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Category Archives: Heavy Metals

Coniston Generating Station Upgrade – Life Extension Project

By Linda Heron on Thursday, March 10th, 2022
Posted in Coniston GS, Dams, Energy, Greenhouse Gas Emissions, Heavy Metals, Hydroelectric, Mercury, ORA Submissions, Regulatory, River Concerns, Rivers at Risk, Wanapitei River, Water Quality

Hydroelectric is not emission-free or clean. A Washington State University study on the effects of damming conducted in a central European impounded river revealed that the reservoir reaches are a major source of methane emissions and that areal emission rates far exceed previous estimates for temperate reservoirs or rivers. It showed that sediment accumulation correlates with methane production and subsequent ebullitive release rates. Results suggested that sedimentation-driven methane emissions from dammed river hot spot sites can potentially increase global freshwater emissions by up to 7%.[1]  Hydroelectric facilities need to acknowledge and account for the associated GHG emissions they produce.

[1] Maeck, A., DelSontro, T., McGinnis, D.F, Fischer, H., Flury, S., Schmidt, M., Fietzek, P. and Lorke, A., 2013.  Sediment Trapping by Dams Creates Methane Emission Hot Spots, Environmental Science and Technology, 8130-8137, Online: http://www.dx.doi.org/10.1021/es4003907

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WWF-Canada and Nature Conservancy Support Adding Turbines to Non-powered Dams

By Linda Heron on Wednesday, February 2nd, 2022
Posted in Dam Removals, Dams, Energy, Fisheries, Greenhouse Gas Emissions, Heavy Metals, Hydroelectric, Mercury, Mercury, ORA Submissions, Removal, River Concerns, Rivers at Risk, Species at Risk, Studies & Reports, Urban Development

It is challenging to understand the logic of a November 2021 CBC article that reports, “The Nature Conservancy and the World Wildlife Fund are two environmental groups that oppose new hydro dams because they can block fish migration, harm water quality, damage surrounding ecosystems and release methane and CO2. But they say adding turbines to non-powered dams can be part of a shift toward low-impact hydro projects that can support expansion of solar and wind power.” Whether it’s a new dam or an older retrofitted dam, they will result in the same negative impacts and produce the same amount of methane for 70 to 100 years or more.

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Canada’s Freshwater in the 21st Century, 2014, Dr. David Schindler

By Linda Heron on Thursday, February 5th, 2015
Posted in Climate Change, Contamination, Dam Impacts, Dams, Energy, Fish Consumption, Fisheries, Greenhouse Gas Emissions, Heavy Metals, Hydroelectric, Media, Mercury, River Concerns, Riverine Health, Rivers at Risk, Studies & Reports, Video, Water Quality
Freshwater is widely recognized as the most pressing environmental issue of the coming century, as roughly 2 billion humans suffer from scarcity of water for drinking or sanitation. Despite its abundance of freshwater, Canada is experiencing great pressure on both its quality and quantity. Despite impending problems, the Canadian government is de-emphasizing freshwater research, both in its funding for university research and its support for federal departments with a freshwater mandate. This lecture describe some of the current threats to Canadian water, and outlines what we must do to solve them.
This is an excellent presentation and it is beneficial to listen to it all; however, if you have specific interest in hydroelectric or pipelines:
Hydroelectric: go to 34:56
Pipelines and the tar sands:  go to 50:00

June 18, 2014 — Water Institute Lecture Series and Faculty of Science Public Lecture Series
Dr. David W. Schindler, Killam Memorial Professor of Ecology, University of Alberta, retired.

Study Reveals Serious Potential for Heavy Metal Release from Hydro Facilities

By Linda Heron on Sunday, February 23rd, 2014
Posted in Dams, E-Newsletter, Heavy Metals, Hydroelectric, Impacts, Media, River Concerns, Rivers at Risk, Studies & Reports, Vermilion River, Wabagishik Rapids

Erik

Posted 8 March 2014

A recent study indicates that peaking facilities have serious potential to damage freshwater ecosystems, particularly in areas with heavy metal deposits from mining and industrial developments.  Based on the study, researcher Erik Szkokan-Emilson advised ORA in their preparation of a Part II Order request to the Minister of Environment regarding a proposed modified peaking hydroelectric facility at Wabagishik Rapids on the Vermilion River. Continue reading →

Drought Induced Flux of Metals from Peatlands in Watersheds Vulnerable to Extreme Events, Erik Szkokan-Emilson

By Linda Heron on Thursday, January 16th, 2014
Posted in Climate Change, Heavy Metals, Mining, River Concerns, Studies & Reports

Erik J. Szkokan-Emilson, S. Watmough, and J. Gunn. – Cooperative Freshwater Ecology Unit, Living with Lakes Centre, Laurentian University, Sudbury, ON, Canada

Recently a study was published that is very relevant to hydroelectric peaking facilities that hold water back to produce power during peak demand hours.  When water is held back for up to 24 hours, large areas of the downstream can become dewatered and dry, only to be flooded again when water is released to produce power.  Also, when the headpond is depleted it can take up to 24 hours to refill the headpond, depending on river flows, and shorelines and adjacent wetlands can become dry, only to be rewetted when the headpond is filled – this goes on daily in a peaking facility.  Check out the study:

Abstract:

“Climate change is predicted to cause an increase in frequency and severity of droughts in the boreal ecozone, which can result in the lowering of water tables and subsequent release of acidic, metal-contaminated waters from wetlands. We believe that in areas where historical deposition of metals and sulphur was severe, these episodic pulses of metals could reach concentrations sufficiently high to severely affect aquatic communities in receiving waters and cause a delay in biological recovery. The objective of this study is to evaluate the impact of drought on the chemistry of water draining from two Sudbury peatlands with widely contrasting peat organic matter content to determine the response of stream water chemistry to drought from peatland types in the region. Stream samples were collected using ISCO™ automated water collectors from June to November 2011. Following a period of drought, there was a decline in pH and a large increase in concentrations of sulphate and metal ions (Al, Co, Cu, Fe, Mn, Ni, and Zn) in water draining both peatlands, with extreme concentrations occurring over a period of about two weeks. At the site with the higher peat organic matter content there was an increase in metals that have a high affinity to bind to DOC (Al, Cu, and Fe) during the onset of drought. This study demonstrates a dramatic response to drought at two sites that differ in metal and nutrient pool sizes, hydrology, and topography, suggesting the potential for a majority of peatlands in the region to experience this response. Efforts to restore aquatic ecosystems and protect freshwater resources must take into account these processes, as disruptions to biogeochemical cycles are likely to become more prevalent in a changing climate.  Click here for more.

Also, below is a slide presentation relating to this study.

Wabagishik Rapids Generating Station – Environmental Report – ORA Part II Order request

By Linda Heron on Saturday, November 2nd, 2013
Posted in Class EA for Waterpower, Dams, Energy, Environmental Reports, Heavy Metals, Hydroelectric, Lake Sturgeon, ORA Submissions, Part II Order requests, River Concerns, Rivers at Risk, Species at Risk, Vermilion River, Wabagishik Rapids

Wabagishik Rapids, Vermilion River – Proposed Dam Site

Excerpt:  “This project has not been planned in an environmentally responsible manner, and has not fully taken into account the interests of local stakeholders and the public. Therefore, it is our position that for all the reasons noted herein, Xeneca has not fulfilled its requirements under the Class EA for Waterpower.”

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Drought-induced release of metals from peatlands in watersheds recovering from historical metal and sulphur deposition

By Linda Heron on Saturday, November 2nd, 2013
Posted in Climate Change, Heavy Metals, Impacts, Pollution, Studies & Reports

This recently published study is very relevant to hydroelectric peaking operations that store water during off-peak hours to produce power during peak demand hours.  This results in daily inundation and drying of upstream and downstream soils, sediments, as well as peat in wetland areas.  This wetting and drying, especially in areas that have been heavily impacted by mining, can result in the release of acidic, metal contaminated waters – see the abstract and slide presentation below.

E. J. Szkokan-Emilson, B. Kielstra, S. Watmough, J. Gunn

Abstract – click to obtain study.

Climate change is predicted to cause an increase in frequency and severity of droughts in the boreal ecozone, which can result in the lowering of water tables and subsequent release of acidic, metal-contaminated waters from wetlands. We believe that in areas where historical deposition of metals and sulphur was severe, these episodic pulses of metals could reach concentrations sufficiently high to severely affect aquatic communities in receiving waters and cause a delay in biological recovery. The objective of this study is to evaluate the impact of drought on the chemistry of water draining from two Sudbury peatlands with widely contrasting peat organic matter content to determine the response of stream water chemistry to drought from peatland types in the region. Stream samples were collected using ISCO™ automated water collectors from June to November 2011. Following a period of drought, there was a decline in pH and a large increase in concentrations of sulphate and metal ions (Al, Co, Cu, Fe, Mn, Ni, and Zn) in water draining both peatlands, with extreme concentrations occurring over a period of about two weeks. At the site with the higher peat organic matter content there was an increase in metals that have a high affinity to bind to DOC (Al, Cu, and Fe) during the onset of drought. This study demonstrates a dramatic response to drought at two sites that differ in metal and nutrient pool sizes, hydrology, and topography, suggesting the potential for a majority of peatlands in the region to experience this response. Efforts to restore aquatic ecosystems and protect freshwater resources must take into account these processes, as disruptions to biogeochemical cycles are likely to become more prevalent in a changing climate.

Download (PDF, 6.66MB)

Methylmercury – Impacts of Reservoir Flooding – Hydroelectric

By Linda Heron on Sunday, April 7th, 2013
Posted in Impacts, Mercury, Rivers at Risk, Studies & Reports

Reservoirs represent a significant portion of the freshwater surface on the planet. In Canada, most reservoirs are constructed to provide stable water supply for the generation of hydro-electric power. Particularly in the relatively low topography of the Precambrian Shield, the creation of reservoirs often results in the flooding of large areas of former wetland and upland forest.

By the late 1970’s, researchers recognized that fish populations in many newly-flooded reservoirs were subject to significant increases in tissue concentrations of methyl mercury. Humans relying of these fish for regular food supply were at risk of developing mercury poisoning, which can result in severe damage to the nervous system. What was causing this mercury problem and how could it be mitigated? Continue reading →