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
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
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.
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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
Harper seals our fate on water and energy sustainability
Note: This is an excerpt of the original article – access by clicking here
The federal government states that Fisheries and Oceans Canada no longer need to do this type of research. And yet when we look at the research being conducted at the ELA, the scientific data is sorely needed for a sustainable energy strategy.
One ELA study assesses the effects of hydroelectric development. Hydroelectric dams are often touted as a ‘clean’ energy solution. However, the ELA study raises questions about whether hydroelectric dams have similar impacts as burning fossil fuels.
“There’s a new idea around that reservoirs may be significant sources of greenhouse gases to the atmosphere. And we want to test that idea, ”says Drew Bodaly, Research Scientist at the Department of Fisheries and Oceans in this Experimental Lakes video (see below). Continue reading