12

A Different Tomorrow

第十二章

不一样的明天

Ever since the Romans pioneered Water 1.0, centralization had been the big idea behind urban water systems. In fact, this original design principlehad been so potent that each of the subsequent upgrades was built on this foundation. Starting with the addition of filtration and chlorine disinfectionon the front end of water distribution systems (Water 2.0), and continuing tothe installation of biological wastewater treatment on the sewer end (Water 3.0) and beyond, modern water infrastructure is still guided by its original blueprint of ancient Roman-style aqueducts and cloacae.

自从古罗马人开创了“水１．０”，“集中化”已成为城市供水系统的重要理念。事实上，这个原始设计的原则性是如此之强大，以至于后续的每一次系统升级都是建立在此基础上。从水分配系统的初端加过滤和氯消毒处理，即“水２．０”；到下水道末端安装生物污水处理设备，即“水３．０”；再到以后每次的升级更新，古罗马式的水渠和下水道的原始蓝图始终在指导着现代的水利基础设施。

(Last four paragraphs of Chapter 12)

If urban runoff is ever going to help cities eliminate the need for imported water, we will have to find a way to put the water from urban runoff back into the local drinking water system. This essential next step in the development of local water supplies could follow two possible paths. The first would be to use advanced treatment technologies such as reverse osmosis and disinfection with ultraviolet light to make urban runoff safe to drink. As we have seen, these technologies can turn sewage effluent or seawater into drinking water. They could also purify urban runoff, but the cost of such projects would be five to ten times higher than it would be for treating wastewater effluent or seawater, because the reuse of urban runoff would require the construction ofnew storage and capture systems.⁵⁶ The treatment plant would also have to dealwith water of highly variable quality, which complicated treatment and drives up costs. A runoff recycling facility would have the added benefit of addressing urban drainage and might be more acceptable to the public than potable water reuse or seawater desalination, but the economic reality is that it is unlikely to be chosen over less expensive water-supply options.

如果城市径流能帮助城市消除对输入水的需求，我们必须找到一个方法把城市径流引入到当地饮用水系统中。这是发展当地供水至关重要的一步，它有两种可以效仿的路径。第一个是使用先进的处理技术，如反渗透和紫外线消毒技术使城市径流能安全饮用。正如我们所看到的，这些技术可以把废水或海水转化为饮用水。它们也可以净化城市径流，但其成本将是处理废水或海水的５～１０倍，因为城市地表径流的重复使用，需要建设新的存储和收集系统^［５６］。水处理厂还必须面对参差不齐的径流水质，这不利于水的处理，从而提高了成本。径流回收设施解决了城市排放的污水，这将是额外的好处。径流比起饮用水再利用或海水淡化可能也更容易为公众认可，但是，经济现实使人们不太可能选择径流回收，因为还有更便宜的供水办法。

The other approach would be to keep urban runoff from getting too polluted in the first place and sending the water to urban drinking water reservoirs. This idea is not as out of reach as it might seem. After all, there are plenty of cities that draw their drinking water downstream of the discharges of storm sewers. In essence, they already have urban runoff reservoirs—only they are located outside of the city. For those cities, urban runoff is converted into drinking water through a combination of dilution with water from more pristine sources and conventional drinking water treatment.

另一个方法是在城市径流被严重污染之前，将其送到城市饮用水水库。这个想法不像看起来那么遥不可及。毕竟，有很多城市在下水道排污口的下游抽取他们的饮用水。从本质上说，他们已经有了城市径流水库———只是它们位于城外而已。对于这些城市，其径流是通过与原始的水源混合稀释和通过传统处理后转化成城市的饮用水。

Some cities have already built systems to route urban runoff to reservoirs located within the city. In Singapore, urban runoff is piped directly into drinking water reservoirs with little or no dilution with pristine water.⁵⁷ Through an elaborate system of stormwater interception, nearly all of the rain that falls on the streets and buildings of the city’s populated residential neighborhoods is captured by a network of urban reservoirs. In part, Singapore has been able to achieve this goal because the city and surrounding region receive monsoon rains that dump large quantities of water over a short period of time. The high quality of the city’s runoff is also attributable to the vigilance of the national water utility and cith planning agencies inpreventing sewer leaks and the rigorous enforcement of laws related to landuse, automobile maintenance, and the application of chemicals on buildings and gardens.

一些城市已经建立了管道系统，将城市径流输送到位于这座城市内的水库。在新加坡，城市径流直接输送到饮用水水库里，几乎没有用原始水先稀释［５７］。通过一个精心设计的雨水截留盆地系统，几乎所有的落在城市人口密集的居民区的街道和建筑物上的雨水，都被城市内的水库网络所收集。在某种程度上，新加坡之所以能够实现这一目标，是因为这座城市以及周边地区的季风降雨能在短时间内倾泻大量的雨水。高质量的城市径流也可归因于国家水务部门和城市规划部门对防止污水泄漏的高度重视，以及在土地利用、汽车维修和化学品在建筑和花园中的应用等相关方面的严格执法。

Because of differences in climate and political systems, this approach probably would not translate easily to many other developed countries. But contamination of urban runoff could be reduced by a combination of low-impact development and policies designed to minimize further contamination of runoff after it leaves an individual property. With some investment in clean streets and functioning sewer systems, coupled with vigilance about land development and chemical use, urban runoff might someday become an important part of our drinking water supply.

因为气候和政治体制的差异，这种方法可能不会那么轻而易举地移植到其他发达国家。但通过降低开发对环境的影响、制定有助于径流二次污染最少化的政策等手段，可以降低城市径流的污染。随着保持街道干净和污水处理系统相关的投资，加上对土地开发和化学品使用的警惕，城市地表径流可能有一天会成为饮用水供应的一个重要组成部分。

ps. I typed up the English myself, so errors are possible.

水４．０：饮用水的过去、现在与未来

［美］戴维·塞德拉克　著

徐向荣　等译    虞左俊　校

上海科学技术出版社

出版时间：2015.08

ISBN：978-7-5478-2729-1

定价：38元

Water 4.0: The Past, Present, and Future of the World's Most Vital Resource

Paperback：March 31, 2015

by David Sedlak (Author)