Large cracks remain in the science assessing Enbridge?s Northern Gateway Pipeline Project
WATER WAY: The Northern Gateway pipeline would traverse north-central Albert and British Columbia and cross 996 watercourses, of which 669 are fish-bearing, including the Nechako River pictured here. Image: Andrew S. Wright/WWF-Canada
As controversy continues around the Keystone XL Pipeline that would snake through the U.S., a similar drama plays out north of the border. Canadian officials are deciding whether to green-light a pipeline that would carry a semiliquid hydrocarbon mix for 1,172 kilometers from Alberta's tar sands over the Canadian Rockies to the Pacific coast of British Columbia. Near its proposed terminus, the proposal has met with public outcry and fierce opposition from the Coastal First Nations, a coalition of indigenous tribes.
Calgary, Alberta?based energy company Enbridge's proposed Northern Gateway Pipeline would cross over 1,000 fish-bearing streams and bring 255 oil supertankers each year to the coastline, making the issue highly contentious in Canada's famously outdoor-loving province. Of 1,161 British Columbians to give oral statements as part of the pipeline's federal review process, only two were in favor of the project.
What's more, the pipeline would be carrying an oil product that no one knows much about: diluted bitumen, or dilbit. University and government scientists emphasize an urgent need to fill the knowledge gaps surrounding what diluted bitumen is made of, how it reacts in the environment when spilled, and what its long-term biological effects are.
Answers to those questions are prerequisites to assessing the ecological risks posed by the eight such pipeline projects in Canada alone and to planning for an effective spill-response when things go wrong. ?I think it's fair to say, there?s been some purposeful denial that the bitumen is really something different,? says Steve Hamilton, an aquatic ecologist at Michigan State University who worked with the U.S. Environmental Protection Agency (EPA) and Enbridge in 2010 to remediate a diluted bitumen spill in Michigan?work that is still ongoing. ?The science has not informed this cleanup very well. There?s a pressing need for research.?
Bitumen is a thick hydrocarbon, the ?tar? in Alberta's tar sands, the third largest deposit of hydrocarbons in the world. To flow through a pipeline, the tarlike bitumen is diluted with gas condensates or synthetic oils known as diluents. This mixture of bitumen and diluent is called diluted bitumen, or dilbit for short, but its precise formulation varies widely and is not publicly released.
Finding out what exactly is included under the umbrella term dilbit is an important first step in understanding this unconventional form of oil. ?It?s not cast in stone exactly what dilbit is,? says Kenneth Lee, head of Fisheries and Oceans Canada?s (DFO) Center for Offshore Oil and Gas Energy Research in Nova Scotia. ?The fate and behavior of the product?the character of the product when it's spilled in the water?will depend on what the final formulation is,? Lee says. Next comes figuring out how dilbit behaves when it is spilled. ?We have to understand the physical behavior of the oil before we can design the optimal cleanup technologies,? he adds.
The chronic, long-term effects of bitumen on an ecosystem present a similar blank, although the Michigan spill will provide some information. "In trying to identify research needs, one of the things that's obvious is the lack of toxicity data," says Peter Hodson, a fish toxicologist at Queens University in Ontario. "Neither dilbit nor gas condensates have been tested, and so far I've not been able to find any literature on the environmental impacts of those two products."
Source: http://rss.sciam.com/click.phdo?i=317ff95e061394ffaf6a1a0fe8fc30cf
London 2012 Synchronized Swimming London 2012 hurdles Taylor Kinney Beach Volleyball Olympics 2012 Jessica Ennis Aliya Mustafina Kirk Urso
কোন মন্তব্য নেই:
একটি মন্তব্য পোস্ট করুন