Learning a Lesson from
by Sean Kelly and David
An innovative system uses living organisms to treat
waste in rural Nova Scotia...and transforms a community at the same time.
Photo © Sean Kelly
“Build it and they will come.”
On the banks of a river that ebbs and flows with the daily tides of the
famous Bay of Fundy, the newest tourist attraction in the picture-postcard
village of Bear River has lured over 8,000 visitors from around the world. “It's
been a nuthouse, just herds of people,” says manager Carol Armstrong – welcome
relief to a rural Nova Scotian community hard-hit by a fisheries crisis and the
closing of a nearby military base. Local inns, retail stores and the town's two
restaurants have all reported big increases in business.
So what's generating all the excitement? A theme park? The world's largest
lobster statue? A casino?
Would you believe a sewage treatment plant?
Bear River (population 881) is home to an innovative wastewater treatment
facility that relies on living organisms to do the dirty work. Bear River Solar
Aquatics Wastewater Treatment Facility is a glass
structure that looks like an ordinary greenhouse. But inside, plants, snails, protozoa
and algae – fueled by the power of the sun – are busy breaking sewage down into
clean water that flows into the tidal river. What the tourists are seeing in
Bear River is a 'living machine,' an award-winning example of designing like a
Bear River, Nova Scotia is home to an innovative
wastewater treatment facility that relies on living organisms to do the dirty
It's something more people need to see, as too many of us are linear thinkers
on this spherical planet. The human-made industrial world extracts resources
from the natural world and transforms them into products, producing pollution
and waste in the process. Many of these products ultimately end up discarded as
yet more waste. Linear economics takes too much from the Earth, and puts too
much pollution back in.
Without a doubt, the modern economy makes a dazzling array of consumer goods,
some of them extraordinary, many of them unattainable by the world's majority.
But in the pursuit of short-term profit, we are using up or destroying our
'capital' – in this case the eco-capital of the Earth's resources – rather than
living off our 'savings' through, for example, the careful use of renewable
resources. As well-known ecological economist Herman Daley aptly puts it, “We
are treating the Earth like it's a business in liquidation.”
Yet the Earth is a source of inspiration when looking for solutions: its
ecosystems are, after all, circular, renewable, no-waste economies powered by
the sun. Waste from one process becomes the raw material for another – nothing
is thrown away. Nature is living testament to the truth of the adage “waste not
want not.” In Bear River, even human waste is a resource that can be put to good
use, if you think like an ecosystem.
Stepping through the sliding glass doors of the sewage treatment plant, one
expects an odorous welcome. Instead, you are greeted with the humid,
verdant-smelling air typical of any large greenhouse. Rows of clear-sided tanks
are topped with an assortment of colorful vegetation: floating aquatic plants
such as duckweed, water hyacinth and mint, and non-aquatic varieties such as
willow and dogwood suspended by netting, their roots continuing down into the
nutrient-rich mixture. Snails cling to the inside of the transparent tanks,
sucking up algae growth that blocks essential sunlight from reaching life in the
water. A large indoor 'pond' contains more plants, including banana and fig
Plant manager Carol Armstrong doubles as an enthusiastic tour-guide. She
walks a constant stream of visitors – many who show up unannounced, curious
about this engineered ecosystem – through the voyage the waste takes before it
flows into Bear River. Pumps first inject fine air bubbles into an underground
tank of blended sewage and septage. When combined with the bacteria Armstrong
adds daily, this sewage becomes, quite literally, food for consumption. It
enters the five-foot high tanks where bacteria, algae and protozoa are at work
detoxifying many harmful microbes in the water. These organisms find a habitat
on the roots of the larger plants suspended on the water's surface, which in
turn absorb toxins not broken down by the smaller species.
“We tried some water lettuce and semi-tropical plants,” Armstrong says,
sounding more like a farmer than a sewage treatment plant operator, “but most of
them were overcrowded by other plants. Local varieties seem to do better than
tropical ones so next spring I will be planting a lot of local stuff. I am going
to have fun with this.” The plants are currently composted but she has plans to
sell the ornamental flowers once more residents are hooked up to the plant; the
facility is only operating at one fifth its capacity of over 50,000 liters of
waste water a day.
Gravity moves the stream of wastewater through the tanks, an indoor pond, and
finally to a small engineered march. There, grasses and irises absorb remaining
toxins. A screen removes the last of the suspended solids, and an ultraviolet
light completes the process by disinfecting the water. The final chemical-free
product is discharged into the river often clean enough to drink. It's a world
of difference from most conventional methods of treating sewage which, while
sometimes using a limited number of organisms to treat sewage, are not symbiotic
ecosystems and have to resort to chemicals like chlorine to clean the water.
And, making the natural treatment facility seem too good to be true, it is less
expensive to build and maintain.
Dr. John Todd, the inventor of Bear River's “living machine” process, has
long advocated this kind of ecological design as the “application of natural
relationships to human need and to the integration of humanity with the larger
natural world around us.” His ideas go beyond just mimicking nature's cyclical
model – he advocates using living organisms themselves as the basis for
engineering. For twenty-five years, he has researched living species that can
form durable, self-designing and above all, useful ecosystems.
Ecological design “grows out of the place itself – what's there now.
The climate, biota, geology, topography.
Ecological design “grows out of the place itself – what's there now. The
climate, biota, geology, topography. Whether it is urban or rural, First World
or Third World...in fact, the opportunities for this in the tropics are just as
great, or greater, than in the North.” And when you begin the work, you carry a
very unique set of tools. “A wonderful example is in one of our living machines,
where we use an Amazonian Catfish which is very effective at ingesting sludge.
How many conventional engineers would think of having an Amazonian Catfish in
their tool kit?”
“Unlike a dead machine, a living machine's parts are primarily live things.
Its structure or its skeleton is inert obviously – tanks, greenhouses, things
like that – but its [inner workings] are thousands or hundreds of thousands of
parts made up of thousands of species. What they have is the ability to interact
with each other, to self-organize, self-design, self-repair, self-reproduce.”
Industry, as well as towns like Bear River, is beginning to recognize the
economic benefits of living machines. “We go to something like a brewery or food
processor and say: 'We can take a problem that is quite troubling or costly to
you, we can clean it up and we can also create a secondary by-product – you can
now grow food as a spin-off of the original activity. We are able to show many
companies that they can comply with environmental standards and actually pay for
the living machines in sometimes as short a period as two years.”
The lessons of cyclical thinking also extend to the broader economy.
Maximizing the use of non-renewable resources through durable design, reuse and
recycling is one application of the philosophy. A more imaginative step is an
industrial park where many businesses are integrated, symbiotic members of one
common closed-loop system. The machine parts remain inert, but the natural cycle
is adopted. A company's waste becomes a needed input in a second company's
industrial process. The heat created in the manufacturing of one product fuels
the energy needs of another.
Products can also be designed for their entire life cycle. The Environmental
Protection Encouragement Agency of Germany promotes what they call Intelligent
Products; for example, products that are created from sustainably-managed
renewable resources in a way that when returned to the earth, they biodegrade
without toxic effects. “Durables” such as cars, televisions and refrigerators
would not be sold but rather licensed from a company. The product would always
belong to the original manufacturer, to be constructed, used and returned within
a closed-loop system. When a company knows their product will end back on their
doorstep yet they cannot legally throw it away, decomposition, reuse and
refurbishment soon become central pillars of design.
Of course, these ideas do not address a primary cause of our growing
ecological crisis: over-consumption. And Dr. Todd would prefer to see more of
our economy incorporate natural, living organisms. “Industrial ecology is a
little artificial, but when industry gets to the point of exchanging energy and
nutrients, then it does become like ecology – in the sense that there is mutual
sharing going on.”
“Humans have to learn to do that. I do foresee a time when communities are
designed as ecosystems: in a sense very large living machines within which
people live and work, do their civic function, their education and their
Back in Bear River, this new thinking is taking root. Their living machine
enjoyed extraordinary grassroots support, and the community continues to build
on this spirit of cooperation and pragmatic optimism. The town's citizens have
transformed a closed school into an arts centre and a recently abandoned bank
building into a community health clinic. As Carol Armstrong says, “This place is
magic.” You can almost smell it in the air.
Sean Kelly works with CUSO Atlantic. David
Redwood, a freelance writer living in Halifax, works with youth and
environmental groups. This article was published in 1996.