Nature Based Solutions For Wastewater Treatment

There are 2.4 billion people without improved sanitation and another 2.1 billion with inadequate sanitation (i.e. wastewater drains directly into surface waters), and despite improvements over the past decades, the unsafe management of fecal waste and wastewater continues to present a major risk to public health and the environment (UN, 2016). There is growing interest in low cost sanitation solutions which harness natural systems. However, it can be difficult for wastewater utility managers to understand under what conditions such nature-based solutions (NBS) might be applicable and how best to combine traditional infrastructure, for example an activated sludge treatment plant, with an NBS such as treatment wetlands. There is increasing scientific evidence that treatment systems with designs inspired by nature are highly efficient treatment technologies. The cost-effective design and implementation of ecosystems in wastewater treatment is something that exists and has the potential to be further promoted globally as both a sustainable and practical solution. This book serves as a compilation of technical references, case examples and guidance for applying nature-based solutions for treatment of domestic wastewater, and enables a wide variety of stakeholders to understand the design parameters, removal efficiencies, costs, co-benefits for both people and nature and trade-offs for consideration in their local context. Examples through case studies are from across the globe and provide practical insights into the variety of potentially applicable solutions.

This book aims to define the concept of Nature Based Solutions (NBS) by using case studies from members of the European Innovation Partnership (EIP) Water Action Group - NatureWat. NBS is defined and characterized in terms of water source, contaminants, removal mechanisms and resource recovery potential. The case studies presented illustrate the appropriateness of NBS promoting climate resilience. Readers will discover a technology portfolio based on a number of demonstration sites in the fields of climate change adaption, water and wastewater treatment, resource recovery and re-use, and restoring ecosystems to promote the use of nature based solutions. The chapters in the book present a multidisciplinary approach involving social scientists, governance representatives and engineers. The underlying philosophy of the book is the circular economy of water which prioritizes the concepts of resource recovery and resilience within water resource management. The first section of the book presents the background and objectives of the study, and how the action group aims to promote the use of nature based solutions through its diverse technology portfolio. Particular attention is given to the goals of finding cost-effective solutions for wastewater treatment, climate change mitigation, disaster risk reduction, flood protection, greening cities, degraded areas restoration and biodiversity preservation. The chapter on reclaimed water addresses water reuse and defines the term fit for purpose. Barriers and limitations related to NBS for water resource management are discussed. The book concludes with several case studies at local, regional and global levels which illustrate a new approach to water management. These case studies illustrate the application of a hybrid green and grey infrastructure system. This is a combination of traditional engineered infrastructure with nature based solutions which combines centralised and decentralised systems to optimise the reclamation of water for reuse in a fit for purpose model.

Water quality standards across the world are being re-written to promote healthier ecosystems, ensure safe potable water sources, increased biodiversity, and enhanced ecological functions. Treatment wetlands are used for treating a variety of pollutant waters, including municipal wastewater, agricultural and urban runoff, industrial effluents, and combined sewer overflows, among others. Treatment wetlands are particularly well-suited for sustainable water management because they can cope with variable influent loads, can be constructed of local materials, have low operations and maintenance requirements compared to other treatment technologies, and they can provide additional ecosystem services. The technology has been successfully implemented in both developed and developing countries. The first IWA Scientific and Technical Report (STR) on Wetland Technology was published in 2000. With the exponential development of the technology since then, the generation of a new STR was facilitated by the IWA Task Group on Mainstreaming Wetland Technology. This STR was conceptualized and written by leading experts in the field. The new report presents the latest technology applications within an innovative planning framework of multi-purpose wetland design. It also includes practical design information collected from over twenty years of experience from practitioners and academics, covering experiments at laboratory and pilot-scale up to full-scale applications. Scientific and Technical Report No.27

By 2025, two thirds of the world’s population will be living in water stressed conditions. Meanwhile, the degradation of water ecosystems is occurring at alarming rates. Water utilities and water regulators that choose to play an active role in catchment management with nature based solutions (NBS) are uniquely positioned to help. Building a robust knowledge base and supporting opportunities for cross-sector collaboration are fundamental to the mainstreaming of NBS. The International Water Association (IWA) and The Nature Conservancy (TNC) are working together to encourage and facilitate active utility involvement in NBS, as well as promoting stronger connections between water utilities and regulatory bodies. Implementation of NBS involves multiple, interdependent stakeholders at various governance levels, and consequently regulators a key role in creating the enabling environments for these interactions and negotiations. This publication taps into diverse geographies and contexts, delving into case studies for a richer conversation that addresses the variety of challenges and elements for success for integrating NBS into water utility operations and planning. By publicizing successful case studies, the IWA/TNC partnership fulfils a dual purpose of endorsing these efforts and providing actionable guidance for other water utilities striving to improve their sustainability and resiliency.

Globally, poor hygiene and sanitation contribute to more than 1,000 daily deaths from diarrhoeal diseases among children under the age of 5, while two thirds of urban wastewaters are discharged without treatment into lakes, rivers and coastal waters. Across Europe the percentage of the population connected to wastewater treatment plants varies from 14% to >99% with many reliant on unsuitable decentralised sanitation systems or no wastewater treatment at all. With less than a decade left to achieve the 2030 sanitation targets as set out in the Sustainable Development Goals, there is an urgent need to develop new treatment solutions that can be rapidly deployed to meet the needs of growing urban and peri-urban populations, together with under-served rural communities. This book discusses decentralised wastewater treatment and the role of nature-based solutions within the context of the twenty-partner international INNOQUA project. INNOQUA set out to develop and demonstrate a suite of modular, low cost, decentralised solutions that use the combined capabilities of earthworms, bacteria, Cladocera and micro-algae to deliver nature-based primary, secondary and tertiary treatment - followed by UV disinfection. Design and operation principles are outlined, together with performance data and practical feedback from pilot and demonstration facilities situated in eleven countries from Ecuador to Scotland and India. Barriers and drivers towards more widespread uptake of these technologies are also examined, alongside an exploration of existing markets for nature-based sanitation in the Global South.

Nature-based solutions (NbS) are solutions inspired or supported by nature. They include ecosystem conservation and restoration measures, as well as the creation or enhancement of natural processes in man-made ecosystems, such as cities. Recent interest in NbS has emphasized their importance for urban water management and cities across the world have begun to experiment with them. Experiences from different contexts, however, are not adequately captured and understood. This book aims to address this gap by compiling case studies and reviews that explore NbS for urban water management from different regions and perspectives and highlight emerging challenges and opportunities for harnessing their potential.

Nature-Based Solutions and Water Security: An Action Agenda for the 21st Century presents an action agenda for natural infrastructure on topics of standards and principles, technical evaluation and design tools, capacity building and innovative finance. Chapters introduce the topic and concepts of natural infrastructure, or nature-based solutions (NBS) and water security, with important background on the urgency of the global water crisis and the role that NBS can, and should play, in addressing this crisis. Sections also present the community of practice’s collective thinking on a prioritized action agenda to guide more rapid progress in mainstreaming NBS. With contributions from global authors, including key individuals and organizations active in developing NBS solutions, users will also find important conclusions and recommendations, thus presenting a collaboratively developed, consensus roadmap to scaling NBS. Covers all issues of water security and natural infrastructures Presents a comprehensive state of synthesis, providing readers with a solid grounding in the field of natural infrastructures and water security Includes a fully workable and intuitive roadmap for action that is presented as a guide to the most important actions for practitioners, research questions for academics, and information on promising careers for students entering the field