This story is part of Headwaters, a series on the future of our most critical resource
Leland Jackson knows scum when he sees it – and he couldn't be happier to find it spreading throughout his $38.6-million state-of-the-art research facility on the banks of the Bow River.
Scum is a key ingredient in Dr. Jackson's plan to plug a gaping hole in our knowledge of water pollution and accelerate the search for effective ways of treating it. The more faithfully he can generate scum that's just like the slimy film found in rivers and streams all around Canadian towns and cities where waste water is released, the better he can replicate what's going on in that water and gauge its downstream effects on people and the environment.
It's also just part of a much larger effort at ACWA (short for Advancing Canadian Wastewater Assets), where the University of Calgary biologist is scientific director. Located about 20 kilometres downstream from Calgary's city centre, the facility, which opened earlier this year, aims to provide water experts and decision-makers with crucial information they need just as climate change, chemical contamination and overuse are all putting a strain on water resources around the world.
"We're built to generate scientifically defensible data that can be used to effect policy change," Dr. Jackson said. To get there, Dr. Jackson and his colleagues have performed a job that any 10-year-old would love: They have engineered an impressive outdoor water system consisting of 12 full-size test streams that they can manipulate at will from an underground control room. The streams, which are fed with treated water drawn from the nearby Pine Creek waste water plant, serve as a test bed where the effects of different contaminants and different ways of treating water can be compared with each other in something close to a real-world setting. If communities and governments are going to learn to use water better in the future, Dr. Jackson notes, they will very likely be relying on this kind of science to help them do it.
"There's nothing else really like this," Dr. Jackson said as he walked between two of the 320-metre-long test streams, which tumbled gently along in separate gravel channels dug across a wide, flat plain overlooking the river. At first glance, the streams seem unsurprising, like a series of roadside drainage ditches running in parallel, but each is a carefully constructed series of "riffles" and "pools" that mimic still and moving water in a realistic setting and provide locations where researchers can sample water for analysis.
This year, scientists here have been busy with things such as getting the scum right – in other words, making sure the microbial and plant life that has spontaneously started to colonize the streams is a faithful analogue to the real world. By next spring, Dr. Jackson plans to introduce small fish into the streams.
The technical term for this kind of creation is a "mesocosm." It is a class of experiments that are far larger and more realistic than can be conducted in a laboratory, yet they provide more clarity and control than can be obtained from traditional field studies of Canadian waterways. Although ACWA is far more compact, its underlying philosophy is identical to that behind the Experimental Lakes Area in northwestern Ontario, a former federal facility where researchers have been allowed to contaminate a set of lakes to study the effects of various pollutants on water. But ACWA is more specific to the waterways that people rely on for their drinking water across Canada. Its multiple streams provide an opportunity to run controlled studies that explore different ways of dealing with – and improving – water quality.
The last part is crucial, because in regions of increasing water scarcity, such as California, officials face a growing imperative to consider strategies for recycling treated waste water. The idea would go beyond simply treating waste water for release into the environment, and to use it to replenish groundwater aquifers for future consumption.
In addition to the streams, ACWA has indoor facilities and labs built into the Pine Creek plant where new water treatment technologies can be tested against the current standard. The facility, which the university created with the combined help of federal, provincial and regional dollars, now sits at the forefront of a trend to tie water management more closely to science – and the idea is spreading.
In another example, researchers at the University of Western Ontario in London have launched the Thames River Experimental Stream Sciences Centre to study phosphorus contamination in rivers that feed into Lake Erie. Although much smaller in size relative to ACWA, it is equally concerned with providing data that can help shape sound water policy. "I think you just have to walk out to any river or lake in a populated area to see the need," said Adam Yates, a professor of geography who heads the effort. When it comes to water quality, "we really don't have a good handle on what's going to happen every time we make a decision."