in-your-face waste

Geoff Manaugh, an editor of Dwell magazine and BLDGBLOG blogger, writes about an investigation into the possiblities for establishing buildings in London that could be purpose-built to house waste management systems. Distributed waste towers not only might make it more practical to use energy generated within these buildings, they also might raise the possibility of ubiquitous waste management - as opposed to dumping trash in landfill sites that are out of sight and out of mind. Making waste is one of the things we do (really well), so maybe if we stopped hiding it, we would stop pretending it doesn't exist.

Of course, here in South Africa our waste is made more obvious by the army of street people who scour our wheelie bins for recyclables and trundle down the streets with Pick 'n Pay trollies laden with goodies. And the network of recycling depots that receive those goodies are well distributed across the city. Even the more formal collection of municipal waste is, in some parts of Cape Town, already carried out by local workers going through informal townships and collecting waste at local depots for the municipal workers to collect. What we need is to find ways to process that waste locally, in ways that can create employment and turn waste into something useful. Compost it, gather methane from it, turn it into public art, create new forms of craft - whatever can make better use of resources.

construction waste needs serious attention

Construction waste makes up a much larger proportion of landfill than household rubbish.

The [UK] government, it seems, has woken up to the construction waste problem. Last April, the Environment Agency mandated site waste management plans for construction projects in England worth more than £300,000, in which, from the pre-construction stage onwards, firms must declare waste materials and how they will be disposed of. The agency says this will cut 100m tonnes of waste annually.

Most recycling in South Africa only happens when there is a financial incentive - whether it's people living on the streets picking through household refuse bins for material to sell to recycling depots, or Ross Demolition salvaging doors and windows to sell to home renovators, or Cape Brick manufacturing bricks from crushed building rubble. It's time to up the ante and increase the cost of dumping to landfill sites. But the Brighton & Hove Wood Recycling Project in Britain illustrates that there's a lot of education needed to turn things around in the construction industry.

the three Rs return

As long as I can remember, we've been told about the three Rs: Reduce, Reuse, Recycle. At some point we've added Repair (to extend the life of a product) and Repurpose (when it isn't suitable any more for what it was made for, use it for something else). That's all very well, but most products aren't designed with this in mind, so it's difficult to take the mantra seriously. With the focus on carbon though, we're starting to move from cradle-to-grave analysis, as a way of looking at a product's lifecycle impacts, to cradle-to-cradle analysis that is intended to encourage products to be designed never to enter landfill sites.

Buildings are given recognition under green accreditation schemes like LEED, BREEAM and Green Star for being designed so that the materials that go into them can be used for something else when the building is disassembled. Products can also be C2C certified, which means they are designed not just to be carbon neutral, but to produce zero waste: either recycled or reused endlessly, or returned to a natural, ecologically benign state. If things are designed this way, then the three Rs become a meaningful paradigm, and the goal of zero waste might just become reachable.

measuring green performance can be tricky

Sustainability is about performance, not about picking the "correct" technology. No individual strategy is right for every occasion - it's a question of what moves the world forwards instead of backwards. Responding to a Popular Science ranking of America's 50 greenest cities, Alex Steffen of WorldChanging raises the interesting challenge of how to define "forwards" and "backwards", and makes a few initial suggestions:

• Instead of measuring the amount of electricity coming from renewable sources, compare energy use with GDP: who's getting most prosperous using the least energy?
• Instead of counting how many people use public transportation, measure vehicle miles traveled per capita and car ownership rates: we should be reducing the need to travel, and distance travelled.
• Instead of assessing the best buildings in a city by counting the number with green accreditation, assess building codes and what the average building is like.
• Instead of assessing how comprehensive recycling systems are and how much material they take in, consider the percentage of solid waste that still goes to landfills: we want to reduce total waste, not just increase recycling.

Unfortunately for the politicians, it's often the more mundane actions and low-profile strategies that make the biggest impact. They are also harder to measure, but I believe we'll have to try.

degradable plastics in South Africa

After writing about agricultural waste on Monday, I picked up a copy of Farmer's Weekly in a bookstore and noticed an article about biodegradable plastics that can be used as sheets for suppressing weeds, maintaining soil moisture, and other applications, or as bags. A company called Self-Destruct Plastics is selling oxo-biodegradable plastics in South Africa beginning this year. The product can be custom-manufactured to degrade at different rates, depending on the intended application.

As noted by British manufacturer Symphony Environmental, plastics made from crops are subject to the same criticisms levelled at biofuels, notably that they compete with food for land and water.

Degradable plastics are a good idea, but Symphony produces oxo-bio bags made from naptha, a waste product of oil refining which would otherwise be wasted, and no crops are involved in its manufacture. Oxo-bio can be recycled and made from recyclate, but if not recycled it will self-destruct in a short time, leaving no fragments, no methane nor harmful residues. As it is made with the same machinery as normal plastic, oxo-bio has little or no extra cost.

[Update on 14 March 2008: Here's some more research into plastics in South Africa from Engineer Simplicity.]

renewable energy from farming

Having spent most of my teenage years on our family farm in Ontario, Canada, I have a tendency to romanticise small-scale agriculture. When you work the farm as a family, with no hired labour, you are forced to work like the devil and confront your demons. It's no walk in the park, and it's certainly no way to get rich. Yet, for me, the cliches are largely true. Dependence on the soil, the plants and the rain, on healthy lambs and helpful neighbours - these things add perspective to life.

Yes, our voracious appetite for meat and dairy products is devouring land and other resources at a frightening rate, and if we don't change our ways, it looks like something's gonna give. So partly because of my own experience, which was little more than subsistence farming, and partly because of the concerns about agricultural impacts, I have an aversion to large-scale farms that seem more like factories than places where animals should live.

That said, I am intrigued by news of a dairy farm near London, Ontario, that must be about as efficient as a farm can be in making best use of available resources. The Stanton farm of 728 hectares has capacity to handle 2,000 cows, and at this scale the business can make use of technologies to improve sustainability performance that would be unaffordable to smaller farms.

The warm milk coming from the cows is cooled with a two-stage system that is unique in Canada. First, it is cooled as it passes next to water pumped up from deep wells. It is further cooled with a heat exchanger until it is 2 degrees C. The well water, which is warmed as it cools the milk, is used for three purposes: to water the cows, to clean the milking equipment, and to supply a radiant in-floor heating system.

The Stantons are constructing a $4.5 million anaerobic digester that will produce methane from cow manure. At full capacity, the farm will have the capacity to produce 300 kilowatts of power, and could increase output by using manure from other farms or waste from commercial food plants. Solids left over after the methane gas is extracted can be used as animal bedding or a peat moss substitute, and the liquid can be used as organic fertilizer. If the biogas wasn't harvested and converted to useful energy, the manure would produce methane anyway, contributing to global warming.

The farmer's consultant, Gary Fortune, believes the biogas could become a significant source of farm income, with the potential to reduce material going to landfills if waste food and other organic products are collected instead of dumped; but under the Ontario government's alternative energy plan, biogas producers get 11 cents a kilowatt hour, compared to 42 cents for solar. This discrepancy makes it hard to compete.

[via London Free Press. Thanks, D.]

[Update on 12 Feb 2008: In South Africa, Agama Technology has installed a biogas digester on a farm outside Pietermaritzburg. The process is less automated than the Ontario example, but it achieves the same thing on a smaller scale at a fraction of the cost: R50,000, or $6,400 (Canadian) at today's exchange rate. According to today's Business Report, Dave Alcock, a consultant to Agama, "piloted the concept seven years ago in KwaZulu Natal at a house and school at eNdwedwe, just outside eThekwini." Interestingly, the school project failed because "there were people who felt that if it was successful, then the community would never be connected to the Eskom grid and the electricity generated from biogas would not be enough for everyone."]

earth audit: turf wars of the future

It's not just established technologies - like those relying on oil - that are facing a resource crunch as supplies decline. As reported in New Scientist [subscription required] we are mining a whole raft of minerals and ores at such a rate that even new technologies will soon be affected.

Gallium and iridium are two minerals that some analysts say may only last ten more years before they run out, but are being used in a new-generation solar cell that promises to be twice as efficient as current technologies. Gallium is also used for making LCDs, which raises serious questions about the long-term future of flat screens for computers and televisions; and for LEDs, which are hailed as the next generation of lighting that will replace compact flurorescent bulbs. And even the CFL bulbs are threatened by the supply of terbium, which could be used up by 2012.

Of course, nobody knows for sure when any mined resource will run out, but without a global storekeeper watching over earth's underground supplies, we are in danger of banking on the wrong technology to address current environmental or energy challenges. What happens if we all switch to LED lighting to reduce energy consumption, and find there's only a five-year supply of the raw materials needed to make them?

We can keep hopping from one technology to the next - or make some drastic changes to the way we consume resources, and completely revolutionise the concept of recycling. As raw materials become more scarce and costly, companies are starting to look at new ways to extract material from what has historically been treated as waste. Mine dumps are one such source. Another, believe it or not, is roadside dust. In countries like the US, where catalytic converters are in widespread use, platinum is lost through vehicle exhausts, and ends up literally everywhere that vehicles go. Platinum is also in short supply (with an otherwise promising future in fuel cells), and geologist Hazel Prichard wonders if there's a way to collect it from road-sweeping machines for recycling.

Is Hazel Prichard the bag lady of the future, wandering the streets in search of platinum? "Hey, buddy, step away from the trash can. This is my turf." The revolution is nigh.

Bostonians do it bigger

On the topic of Boston, the city seems to be working hard at reclaiming lost space. The Big Dig is moving an elevated highway underground, releasing prime downtown land for the Rose Kennedy Greenway and restoring the connection of the city with the waterfront. The Massachusetts Turnpike Authority provides images, plans and descriptions of how the greenway transformation will be done - while removing the highway frees up 30 acres, the total project will create more than 300 acres of landscaped and restored open space, including over 45 parks and major public plazas. The old Central Artery isn't cleared away yet, but the last car drove the highway last weekend.

Whether the Big Dig was worth its $15 billion price tag is another story, but two spinoff projects provide some compensation. One is the Big Dig House that I mentioned in April. Here's another description of how the house reused material from the Central Artery in a way that could be replicated in other building projects. Small in scale, big in ideas.

The other project is reclamation of a 105-acre waste dump on Spectacle Island in Boston Harbor by covering it with 6 million tons of material from the Big Dig tunnelling, creating a new park complete with solar-powered visitor centre with exhibits and information on the island's history. And can the planners be faulted for installing a composting toilet atop an "80-foot-high mound of trash"? [via Metaboston]

urban farm resources

I'm always on the lookout for urban applications of low-impact technologies. City Farmer in Vancouver has a lot of information related to urban agriculture, with a detailed discussion of their compost toilet and information on irrigation using grey water and rain water. Their composting toilet page also has a link to the Biolytix Waste Treatment System that is available in South Africa, New Zealand and Australia. Biolytix uses an aerobic method to break down toilet waste so that the liquids can be used for irrigation, unlike septic tanks where pathogens thrive.

second life presentation on drivers of change

If you're a designer, architect, engineer or planner; if you're interested in the things that are driving change in our world; and if you're at all curious about the virtual world of Second Life* - then here's something you may be interested in.

This Thursday, 14 June at 17h00 GMT, Chris Luebkeman will be presenting some of the work being done by his team at Arup on Drivers of Change. The presentation will be live from Autodesk Island in Second Life. Titled "Future Challenges: Global Creative Contexts", the promotional blurb says:

Population shifts, increasing scarcity, and the wanton consumption of arable land and natural (renewable and nonrenewable) resources amount to what could prove to be a significant global dilemma - a dilemma of disastrous proportion. Yet trends in design and an ever-increasing focus on conservation and environmental issues suggest that we are headed for a collective change. This program considers the impact of global drivers of change on sustainable creative contexts, explores potential implications, and provides attendees with examples of design work that is already responding to the challenges.

Let's hope there isn't another flood during the presentation. In April this year, the virtual world was partially flooded to highlight the risks of global warming.

*Never heard of Second Life? It's a 3D world built and imagined entirely by its residents - some 7 million users. Although it's a virtual world, it has a real economy. You can join for free, but real-world transactions worth millions of dollars take place every week based on interactions within Second Life. If you are not already a member, but want to join the presentation on Thursday, go to Autodesk and register.