title: Flexible design in water and wastewater engineering--definitions, literature and decision guide.
abstract: Urban water and wastewater systems face uncertain developments including technological progress, climate change and urban development. To ensure the sustainability of these systems under dynamic conditions it has been proposed that technologies and infrastructure should be flexible, adaptive and robust. However, in literature it is often unclear what these technologies and infrastructure are. Furthermore, the terms flexible, adaptive and robust are often used interchangeably, despite important differences. In this paper we will i) define the terminology, ii) provide an overview of the status of flexible infrastructure design alternatives for water and wastewater networks and treatment, and iii) develop guidelines for the selection of flexible design alternatives. Results indicate that, with the exception of Net Present Valuation methods, there is little research available on the design and evaluation of technologies that can enable flexibility. Flexible design alternatives reviewed include robust design, phased design, modular design, modular/component platform design and design for remanufacturing. As developments in the water sector are driven by slow variables (climate change, urban development), rather than market forces, it is suggested that phased design or component platform designs are suitable for responding to change, while robust design is an option when operations face highly dynamic variability.
authors.affiliation: Department of Environmental Technology, Wageningen University, Bornse Weilanden 9, P.O. Box 17, 6700 AA Wageningen, The Netherlands. Electronic address: marc.spiller@wur.nl.
authors.forename: Marc
authors.initials: M
authors.lastname: Spiller
authors.affiliation: Department of Environmental Technology, Wageningen University, Bornse Weilanden 9, P.O. Box 17, 6700 AA Wageningen, The Netherlands; KWR Watercycle Research Institute, PO Box 1072, 3430 BB Nieuwegein, The Netherlands.
authors.forename: Jan H G
authors.initials: JH
authors.lastname: Vreeburg
authors.affiliation: Department of Environmental Technology, Wageningen University, Bornse Weilanden 9, P.O. Box 17, 6700 AA Wageningen, The Netherlands.
authors.forename: Ingo
authors.initials: I
authors.lastname: Leusbrock
authors.affiliation: Department of Environmental Technology, Wageningen University, Bornse Weilanden 9, P.O. Box 17, 6700 AA Wageningen, The Netherlands.
authors.forename: Grietje
authors.initials: G
authors.lastname: Zeeman
mesh_terms: D004738:Engineering / Q000379:methods* / Q000592:standards*; D004867:Equipment Design; D009626:Terminology as Topic; D062065:Wastewater / Q000737:chemistry*; D018508:Water Purification / Q000295:instrumentation*; D014881:Water Supply / Q000592:standards*
chemical_list: D062065:Wastewater
keywords: Adaptivity; Design; Flexibility; Planning; Robustness; Sustainability; Uncertainty; Waste water treatment/network