The Architectural Impetus for Decentralized Water Systems

由专筑网雷军，刘庆新编译

密歇根州弗林特的公共健康危机，迫使建筑师探索零净水输送系统。

The public health crisis in Flint, Mich., should compel architects to explore the implications of alternative, net-zero water delivery systems.



水是我们最重要的资源，但我们往往把水的存在当作是理所当然的，特别是在经济发达地区。从饮用水的便捷性很容易掩盖管道运输的复杂性和挑战性，广泛的覆盖，固有的处理设施及排水沟。“除非是必需的，真的没有太多必要去了解我们城市的水源，”环境工程师戴维塞德拉克在《水4.0》中写道：过去，现在，未来的世界上最重要的资源（耶鲁大学出版社，2014年）。“不幸的是，看起来我们正接近那些步伐。”密歇根州弗林特最近的公共健康危机印证了塞德拉克的警告。到目前为止，高含量的铅已经在近400个住宅的供水中发现，在当地儿童的血液中发现了含量超标的铅，纽约时报报道。铅作为一种神经毒素，可引起严重的、甚至终身的健康问题。弗吉尼亚理工大学领导的研究团队也自愿检测细菌在水中引起的疾病。随后媒体在弗林特社会政治状况关于用水情况的报告研究，指出是由于政府机构削减水质量的措施和无视居民投诉的过失行为造成的。（虽然已经引起显著的关注，但是他不是唯一一个在十五年内报告处水源中含有过量铅的城市。）这灾难也引发了一个更大的威胁，从本质上设计失败的始作俑者：集中式供水系统。

“如弗林特这样的城市，非断裂临界式水利服务的发展不仅会减少污染灾害，而且确保生态平衡，减少了能源消耗。”

施特拉克解释说，城市集中式供水系统面临全世界现在人口密度增加的压力，水资源的竞争，降水模式的变化，和新的污染源，如内分泌干扰物。即使没有这些压力，集中供水系统在设计上的关键是对它的任何部分失败都是很敏感的。都市设计中心设计总监建筑学院明尼苏达大学学院的教授，托马斯费舍尔在他的书《设计避免灾难》中写道。《断裂关键设计的本质》（Routledge，2013年）。费舍尔继续说道，设计的关键有四个特点：缺乏冗余，相互联系，效率，和集中供水系统指数应力敏感性。“也许最好的长期解决水问题的方法就是完全放弃集中供水系统，”塞德拉克说。

最近由墨尔本建筑学院维多利亚生态创新实验室提出的建筑和规划，澳大利亚大学，和国际未来生活研究所（国际劳工电影协会）美国绿色建筑委员会（CGBC）呼吁分散式供水系统的建设。如弗林特这样的城市，建设非断裂临界式水利服务不仅会减少污染灾害，而且确保生态平衡的方法和减少能源消耗。以下三个因素将阐明如何分散，净蒸馏水以及可能会产生的积极影响。

污染风险

分散的系统比集中式系统难受到污染。2014年在弗林特检测供水粪大肠菌群广泛分布，并添加氯（除菌），腐蚀导致管道，从而污染整个集水系统，且含有大量的铅，纽约时报报道。弗林特断裂临界水利服务系统本质上是相互关联的，容易失败；根据2011年3月CGBC报告，“灾难性的管道系统使人类容易受到污染，提供不可饮用的水。”国际劳工电影协会建筑提供了一个所谓的“软通道”方法来应对小规模分散供水服务，作为供水系统建设的基础。程序的标准是要保持水土保持LBC程序的“花瓣”，使设计团队面临挑战，设计出最新的独立的供水服务沉淀或闭环系统。从污染的角度来看，任何污染都会被限制在一个建筑的规模上。

资源管理

分散的系统便于更好的管理日益受到威胁的资源。根据联合国经济部和社会事务部的分析，在过去的一个世纪里，水的消费量增长了两倍以上，是世界人口数量的两倍，而且水的重要性成为全球关注的一个主要问题。不仅是含水层被耗尽的速度加快，挥发性沉淀的速度更是日益加快。此外，集中的水利系统通常适合大型基础设施，如水坝和水处理厂，损害复杂的流域系统的恢复力。住宅区主要是以闭环系统为主。研究人员提出了一种分散式模型，通过它的生产、分配和消费系统的设计，极其满足当地的需求和资源的可利用性。这种模式是由多个相互依存的网络，不同规模的运行，增强了服务地区的弹性。

资源状况

分散的水利系统也带来了进步的能源性能。由电力研究所进行的2002项研究发现，移动和处理饮用水和废水用电占美国电力的百分之四。施特拉克对占约百分之八十五的电力消耗的泵作出了解释，主要有两个原因。首先，许多现有的水系统操作对重力的要求所需。其次，现代供水系统必须加压水才能穿越管道的地下网络，我们设定压力的系统值，保证最远的供水所需的最小压力，”他写道。分散的方法是一种更为节能的选择，水的消耗只需要很少甚至为零，如果采用重力的话将是非常明智的做法。

“建筑师应该……发展更多的专业知识，和净蒸馏水系统，因为这些都对建筑设计、施工和操作有直接影响。”

当然，分散的水利系统也存在障碍。现有的方法偏向集中的水利系统，公共卫生规范是公用事业的一部分。成本是另一个障碍，对于一个市级地域来说，升级到分散式供水服务，就会面临着水供应和处理系统的成本负担。分散的系统也被认为是不安全的，因为它们不被中央权威机构所支持。

一份报告中写道：“在许多公用事业中，一个显著的地下基础设施，供应安全的水源，是在其预期寿命边缘的，”这体现着基础设施的“更换时代”。面对过多的价格标签，政府可能更倾向于分散的系统水利作为未来供水的唯一可行的选择。因此，建筑师应潜心于更多的专业知识，净蒸馏水系统，因为这些都对建筑设计、施工和运营有直接影响。

布莱恩布劳内尔，是一个特色专栏作家，他的故事每个星期出现在这个网站。他的观点和结论并不一定代表建筑师杂志，也不是代表美国建筑师协会。

Water is our most important resource, yet it is often taken for granted, particularly in economically developed regions with healthy watersheds. The easy availability of potable water from the tap belies the complexity and challenges inherent in the extensive network of pipes, treatment facilities, and storm drains that operate largely behind the scenes. “Except for periods when major investments are required, there really isn’t much need to understand how water travels in and out of our cities,” writes environmental engineer David Sedlak in Water 4.0: The Past, Present, and Future of the World’s Most Vital Resource (Yale University Press, 2014). “Unfortunately, it looks like we are approaching one of those periods.”
The recent public health crisis in Flint, Mich., affirms Sedlak’s warning. So far, high levels of lead have been found in the water supply of nearly 400 residences, and counting, along with dangerous amounts of lead in the blood of local children, The New York Times reports. A known neurotoxin, lead can cause serious and lifelong health problems. The independent, voluntary research team from Virginia Tech that is leading the tests has also detected bacteria in the water that cause Legionnaires’ disease. The research and subsequent media reports on the state of Flint’s water trend sociopolitical, as the situation was ultimately caused by the negligence and misconduct of the government agencies that cut corners on water-quality measures and scorned initial complaints from residents. (Although Flint has received significant attention, it's not the only municipality to have reported unsafe lead levels in its water over the past decade and a half.) But the catastrophe also raises the specter of a much larger threat in a system that is inherently designed to fail: a centralized water supply.
"The development of non-fracture critical water services would not only reduce the magnitude of a fouling-related disaster, like the one in Flint, but also ensure a more ecologically balanced approach and a reduction in energy consumption."
As Sedlak explains, centralized urban water systems throughout the world are now under significant stress from increasing population density, water-resource competition, changing precipitation patterns, and new sources of pollutants, such as endocrine-disrupting chemicals. Even without these pressures, centralized water is, by design, a fracture-critical system—one that is susceptible “to complete and sudden collapse should any part of it fail,” writes Thomas Fisher, Assoc. AIA, a professor at the University of Minnesota School of Architecture’s College of Design and director of its Metropolitan Design Center, in his book Designing to Avoid Disaster: The Nature of Fracture-Critical Design (Routledge, 2013). Fracture-critical design, Fisher continues, has four characteristics: a lack of redundancy, interconnectedness, efficiency, and sensitivity to exponential stress in the event of failure—all of which describe centralized water systems. “Perhaps the best long-term solution to our water problems will be to abandon centralized water systems altogether,” Sedlak says.
Recent proposals by the Victorian Eco-Innovation Lab (VEIL) at the University in Melbourne's Faculty of Architecture, Building, and Planning, in Australia, and the International Living Future Institute’s (ILFI’s)Cascadia Green Building Council (CGBC) call for the construction of decentralized water systems. The development of non-fracture critical water services would not only reduce the magnitude of a fouling-related disaster, like the one in Flint, but also ensure a more ecologically balanced approach and a reduction in energy consumption. The following three factors show how decentralized, net-zero water could positively impact infrastructure.
Contamination Risk
Decentralized systems are less vulnerable to contamination than are centralized systems. The fecal coliform bacteria detected in Flint’s water supply in 2014 became widely distributed, as did the added chlorine (to get rid of the bacteria) that corroded lead service pipes, thus polluting the entire network with large amounts of lead, according to The New York Times. Flint’s water services—a fracture-critical system—are inherently interconnected and susceptible to complete failure; according to a March 2011 CGBC report, “major catastrophe or malfunction of a big pipe system leaves its service population vulnerable to contamination or without access to potable water.” The ILFI’s Living Building Challenge offers what it calls a “soft path” approach to decentralizing water services based on small-scale, building-based water systems. The program’s list of criteria for projects to maintain water conservation—one “petal” in the latest iteration of the LBC program—challenges design teams to create independent water services based on captured precipitation or closed-loop systems. From a contamination standpoint, any polluting event would thus be limited to the scale of a building.
Resource Management
Decentralized systems also offer better means of managing an increasingly threatened resource. Water consumption has grown at a rate more than twice that of the world’s population in the past century, and water criticality is becoming a major global concern, according to the United Nations Department of Economic and Social Affairs. Not only are aquifers being depleted at an accelerated rate, but volatile precipitation patterns have made municipal water supply increasingly unpredictable. Furthermore, centralized water is typically accompanied by large infrastructure, such as dams and water treatment plants, that erode the resilience of complex watershed systems. The Living Building Challenge method avoids this heavy-handed approach to water services with its closed-loop approach. And VEIL researchers have proposed a distributed model through which production, distribution, and consumption systems are designed specifically to match local demand and resource availability. This model is composed of multiple, interdependent networks that operate at different scales—from the region to the neighborhood—and enhances the resilience of both centralized and decentralized services.
Energy Performance
Decentralized water also brings improved energy performance. A March 2002 study by the Electric Power Research Institute found that moving and treating potable and waste water comprise about 4 percent of U.S. electricity use. Roughly 85 percent of this electricity is consumed by pumps, Sedlak explains, for two primary reasons. First, many existing water systems operate against gravity, rather than working with it. Second, modern water systems must pressurize water in order for it to move through the underground network of pipes, and “… we often set the pressure for large sections of the system at values that assure that the minimum desired pressure will be experienced in the farthest faucet,” he writes. The decentralized approach is a much more energy-efficient option, as water is consumed close to the source and requires little or no pumping, particularly if gravity is employed judiciously.
"Architects should ... develop more expertise related to these net-zero water systems, as they will have direct implications for building design, construction, and operation."
There are, of course, impediments to decentralized water systems. Existing regulations are biased towards centralized systems, and public health codes typically demand connecting to public utilities. Cost is another barrier, either for a municipality that upgrades to distributed water services or for a building owner that faces the added cost burden of a water supply and treatment system. Decentralized systems are also viewed as unsafe, because they are not maintained by a central authority.
We may have no choice but to overcome these challenges. In many utilities today, “a significant amount of buried infrastructure—the underground pipes that make safe water available at the turn of a tap—is at or very near the end of its expected life span,” wrote the American Water Works Association in a 2001 report, suggesting the onset of a “replacement era” for infrastructure. Faced with an excessive price tag, municipalities may welcome decentralized water as the only feasible choice for future water delivery. Architects should therefore develop more expertise related to these net-zero water systems, as they will have direct implications for building design, construction, and operation.
Blaine Brownell, AIA, is a regularly featured columnist whose stories appear on this website each week. His views and conclusions are not necessarily those of ARCHITECT magazine nor of the American Institute of Architects.

出处：本文译自www.architectmagazine.com/，转载请注明出处。