New and surprising information is bubbling to the surface of Greater Sudbury's Ramsey Lake watershed.
Scientists at Laurentian University are using new technology to discover how weather affects the chemical equilibrium of a lake. With it, they can now correlate changes in the chemistry of the water column with changes in climate or atmosphere. This information is being used to answer questions about the health of the water. The ultimate goal is a triggered alarm system to alert health units to potential water concerns.
The health of the Ramsey Lake watershed is being continually monitored, thanks to a remote underwater sampling system (RUSS) linked to a dynamic profiler. RUSS technology is a combination climate station and water quality station. The profiler uses a suite of sensors to measure and monitor chemical and physical changes in the water at different levels.
"This is a semi-intelligent automatic measurement system that allows water to be studied," according to Graeme Spiers, Director for the Centre for
Environmental Monitoring at the Mining Innovation, Rehabilitation and Applied Research Corporation (MIRARCO), explains. "Most people don't sample water during a storm. From RUSS, we have tens of thousands of individual pieces of data about climate and water quality. We have learned a huge amount about Lake Ramsey that we never knew."
The other storm front
The most surprising data resulting from this underwater monitoring is what happens to the thermocline level of the lake during a storm event. The thermocline is the transition zone between the warm water closer to the surface and the lower cold water. This transition zone for water temperature and water chemistry is usually around eight metres below the surface.
Alan Locke is a scientist with MIRARCO. He has studied the data and the answers it provides.
"A change in barometric pressure during storm events effects the thermocline by pushing it down deeper," he explains. "If the thermocline is near the shoreline at a depth of eight metres, pushing it down can mean this layer is now sitting right on the sediment."
In the past, the drinking water intake for Sudbury residents was done below the thermocline. Once city planners understood this underwater pattern, they re-designed the intake for Sudbury's water pumping systems to avoid sucking silt into the drinking water treatment system.
Early warning
That is one of the long-term goals for the RUSS monitoring equipment. Scientists working on this project hope to one day see a triggered alarm type of system. Changes in turbidity levels (the measurement of water clarity) could be electronically relayed to the city, keeping officials abreast of changes in the lake's depth.
Massive amounts of data have also been used to model the lake. This provides a unique opportunity for predictive modeling. Take the case of a faulty sewer line, septic system or even a chemical spill into one of the streams feeding into Lake Ramsey. Materials could be delivered into the lake that could directly feed into an E-coli outbreak. Through predictive modeling and assessment, valuable information can be passed on to alert the health unit.
MIRARCO researcher Francois Prevost is currently working on this predictive model.
"By simulating a spill at a certain location of the lake, calculating wind speed, direction and water properties, we can start predicting where water contaminant will end up, how quickly it will get there, and what risk it poses."
This predictive model, which incorporates the city's infrastructure and the depth of the lake, is not just a series of numbers. The virtual reality laboratory (VRL) at Laurentian University converts massive amounts of data into 3D visualization form. Combined with the monitoring equipment, this scientific visualization facility is a highly effective communication tool.
"In reality we could not have done what we are doing without the presentation and modeling facilities," says Spiers. "This enables us to do far more with the data coming off the system. We not only look back at what we've got, we also look forward."
Spiers hopes the technology can eventually be used in lakes across Northern Ontario.
