A Spill Risk Assessment of the Enbridge Northern Gateway Project

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Separate quantitative analyses estimating return periods 2 for tanker, terminal, and pipeline spills were prepared for the ENGP regulatory application. Enbridge contracted Det Norske Veritas (DNV) to prepare the Technical Data Report entitled Marine Shipping Quantitative Risk Analysis (marine shipping QRA) that examines tanker and terminal spills in the BC study area and spills at the marine terminal in Kitimat (Brandsæter and Hoffman 2010). Furthermore, Enbridge prepared the risk analysis for pipeline spills between Kitimat, BC and Bruderheim, AB (Enbridge 2010b Vol. 7B) included in Volume 7B: Risk Assessment and Management of Spills -‐ Pipelines. An information request from the Joint Review Panel resulted in additional reports submitted in May 2012 evaluating risks associated with Kitimat Terminal (Bercha Group 2012a), public safety in populated areas along the pipeline route (Bercha Group 2012b), pipeline pump stations (Bercha Group 2012c), and pipeline leaks and ruptures (WorleyParsons 2012). The summary of spill estimates for the ENGP in this section largely relies on the following documents submitted as part of the ENGP regulatory application: • Volume 7B: Risk Assessment and Management of Spills -‐ Pipelines • Volume 7C: Risk Assessment and Management of Spills -‐ Kitimat Terminal • Volume 8C: Risk Assessment and Management of Spills -‐ Marine Transportation • TERMPOL Study No. 3.15: General Risk Analysis and Intended Methods of Reducing Risk • Marine Shipping Quantitative Risk Analysis by Det Norske Veritas • Northern Gateway Pipeline Kitimat Terminal Quantitative Risk Analysis by Bercha Group • Northern Gateway Pipeline Public Safety Quantitative Risk Analysis by Bercha Group • Northern Gateway Pipeline Pump Station Quantitative Risk Analysis by Bercha Group • Semi-‐Quantitative Risk Assessment by WorleyParsons. 3.1. Spills from Tanker Traffic Accessing Kitimat Terminal DNV determines spill return periods for tanker traffic accessing Kitimat Terminal in the Marine Shipping Quantitative Risk Analysis. DNV uses a per-‐voyage methodology to forecast spills in the marine shipping QRA based on nautical miles (nm) travelled by tankers within the study area. As part of the per-‐voyage methodology, DNV determines base incident frequencies from historical tanker incident data from Lloyds Register Fairplay (LRFP) for the period 1990-‐2006 (Brandsæter and Hoffman 2010 p. 5-‐49). The LRFP data likely reflects tankers operating in jurisdictions where mitigation measures such as escort tugs and marine safety measures such as those announced by the government of Canada are already in use. However, a lack of transparency in the marine QRA prevents verification of the LRFP data. DNV then calculates incident data for the BC study area by multiplying the international frequency data from LRFP by scaling factors that compare risks in the study area to the international areas on which the incident data are based. The comparison uses 1.0 as a baseline and thus a scaling factor equal to 1.0 suggests that the local conditions 2 DNV defines a return period as the number of years between spill events (Brandsæter and Hoffman 2010 p. 7-‐94). 6
affecting risk are equal to the world average (Brandsæter and Hoffman 2010 p. 5-‐52). DNV uses a range of scaling factors including the number of course changes, use of pilots with local knowledge, and the distance from ship to shore, among others. Table 2 presents base LRFP incident frequencies and the range of local scaling factors for each incident type. Table 2: LRFP Base Incident Frequencies and Local Scaling Factors for Incidents in BC Study Area Tanker Incident Type Base LRFP Incident Frequency (per nm) Range of Total Scaling Factors Powered Grounding 5.98E-‐07 0.001 -‐ 1.94 Drift Grounding 9.96E-‐08 0.01 -‐ 1.56 Collision 4.54E-‐07 0.01 -‐ 0.54 Foundering 5.04E-‐10 0.01 -‐ 1.50 Fire/Explosion Source: Brandsæter and Hoffman (2010). 3.26E-‐08 n/a DNV then determines the probability of a spill resulting from a tanker incident by using two different methods to estimate conditional spill probabilities. The first method (Method 1) determines conditional spill probabilities based on LFRP data. According to Brandsæter and Hoffman (2010), LRFP categorizes damages for the four incident types into minor damage, major damage, and total loss and LRFP provides a frequency distribution for each damage category. The second method (Method 2) estimates spill quantities for bottom and side damages based on information from the International Marine Organization International Convention for the Prevention of Pollution from Ships (MARPOL) and estimates spill size distribution with Naval Architecture Package software. Table 3 compares conditional spill probabilities from Methods 1 and 2 and shows the mean oil outflow for grounding and collision incidents estimated with Method 2. Table 3: Conditional Spill Probabilities for Tanker Incidents (Method 1 and Method 2) Incident Type Method 1 Conditional Spill Probability (%) Method 2 Laden Ballast Laden Ballast Mean Oil Outflow* (m3) Grounding 32.7 6.4 17.5 -‐ 18.7 < 0.1 -‐ 0.2 736 -‐ 1,725 Collision 19.1 2.6 21.0 -‐ 27.7 5.7 -‐ 14.2 638 -‐ 1,399 Foundering 100 100 n/a n/a Fire/Explosion 27.0 7.6 n/a n/a Source: Brandsæter and Hoffman (2010) * Mean oil outflow represents outflow from laden vessels (not vessels in ballast) In addition to determining spill probabilities for various tanker sizes and oil outflows, Method 2 also estimates probabilities for grounding and collision spills exceeding a certain volume. According to the Monte Carlo simulation, the probability of a spill greater than 10,000 m 3 for a laden VLCC grounding is 5.5% and 25% for a collision (Brandsæter and Hoffman 2010 p. 6-‐81 -‐ 6-‐85). The probability of a grounding spill exceeding 25,000 m 3 and 40,000 m 3 is 1% and 0.2%, respectively, while the probability 7
Page 1 and 2: A Spill Risk Assessment of the Enbr
Page 3 and 4: Table ES-‐1: Results for the Qu
Page 5 and 6: These findings show that the defici
Page 7 and 8: Table ES-‐4: Probabilities for
Page 9 and 10: increases to 99.9% if the volume of
Page 11 and 12: List of Equations, Figures and Tabl
Page 13 and 14: 1. Introduction This report provide
Page 15 and 16: Enbridge expects that tankers calli
Page 17: Major facilities at Kitimat Termina
Page 21 and 22: Table 5: Estimated Reduction in the
Page 23 and 24: medium size oil/condensate spills f
Page 25 and 26: Table 12: Return Periods for Spills
Page 27 and 28: adjustments ranging from 60 to 90%.
Page 29 and 30: Table 17: Evaluative Criteria for A
Page 31 and 32: Pollution from Ships (MARPOL) and N
Page 33 and 34: of escort and tethered tugs will re
Page 35 and 36: ENGP regulatory application. Furthe
Page 37 and 38: We acknowledge the difficulty in re
Page 39 and 40: Table 19: Spill Probabilities Over
Page 41 and 42: • Mortality of a small number of
Page 43 and 44: In its regulatory application for t
Page 45 and 46: accidents in Canada, the LRFP datab
Page 47 and 48: Evidence suggests that sulphur conc
Page 49 and 50: anging between 16 and 20 years 22 a
Page 51 and 52: The absence of expert review for th
Page 53 and 54: Risk Acceptability Risk Acceptabili
Page 55 and 56: the likelihood that environmental a
Page 57 and 58: 5. Extended Sensitivity Analysis fo
Page 59 and 60: Table 25: Five-‐Percentage Poin
Page 61 and 62: Sensitivity 6: Aggregating Paramete
Page 63 and 64: effects of different assumptions on
Page 65 and 66: combined, the NEB data suggests tha
Page 67 and 68: United States of America with the O
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2. Estimate the volume of oil and c
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1994 to 2008 international data and
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6.3. Spill Probability Estimates fo
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6.4. Summary of ENGP Spill Probabil
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The OSRA method clearly estimates s
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Evaluation: There is one major defi
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7. Comparison of Spill Estimates fo
Page 83 and 84:
operation. Our application of the O
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8. Conclusion This report evaluates
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Figure 5: Number of ENGP Terminal S
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References Alberta Energy and Utili
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Enbridge. (2004). 2004 Corporate So
Page 93 and 94:
MacDonald, K. (2012). Northern Gate
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United States Department of Transpo
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• Tankers sail in coastal areas w
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• Major Damage: Damage to the tan
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25% for a collision (Brandsæter an
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the overall tanker spill return per
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Table A-‐11: Sensitivity Analys
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Group estimates risks from spills t
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In the event a tanker is struck by
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a spill. Expressed as a return peri
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2012 as a response to an informatio
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Table A-‐23: Return Periods for
Page 117 and 118:
The first Bercha Group (2012c) stud
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A Spill Risk Assessment of the Enbridge Northern Gateway Project

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