City life has isolated us from nature’s laws, so that wetend to see the environment as “out there” and separate from ourselves. We have the illusion of clean homes because we’ve become adept at making the by-products of city life — sewage, garbage, carbon dioxide from our cars — go away, out of sight and out of mind. In nature however, there is no “away.” Nature’s cycles are closed, complete, and perfect.
In my community of
The question is, what kind of treatment? Will we follow traditional thinking and treat waste as a liability, or can the materials that contaminate our ocean become assets?
How Waste Works
We’re actually sitting on a huge source of renewable energy: ourselves. While we ponder a nuclear future, heat pumps could recover enough energy from sewage to heat a third of our buildings. We subsidize oil companies to drill for fossil fuel, while dumping enough vegetable oil through our outfalls to run all 200 of
Waste pollutes twice; first when it hits the environ ment, and again when we extract more resources to replace those we’ve discarded. Most people understand how recycling pop cans reduces new mining. We’re beginning to understand it works the same way with water, but we’re far from competent when it comes to municipal waste and sewage. Landfills and sewage outfalls are dead ends, massive failures of imagination, because the value in waste is greater than the cost of throwing it away: waste is worth more alive than dead.
For example, at current growth rates, Greater Victoria will outstrip its water supply in a few decades, and perhaps sooner with climate change. When we exploit the next source, we’ll do permanent damage to the
I began to wonder what life would be like in a city built on nature’s rules. In October 2006, I visited
When organic waste decomposes in anaerobic digesters, it produces a mixture of methane and carbon dioxide called raw biogas. After the carbon dioxide is removed in an upgrading plant, the biogas is indistinguishable from natural gas except for its origin. Unlike the carbon in fossil fuels, the carbon in biogas is pulled from the atmosphere by plant life each summer. When biogas is burned, the carbon returns to the atmosphere, completing a closed cycle.
Unlike the one-way trip of carbon from fossil fuels, biogas from waste does not contribute to climate change. Another benefit of biogas is that it produces fewer traditional pollutants, like smog and particulate emissions, than fossil fuels.
Picture this: a child in
The plant’s Business Development Manager explained that biogas from her plant also provides cooking fuel for the sustainable development of Hammarby Sjöstad. When dinner is over, food waste in the development is sent through underground vacuum tubes to a central collection point, and diverted to the sewage plant to produce more biogas.
Meanwhile, the heat energy in
When I asked about cost, my hosts explained that the sewage plant is paid for its resources.
Eco-Employment in Gothenburg
In Gothenburg, the Manager of Sustainable Water and Waste Management explained that the financial and environmental benefits of energy from waste are compelling. In the 1970s, fossil fuels caused heavy smog in Gothenburg, and the city responded by developing a district heating network.
District heating costs less than oil or electricity, but gives companies like Gothenburg Energy an incentive to insulate their clients’ buildings, in order to leave more energy in the heating pipes for future subscribers. In this simple arrangement, the economic interests of the energy company and the environmental interests of the community are aligned. After heat is extracted from sewage, the water is cold enough to run separate district cooling networks that provide air conditioning in offices — reducing energy use further still. In
In Gothenburg, a thousand people are employed providing renewable energy from local sources, including waste. Greenhouse gases are reduced and sustainable jobs are created, proving
Kristianstad is a community of 35,000 in the heart of
Kristianstad’s Coordinator of Climate Change Strategy explained how biogas solves several problems: sustainable disposal of organic waste, and the need for clean-burning, carbon-neutral fuel. Agriculture and related food industries produce organic waste, which, in 1995, the city decided to turn from a liability into an asset. The solution was to build the Karpalund biogas plant, which accepts organic waste from kitchens, food factories, and farms. In a wonderful example of closed loops, farmers deliver manure to the Karpalund plant, then reload with the liquid residue from the biogas plant. This residue is rich in nutrients and, being free of contaminants, is returned to farmland. Residue from Swedish sewage plant digesters is composted separately for industrial landscaping.
Before saying goodbye, I refueled my rental car with biogas from the sewage plant. Later, as I drove down the highway, I realized this was my first greenhouse gas-neutral trip, powered by the people of Kristianstad.
I was moved by the generosity of my Swedish hosts and thanked them profusely for their time and help. Environment is a global issue, they replied with a gentle smile.
Some may wonder if the practices in
Beyond the social and environmental value of resource recovery,
Three main principles
Three main principles emerged from my time in
The first is that everything in nature and in cities is connected. When our planning for liquid waste, solid waste, energy, and transportation is integrated, the results for the community are optimized. Planning for each of these areas in isolation, on the other hand, sub-optimizes or “pessimizes” the results for the community.
Second, we can make waste pay its own way by recognizing every output as an input, every waste as a resource. Recovering more value from waste costs less overall, for example when sewage plants are paid to accept kitchen waste, as well as for their heat energy and biogas.
Finally, waste is just a resource in the wrong place, and we need to use each resource for its highest purpose. It makes sense to save drinking water for drinking, and to use reclaimed water for irrigation, for example. Similarly, until last year, the sewage treatment plant in
Instead of just recycling or, worse still, downcycling (in which waste loses value), Swedish cities are upcycling their resources. Biogas and compost are worth more than the apple cores they come from.
It’s All Connected
We’ve failed to see our place in the ecosystem, preferring instead to put ourselves at the top of the food chain and above nature’s laws. Our words for waste reflect our mindset and interfere with creative thinking. Calling sewage an “effluent plume” or boasting that the local dump is an “award-winning landfill” belies the appalling damage these failures create. It’s time to change our minds, beginning with our use of language. The word resource means “to rise again,” and if we talk about resource recovery rather than disposal, we begin on the path toward sustainable cycles.
Senior government may set policy, but in the end we’re the architects of our communities, and planet-saving changes will begin here.
Stephen Salter, PEng is a professional engineer who specializes in energy and the environment. As a consultant, Stephen helps clients reduce pollution, often by reclaiming resources from waste. Stephen also works as a volunteer with the Georgia Strait Alliance and the TBuck Suzuki Environmental Foundation to encourage politicians to think like Swedes. Stephen lives in