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Musings about the environment and all it touches, from education to city planning

Archive for July 2019

Flintenbreite: the original vacuum toilets

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Flintenbreite eco-village in Lubeck

Last week when I described my visit to Jenfelder Au, I mentioned that Flintenbreite served as the inspiration.  Time to find out more about Flintenbreite.

Compared to Jenfelder Au, it’s a smaller development: 117 units in a mix of low-rise townhouses and duplexes over a 5.6-hectare site, in Lübeck, near Hamburg.  It is also older: it was built as one of the ecological complexes for the 2000 World Fair centered in Hanover, and permanent residents have lived in since 2002.

The World Fair was based on environmental concepts that became subsequently known as the Hannover principles.  Among these are:

  • the right of humanity and nature to co-exist in a healthy, supportive, diverse and sustainable condition.
  • the elimination of the concept of waste.
  • reliance on natural energy flows.

In Flintenbreite, this meant trying to use self-sustaining, integrated energy and wastewater concepts, as well as implementing innovative energy saving technologies, with an eye to minimizing interference with nature.  Yes, but how?  Remember, this is happening in the 90s, and some of things we now take for granted, such as cheap solar panels, don’t exist yet.

By all accounts an ordinary suburb -except for the toilets

This is where Dr Otterpohl came in.  He proposed to apply his conviction that human wastes are a resource. The core principle is simple: keep the wastes separated.  Much is the wastewater generated by a household: bath water, wash water, etc, is fairly clean and easy to treat. Toilet water is another story.  Otterpohl’s flash of insight was to use vacuum instead of flush water to dispose of these wastes – and then, ferment them, undiluted, into biogas.

None of the components of the system were new ideas.  Greywater separation was practiced in California. There were vacuum systems here and there, conveying ordinary sewage where large sewage pipes couldn’t be installed.  Methane digesters to produce biogas were already common in sewage treatment plants (but they fermented only sludge, not sewage, which is too dilute).

In Flintenbreite, the system designed by Dr Otterpohl uses an artificial wetland to treat greywater.  Urine, feces, and a small amount of water are conveyed to a central biogas digester which produces methane for the community; it is delivered to a cogeneration engine that supplies electricity and heat to the community. From what I could gather, the small volume of residual liquid produced by the digester is also treated in the wetland. (Originally the system was meant to digest kitchen wastes also; this part was never implemented, and biowastes are collected as part of the now-common municipal green wastes collection system.)

A bird’s eye view

A video, linked here, shows the site, with Dr Otterpohl explaining how the system works.  It is only available in German, and can’t be found in YouTUbe, but you still get an idea of what the place looks like.  It’s under ten minutes long; at 1:30, Otterpohl shows how silly it is to mix the large volume of greywater with the small concentrate of blackwater, using a shot glass and a Bavarian beer stein for comparison. Three minutes in you see the artificial wetland and how it was constructed: requires little energy, it looks good, it produces clear water.  According to a resident, the system never smells, and the kids adjusted quickly to the toilet (which, despite using vacuum, isn’t particularly noisy).  The guts of the system: collection tank, biogas digester, biogas collection tank, and cogen system (engine and generator), are shown from the 8th minute.

The water flows in Flintenbreite

If you’d like more details, you can listen to a podcast – in English, this time – narrated by Dr Otterpohl, here, or take a look at a set of presentation slides, here, or a summary, here.

With all this, you would think Dr Otterpohl is proud of his pioneering system at Flintenbreite, prouder yet that the system is now scaled up at a larger scale at Jenfelder Au.  But when I interviewed him, he was somewhat bitter about Jenfelder Au.  He has been elbowed aside, now that the design has been shown to work. I can imagine why, though – ha may not be an easy person to work with.  Ever the perfectionist, and the visionary, he says that the system should not be copied unless it incorporates one final separation: feces and urine should not be collected together.  Feces are the source of biogas, are semi-solid, and may contain pathogens.  Urine is a liquid that contains fertilizing elements.  It is foolish to blend them, he says.

I’ll be profiling Dr Otterpohl’s new research on separating toilets and management system in another post, because it is also quite remarkable.  But for now, I’d like to give him his due: if the vacuum toilets of Flintenbreite was the only system he ever designed, there would still be a lot to be thankful for.  I’m a bit awe-struck, myself.


Written by enviropaul

July 21, 2019 at 1:20 pm

A visit to Jenfelder Au in Hamburg

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Jenfelder Au, in real life.

I finally got to visit Jenfelder Au, in Hamburg! I was pretty excited.  I had written about the complex several years ago, before I had ever physically seen the place.  And the first time I went, shortly after that, well, it was just a large series of holes in the ground.

What’s so special about the place? It’s the toilets.  They use a vacuum system to convey the waste, so there’s very little dilution.  It makes it practical to send the strong waste to a central tank where it is digested into biogas.  According to the plans, this biogas should generate enough energy for about half of the heat and electricity needs of the 35-hectare complex built for over 700 households.

I wasn’t there in any official capacity; I just visited the site and spotted a couple leaving one of the buildings.  I asked (Dinah helped) if they lived there; they said no, but their son Franz did.  He invited us in and generously answered my questions.

Yes, it’s a very ordinary powder room. You have to pay attention when you flush, or you’ll miss what’s special.

He and his partner had bought an apartment in the complex a few months ago. The main attraction was the up and coming location, very modern and up-coming, but far enough from downtown to be (somewhat) more affordable, while serviced by commuter train.  Like most home buyers, they were mostly interested in how quiet the apartment is, how bright and sunny, and that there is a really large terrace, looking down on the only completed landscape so far.

The modern design was a plus, but they were a bit leery of the newfangled toilet system – what could go wrong? Could it break down and entail costly repairs, or worse, stop functioning for extended periods of time?  They picked the design with one full toilet and one powder room.  Just in case.

In fact, very little can go wrong, and there is less risk of leaks than a regular system.  Both toilets have a vacuum shut-off valve.  Otherwise, the flushing mechanism is oddly familiar: it is similar to an airplane toilet, only nicer and quieter.

Was the potential to save energy a key selling point?  Uh, no, not really.  The apartment is already energy efficient.  But since they are among the first residents, they don’t see any direct benefit from their, uh, personal deposits; there are too few of them at the moment to get the system running yet. Biogas should be coming in a couple of years.

The site is truly enormous; aside from the five or so buildings completed, it is a sterile construction site, scaffoldings everywhere, no landscaping yet, and off course the vaunted central pond designed to treat greywater is still just a murky hole.  But Franz and his partner said that there is an advantage in being among the pioneers: they expect the purchase price to skyrocket once the whole neighbourhood is nearer completion, with a community of residents, amenities, and of course a very pleasant landscape and water focal point. (From what I could gather, a bit uncharacteristically for Hamburg, the whole complex will be sold or rented at market rates, without the affordability programs created in developments such as Mitte Altona or Alsterberg.)

An architect’s rendering of part of the complex

So I’ll have to wait longer yet before I can find someone who can discuss whether the system has lived up to expectations.  Or maybe next time I’ll go visit Flintenbreite, a similar complex a few kilometers away in Lubeck.  Flintenbreite was the inspiration for Jenfelder Au: it is much smaller, but it has been operating, trouble free, for nearly twenty years.  That’ll be my next post, I hope.

Meanwhile, in my previous post on Jenfelder Au, there are many linked references that explain how the complex was designed and how it is expected to function.  There are surprisingly few scientific studies on the concept, at least, that I could find: a PhD thesis by Claudia Wendland; a 2018 comparison in Energy, Sustainability and Society; and a 2016 article in Environmental Earth Science.  I’ll have to look harder.


(Note: Franz is probably not his real name.  I confess, I forgot his name – I was so excited by the toilet.  Tsk, Paul.)

Written by enviropaul

July 19, 2019 at 11:54 am

Choked: a book review

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I just finished reading Choked: Life and Breath in the Age of Air Pollution, by Beth Gardiner.  Can’t say enough good things about it – loved it!

I had picked it up without a lot of enthusiasm – something I should read, if only to stay up to date because I teach a course on air quality.  Well, I found it hard to put the book down.  This is what happens when you put a technical topic in the hands of a good writer.

I also learned a lot.  I know a lot of details about air pollution; Gardiner masterfully ties it together as a whole picture, a picture that had not been coherent for me until then.

After moving to London, Gardiner started wondering why the air quality was so bad and worried that it would have negative consequences for her newborn daughter.  This is the human story arc of the book: many mother-daughter situations, whether interviewing poor villagers in India subjected to the acrid smoke of dried cow dung used as cooking fuel (women do all the cooking); talking to female scientists such as Beate Ritz who showed how air pollution affects fetuses; or vainly searching for Chinese journalist Chia Jing, who likewise worried about the health of her daughter and produced a documentary on air pollution in China that went viral. (Over 200 million viewers days of release, before it was banned; Chai has not been seen since.)

Gardiner is also remarkably adept at presenting numbers and statistics in a light, effective matter.  Every now and then a number will crop up in the narrative: “air pollution causes 20% of all deaths in London” or “the average Londoner loses 9 months of life because of PM2.5, 17 months from NOx.”  Or again, on a more positive note: since the start of pollution control measures in China, “PM2.5 values have dropped by a third”, giving “every single Beijinger more than three additional years of life.”  Still in China, on the solar energy that is replacing the polluting coal power: “China is installing 3 football fields worth of solar panels every hour” (every hour!); “in just one year, Jinko Solar produced panels with an electricity-generating capacity equivalent to about 10 typical coal-fired plants.”

The whole book is filled with interesting stories, deftly told.  The ones that particularly stay with me are the story of fighting air pollution in Krakow (worst in the EU), and why Poles are attached to coal home heating (a cellar full of coal is a guarantee against a cold and hungry winter), thinking that they are supporting the local industry (paradoxically, most of the coal comes from dreaded Russia).  Or how the US Clean Air Act was created along bi-partisan lines: most Senators on the subcommittee had been through World War Two and learned the value of co-operation (a good reason why the act has the crucial word “must” inserted instead of oft-used weasel word “may” when outlining government responsibility).

The last chapter holds Berlin as model of controlling pollution by curbing car use and encouraging transit and bicycle use, and contains gems such as

I’m afraid to ride on London’s busy roads, where cars and trucks barrel past just inches away. Berlin’s streets are wider, with far less traffic. But, trying to be fair, I remind myself how much harder it would be to make room for bikes on London’s ancient, winding streets.  I’m envisioning a particular two-lane road near my home, and it’s a moment before I realize how much my imagination has been constrained by the cars-first design that is the norm nearly everywhere. In fact, the road I’m thinking of isn’t two lanes, but four – two for moving cars and two for parked ones. We’re so used to giving over our public spaces to automobiles that we sometimes don’t even notice we’ve done it.

But Berlin is still plagued by poor air quality, somewhat like London, somewhat for the same reason: restricting older vehicles from driving in the centre has been surprisingly ineffective, defeating predictions.  This is because of the giant scandal that became dubbed as Dieselgate: new cars, much cleaner on paper, are equipped with cheating devices, and during regular use emit nearly as much particulate matter and NOx as the belchers of old.  Understanding the problem is the first step to solving it.

Gardiner’s book has not been covered much in the North American media – reviews are mostly British.  Here are two excerpts.  First Caspar Henderson in the Guardian, then John Vidal in the Literary Review:

Gardiner is nuanced but sharp in her judgments. She is concerned with the particularities of real lives as well as the particulates that often blight them. You couldn’t ask for a better guide for non-specialists and concerned citizens. Choked contains an especially interesting account of the US Clean Air Act of 1970, which remains one of the most important pieces of environmental legislation passed anywhere. It is a key reason why many Americans breathe air that, while still often dirty and dangerous, is much lower in pollutants directly injurious to health than it was in the past, and typically cleaner than the air that most Europeans breathe.

[T]he great Sahara dust episode [in 2014] was the alarm call in Britain. After weeks of choking on traffic fumes, Londoners found their cars covered in a fine red dust. The prime minister, David Cameron, said it was fine because the pollution was natural, but nobody believed him and news desks at last started to tease out the biggest public health scandal of the past fifty years.  And what a scandal! The scale of this modern plague, we have begun to see, is staggering. We have long known that nearly three million people in poor countries die prematurely each year from inhaling wood smoke from open fires used for cooking, but we didn’t know until quite recently that many people in modern cities are having their lives cut short as a result of breathing in vehicle exhaust gases and industrial fumes.

A book really worth reading.  Or you may want to watch the YouTube subtitled version of Chia Jing’s movie:



Gardiner, Beth 2019. Choked: life and breath in the age of air pollution. U Chicago Press. In KPU library at TD883.1

Written by enviropaul

July 15, 2019 at 11:36 am

Notre Dame Cathedral fire

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Notre Dame cathedral, in Paris, caught fire on April 16th.  The fire, possibly caused by an errant cigarette, destroyed the spire and much of the roof before it was put out.  The roof contained up to 275 tonnes of lead, and authorities are urging residents who may have been affected by the smoke to get their blood lead levels checked.

Many people were devastated by the news, of course – crying, upset.  This is a bit surreal: this is, after all, just one of many interesting buildings in Paris, there was no loss of life, so the reaction was seen by some as disproportionate.

The government (which owns the building) pledge to repair it, and many people pledged donations, including some very generous amounts; for instance, billionaire François-Henri Pinault promised 100 million euros.  Then the reaction set in; the Gilets Jaunes, in particular, complained that the government and the rich, were ignoring them as they can find money for old stones but not for people.

The response from the environmental community was interesting: Jane Goodall wrote about how much the cathedral had meant for her: “[T] he experience I had there, when I visited in 1977, marked an epiphany in my thinking about my place on Planet Earth and the meaning of my life.”  Bill McKibben tweeted that watching the cathedral burn reminded him of how he felt diving along sections of the Great Barrier Reef impacted by coral bleaching. “Beauty and meaning can be so vulnerable — not to be taken for granted, ever.”  Greta Thunberg urged leaders in the European parliament to “act to save the planet in the same way they are pledging to rebuild Notre-Dame.”

The first question that comes to mind is: why should people care so much?  I had an inkling on an answer reading a short novel written in the immediate aftermath of the firebombing of Hamburg, in 1943.  In it, the narrator and some co-workers are returning to the city a few days after the fire, going to the downtown office where they work, looking for a return to a normal life, maybe, and retrieve anything worthwhile.  But the roof has partially caved in, all the windows are broken and there are glass shards everywhere.

Suddenly we hesitated; our gaze had fallen through the back window onto Saint Catherine’s church. Shocked, we looked at each other. “Yes, I cried when it caved in,” said the engineer, who was standing next to us. He told us the precise hour when it had happened. It didn’t help when we tried to persuade ourselves: It’s just a church, what about those hundreds of thousands of homes and the people, that’s so much worse. I suppose it was a symbol. All of us who had worked there loved that steeple exceedingly, each in his own way, perhaps without knowing it. We only realized it now. For more than a decade it had stood in front of my desk. The blue-green of the baroque roof enchanted the opalescent waters of the canal. Especially during the spring and fall you would find yourself drawn into reverie by the sight of it. It wasn’t even necessary to know about the old organ there and that this was the only church that had survived the fire of Hamburg a hundred years earlier.”

St. Catherine’s Church in Hamburg

Some buildings – especially religious ones – are laden with meaning and symbolism, and people care for them desperately, even if, as in the case of our narrator, everything else has also fallen apart, things that are materially more important. But nature, the environment, is also fraught with symbolism.  Why then is there not a similar reaction when faced with the wanton destruction of nature?

Thunberg refers to “the planet”, but maybe that is too much of an abstraction.  McKibben may be closer when he talks about the Great Barrier Reef – but then again, few of us have actually seen it, and even for those who have seen it, they have only seen a small part of it, so the reef as a whole remains a mental construct, an abstraction.  We know it to be important, but something difficult to care about in a deep, visceral way.

But I remember an ill-at-ease, pit-in-the-stomach feeling I experienced when I learned that the elms on my parents’ farm had to go, all of them.  Dutch Elm Disease, they have – they need to come down.  My trees, if you will, have created that emotional response – even if I knew that they weren’t part of “nature”, they had been planted by someone over a hundred years ago.  Columnist Bob Ransford expresses it more eloquently:

Every summer I love to photograph the remaining 8 beautiful maple trees my great-grandmother planted 77 years ago among a number of others around the perimeter of the family property at the corner of Steveston Highway and Railway Avenue. My late father used to remind me that he helped my great-grandmother plant the trees that were about as tall as he was as a then 6 year old. I hope one day the City of Richmond will designate them as heritage trees, offering extra protection from removal. They still look pretty healthy despite all the change that has gone on around them. If you ever get a chance to visit O’Hare’s Pub you can sit on the patio and enjoy the shade from these beauties. (Facebook post, June 11 2019)

I had never noticed these maple trees before, but somehow I can relate emotionally to Bob’s trees, because I remember how I felt about “mine”.  I can also somehow imagine how an aboriginal person in a forested land feels when learning that the land – the trees, the creeks, the ponds, the birds he or she knows intimately – the land is threatened by some pipeline or other.

A red cedar victim of the drought.

I want to cultivate that feeling.  I think it is important, if I am to nourish a complete response to what is happening to my planet, to use Greta Thunberg’s words.  Only a puny fraction of the planet is my immediate environment, the one that I care about, the one that is a part of what makes my life, my life. I care that, here, the coastal red cedars are dying. But also,  somehow, I care about African elephants and blue whales that I have never seen, I care about lagoons and forests that I will never visit. I want to care about that as much as Notre Dame (can I?). I want, mostly, to not become jaded and forget that feeling.  How else could I, a teacher, face all those kids that have been inspired by Greta?

At the same time, though, I want to remain realistic: the world changes, and the environment with it.  So, for its symbolic value, I really liked the proposal that architect Vincent Caillebaut offered for the rebuilding.  A glass roof to bathe the choir in natural light while providing a growing space for “a fruit and vegetable farm run by charities and volunteers, in order to produce free food for vulnerable local people.”  The high-tech roof would also produce solar electricity and create natural ventilation.  The architect asked

How can we write the contemporary history of our country, but also that of science, art and spirituality together? We seek to present a transcendent project, a symbol of a resilient and ecological future. [The design would define] the new face of the Church in the 21st century, a fairer symbiotic relationship between humans and nature.

Needless to say, the proposal was rejected.  Ah well.

The Vincent Caillebaut proposal for Notre Dame

The quote is from Nossack, Hans Erich 1943. The end: Hamburg 1943. U Chicago Press. Foreword and translation Joel Agee 2004.  Pg 47.


Addendum: as of July 18, if Aditya Chakrabortti of the Guardian is correct, none of the money promised by the French ultra-rich has been donated yet.  Pas un sou.

Written by enviropaul

July 2, 2019 at 2:42 pm