2009 Annual Tailings Plan Submission Syncrude Aurora North (Leases 10, 12 and 34) Submitted to: Energy Resources Conservation Board

Transcription

1 2009 Annual Tailings Plan Submission Syncrude Aurora North (Leases 10, 12 and 34) Submitted to: Energy Resources Conservation Board Submitted by: Syncrude Canada Ltd. Fort McMurray, Alberta September 30, 2009

2 Table of Contents 1.0 Introduction Current Operations (Leases 10/12/34) Tailings and Mining Plans Tailings Management Strategy Dedicated Disposal Area (DDA) Strategy Current Operations Future Dedicated Disposal Areas Additional Activities Fines Management Reconciliation to Approved Plan Opportunities Under Consideration Planning Details Mining Tailings Aurora Settling Basin: Aurora North Future Storage: Key Milestones Construction Details Aurora Settling Basin: Dyke 1E and N Dyke 1W Dyke Site Wide Material Balance Water Chemistry...39

3 List of Acronyms ACPNE Aurora Center Pit Northeast ACPNW Aurora Center Pit Northwest ACPS Aurora Center Pit South AENV Alberta Environment AEP Aurora East Pit AEPCD Aurora East Pit Closure Dam AEPN Aurora East Pit North AEPNE Aurora East Pit Northeast (merges with AEPNW to form AEPN) AEPNW Aurora East Pit Northwest (merges with AEPNE to form AEPN) AEPS Aurora East Pit South AN Aurora North AS Aurora South ASB Aurora Settling Basin AWPS Aurora West Pit South bbl Barrel bcm Bank Cubic Metre CT Composite Tailings C&R Conservation and Reclamation DDA Dedicated Disposal Area ERCB Energy Resources Conservation Board EPL End Pit Lake FFT Fluid Fine Tailings FHD Fort Hills Dump IB Interburden masl Metres Above Sea Level Mbbls Million Barrels Mbcm Million Bank Cubic Metres MFT Mature Fine Tailings ML Mildred Lake Mm 3 Million cubic metres MR Muskeg River Mt Million Tonnes NS North-South OB Overburden O/F Overflow (referring to the CT Plant hydrocyclone overflow stream) RCW Recycle Water R&D Research and Development SCT Straight Coarse Tailings (or conventional coarse tailings) TFT Thin Fine Tailings TR# Train # TT Thickened Tailings TV:BIP Total Volume to Bitumen In Place µm Micrometer U/F Underflow (referring to the CT Plant hydrocyclone underflow stream)

4 1.0 Introduction The 2009 Annual Tailings Plan for the Aurora North project is submitted in compliance with Section of Directive 074: Tailings Performance Criteria and Requirements for Oil Sands Mining Schemes. The Aurora North project currently operates under ERCB Approval No , as amended. For ease of reference, a concordance table for Appendix E of Directive 074 is included in Appendix Current Operations (Leases 10/12/34) Syncrude s oil sands activities at Aurora North include mining operations and bitumen froth production. Further processing of the bitumen froth at the Mildred Lake upgrader results in the production of a bottomless, light sweet synthetic crude oil. Figure 1.1 provides a schematic of the integrated Syncrude operation. A location map for the facilities at the Aurora North Project is provided in Figure 1.2. Oil sand mining at the Aurora North site uses truck and shovel surface mining technology. The mining sequence consists of ore body and mineable pit delineation, tree clearing, surface and basal aquifer dewatering as required, reclamation material removal, overburden stripping, oil sand mining, in-pit placement of tailings and overburden, and reclamation material placement. At present, approximately 117 million tonnes of ore are mined annually at the Aurora North site. The ore is mixed with hot water and delivered to primary extraction using hydrotransport technology. Separation of bitumen from oil sands is accomplished through warm slurry extraction. Bitumen froth produced at Aurora North is pipelined to the Mildred Lake site where it is blended with Mildred Lake froth prior to froth treatment for further removal of water and solids in froth treatment. The final bitumen product is a relatively clean heavy hydrocarbon used as feedstock to the Syncrude upgrader. Tailings, the materials remaining after bitumen is extracted from oil sands, is a mixture of sand, silt, clay, water, and residual hydrocarbon. Tailings are distributed hydraulically via a network of pipelines to placement areas. Syncrude currently operates one out-ofpit tailings deposition area at Aurora North: namely, the Aurora Settling Basin (ASB). Syncrude will begin in-pit tailings deposition at the Aurora North site in the Aurora East Pit North East (AEPNE) in Syncrude Canada Ltd Directive 074 Submission: Aurora North Page 1 of 39

5 Figure 1.1 Overall Syncrude Process Flow PLANT UTILITIES Athabasca River Water Process Byproduct Utilities Geological structure Oil sand Steam Generator at Mildred Lake and Aurora mines Treated Sanitary Sewage Midred Lake s Base Mine Geological structure Dump pocket Oil Sand Slurry Utility Boiler Potable Water Pipeline terminals and refineries Mildred Lake s Auxiliary Production System Geological structure Mildred Lake s North Mine hydrotransport Geological structure Aurora s North north operation Mine Hydrotransport Aurora s Settling Basin (ASB) at Aurora s North north operation Geological structure Aurora s South south operation Mine Hydrotransport Aurora s South south operation s tailings placement area Oil Sand Slurry Screens Stack Precipitator Primary Separation To be replaced by Cyclofeeder SER Project facilities by Bitumen Froth Bitumen Froth Froth Froth PSV Diluent Inclined Plate Settler DRU Centrifuge Tailings Oil Recovery Tailings Water to Utilities For Recycling Southwest Sand Mildred Lake Tailings Storage (SWSS) Settling Basin (MLSB) Coke CO Boiler Cells Water Treatment Coke Silos Fluid Cokers Blended product to pipeline Synthetic crude oil Hydrotreaters storage and blending Sulphur Vacuum Distillation Unit Sulphur stock pile Hydrogen Plant LC-Finer Natural Gas MINING EXTRACTION UPGRADING DISTRIBUTION Syncrude Canada Ltd Directive 074 Submission: Aurora North Page 2 of 39

6 Figure 1.2 Location Map for Aurora North Facilities Line 2 Line 3 Floats line RCW line TR1 RCW Line TR2 Ramp 4 ACTIVE Cell 56 Cell 57 ACTIVE Cell 58 Ramp 3 Sump Cell 59 Ramp 5 Cell 55 ASB ACTIVE Cell 60 Ramp 3 Muskeg River Sump Pond 3 Cell 54 Cell 53 Cell 62 Cell 61 North Seepage Cell 63 ACTIVE Ramp 6 Cell 52 ACTIVE Ramp 2 RCW Pond Ramp 1 South Seepage Tailings Syncrude Canada Ltd Directive 074 Submission: Aurora North Page 3 of 39

7 2.0 Tailings and Mining Plans 2.1 Tailings Management Strategy Tailings are currently stored out-of-pit in the ASB facility. As advance of the mine face makes in-pit storage available, containment dykes are being constructed and in-pit tailings storage facilities established. Syncrude s tailings disposal plan is integrated throughout all mine areas to optimize the use of available storage capacity. The objectives of the tailings management strategy are to minimize fluid transfer requirements, ensure a reliable recycle water supply for plant operations, and maximize the future use of in-pit capacity for CT and fluid containment. Dykes are licensed structures and must be designed to ensure geotechnical stability. Based on material availability, dyke designs may include the use of overburden, tailings sand, or a combination of both. Overburden dykes are constructed using mobile equipment for material placement, while sand dykes use standard tailings slurry cell construction techniques. Overburden dyke construction often entails zonation of material through the dyke cross section to maximize utilization of overburden materials available. Both types of structures are closely monitored to ensure the geotechnical design criteria are met. The tailings technology portfolio for the Aurora North Project includes CT and water capped mature fine tailings 1 (MFT) in an End Pit Lake (EPL), pending validation of the technology via the Base Mine Lake demonstration at the Mildred Lake site. Commercial scale Composite Tailings (CT) deposition is scheduled to begin in 2013 at Aurora North, with placement of CT in Aurora East Pit North (AEPN). CT remains one of the primary technologies for MFT management at Syncrude and is instrumental in achieving targeted end of mine life MFT inventories. To produce CT, coarse tailings are pipelined from the extraction plant to the CT plant, where they are cycloned to produce a densified coarse tailings stream. The densified coarse tailings stream is combined with MFT and gypsum to form CT. The CT product is then transported hydraulically to the designated tailings disposal facility. Once deposited in the pond, the mixture dewaters relatively rapidly, leaving a soft deposit that is capped using coarse tailings sand to create a trafficable surface for reclamation. The current mass balance assumes the implementation of a supplementary fines management technology to complement CT at Aurora North, beginning in The supplementary technology is represented in the current tailings model as Thickened Tailings (TT); with a portion of the TT stream utilized as the fines feedstock for the CT plant. Syncrude is currently evaluating a number of fines management technologies; a thorough technology selection process will be utilized to come to a decision on the technology to implement to supplement CT at Aurora North. Technologies being considered include, but are not limited to, TT, centrifuged MFT, and accelerated MFT dewatering. Key tailings planning assumptions are included in table 2.1. The containment chart shown in Figure 2.1 summarizes total tailings production and containment availability for the Aurora North site. 1 Syncrude uses the terms mature fine tailings (MFT) and fluid fine tailings (FFT) interchangeably to refer to a fluid deposit composed primarily of tailings fines (<44 micrometers) and water. Syncrude Canada Ltd Directive 074 Submission: Aurora North Page 4 of 39

8 Table 2.1 Key Tailings Planning Assumptions Item Unit Aurora North 1 TVBIP ratio 12 2 Extraction Recovery 90.40% % 3 CT Sand to Fines Ratio 4:1 4 Water Inventory (Year End 2008) Mm MFT Inventory (Year End 2008) Mm Straight Coarse Tails Slurry Sg Tonnes/m Flotation Tails Slurry Sg Tonnes/m CT Slurry Sg Tonnes/m Beach above water slope % 1% 10 Beach below water slope % 4% 11 CT slope % 0.5% 12 MFT Projected Consolidation % 39.3% % Figure 2.1 Tailings Containment Chart for Aurora North Year End Cumulative Tailings Growth (Mm3) Mine Tonnage (Mt) Sand CT Thickened tails MFT RCW Contingency Space Years Containment volume available Syncrude Canada Ltd Directive 074 Submission: Aurora North Page 5 of 39

9 2.2 Dedicated Disposal Area (DDA) Strategy Syncrude is currently evaluating options to create dedicated disposal areas for fines capture technologies concordant with the fines sequestration objectives of ERCB Directive 074. The fines management technology portfolio for the Aurora North site currently includes Composite Tailings (CT) and MFT water capping in an end-of-pit lake (EPL) concept. A supplementary fines management technology is also assumed to complement fines capture from CT; the current mass balance assumes thickened tailings for planning purposes, but the final technology selection decision has not yet been completed. The management strategy prioritizes deposition of MFT and engineered tails deposits in mined out pits Current Operations Tailings field operations flexibility and containment construction within the DDA are key planning considerations in the design and operating strategy of these tailings disposal areas. Prior to start up for the CT plant at the Aurora North site in 2013, Syncrude continues to rely on conventional dykes and beach construction using coarse tailings at the Aurora Settling Basin and at in Aurora East Pit West (AEPW) beginning in Future Dedicated Disposal Areas Dedicated disposal areas (DDA) at the Aurora North site are shown in Figure 2.2. DDA 1 is planned to be operated within the Aurora East Pit Northwest (AEPNW) mining area. This area is contained by the insitu pit walls on the north and west sides and an overburden dyke to the South and a sand dyke to the East. The pit will initially contain coarse tailings to support the dyke construction and the strategy to establish a trafficable surface as early as possible. Upon startup of the CT plant, CT will be deposited in the area until DDA 2 becomes available. As the CT placement shifts to DDA 2, DDA 1 will remain as the deposit area for coarse sand when the CT plant is not operational. Thin fine tailings (TFT) from DDA 1 will be returned via pumps or gravity drains to AEPNE. DDA 2 located in the Aurora East Pit South (AEPS) and is contained by insitu walls on the East and South and overburden dykes constructed on the North and West sides. This DDA will be a CT deposit. Fluids will be returned via a barge to Aurora East Pit Northeast (AEPNE). DDA 3 is located in the Aurora East Pit North (AEPNE). This area is contained by insitu walls to the north and east, an overburden dyke to the south and a sand dyke to the west. This pit is the first inpit area to be completed by mining, but will initially serve as the primary TFT collection pond and will not be used as a DDA until later in the plan. Collected fluids will be transferred to ASB for clarification and water recycle. Placement of sand during tailings line or CT plant outages is also planned. Subsequent placement includes CT and sand capping. DDA s 4 through 7 are developed in sequence with mine advance and subsequent in-pit volume availability. All of these DDA s utilize overburden dykes to provide containment. Placement of engineered tails is concurrent with sand capping activities. Sand will also be required for the construction of the East pit closure dam. The TFT storage pond will be relocated in sequence with DDA development. This fluid will be transferred to the plant or to ASB for clarification. DDA s 4,5 and 6 are located along a common lease boundary with other lease operators. Syncrude is currently working with these operators to develop common lease boundary plans and will adjust the DDA s plans accordingly. Syncrude Canada Ltd Directive 074 Submission: Aurora North Page 6 of 39

10 Figure 2.2 Aurora North Proposed DDA Locations Syncrude Canada Ltd Directive 074 Submission: Aurora North Page 7 of 39

11 2.2.3 Additional Activities Fines management remains a focus area for Research and Development (R&D) efforts at Syncrude. R&D activities are concentrated on continuous improvement and reclamation for the existing fines management technologies (CT, MFT centrifuging and MFT water capping) as well as continued exploration of new alternatives. Depending on R&D results, the future DDA plans may be adjusted to include other technologies for fines capture Fines Management Figure 2.3 displays estimated MFT inventory for the Aurora North Project assuming both continued reliance on CT and the staged implementation of supplementary fines management technology. The remaining fluid fines inventory at the end of mine life will be stored into an EPL facility. Figure 2.3 MFT Inventory Curve Aurora North MFT projections MFT volume (Mm 3 ) Years Syncrude Canada Ltd Directive 074 Submission: Aurora North Page 8 of 39

12 2.3 Reconciliation to Approved Plan The tailings plan for the Aurora North site included in this annual submission uses the material balance submitted to the ERCB on 25 October 2007 as a starting point; incorporating the following changes to reflect technology selection and development timing at Aurora North: o CT production beginning in 2013 (as noted in the text of the 2007 letter); o Application of the supplementary fines management technology (TT) delayed to 2018; and o Overall efficiency of the TT facilities adjusted down to 80% from 100%. Future submissions will reconcile to this Tailings Management Plan submission. The tailings plan included in this submission supports the landform and drainage features included in the C&R Plan approved by AENV in Opportunities Under Consideration Syncrude will be updating its tailings management plans to reflect business / strategic decisions being made. Opportunities currently under consideration that would potentially result in changes to future tailings plans include: o Changes in mining rates in the North Mine from 2015 onward; o Potential integration of the Fort Hills Dump design with the AEPN DDA designs; o Mining to TV:BIP limits greater than 12.0 in some areas; and o Integration of the Mildred Lake and Aurora South projects. Syncrude Canada Ltd Directive 074 Submission: Aurora North Page 9 of 39

13 3.0 Planning Details 3.1 Mining The Aurora North Mine development sequence is shown on Figure 3.1, with corresponding ore production rates provided in Table 3.1. Ore quality parameters based on the Syncrude geology block model are also included in Table 3.1. Aurora North Mine advance in 2010 is confined to the East Pit, prioritizing development of dyke footprint areas in preparation for in-pit tailings while allowing for ore blending and dyke construction. Also in 2010 the Center Pit overburden removal begins. The south end of the East Pit is completed in 2013 while Center Pit mining commences in 2011, advancing north. Beyond 2022 Center and West Pit development continues south and west. Completion of mining occurs in The waste disposal schedule is shown in Table 3.2. Rejects and reclamation material volumes are not included in this table. This plan assumes a new out-of-pit dump being developed northeast of the existing Fort Hills Dump, the Area 2 Dump. Syncrude has recently reassessed out-of-pit dump alternatives and is currently planning on moving ahead with an expanded FHD instead of constructing the Area 2 Dump as shown in this plan. An application is planned to be submitted to the ERCB in Q Syncrude Canada Ltd Directive 074 Submission: Aurora North Page 10 of 39

14 Figure 3.1 Mine Development Sequence Syncrude Canada Ltd Directive 074 Submission: Aurora North Page 11 of 39

15 Table 3.1 Mine Plan Ore Summary Ore Grade Water Solid Fines (<44μ m) Coarse solids (>44μ m) Recovered Bitumen Year Million Tonnes % (weight) % (weight) % (weight) % (weight) % (weight) Million Barrels (per ID ) % 3.5% 85.2% 21.8% 78.2% % 3.5% 85.8% 25.2% 74.8% % 3.5% 85.3% 25.1% 74.9% % 3.5% 85.6% 26.3% 73.7% % 3.5% 84.9% 23.4% 76.6% % 3.5% 84.7% 22.3% 77.7% % 3.5% 85.2% 22.3% 77.7% % 3.5% 85.5% 23.5% 76.5% % 3.5% 85.3% 23.3% 76.7% % 3.5% 85.4% 23.4% 76.6% % 3.5% 85.4% 23.7% 76.3% % 3.5% 85.4% 24.7% 75.3% % 3.5% 85.6% 23.3% 76.7% % 3.5% 85.7% 21.8% 78.2% % 3.5% 85.6% 20.9% 79.1% % 3.5% 85.4% 20.0% 80.0% % 3.5% 85.7% 26.7% 73.3% % 3.5% 85.5% 24.9% 75.1% % 3.5% 85.3% 24.5% 75.5% % 3.5% 85.2% 24.5% 75.5% % 3.5% 85.2% 20.7% 79.3% % 3.5% 85.2% 21.1% 78.9% % 3.5% 85.1% 21.1% 78.9% % 3.5% 85.3% 21.9% 78.1% % 3.5% 85.8% 25.0% 75.0% % 3.5% 85.5% 27.0% 73.0% % 3.5% 85.6% 25.6% 74.4% % 3.5% 85.3% 25.7% 74.3% % 3.5% 85.6% 24.5% 75.5% % 3.5% 86.0% 25.3% 74.7% 55.6 Syncrude Canada Ltd Directive 074 Submission: Aurora North Page 12 of 39

16 Table 3.2 Mine Plan Waste Summary Year Overburden Interburden Total OBIB Million BCM Million BCM Million BCM Tailings The tailings production schedule is shown in Table 3.3. The tailings volumes shown in the table represent final deposit volumes. The tailings disposal sequence at the Aurora North site balances fluid containment needs and dyke construction, while supporting closure initiatives. The tailings disposal schedule is closely integrated with the mine plan, in-pit tailings storage space being utilized as soon as it becomes available. The tailings plan is based on the following key assumptions: Syncrude Canada Ltd Directive 074 Submission: Aurora North Page 13 of 39

17 o Sand allocation consistent with the following priorities: o Containment construction, o Geotechnical beaching, o CT capping, and o Maximization of CT production with remaining sand. o Tailings placement in Aurora East Pit (AEPNE) starting in 2010; o Implementation of CT technology for fines management starting in 2013; and o Implementation of a supplementary fines management technology in Tailings deposit types and volumes for each facility are included in Table Aurora Settling Basin: The ASB is used primarily as a fluid storage facility. It currently provides storage for coarse tailings (SCT), MFT and recycle water. ASB is planned to remain the primary settling area and source of recycle water until closure. At closure, remaining fluid MFT and water from the ASB will be transferred to the End Pit Lake (EPL) Aurora North Future Storage: The Aurora North in-pit tailings dykes will be constructed mainly using mine waste material, including overburden and interburden. The construction of Dyke1E and 1N in the East Pit will be completed in The north and east portions of this dyke will be constructed to allow tailings deposition in Aurora East Pit North East (AEPNE) in Dyke1 West is to be constructed between 2012 and 2015 with tailings deposition starting in Aurora East Pit North West (AEPNW) in Dyke2 between East and Center Pit is to be built for containment beginning in 2014 in the southern portion of Aurora East Pit (AEP). The Aurora East Pit Closure Dam (AEPCD) is to be constructed by 2018 to ensure containment in the northeast portion of the AEP, above original ground. Dyke3 (Center Pit) and Dyke4 are required for containment in Aurora Center Pit North East (ACPNE) in 2022 and Aurora Center Pit North West (ACPNW) in A Boundary Dyke along the lease boundary shared by Shell and Syncrude at the south end of Center and West Pit is required for containment in Aurora Center Pit South (ACPS) in Syncrude will continue to work with Shell on an integrated strategy to manage the common pit boundary. The West Dyke is required for containment in Aurora West Pit South (AWPS) in Syncrude Canada Ltd Directive 074 Submission: Aurora North Page 14 of 39

18 Year Table 3.3 Tailings Production Summary Aurora North Production Million Tonnes Aurora North Fines to Rejects Million Tonnes AN Aurora Froth North Fines Froth to Fines ML to Coarse Tailings Cyclone Overflow Thickened Tailings Cell Beach Total Annually Cumulative Million % of fines in Tonnes Mm 3 /y Mm 3 /y Mm 3 /y Mm 3 /y Mm 3 /y Mm 3 /y Mm 3 /y Mm 3 /y Mm 3 Mm 3 Feed % % % % % % % % % % % % % % % % % % % % % % % % % % #N/A #N/A #N/A #N/A #N/A #N/A #N/A Note: all tailings volumes shown represent deposit volumes. * Fines Capture = (Weight of fines in CT + Weight of fines in thickened tails) / (Weight of fines in ore - Weight of fines in rejects) Syncrude Canada Ltd Directive 074 Submission: Aurora North Page 15 of 39 CT Flotation Tailings Centrifuge Cake MFT (Cumulative) Water (Cumulative) Fines Capture * (CT and Thicked Tails) Million Tonnes

19 3.3 Key Milestones The integrated mining/tailings plan is illustrated for the years 2009, 2010, 2012, 2014, 2022, 2026, 2030, 2036, 2038, 2039 and 2046 in Figures 3.2 to Fluid elevations are posted at each relevant location. In 2009 (Figure 3.2), tailings placement is confined to ASB. Dyke 1 is being constructed in preparation for future tailings containment. The Fort Hills Dump (FHD) is the major location for hauling non-construction mine waste. The 2010 status map (Figure 3.3) shows progress in building Dyke 1 West. In-pit active tailings placement starts in AEPNE. Tailings placement will be limited to coarse tailings beaching until CT plant startup in The 2012 status map (Figure 3.4) shows progress in building Dyke 1 and Dyke 2. Coarse tailings beaching continues in AEPNE. The Area 2 out-of-pit dump footprint has been established and it becomes the primary location for non-construction mine waste. Note that Syncrude is currently planning on moving ahead with an expanded FHD instead of constructing the Area 2 Dump as shown on in this plan. The 2014 status map (Figure 3.5) assumes use of the AEPS as an active tailings placement area. CT is the primary deposit in this DDA. Dyke2 is nearing completion. By 2022 (Figure 3.6), Dyke 3 and Center Pit NS Dyke have progressed sufficiently to allow CT and coarse tailings beach to be placed in Center Pit North East (ACPNE). The Aurora East Pit Closure Dam (AEPCD) has been completed. The 2026 status map (Figure 3.7) shows completion of the Dyke 3 footprint and placement of tailings in Center Pit North West (ACPNW). By 2030 (Figure 3.8), the Dyke 4 and Boundary Dyke footprints have been established to provide tailings storage in the Aurora Center Pit South (ACPS). The 2036 status map (Figure 3.9) notes that the West Dyke is in place for tailings placement to begin in the Aurora West Pit South (AWPS). Overburden stripping is complete in 2038 (Figure 3.10) and ore mining is complete in 2039 (Figure 3.11). At closure, the ASB, East Pit, Center Pit and north portion of the West Pit are reclaimed as dry landscape features, as shown in Figure An EPL is established in the West Pit area. Syncrude Canada Ltd Directive 074 Submission: Aurora North Page 16 of 39

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31 4.0 Construction Details Aurora North Mine Waste Specification by construction material type is as shown in Table 4.1. Available High spec. is 50% of total Gr15 material. Gr15 is determined based on very low clay content facies that provide high quality construction material. Medium Spec. volume available is 50% of total Gr15 material plus 60% of Gr25 and Gr50 material. Gr25 and Gr50 material contains facies that provide medium quality construction material. The difference between available and planned use volumes in Table 4.1 accounts for weather and operational restrictions limiting placement in structures. Table 4.1 Mine Waste Construction Material Schedule Year High Spec. Medium Spec. Low Spec. TOTAL WASTE Available Planned use Available Planned use Available Planned use Available Planned use MBCM MBCM MBCM MBCM MBCM MBCM MBCM MBCM Syncrude Canada Ltd Directive 074 Submission: Aurora North Page 28 of 39

32 The Waste Disposal Schedule by placement area is shown in Table 4.2. Table 4.2 Mine Waste Disposal Schedule Year Dyke Construction (East pit, Center pit and West pit dykes) Waste Dumps Total Dyke 1 Dyke 1 Dyke 2 Dyke3 E Dyke3 NS Dyke3 W Dyke4 West Dyke Fort Hills Area2 Inpit Waste (E+N) (west) (west dyke) (CP dyke) (CP dyke) (CP dyke) (CP dyke) (WP dyke) Dump dump Dump MBCM MBCM MBCM MBCM MBCM MBCM MBCM MBCM MBCM MBCM MBCM MBCM Syncrude Canada Ltd Directive 074 Submission: Aurora North Page 29 of 39

33 The Aurora North tailings disposal schedule by placement area is shown in Table 4.3. The breakdown is by storage facility and material type. Values represent incremental deposit volumes from 2008 onward (MFT and water are net volumes). Table 4.3 Tailings Disposal Schedule Year Aurora Settling Basin (ASB) Aurora East Pit (AEP) Aurora Center Pit (ACP) Aurora West Pit (AWP) CT SCT Flotatio Thickene Cyclone MFT Water CT SCT Flotatio Thickene Cyclone MFT Water CT SCT Flotatio Thickene Cyclone MFT Water CT SCT Flotatio Thickene Cyclone MFT Water n tails d tails O/F n tails d tails O/F n tails d tails O/F n tails d tails O/F Note: all numbers are in million m 3 and represent Incremental deposit volumes from 2008 onward (MFT and water are net volumes) Syncrude Canada Ltd Directive 074 Submission: Aurora North Page 30 of 39

34 4.1 Aurora Settling Basin Construction of the ASB facility will be executed using conventional cell techniques. The final dyke crest elevation of 350 masl will be complete in Dyke 1E and N Dyke 1E (East) and 1N (North) are now being constructed. They will be completed in Dyke 1N (North) partitions AEPNE and AEPNW and is partially built with tailings sand. Dyke 1E Is built entirely of mine waste and allows for earlier tailings disposal in the AEPNE area, while protecting mine equipment operating at the base of the pit. Figure 4.1 shows the current asbuilt for Dyke 1E and N. The 2012 status map (Figure 3.4) provides an overview of the entire Dyke 1 configuration relative to other features. A typical design cross section for Dyke 1 is illustrated in Figure 4.2. The construction schedule for Dyke 1E and N is shown in Table 4.4 below. 4.3 Dyke 1W Dyke 1W (West) allows containment in AEPNW and is to be completed in Dyke 1E Is built entirely of mine waste and protects mining equipment operating at pit bottom. 4.4 Dyke 2 Dyke 2 partitions the Center Pit from the East Pit. Table 4.4 has the yearly volume placement to 2014 and top elevation(s) of the in-pit structures. Dyke 2 is scheduled for completion in 2014 at 300 masl. Syncrude Canada Ltd Directive 074 Submission: Aurora North Page 31 of 39

35 Table 4.4 Structure Construction Schedule AN Dyke1(E+N) AN Dyke1(west) AN Dyke2 AN Dyke3 E(CP) AN Dyke3 NS(CP) AN Dyke3 W(CP) AN Dyke4(CP) AN West Dyke(WP) Year Volume Elevation Volume Elevation Volume Elevation Volume Elevation Volume Elevation Volume Elevation Volume Elevation Volume Elevation MBCM masl. MBCM masl. MBCM masl. MBCM masl. MBCM masl. MBCM masl. MBCM masl. MBCM masl Syncrude Canada Ltd Directive 074 Submission: Aurora North Page 32 of 39

36 Figure 4.1 Dyke 1 Asbuilt (Year End 2008) Syncrude Canada Ltd Directive 074 Submission: Aurora North Page 33 of 39

37 Figure 4.2 Typical Design Cross Section for Dyke 1 Gr. 15 (-15% clay content) Gr. 50 ( - 50% clay content) Gr. 25 Filter Gr. 15 (-15% clay content) Gr. 50 (-50% clay content) Capped Dump PON 2m Base Prep Gr. 15 (-15% clay content) Gr. 25 ( - 25% clay content) Tailings Sand Gr. (-15% clay content) PON Syncrude Canada Ltd Directive 074 Submission: Aurora North Page 34 of 39

38 5.0 Site Wide Material Balance A projected site wide material balance is provided in Tables 5.1 to 5.3. The table is provided in three parts: Sand Management (> 44µm Solids Fraction), Fines Management (< 44µm Solids Fraction and Aurora North Free (i.e. Recycle) Water Management. Syncrude Canada Ltd Directive 074 Submission: Aurora North Page 35 of 39

39 Table 5.1 Site Wide Material Balance Sand Management Sand Management (> 44µ Solids Fraction) Net Feed Sand Sand in Slurry Streams Cycloned & Straight Coarse Tails Sand Sand to Deposits Other Information Froth Sand to Pri. Extract Sec. Extract Non- Cycloned Sand to CT SCT Cyclone CT (U/F) Thickener U/F CT Thickened New MFT Float / Sand in CT % Total Year Recovered Bit Sand in feed Rejects ML Sand Sand Sand Cyclones SCT Cell Cell/Beach O/F Feedstock Feedstock Tails Solids Froth Tails Middlings MFT to CT Deposit sand to CT MBBl bit (dry Mt) (dry Mt) (dry Mt) (dry Mt) (dry Mt) (dry Mt) (dry Mt) (dry Mt) (dry Mt) (dry Mt) (dry Mt) (dry Mt) (dry Mt) (dry Mt) (dry Mt) (dry Mt) (dry Mt) (dry Mt) (dry Mt) % % % % % % % % % % % % % % % % % % % % % % % % % % Net Sand Feed Balance: [Sand in Feed] - [Rejects] - [Froth h Sand to ML] = [Primary Extraction Sand] + [Secondary Extraction Sand] Complete Sand Balance: [Primary Extraction Sand] + [Secondary Extraction Sand] = [Cell] + [Beach] + [Cyclone O/F] + [Cyclone U/F (CT Feedstock)] + [Cyclone U/F (CT Feedstock)] + [Thickener U/F (CT Feedstock)] + [Thickened Tails] + [Sand to new MFT] + [Froth Tails] + [Float / Middlings Tails] Construction Sand Balance: [Primary Extraction Sand] = [Non-Cycloned Sand] + [Sand to CT Cyclones] Sand in CT Deposit Balance: [CT Deposit Sand] = [Cyclone Feedstock Sand (U/F) to CT] + [Sand in MFT to CT] + [Thickener U/F (CT Feedstock)] % Sand to CT Process = [Sand to CT Cyclones] [Primary Extraction Sand] Syncrude Canada Ltd Directive 074 Submission: Aurora North Page 36 of 39

40 Table 5.2 Site Wide Material Balance Fines Management Fines Management (< 44µ Solids Fraction) Fines in Net Feed Fines in Suspension Fines to Deposits New Fines Rejects Froth Fines Total Site Site MFT Inventory New TFT Fines in Site MFT Inventory Cell/Beach Cyclone U/F CT Thickener U/F CT Thickened Float Tails & CT Deposit CT SFR Year Recovered Bit in Feed Fines to ML MFT (Start) Fines MFT to CT (End) Fines Feedstock Feedstock Tails Cyc. O/F Fines Ratio MBBl bit (dry Mt) (dry Mt) (dry Mt) % solids by w t. (dry Mt) (dry Mt) (dry Mt) (dry Mt) (dry Mt) (dry Mt) (dry Mt) (dry Mt) (dry Mt) (dry Mt) Fines in n Suspension (MFT) Balance: [Site MFT Inv. (Start)] + [New TFT Fines] - [Fines in MFT to CT Process] = [Net Site MFT Inventory (Ending)] New Fines Balance: [New Fines in Feed] - [Reject Fines] - [Froth Fines to ML] = [New TFT Fines] + [Cell/Beach Fines] + [Cyclone U/F Fines to CT] + [Thickener U/F Fines to CT] + [Thickened Tails Deposit] + [Cyc. O/F; Froth; & middlings Fines] Fines in n CT Deposit Balance: [CT Deposit Fines] = [Fines in MFT to CT] + [Cyclone U/F Fines to CT] + [Thickener U/F Fines to CT] Syncrude Canada Ltd Directive 074 Submission: Aurora North Page 37 of 39

41 Table 5.3 Site Wide Material Balance Water Management Aurora North Free (i.e. Recycle) Water Management Free Water Inventory (start) Net New Free Water Free Water Inventory (end) Year Recovered Bit MBbl bit (Mm 3 ) (Mm 3 ) (Mm 3 ) (5.00) (5.00) (5.00) Syncrude Canada Ltd Directive 074 Submission: Aurora North Page 38 of 39

42 6.0 Water Chemistry A summary of the monitoring program in place in the vicinity of tailings disposal areas at the Aurora North site has been prepared from the 2008 Groundwater Monitoring Report Syncrude Aurora North, submitted to AENV on March 15, The Aurora North monitoring program at the Aurora North site currently includes seventy-three wells sitewide. The groundwater monitoring network focuses on the tailings area, with particular emphasis on the north and east side. An integral part of the external tailings pond design is the perimeter ditch, which is designed to act as a hydraulic sink. The ditch was excavated below the local groundwater table, to create a gradient towards the ditch from both the tailings pond and the surrounding environment. The perimeter ditch flows into sumps at various locations, from which water is pumped back into the tailings pond. The system has operated effectively in most areas over the year and has reduced the import of significant volumes of water from the environment. There are four areas where contamination from process water has been identified beyond the perimeter ditch. All other monitoring wells continue to indicate background conditions. Three wells in the South Seepage Area have shown chemistry similar with the type of water influenced by process water. Despite these localized change in water chemistry, Syncrude believes that the procedures are adequate to monitor and control seepage in this area. South Seepage is to be operated with a maximum water elevation of 280m. The 280 masl elevation is below the mean Muskeg River elevation and approximately equal to the seasonal low river elevation. All other monitoring wells in the area exhibit water chemistry typical of background conditions. Syncrude believes that the hydraulic control provided by the sump combined with the limited aquifer thickness in the area; provide reasonable containment of the process water. In the East Tailings Area process water was identified migrating beyond the perimeter ditch on the east side of the Aurora Settling Basin during The MR Sump was constructed to intercept the seepage and return the water to the perimeter ditch. In 2005 a cut-off wall was constructed south of Ramp 3. Syncrude is satisfied that the cut-off wall is impeding the influx of clean water but is permitting the egress of processaffected waters. Pumping of the MR Sump to the perimeter ditch has commenced again to mitigate the influence of process water in the area. In the North Tailings Area groundwater contamination was identified north of the tailings dyke in It is believed that the plume is still being influenced by additional process water though the cut-off wall. The cut-off wall is slowing down the recharge but is not completely preventing it. Syncrude will continue monitoring and tracking the movement of process affected waters in the area. The area affected by the plume is within the boundaries of the future Northeast Pit, planned to be mined out in the future. The water chemistry along the Muskeg River continues to show seasonal variability that corresponds with river flows. The water monitoring has not identified any impact from the Aurora North site facilities. Syncrude Canada Ltd Directive 074 Submission: Aurora North Page 39 of 39