Wastewater - Turning Problem to Solution

• Environmental and human health concerns, and potential risks from pollutants, pathogens, antimicrobial resistance (AMR) and contaminants of concern – including emerging and persistent pollutants and microplastics that may still be present in reclaimed resources and recycled water. The solution As an integral part of sustainable water management, wastewater resource recovery and safe reuse can be a consistent and effective way to address a range of sustainable development issues: from water scarcity to pollution, climate change adaptation and resilience, energy security, sustaining food systems, and human and ecosystem health. This central role of wastewater in securing our common future was recognized in target 6.3 of the SDGs, calling for improved water quality, including reducing the proportion of untreated wastewater, and increasing recycling and safe reuse. The transformation needed to move away from seeing wastewater as a waste management issue to a valued resource is increasingly urgent. This can only be delivered by combining technical solutions with capacity development, mobilizing adequate resources, and a clear, shared strategy to create the social, cultural, regulatory and institutional shifts that can develop new values and norms in society. It is possible to recover valuable resources, such as nutrients, energy and water, when appropriate wastewater collection, treatment and management are in place. A key requirement for any sustainable resource recovery and reuse from waste streams is to ensure that it is safe for people and the environment. When fit for purpose, these resources can deliver multiple co-benefits, such as: reduced dependence on synthetic fertilizers (i.e. up to 25 per cent of the global nitrogen and phosphorus demand in agriculture could be met by recycling human urine-derived nutrients); diversification of energy production (i.e. providing electricity for around half a billion people per year, based on potential methane production); and increased water security (i.e. the untapped potential for wastewater reuse is around 320 billion m 3 /year, with the potential to irrigate around 40 million hectares. Noting the continued relevance of the recommendations made in the 2010 Sick Water? report, this new report examines the challenges to realizing the benefits and opportunities of wastewater resource recovery and reuse.

It draws on case studies to explore potential interventions and approaches to overcome these challenges. It defines three key action areas and identifies six building blocks to maximize the opportunities of wastewater resource recovery and safe reuse. The aim is to inspire policymakers and decision makers to be proactive in leading transformational change in sustainable wastewater management, providing options for solutions. The right solution, or combination of solutions, will depend on the local or regional circumstance, and must fit the economic, environmental, social and cultural contexts. There are many excellent experiences to learn from, to realize the opportunities of wastewater reuse, some of which are provided as case studies in this report. 1. Reduce the volume of wastewater produced Freshwater resources must be used more responsibly. Reducing water consumption will lower the wastewater volumes produced, making the task of recovering and reusing wastewater more achievable, by reducing energy requirements and the cost of collection and treatment. It will also reduce pollution risks to people and nature. 2. Prevent and reduce contamination What goes in = what comes out. More attention must be paid to what is put into water when it is used, and where feasible, separating and eliminating compounds at source before they enter the wastewater flow. By reducing and restricting the contaminants of concern in our water (e.g. pharmaceutical compounds, chemical and synthetic compounds, microplastics or nanoparticles), it is easier and cheaper to treat, and safer to reuse the resources in wastewater or to release treated water back to the environment. Collection is a prerequisite to treatment. There are many solutions for the collection and treatment of wastewater to recover resources of appropriate quality standards, depending on its application. Investments are needed to expand the capacity for wastewater collection and treatment that includes the recovery of resources for reuse. Investment is also needed to address the neglect or insufficiency of existing wastewater management facilities to ensure they are fit for purpose. These action areas must be addressed in conjunction with each other and at multiple levels. As with the three action areas, successfully expanding the reuse of wastewater will require urgent progress on the following The three key action areas: 3. Sustainably manage wastewater for resource recovery and reuse

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