Carol Hufnagel is Tetra Tech’s national wet weather practice leader.
She has worked on combined sewer overflow (CSO), sanitary sewer overflow (SSO), and stormwater projects for more than 35 years.
Carol’s expertise includes CSO and SSO control planning and implementation, green stormwater infrastructure (GSI), regulatory policy, and hydraulics and hydrology. 她获得了密歇根大学土木工程学士学位和硕士学位.
What are CSOs and SSOs?
A CSO is a designed release point from a combined sewer system. 在美国的许多地区都修建了用于输送废水和雨水的联合下水道, Canada, and other countries. Dry weather flows go to treatment plants. 来自较大降雨事件的多余流量被未经处理地排放到接收水域.
当一个独立的卫生下水道系统在潮湿的天气里被水流淹没，或者由于管道堵塞或某些损坏，废水被释放到地表水或地下时，就会发生SSO.
As society has placed greater value on water quality, 经常从下水道系统排放未经处理的污水不再被认为是可以接受的. 问题变成了这些排放必须控制或消除到什么程度. Standards vary by location, but general approaches are the same.
What actions are communities with combined sewers implementing?
必须减少民间社会组织以保护水质，并从三个主要方面加以控制. First, 通过GSI或下水道分离等措施减少进入联合下水道系统的流量. Second, storing excess flow in basins, tunnels, 或者暂时用超大的管道，直到它可以被运送到处理厂. Third, 通过扩大现有污水处理厂或使用卫星处理来增加处理能力. In recent years, GSI has become a significant component of many programs. 市政当局寻求最大限度地提高项目效益，同时尽量减少总体支出. Regardless of predominate technololgy, the best plans respond to the community’s goals and unique circumstances.
What makes control of overflows particularly challenging?
溢出控制程序的目标是定义组件计划和项目，以达到期望的性能，而不会过于保守. 实施成本很高，许多社区都在为项目融资而苦苦挣扎. At issue is not only the initial construction cost, 还要考虑生命周期成本以及是否实现了对社区的其他好处.
Attention to detail is critical in developing successful projects. 投资于数据收集和现场信息对于实现项目总成本的节约是必要的. Project design hinges on flow quantification, in-depth understanding of how the system works, and attention to long-term operation and maintenance.
How does Tetra Tech help?
作为长期控制计划的一部分，利乐全球最大体育平台一直致力于优化项目选择. 我们根据当地的具体情况提出建议，并与客户合作，确定最适合社区的项目. 我们平衡了作为项目实施技术工作一部分的多个问题, financing, regulatory issues, operations and maintenance, and public engagement.
我们对关键问题的理解来自于在项目生命周期的各个阶段成功实施项目的强大背景. 利乐全球最大体育平台的CSO投资组合包括超过10亿美元的实施项目. 我们在实现各种技术类型方面的经验有助于我们为每个社区的独特情况找到最佳解决方案. We have unique expertise in real-time control and GSI.
实时控制和系统优化最大限度地利用现有的基础设施, reducing the need for additional facilities and associated costs. Tetra Tech’s projects in Louisville, Kentucky, and Montreal, Quebec, 展示通过对现有基础设施的有效管理可以节省大量成本.
在潮湿的天气里，GSI减少了到达联合下水道系统的雨水. 由于生活质量的次要好处，许多市政当局正在转向这种方法来控制公民社会组织. It requires a range of efforts including financing programs, code and ordinance coordination, public engagement, and coordination with private property owners. 需要解决两个关键问题——在哪里以及如何应用gsi——这两个问题都不容易回答. 在回答这些问题时，我们必须考虑到短期和长期的观点. 利乐全球最大体育平台在优化gsi的放置方面具有独特的能力，从而降低了成本, addressing institutional barriers, and providing expert design. 我们的跨学科方法已经在奥马哈等地取得了成本效益, Nebraska and Detroit, Michigan.
What are the challenges associated with GSI?
GSI has gained significant interest over the past several years for CSO control. In numerous recent consent decrees, GSI has been either an exploratory or integral component of the plan. 关键问题包括GSI将如何在下水道规模上发挥作用，以及如何经济有效地应用并在制度上实施. Tetra Tech has worked with the U.S. 环境保护局研究与发展办公室，并与主要市政当局就解决这些问题的项目进行合作.
利乐全球最大体育平台在哪些地方开发了CSO和SSO控制程序?
利乐全球最大体育平台通过在波士顿建立CSO和SSO控制程序进行规划, Massachusetts, to Seattle, Washington, in the United States, as well as major cities in Canada and France. We have planned and implemented more than 60 wet weather facilities. We are currently working with such diverse communities as Seattle, Washington; Tulsa, Oklahoma; and Houston, Texas, on their wet weather programs.
What gives Tetra Tech its expertise in addressing CSOs?
利乐全球最大体育平台是独特的定位，以支持CSO控制，因为我们的历史项目实施. 利乐全球最大体育平台与市政当局合作建立CSO控制系统已有超过35年的历史. CSO controls were pioneered in Michigan, New England, and the Pacific Northwest. 利乐全球最大体育平台在这些地区的悠久历史为我们的团队提供了丰富的技术组合实施经验, including retention treatment basins, sewer separation, in-system storage, and GSI. 我们已经完成了项目的整个生命周期，并从中吸取了可以应用于后续项目的经验教训. 与广泛的方法和技术合作有助于我们成功地选择和应用它们.