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4 Spill Response Planning and Implementation
Pages 73-88

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From page 73...
... The multiple factors that can contribute to spill occurrence can include unpredictable accidents resulting from human actions; for example, the 2007 diluted bitumen spill in Burnaby, British Columbia (Box 3-4) , was the result of construction activities unrelated to pipeline operations.37b The vulnerability of communities and environments potentially affected can be assessed in advance, however, and these factors become a key component of spill response planning.
From page 74...
... Responders on scene must use their experience to adjust the response plan to the circumstances that confront them. Given this uncertainty regarding the magnitude and character of any specific incident, spill response planning for pipelines is based on the concept of the "Worst Case Discharge," which is the largest foreseeable discharge of oil, including a discharge from fire or explosion, in adverse weather conditions.
From page 75...
... The chapter concludes with a summary of the specific challenges for spill response planning and implementation presented by the transport of diluted bitumen in pipelines. IMPLEMENTATION OF PLANS Predicting the Behavior of Spilled Oil In framing and scaling an actual incident, responders ask the following questions: • What and how much was/is being spilled?
From page 76...
... For example, the windage factor, which provides the transport speed of oil, is typically equal to 3% to 4% in the early stages of a conventional oil spill,87 and it is later decreased further as the oil weathers and forms emulsions. For diluted bitumen, the residual oil density can increase rapidly with the evaporation of the volatile diluent components.
From page 77...
... There may also be a need for real-time measurements of concentrations in work areas and for use by workers of passive air-monitoring and dosimeter badges, which are sent for analysis in order to monitor exposure. A program of this kind was implemented during the recent spills of diluted bitumen in Marshall, MI (Box 3-1)
From page 78...
... Achieving consensus on cleanup endpoints for spills of diluted bitumen can be challenging if the crude oil sinks and continues to generate sheens in areas of high public use, or where the residual crude oil adhering to substrates is difficult to remove.
From page 79...
... TABLE 4-1  Guidelines for Selecting Cleanup Methods and Endpoints for Different Inland Habitats Example Primarya Guidelines for No Further Basis for Treatment Applicable Habitats Treatment Methods Cleanup Endpoints Treatment Determination Protection of Public • High public use • Whatever needed • No visible oil • When oil residues are no Health and Safety areas to remove threats: • No detectable oil longer a threat to human • Residential areas excavate, cut, flush, (sight or smell) health and safety • Groundwater remove/replace • Falls below threshold odor supplies or exposure limits Protection of Sensitive Wetlands, bird nesting • Gross oil removal • No free-floating • Usually determined by Resources and Habitats areas, T&E species using vacuum, black oil or mousse resource manager or land habitat, wildlife skimming, manual on the water surface manager experts refuges, national removal using • No accessible oiled • Case studies that show parks, other walking boards in debris habitat damage from protected areas soft substrates • No oil in sediments aggressive treatment • Passive recovery of that are used • Particular sensitivity of a sheens for nesting, species or habitat hibernating, • Inability to replace habitat grubbing for food Removing Aesthetic • Hard substrates • Wipe, high • No visible oil • Less aggressive removal Impacts in High-Use such as bedrock, pressure, high • No more than 20% during seasonal lowAreas gravel, seawalls, temperature flush, stain or coat use periods could allow riprap cut, remove/replace natural processes to work • Beaches • Consider how long before • Vegetation the oil weathers • Debris • Public information campaign concerning remaining staining required 79 Continued
From page 80...
... black oil or mousse removal) bodies • Passively contain/ during flushing In high-use areas: • Seasonally flooded recover sheens with operations • Education on wetlands booms and sorbents • No longer generates considerations between black oil or mousse aggressive removal and during high-water chronic sheens events • Site specific studies to assess receptor risk 80
From page 81...
... chronic sheens bodies • Passively contain/ In high-use areas: • Seasonally flooded recover sheens with • Education on wetlands booms and sorbents considerations between aggressive removal and chronic sheens • Site specific studies to assess receptor risk Mitigating Sediment/Soil • Upland soils • Acutely remove the • No visual oil • High risk of erosion or Contamination • River/lake bed gross contamination greater than stain or excessive sedimentation sediments (excavate, dredge, coat • Unacceptable changes in • Wetland sediments flush, cut, remove/ • Does not release surface topography replace) black oil when • Avoid excessive change in • Passively contain/ disturbed sediment/soil quality, e.g., recover remobilized • Agriculture or organic matter content, oil with booms and pasture for human grain size sorbents use may need a • Potential permanent • In situ techniques ppm endpoint change to the habitat type such as e.g., wetland to open aeration, tilling, water phytoremediation, adding nutrients aSecondary Cleanup Endpoints should include "Or, as low as reasonably practicable considering net environmental benefit." SOURCE: Adapted from Whelan et al.92 81
From page 82...
... . One recent study93 found that diluted bitumen penetrated a sand column more slowly than light, medium, and heavy conventional crude oils, indicating diluted bitumen soaked into sandy substrates may be no more difficult to recover than other crude oils.
From page 83...
... , a possibility not addressed by most spill response plans that exist today. Weathered diluted bitumen adheres strongly to shorelines, vegetation, and debris and will be more difficult to remove from these surfaces
From page 84...
... Diluted bitumen, for which the viscosity thresholds are reached within 6-12 hours under mild to moderate open water conditions and at temperatures of 15°C to 20°C, therefore have a narrower window of opportunity for effective use of dispersants than conventional crude oils. In comparison, medium crude oils are expected to reach these thresholds within 24-72 hours in temperate conditions and possibly within 12-24 hours during the winter.46a In situ Burning Mesoscale tests9c showed that burning is viable on diluted bitumen weathered up to 1 day, with removal efficiencies of 50% to 75%.
From page 85...
... .76 As in all spills, early application of surface washing agents increases their effectiveness. In fact, their use has been preapproved by Regional Response Team 6 since 2003.97 During the Refugio spill, responders reported success in removing weathered oil from surfaces using dry-ice blasting, a technique that may also find application with surface cleaning of diluted bitumen (Box 3-3)
From page 86...
... Where the sunken material consists of oil-particle aggregates, it may be possible to refloat the crude oil by agitation of the bottom. Agitation using rakes or similar tools, injection of water using water wands, and injection of air using equipment such as pond aerators were all used during the cleanup of the Enbridge pipeline spill in the Kalamazoo River (Box 3-1)
From page 87...
... Table 4-2 provides a summary of the effectiveness of selected response tactics for spills of conventional crude oils compared to spills of diluted bitumen. CONCLUSIONS Spills of diluted bitumen will initially float regardless of the water density; thus, the first response actions are similar to those employed after spills of conventional crude oil.
From page 88...
... When sunken crude oil refloats spontaneously over a protected period, it can trigger the need for aggressive removal to mitigate the threats to water intakes, the public, fish, and wildlife. All of these threats are greater for spills of diluted bitumen than for spills of commonly transported crude oils.


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