Resources From Waste Remember when we used to throw everything away when we were done with it? Old televisions? Stacks of magazines? Packaging? Tires? Old paint? Now, it all seems thoughtless, almost primitive, doesn’t it? Now, we understand that nature isn’t a garbage can. It’s a ‘living system’ that recycles and renews everything; and we understand increasingly that we are part of that process and need to meet its conditions in all of our urban practices. These ideas represent a fresh approach, inspired by nature, called whole-systems thinking. IRM—short for Integrated Resource Management—takes the view that there should be no waste in waste—specifically, wastewater. Urban water systems are very simple: from freshwater sources we bring water via gravity or pumps to our communities and cities in pipes; use it in our sinks, showers, toilets, washing machines; then pump the wastewater in pipes to a receiving source—the ground, rivers, oceans. Along the way, we ‘treat’ the wastewater to neutralize certain contaminants or polluting elements. Nature, on the other hand, has created a very complex water cycle. Nature’s way is to recycle water hundreds of times as it makes its way from mountaintop to ocean, and to constantly clean and renew it. Just as the old model of throwing things away has come into question, we now realize that our entire wastewater process ‘throws away’ a number of things: the water itself after we have used it only once, beneficial nutrients in the sewage, and a significant amount of ‘embedded’ energy, including heat. In other words, there is value of all kinds worth extracting—and available to be extracted—from wastewater by taking an integrated, whole-systems approach. Did you know for example that the temperature of the wastewater in our sewer pipes is usually around 17°C, even in winter? Did you also know that sewage can actually warm up when it is treated? Imagine that the heat could be captured and sent to our homes and businesses in district heating loops, instead of warming up our rivers and marine waters. Now imagine what could happen with the cold water, once the heat was extracted. Think of all the air conditioning that could be eliminated and all the energy that could be saved. Now imagine all the uses that the reclaimed water could be put to- watering our lawns, washing our cars, flushing our toilets, cooling our factories- all things that do not require precious drinking water. All of this value speaks to an obvious additional consideration: cost. Talk to any city engineer, any politician, anyone in the municipal budget office, and you will quickly learn about the staggering cost to taxpayers of infrastructure—particularly the capital and operating costs associated with the planning, creation, maintenance and repair of our urban water and sewage treatment systems. Many of our sewerage systems are old and need replacing. Let’s not replace them with the same old wasteful systems. In our personal lives and as taxpayers, we all get the idea that money is energy, and that our ability to be thrifty, or to create more benefit from the same investment, is a smart way to go. This is the central idea of IRM, which turns conventional thinking on its head by considering the wastewater system as a utility and a resource—not as costly infrastructure, but a revenue source. In summary, three simple and powerful factors come together in IRM: We can take this idea one step further and also extract energy from our wet and dry organic wastes (instead of throwing them away or composting them) using the same digesters that capture the energy from the solids in the sewage. We can dramatically reduce the size of our landfills (perhaps even eliminate them), stop shipping our garbage to our neighbours, and use the savings and money from the sales of the energy to offset the costs of our wastewater treatment. Why wouldn’t we do it? IRM can also help us in another way: it can help us restore the ecology of our communities. Like it or not, we see the effects of climate change all around us. Our trees are drought stressed, our streams are drying up, and our water supplies are no longer as predictable as they once were. What if, once we have used it as many times as we can, we put the clean reclaimed water back into the soil where it could recharge our aquifers? What if we used the water to irrigate street trees, provide shade and cool our cities? If it all sounds too good to be true, then consider that each and every one of the ideas mentioned here is in use somewhere in BC: Lonsdale Energy Corporation pioneered district heat to customers in the City of North Vancouver[i] ; The City of Vernon irrigates 2400 acres with reclaimed water including two golf courses[ii] ; The South East False Creek Sewer Heat Recovery Project will use heat reclaimed from sewers to heat residential buildings in Vancouver’s Olympic Village and save 6000 tonnes of greenhouse gases each year[iii] ; Dockside Green in Victoria treats all its own wastewater on site and reuses the water for irrigation, to flush toilets and to maintain flow in a brand-new stream[iv]. Dockside also mixes the solids from its sewage treatment with wood waste from construction to generate energy on-site in a gasification plant[v] . The gas is used to create hot water for the district energy system that heats the entire 15-acre development. B.C.’s new challenge is to put all the pieces together in one place. The economic and environmental arguments in support of Integrated Resource Management are compelling. The Province of BC is currently examining what changes need to be made to our regulatory, social and financial systems to make such a vision possible[vi] and have established new policies to promote these ideas[vii] . The technologies are currently available. The business case is prepared. Now, we’re on the threshold of implementation, and pretty soon we’ll only ‘remember when’ we used to let wastewater and its enormous revenue potential just go down the drain.
[i] http://www.cnv.org/server.aspx?c=2&i=98 [ii]http://www.vernon.ca/services/utilities/reclamation/index.html [iii] http://vancouver.ca/commsvcs/southeast/public/07dec4+6/index.htm [iv] http://docksidegreen.com/sustainability/eco-friendly/eco-friendly.html [v] http://nexterra.ca/PDF/2_MunicipalWorldDockside-Jan2008.pdf [vi] http://www.cd.gov.bc.ca/ministry/whatsnew/IRM.htm [vii] http://www.livesmartbc.ca/ and www.livingwatersmart.ca
Our original report outlining this concept was released by the Province last May: http://www.cd.gov.bc.ca/ministry/whatsnew/IRM.htm.
Please note: the opinions expressed in these stories are those of the authors and not necessarily shared or endorsed by Dialogue Programs |
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