National Academy of Science report points to dangers of bitumen spills

Pipeline spill

The National Academy of Sciences has released a major study on diluted bitumen (dilbit). The study, titled Spills of Diluted Bitumen from Pipelines: A Comparative Study of Environmental Fate, Effects, and Response, says dilbit presents unique risks compared to conventional oil.

Dilbit, simply refers to tar-like bitumen that has been diluted with one or more lighter petroleum products so that it can flow through a pipeline, such as the TransCanada Energy East and Kinder Morgan Trans Mountain pipelines. In short, the study confirms that diluted bitumen sinks in water if not cleaned up immediately.

Inside Climate News reports, "[The study] offers the most comprehensive analysis to date of dilbit spill properties, environmental and health impacts and effectiveness of response methods. ...The 144-page report's main message is that the thick type of oil called diluted bitumen ... initially behaves like conventional oil in the first few days following a spill but then quickly degrades, or weathers, into a substance so chemically and physically different that it defies standard spill responses."

The study states, "The prospect of a release of crude oil into the environment through a pipeline failure inherently raises a number of concerns. These concerns include not only minimizing a number of possible long-term environmental impacts but also protecting the safety of responders and the public during and after the spill response. When all risks are considered systematically, there must be a greater level of concern associated with spills of diluted bitumen compared to spills of commonly transported crude oils."

It also states, "Spills of diluted bitumen into a body of water initially float and spread while evaporation of volatile compounds may present health and explosion hazards, as occurs with nearly all crude oils. It is the subsequent weathering effects, unique to diluted bitumen, that merit special response strategies and tactics... In cases where traditional removal or containment techniques are not immediately successful, the possibility of submerged and sunken oil increases. This situation is highly problematic for spill response because 1) there are few effective techniques for detection, containment, and recovery of oil that is submerged in the water column, and 2) available techniques for responding to oil that has sunken to the bottom have variable effectiveness depending on the spill conditions."

The study recommends that:

  • oil companies need to inform regulators which type of crude oil they are transporting in every pipeline segment before a spill occurs
  • operators should also design different spill response plans depending on the oil type
  • when a spill does occur, operators must identify the oil type—by industry name—within six hours and, if requested, analyze a sample within 24 hours.

The National Academy of Science study follows a Royal Society of Canada report released last month.

The Canadian Press reported that the expert panel that wrote the report "says the heavy oilsands-derived crude that would move through proposed pipelines such as Energy East and the Trans Mountain Expansion has components that are less likely to break down in water than lighter types of oil. ...The panel identified seven 'high-priority research needs', which are:

  • the impact of oil spills in high-risk and poorly understood areas, such as the Arctic
  • the effects on aquatic wildlife
  • a national baseline research and monitoring program for areas that may be affected by a spill in the future
  • controlled field research to understand how a spectrum of crude types behave in different ecosystems and conditions
  • investigating the efficacy of spill response and being able to learn from spills soon after they occur
  • improved spill prevention
  • improved risk assessment protocols for oil spills."

And a November 2013 federal government report also found that diluted bitumen sinks in seawater. The Canadian Press has reported, "Diluted bitumen ... sinks in salt water when battered by waves and mixed with sediments, according to a new study by the federal government. However, when free of sediments, the crude floats even after evaporation and exposure to light, the study determined. The report, conducted by Environment Canada, the Department of Fisheries and Oceans and Natural Resources Canada, also said that the commercial dispersant Corexit 9500 used in cleaning up conventional spills had a limited effect on dispersing diluted bitumen."

The Energy East pipeline would move 1.1 million barrels per day over 961 waterways to an export terminal on the Bay of Fundy. The Trans Mountain expansion would move 890,000 barrels per day through Jasper National Park, across the Vedder Fan aquifer, and could see a supertanker loaded every day at the Burrard Inlet marine terminal on the Pacific Ocean.

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