Human waste is rich in water, nutrients and organic compounds, most of which nowadays are just going down the drain. The concept of “brown gold” highlights the sheer scale of the economic benefits if we were able to recover all these hidden resources by reusing the treated waste.
While some resource recovery practices are long established, such as reusing treated wastewater for irrigation, other applications remain marginal, such as the reuse of urine as a fertiliser, composted faecal waste as fertiliser or soil conditioner, or the production of biogas.
There are signs, however, that we might be at the beginning of a brown gold rush. Northern European countries have been piloting new approaches at increasing scale, such as having separate sewers for blackwater and greywater – from the home to the treatment plant – to maximise resource recovery.
Similar initiatives are also happening in low- and middle-income countries, home to most of the 3.5 billion people still lacking access to safe sanitation, according to WHO and UNICEF. For instance, the Bill and Melinda Gates Foundation launched the “reinvent the toilet” challenge over a decade ago, and among its aims was to “recover valuable resources such as energy, clean water, and nutrients” from human waste. They are now planning to take the solutions developed to a commercial scale. The so-called circular sanitation economy holds the promise to harness resource recovery to accelerate progress towards safely managed sanitation for all.
However, recent research has found that the challenges of resource recovery from human waste might have been underestimated. The ‘Towards Brown Gold’ interdisciplinary research project, led by the Institute of Development Studies, explored the potential of reusing human waste as part of the circular sanitation economy in five rapidly urbanising areas in India, Nepal, Ghana and Ethiopia.
It found that potential is limited by the poor condition of existing sanitation infrastructure, cultural perceptions of waste, a lack of cross-sector collaboration, and a narrative that overpromises the benefits of the circular sanitation economy.
It also found low levels of safely managed sanitation services (access to a toilet and treatment of faecal waste) and extremely poor working conditions for sanitation workers. Progress is particularly slow among groups marginalised due to their caste, class, gender and migration history. They tend to live in informal areas, which are disproportionately underfunded as resources are skewed towards formal areas and elites. Unclear roles and responsibilities, and limited understanding of and skills on safely managed sanitation are additional obstacles to progress towards universal sanitation in rapidly urbanising urban areas. The role of smaller-scale, non-networked systems and localised solutions is critical in these areas, but not properly recognised in policy and financing. In the meantime, capital-intensive sanitation and waste management systems that serve bigger cities are getting the lion’s share of the investments in the sector.
Recommendations to realise the potential of brown gold
This policy brief from the “Towards Brown Gold” research project highlights six ways decision-makers can realise the potential for resource recovery from human waste in rapidly urbanising areas, and accelerate progress towards universal safely managed sanitation:
1. Make safely managed sanitation a political priority
National and urban level governments need to create, reform, and implement policies, strategies, and regulations to ensure there are sufficient funding and resources to ensure that everybody has access to a toilet at home and that the faecal waste is managed in a way that protects public health and the environment. This involves acknowledging the prevalence of non-sewered systems and making them central to revised policy and financing. Particular attention should be on reaching and involving communities and residents who are poor and marginalised by society, such as those living in informal settlements.
2. Facilitate inclusive sanitation planning
Urban planners and policymakers need to address the multifaceted challenges of sanitation in an inclusive way, recognising historical and social contexts of sanitation issues, and how communities who are marginalised – by caste, class, migration, gender, and profession – experience sanitation. These communities’ voices and demands must be central in the planning process, and in holding authorities and service providers to account.
3. Protect the rights of sanitation workers
Governments need to properly recognise the crucial roles of sanitation workers -those emptying septic tanks and pits, unblocking sewers or operating treatment plants- in keeping sanitation services running and their towns and communities clean and liveable. Recognising their work includes protecting their rights to fair wages, social security, safety at work and self-organisation (such as with unions). Sanitation efforts must always include the health, safety, and dignity of sanitation workers, both formal and informal.
4. Cautiously promote the circular sanitation economy
Reusing treated faecal waste -e-g- for irrigation or as compost- has positive impacts for the economy, the environment and climate change mitigation and adaptation. This so-called circular sanitation economy can help accelerate progress, but overselling the benefits of the circular sanitation economy can be counterproductive. For instance, when the potential return from reuse is exaggerated, it undermines the message that public investment is critical to ensure sanitation services for all. The promotion of the circular sanitation economy should instead be realistic about both the benefits and the many challenges involved; be aware of community priorities; and be integrated into a wider sanitation push to close any gaps in access to toilets and to address the whole sanitation service chain.
5. Ground reuse efforts in the context
Those designing and leading sanitation circular economy initiatives should ensure that their efforts are grounded in local economic, social and cultural contexts. This includes considering economic aspects such as where farmers buy compost, or whether other product types are more profitable. It also includes social aspects such as cultural perceptions of waste, or how to effectively raise awareness of the benefits of reuse. Engaging an interdisciplinary team is an effective way of doing this, combining natural and social sciences, as well as art-based approaches to community engagement.
6. Reform policy to enable reuse
Decision-makers need to invest in understanding and improving the enabling environment (policies and regulations, coordination mechanisms, accountability channels) for sanitation in general, and reuse in particular. For instance, policies and regulations should create positive incentives to reuse and eliminate existing barriers, such as bans on the use of treated faecal sludge in agriculture or subsidising chemical fertiliser manufacturers instead of organic compost.
This blog is based on a policy brief, ‘Towards Brown Gold? Challenges and opportunities of reuse for universal sanitation in urban areas’.
