专英第二课翻译.doc

Collection of wastewater（废水的收集）

The “Shambles” is a street or area in many medieval English cities（单词“Shambles”在中世纪的英国城市是指一条街或地区）, like London and York（如伦敦和纽约）. During the eighteenth and nineteenth centuries（在18和19世纪）, Shambles were commercialized areas（意指商业化地区）, with meat packing as a major industry（是一个把屠宰和分割肉制品作为主业的地方）. The butchers of the Shambles would throw all of their waste into the street（区域内的屠户会把所有的废弃物扔在街上）, where is was washed away by rainwater into drainage ditches（这些废弃物在下雨时被冲入排水沟）. The condition of the street was so bad that it contributed its name to the English language originally as a synonym for butchery or a bloody battlefield（因为环境是如此的恶劣，它在英文中的原始含义就是屠场或血腥场地的同义词）.

In old cities（在老城里）, drainage ditches like those at the Shambles were constructed for the sole purpose of moving storm water out of the cities（排水沟的唯一目的跟它们最初建在Shambles里一样，就是用于排放雨水）. In fact, discarding human excrement into these ditches was illegal in London（实际上，把人类排泄物排入这些沟渠是非法的）. Eventually, the ditches were covered over and became what we now know as storm sewers（最终，这些沟渠被遮盖起来，并且变成了我们现在所知道的雨水管道）. As water supplies developed and the use of the indoor water closet increased（随着城市供水和室内厕所的发展）, the need for transporting domestic wastewater（排放家庭污水）, called sanitary waste（即生活污水）, became obvious（变得显而易见）. In the United States（在美国）, sanitary wastes were first discharged into the storm sewers（生活污水首先被排入雨水道）, which then carried both sanitary waste and storm water and were known as combined sewers（它们既排放生活污水，也排放雨水，被称为合流制下水道）. Eventually a new system of underground pipes（最终一种新的地下管道系统出现了）, known as sanitary sewers（即生活污水排水管道）, was a constructed for removing the sanitary wastes（被建造用于专门输送排放生活污水）. Cities and parts of cities built in the twentieth century almost all built separate sewers for sanitary waste and storm water（在20世纪所建设的城市或城市部分，基本上都建设了分流制排水系统分别排放生活污水和雨水）.

Estimation Wastewater Quantities（排水量计算）

Domestic wastewater (sewage) comes from various sources within the home（生活污水来自于家庭各处）, including the washing machine（如洗衣机）, dishwasher, shower, sinks, and of course the toilet（洗碗机、淋浴、水槽，当然也包括盥洗室）. The toilet or water closet (WC) （盥洗室或水冲厕所）, as it is still known in Europe（就像欧洲一样）, has become a standard fixture of modern urban society（已经成为现代城镇生活的标准配备）. As important as this invention is（与这些发明同等重要的是）, however, there is some dispute as to its inventor（它的发明者是谁却存在争议）. Some authors credit John Bramah with its invention in 1778（一些人相信John Bramah发明于1778）; others recognize it as the brainchild of Sir John Harrington in 1596（另一些人却认可John Harrington 在1596就有了思路）. The latter argument is strengthened by Sir John’s original description of the device（后一种观点由于发现了John对于设备最初描述而得到强化）, although there is no record of his donation his name to the invention（尽管有关发明的记录上没有他的名字）. The first recorded use of that euphemism is found in a 1735 regulation at Harvard University that decreed（一个委婉的说法是根据哈佛大学1735条规则）, “No Freshman shall go to the Fellows’ John.” （大学新生不会追随John小伙）

  The term sewage is used here to mean only domestic wastewater（此处的下水道意指生活污水排水管）. Domestic wastewater flows vary with the season（生活污水的排放因季节而异）, the day of the week, and the hour of the day（每日每时不一样）. Note the wide variation in flow and strength（污水流量和浓度的变化范围很宽）. Typically（有代表性的是）, average sewage flows are in the range of 100 gallons per day per person（每人每天的平均排水量约100加仑）, but especially in smaller communities that average can range widely（但在一些小社区，这个平均流量的变化范围较大）.

       Sewers also commonly carry industrial wastewater（下水道一般也排放工业废水）. The quantity of industrial wastes may usually be established by water use records（工业废水的排放根据水的用途可以确定）, or the flows may be measured in manholes that serve only a specific industry（在一些工业领域，流量也可以通过人孔加以测量）, using a small flow meter（采用一个小型的流量计）. Industrial flows also often vary considerably throughout the day（工业废水的流量在一天内也通常不一样）, the day of the week, and the season（随日随季节有所变化）.

In addition to sewage and industrial wastewater（除了生活污水和工业废水）, sewers carry groundwater and surface water that seeps into the pipes（下水道也输送渗透入管道的地表水和地下水）. Since sewer pipes can and often do have holes in them (due to faulty construction, cracking by roots, or other causes) （因为下水道不可避免地出现一些漏洞（如建造原因、树根的缠绕或其他原因））, groundwater can seep into the sewer pipe if the pipe is lower than the top of the groundwater table（当下水道低于地下水位标高时，地下水将渗入管道）. This flow into sewers is called infiltration（这种现象称为渗透）. Infiltration is least for new, well-constructed sewers（即使是新管道也会存在渗透）, but can be as high as 500m3/(km.day)(200000gal/mi.day)) （可以高达每公里每日500m3）. For older systems（对于陈旧系统）, 700 m3/(km.day)(300000gal/mi.day)) is the commonly estimated infiltration（一般估计的渗透量为700 m3/(km.day)）. Infiltration flow is detrimental since the extra volume of water must go through the sewers and the wastewater treatment plant（渗流是有害的，因为它对排水管道和污水处理厂都提出了额外的空间要求）. It should be reduced as much as possible by maintaining and repairing sewers and keeping sewerage easements clear of large trees whose roots can severely damage the sewers（通过搞好维修、养护工作，保证管道地面的绿化清理，预防粗大树木根部对下水道的破坏等可以减小渗流量）.

Inflow is storm-water collected unintentionally by the sanitary sewers（生活污水管道会无意中收集雨雪水）. A common source of inflow is a perforated manhole cover placed in a depression（主要原因是在低气压条件下人孔盖上的洞）, so that storm-water flows into the manhole（以致于雨雪水沿此流入）. Sewers laid next to creeks and drainage ways that rise up higher than the manhole elevation（污水管道首尾相连输送水的过程中，上升幅度高于人孔的位置）, or where the manhole is broken（或者人孔受到破坏）, are also a major source（都有可能是主要原因）. Illegal connections to sanitary sewers（不合规定的排水量）, such as roof drains（如浮顶油罐的排水系统）, can substantially increase the wet weather flow over the dry weather flow（能够在潮湿天气明显增长水量）. The ratio of dry weather flow to wet weather flow is usually between 1:2 and 1:4（干燥天气和湿潮天气的流量比在1∶2和1∶4之间）.

        For these reasons, the sizing of sewers is often difficult（因为这些原因，确定排水管道的规格经常是困难的）, since not all of the expected flows can be estimated and their variability is unknown（因为不可能所有的预计流量都能确定，他们的可变性也是未知的）. The more important the sewer and the more difficult is to replace it（排水管道越重要，替代它们就越困难）, the more important it is to make sure that it is sufficiently large to be able to handle all the expected flows for the foreseeable future（有一点确信越来越重要，那就是：在可预测的未来，排水管道的空间应足够大，以便能够输送所有可预见的流量）.

System Layout（系统规划）

Sewers collect wastewater from residences and industrial establishments（排水管理从居住区和工矿企业收集污废水）. A system of sewers installed for the purpose of collecting wastewater is known as a sewerage system (not a sewage system ) （一个排水系统收集污水的目的，就是为排水设备系统服务）. Sewers almost always operate as open channels or gravity flow conduits（排水管道几乎一起都在工作，犹如明渠或重力流管渠）. Pressure sewers are used in a few places（压力排水系统用在少数地方）, but these are expensive to maintain and are useful only when there are severe restrictions on water use or when the terrain is such that gravity flow conduits cannot be efficiently maintained（但这种系统维护成本高，只适用于那些对水有严格限制或者地形特殊，无法有效利用重力流的情况）.

A typical system for a residential area is shown in Figure 1（生活区域典型的系统如图1所示）. Building connections are usually made with clay or plastic pipe, 6 inches in diameter（通常采用直径6英寸的陶土管或塑料管用作连接管）, to the collecting sewers that run under the street（把水排入街道下的市政管道）. Collecting sewers are sized to carry the maximum anticipated peak flows without surcharging (filling up) and are ordinarily made of plastic, clay, cement, concrete or cast iron pipe（市政管道的大小，以满足最大预期的洪峰流量为准，以免溢流；通常采用塑料管、陶土管、水泥管、混凝土管或铸铁管）. They discharge into intercepting sewers, or interceptors（它们把水送到截流井或截流管道）, that collect from large areas and discharge finally into the wastewater treatment plant（它们收集更大范围的污水并且最终把污水送到污水处理厂）.

Collecting and intercepting sewers must e constructed with adequate slope for adequate flow velocity during periods of low flow（连接管和截流管建造时的采用合适的坡度，以满足小流量时的流速需要）, but not so steep a slope as to promote excessively high velocities when flows are at their maximum（但坡度又不过度陡峭，以免在最大流量时出现雍水）. In addition, sewers must have manholes（另外，排水管道必须建造检查井）, usually every 120 to 180 m(400 to 600 ft) to facilitate cleaning and repair（其通常间距120至180米，即400至600英尺，以便疏浚和维修）. Manholes are necessary whenever the sewer changes slope size, or direction（无论排水管道的坡度、大小或方向，检查井都是必须的）. Typical manholes are shown in Figure 2（典型的检查井如图2所示）.

缺少两段的译文

Conclusion（结语）

        Sewers have been a part of civilized settlements for thousands of year（排水系统只是千百年来人类文明的一部分）, and in the modern United States we have become accustomed to and even complacent about the sewers that serve our communities（在现代美国，我们已经对排水系统提供的服务习以为常甚至意得志满）. They never seem to fail, and there never seems to be a problem with them（它们看起来从未怠工，甚至看不出有什么问题）. Most important, we can dump whatever we want to down the drain, and it just disappears（最重要的是，我们随手往下水道丢弃废物，它们一下去就消失了）.

        Of course, it doesn’t just disappear（当然，它们并没有消失）. It flows through the sewer and ends up in a wastewater treatment plant（丢弃物沿着排水管道到了污水处理厂）. The stuff we often thoughtlessly dump down the drain can in fact cause serious problems in wastewater treatment and may even cause health problems in future drinking water supplies（我们未加思考就仍进下水道的东西有可能引起污水处理厂的严重故障，甚至有可能在未来导致供水水质安全问题）. Therefore, we must be cognizant of what we flush down the drain and recognize that it does not just disappear（因此，我们必须清楚认识我们扔入下水道的东西，并且要知道，它们进入排水系统并未消失）.