Hungry City: How Food Shapes Our Lives (41 page)

Rome’s sewers were a magnificent achievement, but to Liebig they were hardly a suitable model for London to follow; or for any other city, for that matter. To him, the Cloaca Maxima represented not an engineering marvel, but an environmental catastrophe – the means by which the greatest nutrient-squandering sump on earth had sucked up all the goodness from the soil and dumped it, never to be recovered, into the Mediterranean. Liebig wrote to the British prime minster, Robert Peel, urging him not to repeat the mistake:

The cause of the exhaustion of the soil is sought in the customs and habits of the townspeople, i.e., in the construction of water-closets, which do not admit of a collection and preservation of the liquid and solid excrement. They do not return in Britain to the fields, but are carried by the rivers into the sea. The equilibrium in the fertility of the soil is destroyed by this incessant removal of phosphates and can only be restored by an equivalent supply …
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Liebig’s arguments were supported by Chadwick, who, despite his recommendation to flush out London’s ancient sewers, understood the value of fresh dung. Chadwick’s own conversion to the uses of sewage had come on a trip to Edinburgh, where he had witnessed the prodigious fertility of a patch of farmland irrigated by the waters of one of the city’s main outflows, the descriptively titled Foul Burn. In 1845, Chadwick had urged that London’s sewers ultimately be reconfigured to create a ‘hydrological ouroboros’ that would, as he put it, ‘complete the circle and realise the Egyptian type of eternity by bringing as it were the serpent’s tail into the serpent’s mouth’.
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Although increasing awareness of pathogens made the use of night soil more problematic than of yore, the government was reluctant to give up on it altogether;
and two chemists, Messrs Hoffman and Will, were commissioned in 1857 to look into the practicality of converting London’s sewage into manure – a practice that had gone on unofficially for centuries. But despite admitting that the nutritional value of the city’s sewage was equivalent to Britain’s entire annual imports of guano, the chemists ended up rejecting the idea:

We have been taunted with the superior wisdom of the despised Chinese, who have no elaborate sewerage system, and who, instead of carrying away their floods of sewerage wealth into the sea … gather it every morning by public servant … and take it away to nourish agriculture. Our reply to these taunts is that people (adopting the vulgar superstition) who are as numerous as ants, and who have to live in boats because the land is too crowded to hold them with any comfort, must be often at their wits’ end to procure food, and are, therefore, no models for a well-to-do civilised nation to copy.
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Just a few months after Hoffman and Will’s verdict, the blazing hot summer of 1858 made the niceties of what a ‘well-to-do civilised nation’ ought to do with its sewage appear somewhat immaterial. As the summer wore on, a ‘Great Stink’ began to emanate from the black and poisoned river, causing a stench so unbearable that the windows of the House of Commons had to be draped with lime-chloride-soaked cloth, while choking MPs inside debated whether or not to decamp to the relative fragrance of Hampton Court.
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Heavy rains eventually dissipated the Stink, but by then it had accomplished its work. After centuries dabbling ineffectually with London’s sewage, MPs were finally persuaded it was time for a Plan B. The Metropolitan Board of Works, set up to replace the Consolidated Commission of Sewers, was tasked with coming up with a solution that would deal with the problem once and for all. Submissions were invited from members of the public, whose various contributions, numbering 140 in all, covered the full gamut of possibility. London’s sewage, according to one, should be conveyed to the countryside via a series of radiating drains like the spokes of a wheel, where it could be sold from small shops as fertiliser. Another suggested collecting the sewage in
floating tanks and towing it out to sea; a third, building two enormous vacuum tubes capable of sucking all the waste from Westminster to the East End, where its fate remained unspecified. And so on.

In 1859, having received and rejected all 140 proposals, the Board finally plumped for a scheme put forward by its own engineer, Joseph Bazalgette. The scheme was based on one submitted 25 years earlier by the biblical painter John Martin, whose apocalyptic visions of doom and destruction seem to have given him an abiding interest in London’s sewage. In 1834, Martin had published a pamphlet (illustrated with painterly finesse by the author) in which he proposed ridding the Thames of its pollution by building two ‘interceptory’ sewers to run either side of the river beneath graceful arcades, which would encourage the ‘working population to indulge in the healthy exercise of walking’.
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The sewers were to terminate at two large receptacles at Limehouse and Rotherhithe, where their contents would be converted into manure and sold on to farmers, as ‘practised in China’. Despite the brilliance of Martin’s vision, he lacked the engineering genius to turn his idea into reality. That was where Bazalgette came in. Bazalgette proposed five interceptory sewers in all, laid to gentle falls in order to harness the natural drainage of the Thames basin, intersecting with existing sewers and tributaries and carrying their contents downstream under the force of gravity. The system would terminate at two main outfalls, at Beckton to the north and Crossness to the south, where its contents would be held in vast storage tanks to await the high tide, when they would be discharged and so carried off to sea.

Bazalgette’s method of disposal was a departure from Martin’s scheme, and it put an end to any notion that London might extend its ancient habit of recycling its own waste. After the Great Stink, all the government was interested in doing was getting rid of the stuff, as quickly and effectively as possible. That was the task with which Bazalgette was charged, and the one which, triumphantly, he achieved. Completed within the astonishingly short space of just six years (including the wettest summer and coldest winter of the century), the project involved the excavation of 3.5 million cubic yards of earth and the use of 318 million bricks, the price of which rose by 50 per cent during construction. Eighty-five miles of interceptory sewers were
built in all, each with graded egg-shaped cross-sections to maximise the speed of flow, whatever volume of fluid they were carrying. The network, which connected 450 miles of main sewers, was capable of shifting half a million gallons of sewage a day almost entirely by gravity. That ‘almost’ was where Crossness Pumping Station came in. Although Bazalgette used every ruse at his disposal to let gravity do its work, he still required four pumping stations (one north of the river and three to the lower-lying south) to raise the sewage to the correct height at the outfalls. Crossness, situated at the lowest section of the entire system, handled the greatest burden: that of raising half of London’s sewage by up to 40 feet and storing it in vast underground reservoirs. That was the task that Victoria, Prince Consort and the others accomplished, and although the monsters are no longer on active duty, they serve as powerful testimony to the pride and skill it took to empty the bowels of the greatest nineteenth-century city on earth.
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Strolling along the Embankment today, few of us pause to think of what passes beneath our feet, or of the magnitude of Bazalgette’s achievement. The network he built is still in operation, and although much of it is hidden, no building project has had a greater impact on London. The Thames, previously a ramshackle waterway bounded by shingle banks and rickety wharves, was transformed into the smooth, canalised thoroughfare we know today, while the city, long mired in the mephitic stench of filth and disease, was purged at last. Where the likes of Wren and Evelyn had failed, Bazalgette (with the assistance of several thousand flushing lavatories) finally succeeded. His feat was no less remarkable in its way than any carried out by his more glamorous contemporary, Isambard Kingdom Brunel, but Bazalgette’s genius has never resonated in the public consciousness quite as powerfully as has that of his rival. People are never grateful for being made to think about their own shit.

Although the modern sewage treatment works at Crossness lack the charm of their Victorian predecessor, they continue to do a vital job for the city, processing some 700,000 cubic metres of waste water each day.
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Getting rid of London’s sewage has become a lot more complicated since Bazalgette’s day, too. Before it can be released back into the wild, sewage must pass through a series of processes designed
to remove all its polluting organic matter, so that what is left is water at least as pure as that of the river itself. The solid matter removed during purification (known collectively as ‘sludge’, the modern term for ‘muck’) was until recently taken by barge and dumped in the North Sea, so fulfilling the vision of at least one disappointed entrant from the 1858 competition. However, an EU directive in 1998 forbade the sea-dumping of sludge, since when Crossness has been consolidating and dehydrating it on site, baking it into cakes and burning it in its sludge-powered generator, a rather menacing-looking building with a swooping metal roof and tall chimney that dominates the site and provides it with three quarters of all its power.

With its primary digestion tanks, sludge-powered generator, aquabelt thickeners and so on (none of them, disappointingly, named Elizabeth, Duke of Edinburgh, Charles or Anne), Crossness represents the state of the art when it comes to treating human waste – the approach to it, at least, that sees sewage as a problem, not a resource. Despite the on-site incineration that was forced upon it, Crossness remains the product of the one-way approach to waste disposal typical of ‘well-to-do civilised’ nations ever since industrialisation. Contrary to the approach common among pre-industrial cities, commercial market gardeners and (as Will and Hoffmann noted) the Chinese, it is one that uses engineered solutions to find ways not of using waste better, but of getting rid of it more effectively. Yet as Herbert Girardet pointed out in his book
Cities, People, Planet
, the nutrients found in sewage are a finite commodity. Phosphates, one of the key ingredients of artificial fertiliser, are currently mined in North Africa, Florida and Russia, but when deposits run out in a few decades’ time, human sewage will be their most easily available source.
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Societies have always differed in their attitudes towards waste; not just sewage (by its nature a highly provocative substance), but every by-product of their lives. What is wasted by society is the direct and opposite expression of what is valued. As a way of understanding the material basis of civilisations, nothing could be more telling.

If our gold is so much waste, then, on the other hand, our waste is so much gold.

What is waste? Rubbish, detritus, effluent, excess, garbage, scrap: it has so many names, and comes in so many different forms, that to try to sum it up in a word can be misleading – even meaningless. Just about the only thing that can be said about waste is that it is stuff that someone, somewhere, does not want. However, that is not to say that someone, somewhere else, might not want it. What is considered waste – what is wasted – differs from one nation to another, from one section of society to the next, from one man to his neighbour. Waste, like beauty, is in the eye of the beholder.

Attitudes towards waste in the pre-industrial world were straightforward compared to those of today. Since most waste was organic (either the direct or indirect by-product of the food chain), its re-use was taken for granted. Cities formed part of an organic cycle in which the food supply was fuelled by the waste it generated. Any inconvenience caused by the arrangement (not least its smell) was simply something one had to put up with. Squeamishness in the pre-industrial world was a luxury few could afford. But our attitudes in the post-industrial West are very different. Much of the waste we produce today is both non-organic and highly differentiated, ranging from material with high embodied value (scrap paper, second-hand cars) to substances so toxic they could kill us or our descendants on contact (nuclear waste). In such a complex material landscape, waste has itself become a highly differentiated industry, with its own logic, processes and dilemmas. All of which tends to obscure the fact that a city’s organic inputs and outputs are vitally connected: that they constitute the cycle of life itself.

A century and a half after London’s decision not to recycle its sewage, the British approach to waste remains essentially one-way. We live in a consumer society in which everything is expendable: we throw away cars and clothes, mobiles and computers, not because they have
worn out, but because they have reached their
cultural
‘use by’ date. We have, in other words, lost the ability to distinguish between embodied and applied value. Wastefulness epitomises our way of life, not just in what we throw away, but in what we consume and how it is made. In those terms, we consume nothing more wastefully than we do food. Despite its obsession with ‘efficiency’, everything about the modern food industry is precisely the opposite: beef reared in feed lots instead of on grass, out-of-season produce raised in heated polytunnels, carbon emissions from subsidised aviation fuel, refrigerated containers on the international ‘chill-chain’ – the list goes on. Yet of all the forms of waste involved in modern food production, none is more damaging than that of food itself, because it contains all the others put together. When we waste food, we waste all the effort, labour, water, sunshine, fossil fuels – even life itself – that went into making it.