 1.1 ± 0.2 Canada West 40,934,020 39.1% 1.6 ± 0.3 1.5 ± 0.1 1.6 ± 0.3 Foreign 28,187,739 26.9% 3.9 ± 0.6 5.0 ± 0.5 4.5 ± 0.8 Refinery District QC & Atlantic 22,340,627 21.3% 4.0 ± 0.6 5.1 ± 0.5 4.5 ± 0.8 Ontario 27,624,777 26.4% 2.1 ± 0.3 2.1 ± 0.2 2.1 ± 0.4 Western Canada 24,749,204 23.6% 1.4 ± 0.2 1.4 ± 0.1 1.4 ± 0.3 Synthetic Crude Oils 13,617,885 13.0% 2.1 ± 0.3 2.2 ± 0.2 2.2 ± 0.4

40

[TH

g]V

ol

0

2

4

6

8

10

Ottawa University LaboratoryCEBAM Analytical

Cana

dian

Aver

age Ea

st

Wes

t

Fore

ign

Queb

ec &

Atlan

tic Ontar

ioW

ester

nCa

nada

Synt

hetic

Crud

e Oils

Figure 16 Comparison of Volume-Weighted Average Total Mercury Concentrations

[THg] in Crude Oil

It is useful to compare the results listed in Table 10 with the historical values discussed in Section 2 and shown in Figure 1. Figure 1 is reproduced in Figure 17 with the historical literature ranges on the left compared to the current results on the right. The black circles in Figure 17 plot the average values or in the case of some of the literature results, recommended values, for total mercury concentration, while the vertical lines represent the minimum and maximum observed values for each study or category. Note that the vertical scale in Figure 17 is logarithmic. It can be seen in Figure 17 that the average total mercury concentrations measured in the present work, reported in Table 10, are orders of magnitude lower than several of the historical results. In particular, it appears that the estimate of 3,500 ppbw (Brooks, 1989) used by the U.S. EPA as the value for estimating mercury budgets is much too high (U.S. EPA, 1997). On the other hand, more recent studies and reviews including those of Liang et al. (2000) and Morris (2000), and the 10 ppbw value recommended in the review by Wilhelm (2001) are all within the ranges observed in the present work.

41

Figure 17 Measured Total Mercury Concentration [THg] Compared to Historical Ranges of Mercury It is important to note, however, that while in the more recent literature these values are within the range of mercury concentrations observed in this work, in most cases these authors report values that are several times higher than the weighted averages measured in this study. Several factors may account for this. Firstly, as can be seen in Table 10, Canadian crude oils have lower concentrations of total mercury than those from non-Canadian sources. This can also be seen indirectly in the averages based on refinery districts. Refineries in the Quebec and Atlantic regions process mostly crude oils of foreign origin. Processed oils from this region have the highest average concentrations of total mercury. In contrast, refineries in western Canada process crude oils almost exclusively from western Canada. This refinery district has the lowest average mercury level in its crude oil input stream.Oils produced in eastern Canada, which come primarily from offshore Newfoundland, have some of the lowest mercury concentrations found in this study. As these oils were not yet in wide use in Canadian refineries in 2002, however, they do not significantly affect the volume-weighted average mercury concentrations. Secondly, the historical values have been biased high because instrumental detection limits were higher than the methods used in the present work. In several cases, the “low values” for the historical ranges (Figure 1) are the method detection limits. As it was therefore not possible to determine low concentrations for these studies, the reported averages are higher. It should be

[THg] (ppb)

0.1

1

10

100

1000

10000

100000

National CanadaEast

CanadaWest

Foreign QC andAtlantic

Ontario

WesternCanada

SyntheticCrude Oils

0.1

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100

1000

10000

100000

Literature Ranges (see Figure 1)

Region ofOrigin

RefineryDistrict

42

noted that in the present work no sample was found to be below the method detection limit for either laboratory. Finally, many of the previous studies were limited in their selection of oils. It can be very difficult to arrange for sampling of a set of oils that are representative of use patterns at refineries. Many authors were able to study only a limited set of oils and no literature studies attempt to weight the reported averages by refinery or commercial use. Many of the oils used in past studies were not selected for the purpose of estimating a broad average. Authors often deliberately selected oils with high mercury concentrations in order to measure “pathological” cases. In the present study, however, care has been taken to sample accurately in order to reflect the actual use of crude oils by refineries. This should lead to a more accurate and lower estimate of the broader volume-weighted average for mercury concentrations in crude oil.

43

8.2 Total Mass of Mercury in Crude Oil refined in Canada The total mass of mercury in crude oil was calculated by multiplying the individual oil total mercury concentrations [ ]iTHg by the corresponding production volume (PVi) and the individual oil densities ρi:

[ ]∑ ××=i

iii PVTHgMass ρ (6)

Where [ ]iTHg and ρi are taken from Table 8, and PVi is taken from Table 3. Estimated uncertainties in the mercury mass were computed by multiplying the relative estimated uncertainties, shown in Table 10, from Sections 6.2.4 and 6.3.4 for the Ottawa University results and CEBAM Analytical values respectively. Similar to the volume weighted sub-averages in section 8.1, total masses of mercury were also computed for each geographic origin and for region of refiners from the data in Table 8, with groupings and volumes taken from Table 3. Note that these mercury masses are calculated only for the oil volumes included in the study. The total and partial amounts of mercury in crude oil refined in Canada in 2002 are shown in Table 11 in kilograms. Table 11 Mass of Mercury in Crude Oil*

Mercury Mass In Oil Refined

(kg Hg/yr) Canada 2002 227 ± 30 Production District Canada East 7.0 ± 1.4 Canada West 77 ± 15 Foreign 143 ± 26 Refinery District QC & Atlantic 115 ± 21 Ontario 71 ± 13 Western Canada 41 ± 8 Alberta Tar Sands Product Synthetic Crude Oils 37 ± 7

*Production Volume Weighted for 2002

44

8.3 Total Mercury in Crude Oil in the Context of Canadian Emissions

Releases of mercury to the environment in Canada from industrial sources must be reported to the National Pollutant Release Inventory (NPRI) program. The NPRI is managed by Environment Canada and tracks 323 classes of substances. The total emissions from each class are compiled from the NPRI database every calendar year. Mercury and its compounds are considered as a single pollutant class by the NPRI. The NPRI totals for mercury for 2002 are shown in Table 12 and compared to the total mercury in crude oils processed in Canada, taken from Table 11. These results are also plotted in Figure 18.

Table 12 Total Mercury Emissions in 2002 Compared to Mercury in Processed

Crude Oils

Total Emissions from all Mercury Sources (kg/year)

Mercury in Crude Oil (kg/year)

Mercury in Oil - Total Emissions

(%) NPRI: QC & Atlantic 1,338 115.4 8.6% NPRI: Ontario 1,483 70.5 4.8% NPRI: Western Canada 4,354 41.3 1.4% National NPRI Total 5,837 227.2 3.9%

Estimated Total Canadian Anthropogenic Emissions

6,340 3.6%

Assuming the worst case, the release of all the mercury in crude oil refined in Canada to the environment, the percentage of the total mercury emissions budget that could be attributed to the refined oils is shown in Table 12. While the Quebec and Atlantic region has the lowest total emissions from all sources, it also has the highest total mercury in crude oil refined in that region. This can be attributed to the high mercury content of the oils refined in Quebec and the Maritimes coming from foreign sources. By contrast, western Canada has the lowest total amount of mercury in processed crudes and refines almost exclusively domestic Canadian crudes. While the NPRI database includes most of the industrial and institutional releases of mercury, some sources, including small commercial and residential sources, are not required to report emissions. The Pollution Data Branch of Environment Canada estimates emissions from all of these non-NPRI sources. Their estimate for all anthropogenic emissions of mercury in Canada for the year 2002 was 6,340 kg as shown in Table 12. The trends shown in the data in Table 12 are also shown in Figure 18. While the total mercury in refined crude oil is lowest in the western district and highest in Quebec and the Atlantic regions, the total mercury emissions reported by the NPRI show the opposite trend. While the percentages of mercury in crude oil to total emissions differ by an order of magnitude in Table 12, it can be seen in Figure 18 that these differences are caused mainly by the relatively large emissions of mercury in western Canada.

45

0

1000

2000

3000

4000

5000

6000

7000

Emis

sion

s of H

g (k

g/ye

ar)

Refined Oil Total

Total NPRI

Quebec &Atlantic Regions

OntarioWesternCanada

Canadian Total

NPRI Sources Only

All sources including NPRI

Figure 18 Total Canadian Mercury Emissions in 2002 Compared to Mercury in

Refined Crude Oils

46

From the average mercury concentration of 2.6 ng/g (from Table 12) and an average oil density of 0.8477 g/mL (from Table 8), the total amount of mercury in all crude oil processed in Canada from 2002 to 2005 can be estimated using equation 6 in Section 8.1. The amounts for each year are shown in Table 13. Note that the variations from year-to-year in the estimated total mercury are within the uncertainty of the estimated total mercury values of approximately ±30 kg/year. Table 13 Mercury in Crude Oil Processed in Canada from 2002 to 2005

Year Volume of Crude Oil Processed (1000 m3)*

Estimated Total Mercury (kg/year)

2002 104,719 227 2003 106,742 231 2004 110,908 240 2005 107,420 233

*Source: Statistics Canada, 2006 9 Conclusions and Recommendations

During this study, 32 types of oil were sampled and 109 individual oil samples were measured. The crude oils were selected for type based on the list of oils processed by participating refineries in Canada in 2002. The oils were chosen based on geographical origin (western Canada, eastern Canada, and foreign), the district in which the refineries were located (western Canada, Ontario, and Quebec and Atlantic Canada), by oil type (condensate, crude, and synthetic crude), and their availability for sampling. The oils sampled covered 71% of all oil (by volume refined) in Canada in 2002. The samples measured were chosen from a list of 103 types of crude oil representing more than 88% of crude oil processed in Canada. It is assumed that the results for all 10 reporting refineries (103 types of crude oil, 88% by volume) can be extrapolated to 100% of the refined volume of crude oil in 2002 for all 19 refineries reporting to the NPRI in that year. The average total mercury concentration in crude oil weighted by volume used in the Canadian refining sector in 2002 is 2.6 ± 0.5 ng/g of oil or parts per billion by weight (ppbw) at 95% confidence. In general, Canadian crude oils have lower concentrations of total mercury (1.2 to 1.6 ± 0.3 ppbw) than crude oils from outside Canada (4.5 ± 0.8 ppbw). As a result, the average mercury concentrations in the input streams of Quebec and Atlantic refineries were the highest in the country (4.5 ± 0.8 ppbw) because of their reliance on foreign inputs. In contrast, refineries in Ontario and western Canada used crude oils that were on average lower in total mercury concentrations: 2.1 ± 0.4 ppbw and 1.4 ± 0.3 ppbw, respectively. Finally, it was found that three “synthetic” crude oils manufactured from bitumen from the Alberta tars sands had an average total mercury concentration of 2.2 ± 0.4 ppbw (weighted by refined volumes). Each sample was measured by two laboratories, one using cold-vapour/atomic absorption (CVAA) and the other using cold-vapour atomic fluorescence spectrometry (CVAFS). Both laboratories met or exceeded the following quality objectives over the entire study: accuracies of ± 15% based on spike recoveries and precisions of ± 20% based on pooled replicates. The estimated relative uncertainties of measurement were 16% for CVAA and 10% for the CVAFS techniques at 95.45% (2σ) confidence. The detection limit of both methods was 0.1 ppbw. All samples measured were at or above 0.1 ppbw. No oil sample reported in the present work was found to be below this detection limit.

47

These average total mercury concentrations are significantly lower than those reported in the literature. Reviewers have reported values from 3,500 ppbw (Brooks, 1989) to 10 ppbw (Wilhelm, 2001). In the present work, values of 0.3 to 15 ppbw were observed for the 32 types of oil sampled. The arithmetic mean of all values, i.e., not weighted by refinery-usage volume, was found to be 2.1 ppbw. The median (50th percentile) total mercury concentration was 1.2 ppbw. The distribution of concentrations skewed low - most oils had low total mercury concentrations with the mean being brought up by a very few oils with higher concentrations (above 5 ppbw). The differences between the range of concentrations measured in this work and those reported by other authors can be explained by the following three factors. 1. Canadian crude oils make up approximately half by volume of all the crude oils used by

Canadian refineries. The total mercury levels of these Canadian oils are lower than oils from the rest of the world and thus tend to bring down the averages.

2. Improvements in detection limits allow lower concentrations to be quantified and included in the averages.

3. Previous studies focused in part on oils with very high concentrations of mercury. It is difficult to obtain representative average concentrations of total mercury from these datasets.

The density and sulphur content of each oil sample were also measured. No correlation could be found between density and total mercury concentration. Mercury levels in crude oil vary independently of their density. The case for sulphur was more ambiguous. The oils sampled consisted of sweet (<1.5% sulphur) and sour (>2.5% sulphur). High mercury concentrations were found in some of the very sweetest (low sulphur) oil samples. In addition, observations of the sour crude oils suggested a trend, with very sour crude oils (5% sulphur) having moderate mercury concentrations (5 ppbw). The Canadian refinery sector processed 104,719,128 m3 of crude oil in total in 2002. Multiplying this volume by the production-weighted average of 2.6 ± 0.5 ppbw, it is estimated that a total of 227 ± 30 kg of mercury was contained in all of the oil refined in Canada in 2002. In comparison, a total of 5,837 kg of mercury emissions were reported to Environment Canada’s National Pollutant Release Inventory (NPRI) in 2002. Assuming the worst case that all of the mercury in the crude oil processed in Canada is released to the environment, the petroleum-refining sector and all associated downstream activities could constitute 3.9% of the 2002 annual total release of mercury reported to the NPRI. In 2002, the total emissions to the Canadian environment estimated from typical use were 6,340 kg. This value for total emissions includes non-NPRI reporting sources, such as the residential sector. The petroleum-refining sector could then constitute 3.6% of that total. The potential mercury emissions that could originate from the refining of crude oil vary greatly from region to region. Because of their use of foreign crude oils, the refineries in Quebec and Atlantic regions could have emitted as much as 115 kg of mercury in 2002. Refineries in Ontario could have been responsible for approximately 70 kg and those in western Canada could have accounted for as little as 41 kg. These variations are almost entirely caused by the use of oil from different sources. Note that almost equal amounts of crude oil were refined in all three regions in 2002.

48

9.1 Main Findings The main findings of this study are summarized here.

• More than 100 types and 104.7 million m3 of crude oil were processed in Canada in 2002, approximately half of which originated from Canada and the other half from foreign countries.

• The average concentration of total mercury weighted by refined volumes in Canadian crude oil (2002 data) is 2.6 ± 0.5 ng/g of oil.

• The observed range of mercury concentrations in oil was 0.1 to 50 ng/g of oil. • This average concentration and range of values are significantly lower than those

reported in the literature. • No strong correlations were found between total mercury concentration and either the

density or total sulphur content of the crude oil. Sulphur content of the various types of crude oil ranged from 0.1% to 3.1% w/w. The average density was calculated at 0.8477 g/mL.

• In 2002, Canadian refineries processed crude oil containing a total of 227 ± 30 kg of mercury.

• If all of this mercury had been emitted to the environment, it would have made up 3.6% of the total anthropogenic air emissions, including both NPRI and non-NPRI sources, in 2002.

• There are significant regional differences in the levels of mercury in crude oil. Oils from eastern Canada contain less mercury (<1 ppbw) than oils from western Canada (<2 ppbw). Products from the tar sands have among the highest levels of all crude oils produced in Canada. The mercury levels in foreign crude oils can be ten times or more than those in domestic crude oils.

• Because of their usage patterns, refineries on Canada’s east coast process crude oils with higher levels of mercury than those used in Ontario or western Canada. Refineries in Quebec and the Atlantic provinces thus have a higher potential for mercury emissions than those in other parts of the country.

• The study results represent the crude oil processing pattern for the 10 participating refineries in 2002. These refineries make up 88% by volume of the refining sector. If the usage of crude oil for refining changes significantly, the study results will no longer apply.

This study has produced an estimate for total mercury concentration in crude oil and potential emissions of mercury to the environment from refinery inputs based on real-world usage data. These data, which represent the concentrations and total mercury in the crude oil refinery input stream, can be used with for estimating emissions from the petroleum sector and activities associated with its outputs, including heating with petroleum fuel; road, ship, and diesel rail transportation; and petroleum-fueled power generation. It should be emphasized, however, that these estimates account only for the mercury contained in the crude oil used by the refineries. The actual disposition of mercury in the refining process is not well understood at the present time. It is still largely unknown how much mercury is removed by the refineries during processing and how it fractionates into each type of refined product, e.g., gasoline, diesel, marine fuel oils, and asphalts. The mercury lost to the air from crude oil between extraction and its arrival at the refinery has also not been included in this study.

49

While it seems that the overall worst-case estimate of possible contributions of crude oil to the total anthropogenic emissions of mercury is quite low, it is useful to remember that total mercury emissions have fallen swiftly in the past two decades and continue to fall. With petroleum products becoming an increasingly important source of fuel and with petroleum extraction and refining setting record volumes every year, it will become even more important to assess potential mercury emissions from the oil and gas sector each year. 9.2 Recommendations

The value of 2.6 ± 0.5 ng of mercury/g oil (ppbw) can be used as an estimate of the average total mercury concentration in Canadian crude oil weighted by refined volumes. Using this average mercury concentration, the total amount of mercury in crude oil processed in Canada is estimated to be 227 kg in 2002, 231 kg in 2003, 240 kg in 2004, and 233 kg in 2005, based on the total amount of crude oil refined in Canada in those years. The pattern of processing crude oil reported here was that for 2002. In this year, eight types of crude oil accounted for 30% of the Canadian processing volume but contained more than 80% of all the mercury in crude oil processed in Canada. These eight crude oils originated from western Canada, Europe, and Africa. However, the processing pattern of crude oil in Canada has changed slightly each year. In future, if crude oil use deviates significantly from the usage pattern evaluated in this work, the results of this study will need to be re-evaluated. The total amount of mercury in all crude oil processed in Canada in 2002 (227 ± 30 kg) can be used as an estimate of the upper limit of potential mercury emissions from the petroleum-refining sector. This includes both potential mercury emissions from all refined petroleum products and all potential mercury releases from refineries. This study targeted only that mercury contained in the crude oil received by the refinery. Actual emissions from refineries were not measured. In addition, mercury released from upstream oil, gas extraction, and handling and transport to refineries should not be included in this estimate. Mercury from other refinery inputs, such as natural gas, may also affect this estimate. The value for the total amount of mercury in the inputs of crude oil refineries can also be used as an estimate of the upper limit of mercury in refined fuels. Atmospheric mercury emissions from the exhaust of on-road motor vehicles as a result of combustion of refined petroleum products is estimated to be no more than 227 ± 30 kg/yr. Using this worst-case estimate, the maximum potential anthropogenic atmospheric emissions of mercury from the combustion of refined fuel would be 3.6% of the total Canadian total (6,340 kg of mercury) in 2002. Note that the actual disposition of mercury in each stream of petroleum products, including gasoline and diesel fuels used to power on-road motor vehicles, was not measured in the present study.

50

10 References ASTM (American Society for Testing and Materials), “ASTM D5002, Standard Test Method for Density and Relative Density of Crude Oils by Digital Density Analyzer”, in Annual Books of ASTM Standards Section 5 - Petroleum Products, Lubricants and Fossil Fuels, Volume 05.03, West Conshohocken, PA, 1999a. ASTM (American Society for Testing and Materials), “ASTM D4294, Standard Test Method for Sulfur in Petroleum Products by Energy-Dispersive X-ray Fluorescence Spectroscopy”, in Annual Books of ASTM Standards Section 5 - Petroleum Products, Lubricants and Fossil Fuels, Volume 05.02, West Conshohocken, PA, 1999b. Bloom, N., “Analysis and Stability of Mercury Speciation in Petroleum Hydrocarbons”, Fresenius’ J. Anal. Chem., 366(5):438-443, 2000. Brooks, G., “Estimating Air Toxics Emissions from Coal and Oil Combustion Sources”, prepared by Radian Corporation for U.S. Environmental Protection Agency, EPA-450/2-89-001 (NTIS PB89-194229), Research Triangle Park, NC, 1989. Cao, J.R., “Microwave Digestion of Crude Oils and Oil Products for the Determination of Trace Metals and Sulphur by Inductively-Coupled Plasma Atomic Emission Spectroscopy”, Manuscript Report EE-140, Environmental Protection Service, Environment Canada, ON, 1992. Canadian Environmental Protection Act (CEPA), Canada Gazette Part III, 22 (3), Chapter 33, 1999. (See also: http://laws.justice.gc.ca/en/C-15.31/index.html) Corns, W.T., “Mercury Speciation in Crude Oil and Natural Gas Condensates using Cold Vapour Atomic Fluorescence Spectrometry”, RMZ-Materials & Geoenvironment, 51:1885-1889, 2004. Filby, R.H. and K.R. Shah, “Mercury in Refined Products”, in The Role of Trace Metals in Petroleum, T.F. Yen, (ed.), Ann Arbor Science Publishers, Ann Arbor, MI, 1975 Hitchon, B. and R.H. Filby, “Geochemical Studies - Trace Elements in Alberta Crude Oils”, Alberta Research Council for Alberta Energy and Utilities Board and Alberta Geological Survey, Alberta, Canada, Open File Report 1983-02, 1983. Kelly, R.W., S.E. Long, J.L. Mann, “Distribution of Mercury in SRM Crude Oils and Refined Products by Isotope Dilution Cold Vapour ICP-MS using Closed-system Combustion”, Anal. Bioanal. Chem., 376:753-758, 2003. Levelton Engineering, “Mercury Emissions from the Petroleum Refining Sector”, Report to Trans-Boundary Air Issues Branch, Hazardous Air Pollutants Program, Environment Canada, Richmond, BC, 2000. Liang L. and N.S. Bloom, “Determination of Total Mercury by Single-stage Gold Amalgamation with Cold Vapor Atomic Spectrometry”, Analyst, 8:591-594, 1993. Liang, L., M. Horvat, and P. Danilchik, “A Novel Analytical Method for Determination of Picogram Levels of Total Mercury in Petroleum-based Products”, The Science of the Total Environment, 187:57-64, 1996.

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Liang, L., S. Lazoff, M. Horvat, E. Swain, and J. Gilkeson, “Determination of Mercury in Crude Oil by In-situ Thermal Decomposition using a Simple Lab-built System”, Fresenius' J. Anal. Chem., 367 (8):8, 2000. Liang, L., M. Horvat, V. Fajon, N. Prosenc, J. Li, and P. Pang, “Comparison of Improved Combustion/Trap Technique to Wet Extraction Methods for Determination of Mercury in Crude Oil and Related Products by Atomic Fluorescence”, Energy & Fuels, 17:1175-1179, 2003. Magaw, R., S. McMillen, W. Gala, J. Trefry, and R. Trocine, “Risk Evaluation of Metals in Crude Oils”, in Proceedings of the SPE/EPA Exploration & Production Environmental Conference, SPE Paper No. 52725, 1999. Morris, R., “New TRI Reporting Rules on Mercury”, presented at the National Petroleum Refineries Association Meeting, San Antonio, TX, Sept. 2000. Musa, M., W. Markus, A. Elghondi, R. Etwir, A. Hannan, and E. Arafa, “Neutron Activation Analysis of Major and Trace Elements in Crude Petroleum”, J. Radioanal. Nucl. Chem., 198(1):17, 1995 NPRI (National Pollutant Release Inventory), “NRPI National Overview 2000, Appendix D - National Atmospheric Releases of Mercury”, http://www.ec.gc.ca/pdb/npri/2002Highlights/NPRI2000Overview/appendixd_e.cfm, 2000. Olsen, S., S. Westerlund, and R. Visser, “Analysis of Metals in Condensates and Naphthas by ICP-MS”, Analyst, 122:1229, 1997. Shah, K.R., R.H. Filby, and W.A. Haller, “Determination of Trace Elements in Petroleum by Neutron Activation Analysis”, J Radioanal. Chem., 6:413-422, 1970 Shafawi, A., L. Ebdon, M. Foulkes, P. Stockwell, and W. Corns, “Determination of Total Mercury in Hydrocarbons and Natural Gas Condensate by Atomic Fluorescence Spectrometry”, Analyst, 124:185, 1999. Spiric, Z., “Innovative Approach to the Mercury Control during Natural Gas Processing”, Proceedings of the ETCE 2001 Engineering Technology Conference on Energy, Feb. 5-7, pp. 1-4, 2001. Statistics Canada, “The Supply and Disposition of Refined Petroleum Products in Canada”, Statistics Canada, Catalogue No. 45-004-XIB, 100 p., Ottawa, ON, 2006. Sunderland, E.M., and G.L. Chmura, “The History of Mercury Emissions from Fuel Combustion in Maritime Canada”, Environmental Pollution, 110:297-306, 2000. Tao, H., T. Murakami, M. Tominagaa, and A. Miyazakia, “Mercury Speciation in Natural Gas Condensate by Gas Chromatography Inductively Coupled Plasma Mass Spectrometry”, J. Anal. At. Spectrom., 13:1085-1093, 1998. U.S. EPA (Environmental Protection Agency), “Method 7473, Mercury in Solids and Solutions by Thermal Decomposition, Amalgamation, and Atomic Absorption Spectrometry”, 1998.

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U.S. EPA (Environmental Protection Agency), “Mercury Study Report to Congress”, EPA/452/R-97/003 (NTIS PB98-124738), Office of Air Quality Planning and Standards, Research Triangle Park, NC and Office of Research and Development, Washington, DC, 1997. U.S. EPA (Environmental Protection Agency), “Specifications and Guidance for Contaminant-Free Sample Containers”, Office of Solid Waste and Emergency Response, EPA 540/R-93/051, Washington, DC, 1992. Wilhelm, S.M., “Design Mercury Removal Systems for Liquid Hydrocarbons”, Hydrocarbon Processing, April, pp. 61-71, 1999. Wilhelm, S.M. “An Estimate of Mercury Emissions to the Atmosphere from Petroleum”, Environ. Sci. Tech., 35(24):4704-4710, 2001a. Wilhelm, S.M., “Mercury in Petroleum and Natural Gas: Estimation of Emissions from Production, Processing, and Combustion”, for U.S. Environmental Protection Agency, Office of Research and Development, EPA-600/R-01/066, Washington, DC, 2001b. Wilhelm, S.M. and N. Bloom, “Mercury in Petroleum”, Fuel Processing Technology, 63:1-27, 2000. Wilhelm, S.M. and D. Kirchgessner, “Mercury in U.S. Crude Oil: A Study by U.S. EPA, API and NPRA”, SPE/EPA/DOE Exploration and Production Environmental Conference, Society of Petroleum Engineers Paper 80573, San Antonia, TX, 2003. Wilhelm, M., L. Liang, D. Cussen, and D. Kirchgessner, “Mercury in Crude Oil Processes in the United States (2004)”, Env. Sci. & Technol., (in press).

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54

Appendix A Crude Oils and Refined Volumes Processed by Reporting Refineries in 2002 Crude Oil

Code Origin of Crude Oil

Location of Refinery

Volume by

Location (m3/yr)

Volume Processed

in 2002 (m3/year)

Fraction 2002

Total (%)

Sampled in this Study

Sampled in U.S. EPA/ API Study

Canada Total (2002) 104,719,128 Canadian Study Total 74,714,601 71.35% Combined Canadian and U.S. Study Total 82,735,621 79.01%

Major Types of Crude Oils (Volume > 1%)

CCCN67a Canada West Ontario & Western Canada 8,760,725 8.37% YES

Ontario 3,391,951 Western Canada 5,368,774 CCEP30 Europe Ontario & QC/Atlantic 6,095,688 5.82% YES YES QC/Atlantic 1,446,040 Ontario 4,649,648 CCCN65 Canada West Western Canada 5,819,171 5.56% YES YES CCAF43 Africa Ontario & QC/Atlantic 5,645,287 5.39% YES YES QC/Atlantic 5,533,481 Ontario 111,816 CCEP33 Europe QC/Atlantic 4,297,500 4.10% YES YES CCCN32 Canada East Ontario & QC/Atlantic 3,738,838 3.57% YES YES QC/Atlantic 2,130,429 Ontario 1,608,409 CCME57 Middle East QC/Atlantic 3,696,238 3.53% YES CCCN64 Canada West Western Canada 3,346,093 3.20% YES YES CCCN51 Canada West Ontario 3,331,872 3.18% YES YES

CCCN43b Canada West Ontario & Western Canada 2,806,402 2.68% YES YES

Ontario 1,918,218 Western Canada 888,184 CCCN38 Canada West Western Canada 2,586,216 2.47% YES YES CCCN62 Canada West Western Canada 2,494,699 2.38% YES CCEP29 Europe QC/Atlantic 2,194,478 2.10% YES YES CCEP32 Europe Ontario & QC/Atlantic 2,171,157 2.07% YES YES QC/Atlantic 1,015,774 Ontario 1,155,383 CCCN42 Canada West Ontario 2,068,005 1.97% YES YES CCCN66a Canada West Western Canada 2,050,758 1.96% YES CCEP22 Europe Ontario & QC/Atlantic 1,894,392 1.81% YES QC/Atlantic 346,324 Ontario 1,548,068 CCCN53 Canada West Ontario 1,862,063 1.78% YES YES CCUS105 United States Ontario & QC/Atlantic 1,618,401 1.55% YES YES QC/Atlantic 1,129,454 Ontario 488,944 CCME56 Middle East QC/Atlantic 1,416,160 1.35% YES YES CCCN60 Canada West Ontario 1,371,238 1.31% YES YES CCEP24 Europe QC/Atlantic 1,209,664 1.16% YES YES CCCN71 Canada West Ontario 1,170,900 1.12% YES

55

Crude Oil Code

Origin of Crude Oil

Location of Refinery

Volume by

Location (m3/yr)

Volume Processed

in 2002 (m3/year)

Fraction 2002

Total (%)

Sampled in this Study

Sampled in U.S. EPA/ API Study

CCCN37 Canada East Ontario & QC/Atlantic 1,142,046 1.09% YES YES QC/Atlantic 1,082,585 Ontario 59,461 CCCN50 Canada West Western Canada 1,083,517 1.03% YES YES CCAF46 Africa QC/Atlantic 1,059,383 1.01% YES

Minor Types of Crude Oil (Volume < 1%)

CCCN30 Canada West Western Canada 798,232 0.76% CCCN41 Canada West Western Canada 791,533 0.76% YES CCMX15 Mexico QC/Atlantic 731,798 0.70% CCCN54 Canada West Ontario 719,824 0.69%

CCSA36 South America QC/Atlantic 716,092 0.68%

CCCN49 Canada West Ontario 611,571 0.58% YES CCEP34 Europe Ontario & QC/Atlantic 596,892 0.57% QC/Atlantic 295,371 0.00% Ontario 301,521 0.00% CCEP23 Europe Ontario 595,257 0.57% YES

CCSA38 South America QC/Atlantic 538,738 0.51% YES YES

CCCN36c Canada East Ontario 536,416 0.51% YES CCAF41 Africa QC/Atlantic 526,101 0.50% CCAF45c Africa Ontario 511,017 0.49% YES CCEP21 Europe Ontario & QC/Atlantic 490,971 0.47% YES QC/Atlantic 431,523 Ontario 59,448 CCUS102 USA Ontario 483,729 0.46% CCCN48 Canada West Ontario 462,814 0.44% CCCN39 Canada West Ontario 458,998 0.44% YES CCCN59 Canada West Ontario 456,520 0.44% CCCN55 Canada West Ontario 426,898 0.41% CCCN75 Canada West Western Canada 421,076 0.40% CCCN31 Canada East Ontario 390,826 0.37% CCAF44 Africa Ontario & QC/Atlantic 330,396 0.32% YES QC/Atlantic 189,073 Ontario 141,323

CCSA34 South America QC/Atlantic 330,128 0.32%

CCCN40 Canada West Western Canada 313,560 0.30% YES CCMX17 Mexico QC/Atlantic 313,483 0.30% CCEP28 Europe Ontario & QC/Atlantic 297,287 0.28% YES QC/Atlantic 237,813 Ontario 59,474 CCCN52 Canada West Ontario 247,440 0.24% YES CCMX16 Mexico QC/Atlantic 206,617 0.20%

CCSA30 South America QC/Atlantic 188,499 0.18%

CCUS104 USA Ontario 177,296 0.17%

56

Crude Oil Code

Origin of Crude Oil

Location of Refinery

Volume by

Location (m3/yr)

Volume Processed

in 2002 (m3/year)

Fraction 2002

Total (%)

Sampled in this Study

Sampled in U.S. EPA/ API Study

CCCN33 Canada East Ontario 175,542 0.17% YES CCEP25 Europe Ontario & QC/Atlantic 171,142 0.16% QC/Atlantic 171,138 0.00% Ontario 4 0.00% CCCN72 Canada West Ontario 167,600 0.16% CCME59 Middle East QC/Atlantic 160,464 0.15% CCCN79 Canada West Western Canada 182,623 0.17% CCAF42 Africa Ontario & QC/Atlantic 148,611 0.14% YES QC/Atlantic 127,711 Ontario 20,900 CCEP31 Europe QC/Atlantic 144,855 0.14% YES CCEP27 Europe QC/Atlantic 142,223 0.14% YES CCCN45 Canada West Ontario 139,023 0.13% CCUS106 USA Ontario 135,658 0.13% CCCN69 Canada West Ontario 113,300 0.11% CCEP35 Europe QC/Atlantic 109,231 0.10% CCEP26 Europe QC/Atlantic 106,888 0.10% YES

CCSA32 South America QC/Atlantic 103,889 0.10% YES

CCCN74 Canada West Ontario 102,100 0.10% CCME55 Middle East QC/Atlantic 86,957 0.08% YES

CCSA35 South America QC/Atlantic 84,083 0.08%

CCME54 Middle East QC/Atlantic 83,242 0.08% YES

CCSA37 South America QC/Atlantic 82,584 0.08%

CCCN46 Canada West Ontario 76,791 0.07% YES CCEP37 Europe Ontario 75,209 0.07% CCCN58 Canada West Ontario 58,942 0.06% YES

CCSA33 South America QC/Atlantic 54,506 0.05%

CCAS11 Asia Ontario 52,365 0.05% CCUS107 USA Ontario 51,988 0.05% YES

CCSA31 South America QC/Atlantic 48,940 0.05%

CCCN68 Canada West Ontario 44,916 0.04% CCCN73 Canada West Ontario 40,100 0.04% CCCN34 Canada East Ontario 33,895 0.03% CCCN77 Canada West Western Canada 33,458 0.03% CCCN35 Canada East QC/Atlantic 31,653 0.03% YES CCME58 Middle East QC/Atlantic 28,890 0.03% CCCN47 Canada West Ontario 25,896 0.02% CCUS103 USA Ontario 23,611 0.02% CCCN44 Canada West Ontario 21,010 0.02% CCCN70 Canada West Ontario 19,700 0.02% CCCN78 Canada West Western Canada 19,097 0.02% CCCN56 Canada West QC/Atlantic 18,590 0.02% YES CCMX18 Mexico QC/Atlantic 18,514 0.02% YES

57

Crude Oil Code

Origin of Crude Oil

Location of Refinery

Volume by

Location (m3/yr)

Volume Processed

in 2002 (m3/year)

Fraction 2002

Total (%)

Sampled in this Study

Sampled in U.S. EPA/ API Study

CCUS100 USA Ontario 16,000 0.02% CCUS108 USA Ontario 13,100 0.01% CCCN80 Canada West Western Canada 11,093 0.01% CCEP36 Europe Ontario 9,800 0.01% CCCN61 Canada West Ontario 9,758 0.01% YES CCUS101 USA Ontario 3,486 0.00% CCMX14 Mexico QC/Atlantic 1,260 0.00% YES CCCN76 Canada West Western Canada 781 0.00% CCCN63 Canada West Western Canada 126 0.00%

aSynthetic Crude Oil (upgraded bitumen): CCCN66 and CCCN67 bnon-upgraded oil sands bitumen: CCCN43 cGas Condensates: CCAF45 and CCCN36

58

Appendix B Sampling Protocol This document was included in every sampling kit provided to the refineries. Mercury has many forms in oil. Elemental mercury and organic mercury compounds are very volatile and evaporate readily. Inorganic forms of mercury can form sediments that sink in oil. Some mercury compounds absorb on metal surfaces. When sampling the oil, the sampling personnel must make every effort to:

• thoroughly mix the oil; • minimize the contact of the oil and the sample with air; and • use only glass containers if possible and minimize all contact with metal.

A single “sample” consists of 6 vials of oil sampled from the same batch of oil, one immediately after another. A crude oil type should be sampled (6 vials collected) three or more times. As far as possible, each sample (of 6 vials) should be taken from a different shipment or batch of oil. As far as possible, oils should be sampled soon after receipt by the refinery, ideally directly from the incoming pipeline or the tanker, and preferably not from long-term storage tanks. Oil samples are only to be identified by the 7-digit code (e.g., CCCNxxx) assigned by CPPI. No identifying marks should be made on the sample vials, except those described below. Sampling Procedure The sampling kit provided includes 6 glass bottles with septa caps (pre-cleaned, 40-mL EPA/VOA clear glass vials, caps with Teflon septa), bottle labels, a chain-of-custody form, return packaging, and a shipping label. The bottles are ready for use. No preparation is necessary. A single sample is considered to be the 6 replicate sample vials.

• As far as possible, this procedure should be performed by a single individual. • Before sampling, ensure that the oil is as well mixed as practicable. • During sampling operations, minimize sample contact with metal surfaces, as is practical.

Glass-sampling equipment is preferred. • Samples should be taken as close and as soon as practical to the point of entry of the

crude oil into the refinery. When sampling from a pipeline, take samples as close as possible to the point of entry of the pipeline into a refinery. When sampling from a tanker, grab samples are preferred, taken from the bulk of the oil, away from the vessel walls. Autosamplers or grab samples are the preferred sampling methods. Other sampling techniques are acceptable, but should be noted on the chain-of-custody form.

• Sampling directly into the supplied vials is preferred. Intermediate transfers should be minimized. Glass or PTFE transfer equipment is preferred.

• When sampling, minimize contact with the air: reduce open-air transit times and cap the vials as soon as possible.

• Minimize headspace in the sample vials. Fill the vials as full as possible. • All six vials should be filled together, in a single batch. Use the same grab sample, if

possible, or sample from the same location in the oil. • Cap samples immediately, ensuring a good seal. • After samples have reached the ambient temperature, check that vial caps are sealed

tightly. • Clean vials and affix the supplied labels.

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• Ensure each label has the following information: - Crude oil code assigned by CPPI to the sampled oil (e.g., CCCN01) - Sampling date in the form MM/DD/YY (e.g., 03/24/04 for March 24, 2004) - A letter from A to F, where A was the first vial collected, F the last. - Complete the chain of custody form including: - Crude oil code - Sampling date in the form MM/DD/YY (e.g. 03/24/04 for March 24, 2004) - Sampling location (pipeline/tanker/other) - Notes on collection process, including sample mixing, sampling method (grab

samples, auto sampler, etc.), intermediate transfer stages, etc. - Ensure that caps are tight on vials. - Seal each vial in the supplied plastic bag with supplied chain-of-custody seals and

sign and date seals. - Pack bagged vials into the shipping container. - Label the shipping container with the oil code and the sampling date on the supplied

label. - Package the shipping container with the supplied materials and ship to the sample

manager at the address below. DO NOT REFRIGERATE SAMPLES. Store samples at between 15°C and 25°C. Samples must be shipped within two days of sampling.

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Appendix C Sampling Kits, Packing Materials, and Documentation

Sampling Kit - Vials and Packing Materials – This shows the typical sample kits, packaging, and forms and labels that are provided for each sample of oil.

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Documentation for Sampling Kits - Clockwise from bottom left, Vial Labels, Sampling Protocol (see Section 4.1), Chain of Custody form (see Section 4.2), return mailing label, and custody seal for the return packaging.

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Appendix D Chain of Custody Forms The following is the Chain of Custody form sent to refineries to be completed by sampling personnel.

CHAIN OF CUSTODY RECORD Mercury in Crude Oil Project (2004) Project Partners: Environment Canada, CPPI, NA Refinery

SAMPLE CODE:

SAMPLING DATE (MM/DD/YY):

SAMPLING LOCATION: ___ Pipeline ___ Tanker ___ Other DETAILS:

SAMPLING CONDITIONS: Method (grab, autosampler, other), Intermediate Containers (size, material, headspace), Mixing, Other Special Conditions

OIL TEMPERATURE (when sampled):

SAMPLED BY:

DATA RECORDED BY:

SAMPLE DATE

COLLECTED TIME COLLECTED

ANALYSIS REQUIRED

MATRIX LAB ID

REMARKS

A THg Oil B THg Oil C THg Oil D THg Oil E THg Oil F THg Oil

CONDITION OF SAMPLES ON RECEIPT: Custody Seals Intact: ___Yes ___ No ___ None

ITEMS RELINQUISHED BY DATE/TIME RECEIVED BY DATE/TIME

Notes:

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The following is the Chain of Custody form sent by Ottawa University to the Environment Canada laboratory and to CEBAM Analytical.

CHAIN OF CUSTODY RECORD (ID BLIND) Mercury in Crude Oil Project (2004) To be sent on to EC/CEBAM Project Partners: Environment Canada, CPPI, NA Refinery

SAMPLE CODE:

SAMPLING DATE (MM/DD/YY):

RECORD STARTED BY:

Condition of Samples on Receipt: Custody Seal Intact: ___Yes ___ No ___ None

ITEMS RELINQUISHED BY DATE/TIME RECEIVED BY DATE/TIME

NOTES: