Fate and Transport of Wheat in a River System - Environmental ...
28 Fate and Transport of Wheat in a River System: Research and Development in the Context of a Grain Derailment Response Strategy Loni Waldner, Golder Associates Ltd On December 10, 2015, 12 rail cars containing 1,287 tonnes of wheat derailed on a Canadian National Railway (CN) Rightof-Way (ROW) within a National Park, releasing wheat into the Athabasca River, a Canadian Heritage River (designated in 1989). It was estimated 900 tonnes of wheat was recoverable from within the rail cars and above the ice on the river with just under 400 tonnes of wheat that could potentially have been below the ice within the river. CN engaged with both Parks Canada and the Department of Fisheries and Oceans (DFO) from the onset of response activities. The primary aquatic concern of the Regulators appeared to be the potential for a fish kill associated with dissolved oxygen depletion from decomposing submerged wheat. The derailment response strategy involved the use of a scientific-based approach to evaluate the risk of the wheat remaining in the river system. This was compared to the potentially significant impacts that a full scale submerged wheat recovery program may have entailed, given the need for in-water works, in a system supporting listed species (e.g. Pygmy Whitefish), outside of standard in-water work windows and under logistically challenging winter conditions posing both environmental and safety risks. Given the time of year, any efforts to fully recover the wheat would have posed safety issues to project personnel, and would have required further aquatic and terrestrial habitat disruption, over an unknown timeframe during a sensitive time period for fish and wildlife populations. Grain releases into aquatic systems have occurred in the past, but no documentation of the fate, transport, and/or ecological risks associated with grain releases could be found. The response team recognized this as an opportunity to address the Regulators’ primary concern by completing a quantitative evaluation of the fate and transport of wheat in the river.
There were significant challenges in assessing the fate and transport of wheat in an aquatic environment at this Site. Access to the Site was difficult being a remote, hi-rail access only location, along with restricted access through a tunnel and ongoing operations on an extremely busy mainline. The logistical challenges were magnified by a steep rock face on the north side, and a sharp drop to the river to the south side at the derailment Site. Additionally, challenges at the Site intensified and changed as the winter progressed. Bighorn sheep were an ongoing concern, with a professional dog handler employed at the Site from December to February, and a high-tensile electric fence installed into the rock face to the north. There was no channel geometry or bathymetry available for the Site itself or the downstream lake. This data gap was filled by an exceptional effort to obtain ground penetrating radar data through the ice on the river. There was no relevant scientific documentation of physical and chemical behaviour of wheat kernels in aquatic systems, and as part of the quantitative evaluation of the fate and transport of wheat in the river, a number of laboratory tests were conducted to assess submerged wheat behaviour. The fate and transport evaluation revealed that the presence of wheat within the river system did not pose a risk to the aquatic environment and removal of the submerged wheat from the river was not required. However, selective removal of high concentrations of submerged wheat, based on measured thicknesses obtained during dive surveys, was completed using a diver-assisted dredging system designed and implemented by Golder. Golder will present how developing a fate and transport model for this Site facilitated quantification of the risks and guided the derailment response strategy, demonstrating a path to closure that minimized environmental effects and added to the body of scientific knowledge.
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Loni Waldner, PEng
Corey Johnston, BScE
Ms. Waldner is the western regional manager for CN’s active rail environmental projects with Golder Associates’ Calgary office. Ms. Waldner holds a B.Sc. in Petroleum Engineering from the University of Alberta, and she is a professional member of the Association of Professional Engineers, Geoscientists and Geophysicists of Alberta.
Mr. Corey Johnston is the Environment Officer for Canadian National Railway based out of Edmonton, Alberta. Corey holds a B.Sc.E. in Civil Engineering from the University of New Brunswick, with four years of experience in working in environmental consulting focusing and an additional 4 years of experience working for CN.
Ms. Waldner has nearly fourteen years of experience in environmental consulting focusing in recent years on providing emergency response services in British Columbia, Alberta, Saskatchewan and Manitoba.
Acknowledgments: Golder extends their thanks to Ms. Karla Graf, Manager–Environmental Impact Assessment, whom provided guidance and support throughout the derailment response program.
There were significant challenges in assessing the fate and transport of wheat in an aquatic environment at this Site. Access to the Site was difficult being a remote, hi-rail access only location, along with restricted access through a tunnel and ongoing operations on an extremely busy mainline. The logistical challenges were magnified by a steep rock face on the north side, and a sharp drop to the river to the south side at the derailment Site. Additionally, challenges at the Site intensified and changed as the winter progressed. Bighorn sheep were an ongoing concern, with a professional dog handler employed at the Site from December to February, and a high-tensile electric fence installed into the rock face to the north. There was no channel geometry or bathymetry available for the Site itself or the downstream lake. This data gap was filled by an exceptional effort to obtain ground penetrating radar data through the ice on the river. There was no relevant scientific documentation of physical and chemical behaviour of wheat kernels in aquatic systems, and as part of the quantitative evaluation of the fate and transport of wheat in the river, a number of laboratory tests were conducted to assess submerged wheat behaviour. The fate and transport evaluation revealed that the presence of wheat within the river system did not pose a risk to the aquatic environment and removal of the submerged wheat from the river was not required. However, selective removal of high concentrations of submerged wheat, based on measured thicknesses obtained during dive surveys, was completed using a diver-assisted dredging system designed and implemented by Golder. Golder will present how developing a fate and transport model for this Site facilitated quantification of the risks and guided the derailment response strategy, demonstrating a path to closure that minimized environmental effects and added to the body of scientific knowledge.
continued …
28 … continued
Loni Waldner, PEng
Corey Johnston, BScE
Ms. Waldner is the western regional manager for CN’s active rail environmental projects with Golder Associates’ Calgary office. Ms. Waldner holds a B.Sc. in Petroleum Engineering from the University of Alberta, and she is a professional member of the Association of Professional Engineers, Geoscientists and Geophysicists of Alberta.
Mr. Corey Johnston is the Environment Officer for Canadian National Railway based out of Edmonton, Alberta. Corey holds a B.Sc.E. in Civil Engineering from the University of New Brunswick, with four years of experience in working in environmental consulting focusing and an additional 4 years of experience working for CN.
Ms. Waldner has nearly fourteen years of experience in environmental consulting focusing in recent years on providing emergency response services in British Columbia, Alberta, Saskatchewan and Manitoba.
Acknowledgments: Golder extends their thanks to Ms. Karla Graf, Manager–Environmental Impact Assessment, whom provided guidance and support throughout the derailment response program.
