The theme of this year’s World Toilet Day is to ‘leave no one behind’ and fulfil Sustainable Development Goal 6 to ensure sanitation for all by 2030. It’s a goal that will only be achieved if there is greater recognition of how faecal sludge management can be used to deliver inclusive sanitation more quickly and more sustainably, writes senior process engineer Joel Westberg.
When plans for a centralised wastewater network in a sub-Saharan African city proved to be unworkable, I helped develop a more sustainable solution using faecal sludge management (FSM).
One day I took my client to visit the site of the new FSM facility and I explained how the system would provide sanitation for 60,000 people, just like the conventional sewerage they had originally wanted, but for 70% less capital investment.
The client was astonished and wondered why they had not considered FSM in the first place.
In my experience of working as an engineer in the developing world, FSM is often dismissed as an option on sanitation infrastructure projects, even before a feasibility study is commissioned.
I believe this is because of a common and widespread misconception of what sanitation means.
Say ‘sanitation’ to people and most will think of sewers, pipelines and wastewater treatment plants.
But there are other ways to achieve equitable access to sanitation, notably FSM.
FSM is disregarded as the cheap and least preferred option when on closer analysis it will be the most effective, sustainable and economic solution.
What’s more, FSM systems can be just as innovative and sophisticated as conventional wastewater infrastructure and offer many advantages.
Technical challenges and varying topography can make it difficult to connect all parts of a city to a centralised wastewater system. The decentralised nature of FSM-based systems makes them more practical in informal, high-density or peri-urban areas of cities in developing countries.
Research shows they are significantly more affordable to build and maintain, offering 10 to 15 times lower capital costs and 80% whole-life cost savings compared to sewer networks.
This is why it is widely accepted Sustainable Development Goal 6 (SDG6), to achieve access to adequate and equitable sanitation and hygiene for all and end open defecation by 2030, will never be reached without FSM-based systems.
It is also important to remember that SDG6 calls for universal and equitable access through ‘safely managed sanitation’, and that definition is applicable to FSM as much as centralised sewer systems.
When cities in the developing world receive funds to invest in improving access to sanitation for their citizens, it is easy to understand why the big and expensive showcase infrastructure projects are put on the table first.
They don’t know if they will ever receive such investment again and they want equality. They want what cities in the developed world have – sewers, modern wastewater treatment plants and the latest technology.
But in many cases FSM will deliver the same level of sanitation coverage and the same desired outcomes for less cost and in less time.
This is where consultant engineers have a crucial role, working to eliminate the bias in the industry towards centralised sewer systems and raising awareness among donors and stakeholders of the alternatives to sewers.
All too often when the terms of reference are defined for a project to extend sanitation coverage in a city, it has been decided almost by default, rather than by discussion and analysis, that a centralised sewer system is the right option.
Instead, consultants should have the freedom to assess all options objectively and without bias, enabling them to plan and design the most appropriate solution to provide inclusive urban sanitation.
For a long-term strategy, the right solution will often be a mix of centralised and decentralised systems, rather than one or the other.
Another advantage of FSM systems is that they can grow in an integrated way alongside waterborne solutions, with areas transitioning from one to the other depending on population and wastewater density, and as economic growth makes sewerage services financially viable.
Improved life chances
Universal access to basic sanitation is essential for the health, dignity and wellbeing of people, and the social, economic and environmental development of nations.
Quite simply, sanitation improves people’s lives. They are healthier, more productive and have improved life chances. It will also tackle gender inequality: absenteeism of young girls is drastically reduced at schools that gain access to gender-inclusive sanitation for the first time.
But the alarm is ringing. The UN has warned that the world is off track to meet SDG6 and ensure sanitation for all by 2030.
If we are going to get back on track, we will have to invest in both FSM and conventional wastewater infrastructure.
And having a balanced view and knowing when one option is better than the other is just as important if we are to achieve inclusive urban sanitation.
The ultimate decision on the feasibility of one system over another should never be based purely on the engineering and technical aspects, but on what solution will deliver the best and most sustainable outcomes for the people who should ultimately benefit from it.