Marc Spiller

Flexible design in water and wastewater engineering--definitions, literature and decision guide.

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.

An organisational innovation perspective on change in water and wastewater systems – the implementation of the Water Framework Directive in England and Wales

This paper presents an assessment of how the European Water Framework Directive (WFD) is stimulating change in water and wastewater management. The paper aims to provide an organisational innovation contribution towards understanding the processes by which policy and legislation stimulate change in water and wastewater systems. Results were produced by analysing interviews with environmental managers from all water and sewerage companies in England and Wales. Results show that integrated water supply approaches are emerging in response to the WFD, while wastewater approaches are not changing to the same extent. Reasons for this difference are located in a mix of factors including: economic regulation; conflicting national and EU regulations; uncertainty; lock-in to infrastructure; the way in which different WaSCs frame business problems and opportunities, and a lack of technological knowledge. Results are discussed against an international review of water sector change and against government reviews of the water sector economic regulator.

Centralised, decentralised or hybrid sanitation systems? Economic evaluation under urban development uncertainty and phased expansion

Sanitation systems are built to be robust, that is, they are dimensioned to cope with population growth and other variability that occurs throughout their lifetime. It was recently shown that building sanitation systems in phases is more cost effective than one robust design. This phasing can take place by building small autonomous decentralised units that operate closer to the actual demand. Research has shown that variability and uncertainty in urban development does affect the cost effectiveness of this approach. Previous studies do not, however, consider the entire sanitation system from collection to treatment. The aim of this study is to assess the economic performance of three sanitation systems with different scales and systems characteristics under a variety of urban development pathways. Three systems are studied: (I) a centralised conventional activated sludge treatment, (II) a community on site source separation grey water and black water treatment and (III) a hybrid with grey water treatment at neighbourhood scale and black water treatment off site. A modelling approach is taken that combines a simulation of greenfield urban growth, a model of the wastewater collection and treatment infrastructure design properties and a model that translates design parameters into discounted asset lifetime costs. Monte Carlo simulations are used to evaluate the economic performance under uncertain development trends. Results show that the conventional system outperforms both of the other systems when total discounted lifetime costs are assessed, because it benefits from economies of scale. However, when population growth is lower than expected, the source-separated system is more cost effective, because of reduced idle capacity. The hybrid system is not competitive under any circumstance due to the costly double piping and treatment.

Integrating Process and Factor Understanding of Environmental Innovation by Water Utilities

Innovations in technology and organisations are central to enabling the water sector to adapt to major environmental changes such as climate change, land degradation or drinking water pollution. While there are literatures on innovation as a process and on the factors that influence it, there is little research that integrates these. Development of such an integrated understanding of innovation is central to understanding how policy makers and organisations can stimulate and direct environmental innovation. In the research reported here a framework is developed that enables such an integrated analysis of innovation process and factors. From research interviews and the literature twenty factors were identified that affect the five stages of the environmental innovation process in English and Welsh water utilities. The environmental innovations investigated are measures taken by water utilities to reduce or prevent pollution in drinking water catchments rather than technical measures to treat water. These Source Control Interventions are similar to other environmental innovations, such as ecosystem and species conservation, in that they emphasise the mix of technology, management and engagement with multiple actors. Results show that in water utilities direct performance regulation and regulation that raises awareness of a ‘performance’ gap as a ‘problem’ can stimulate innovation, but only under particular organisational, natural physical and regulatory conditions. The integrated framework also suggests that while flexible or framework legislation (e.g. Water Framework Directive) does not stimulate innovation in itself, it has shaped the option spaces and characteristics of innovations selected towards source control instead of technical end-of-pipe solutions.

A new approach to nationwide sanitation planning for developing countries : Case study of Indonesia

Many developing countries struggle to provide wastewater and solid waste services. The backlog in access has been partly attributed to the absence of a functional sanitation planning framework. Various planning tools are available; however a comprehensive framework that directly links a government policy to nationwide planning is missing. Therefore, we propose a framework to facilitate the nationwide planning process for the implementation of wastewater and solid waste services. The framework requires inputs from government planners and experts in the formulation of starting points and targets. Based on a limited number of indicators (population density, urban functions) three outputs are generated. The first output is a visualization of the spatial distribution of wastewater and solid waste systems to support regional priority setting in planning and create awareness. Secondly, the total number of people served, budget requirements and distribution of systems is determined. Thirdly, the required budget is allocated to the responsible institution to assure effective implementation. The determined budgets are specified by their beneficiaries, distinguishing urban, rural, poor and non-poor households. The framework was applied for Indonesia and outputs were adopted in the National Development Plan. The required budget to reach the Indonesian governments 2019 target was determined to be 25 billion US

Assessment of nitrogen and phosphorus flows in agricultural and urban systems in a small island under limited data availability.

over 5years. The contribution from the national budget required a more than fivefold increase compared to the current budget allocation in Indonesia, corresponding to an increase from 0.5 to 2.7 billion US

Implementing Pollution Source Control—Learning from the Innovation Process in English and Welsh Water Companies

per year. The budget for campaigning, advocacy and institutional strengthening to enable implementation was determined to be 10% of the total budget. The proposed framework is not only suitable for Indonesia, but could also be applied to any developing country that aims to increase access to wastewater and solid waste facilities.

Scenario analysis of rainwater harvesting and use on a large scale – assessment of runoff, storage and economic performance for the case study Amsterdam Airport Schiphol

Nitrogen (N) and phosphorus (P) are two essential macronutrients required in agricultural production. The major share of this production relies on chemical fertilizer that requires energy and relies on limited resources (P). Since these nutrients are lost to the environment, there is a need to shift from this linear urban metabolism to a circular metabolism in which N and P from domestic waste and wastewater are reused in agriculture. A first step to facilitate a transition to more circular urban N and P management is to understand the flows of these resources in a coupled urban-agricultural system. For the first time this paper presents a Substance Flow Analysis (SFA) approach for the assessment of the coupled agricultural and urban systems under limited data availability in a small island. The developed SFA approach is used to identify intervention points that can provide N and P stocks for agricultural production. The island of St. Eustatius, a small island in the Caribbean, was used as a case study. The model developed in this study consists of eight sub-systems: agricultural and natural lands, urban lands, crop production, animal production, market, household consumption, soakage pit and open-dump landfill. A total of 26 flows were identified and quantified for a period of one year (2013). The results showed that the agricultural system is a significant source for N and P loss because of erosion/run-off and leaching. Moreover, urban sanitation systems contribute to deterioration of the islands ecosystem through N and P losses from domestic waste and wastewater by leaching and atmospheric emission. Proposed interventions are the treatment of blackwater and greywater for the recovery of N and P. In conclusion, this study allows for identification of potential N and P losses and proposes mitigation measures to improve nutrient management in a small island context.

Capture–Ferment–Upgrade: A Three-Step Approach for the Valorization of Sewage Organics as Commodities

Improving the stimulation and management of innovation by water utilities is a key mechanism through which the challenges of securing sustainable water and wastewater services will be achieved. This paper describes the process of adopting source control interventions (SCIs) by water and sewerage companies (WaSCs) in England and Wales. SCIs can be defined as efforts by water suppliers to control agricultural pollution where it arises. To investigate differences in the extent to which SCIs have and are being adopted across all ten WaSCs in England and Wales, Rogers’ five stage innovation model is used to structure and interpret results from a series of semi-structured interviews with raw water quality and catchment management personnel. Results suggest that to promote SCI innovation by WaSCs, regulation should be designed in two interdependent ways. First, regulation must generate awareness of a performance gap so as to set an agenda for change and initiate innovation. This can be achieved either through direct regulation or regulation which raises the awareness of an organisations performance gap, for example through additional monitoring. Simultaneously, regulation needs to create possibilities for implementation of innovation through enabling WaSCs to utilise SCIs where appropriate. Evidence from the research suggests that appropriate intermediary organisations can assist in this process by providing a resource of relevant and local knowledge and data. Future research should seek to characterise the factors affecting each stage in the WaSC innovation process both to confirm the conclusions of this study and to reveal more detail about various influences on innovation outcomes.

Resource recovery from pig manure via an integrated approach: A technical and economic assessment for full-scale applications

Abstract Research on rainwater harvesting mainly focuses on a building scale. Scant information is available about its performance on a large scale. This study aims to determine the potential for, and economic viability of meeting non-potable water demand by rainwater harvesting for a large scale case (21.5 km2): Amsterdam Airport Schiphol. A dynamic model was developed to analyse scenarios of varying rainfall, catchment surfaces and storage capacity. Four potential system configurations of catchments and non-potable uses were analysed for their economic performance with different water prices and storage options. This study found that, given sufficient storage and catchment size, all non-potable water demand of Schiphol can be supplied, reducing drinking water demand by up to 58%. Diminishing returns for adding storage and catchment to the system make full supply inefficient. Current water charges make most large scale system configurations not viable due to high investment costs for supply networks and storage infrastructure.