Cradle to Cradle by William McDonough & Michael Braungart

Author:William McDonough & Michael Braungart
Language: eng
Format: mobi
Tags: Development, Technology & Engineering, House & Home, Natural Resources, Sustainability & Green Design, Waste Management, Nature, Architecture, Alternative & Renewable, Power Resources, Sustainable Living, Environmental, Business & Economics, Sustainable Development
ISBN: 9781407021324
Publisher: Random House
Published: 2009-01-29T01:21:37.677512+00:00

A Confusion of Flows

There may be no more potent image of disagreeable waste than sewage. It is a kind of waste people are happy to get “away” from. Before modern sewage systems, people in cities would dump their wastes outside (which might mean out the window), bury them, slop them into cesspools at the bottom of a house, or dispose of them in bodies of water, sometimes upstream from drinking sources. It wasn’t until the late nineteenth century that people began to make the connection between sanitation and public health, which provided the impetus for more sophisticated sewage treatment. Engineers saw pipes taking storm water to rivers and realized this would be a convenient way to remove waterborne sewage. But that didn’t end the problem. From time to time the disposal of raw sewage in rivers close to home became unbearable; during the Great Stink of London in 1858, for example, the reek of raw sewage in the nearby Thames disrupted sittings of the House of Commons. Eventually, sewage treatment plants were built to treat effluents and sized to accommodate waterborne sewage combined with added storm water during major rains.

The original idea was to take relatively active biologically based sewage, principally from humans (urine and excrement, the kind of waste that has interacted with the natural world for millennia), and render it harmless. Sewage treatment was a process of microbial and bacterial digestion. The solids were removed as sludge, and the remaining liquid, which had brought the sewage to treatment in the first place, could be released essentially as water. That was the original strategy. But once the volume of sewage overwhelmed the waterways into which it flowed, harsh chemical treatments like chlorination were added to manage the process. At the same time, new products were being marketed for household use that were never designed with sewage treatment plants (or aquatic ecosystems) in mind. In addition to biological wastes, people began to pour all kinds of things down the drain: cans of paint, harsh chemicals to unclog pipes, bleach, paint thinners, nail-polish removers. And the waste itself now carried antibiotics and even estrogens from birth control pills. Add the various industrial wastes, cleaners, chemicals, and other substances that will join household wastes, and you have highly complex mixtures of chemical and biological substances that still go by the name of sewage. Antimicrobial products—like many soaps currently marketed for bathroom use—may sound desirable, but they are a problematic addition to a system that relies on microbes to be effective. Combine them with antibiotics and other antibacterial ingredients, and you may even set in motion a program to create hyperresistant superbacteria.

Recent studies have found hormones, endocrine disrupters, and other dangerous compounds in bodies of water that receive “treated” sewage effluents. These substances can contaminate natural systems and drinking-water supplies and, as we have noted, can lead to mutations of aquatic and animal life. Nor have the sewage pipes themselves been designed for biological systems; they contain materials and coatings that could degrade and contaminate effluents.

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