According to the International Monetary fund (IMF), there are currently 152 countries that make up the developing world. Although water scarcity is an issue that will affect every nation worldwise, for the people in the developing world, water pollution is inevitable. A large portion of the populations in the countries live near rivers, lakes, and other water sources that are often a site of landfill, industrial dumping, and malfunctioning sewage systems. Besides providing an awfully uncomfortable space to live and breathe in, the health effects of wastewater are tremendous on the citizens. For reference, according to the United Nations Environment Programme, “Once water is contaminated, it is difficult, costly, and often impossible to remove the pollutants. But 80 per cent of global wastewater goes untreated, containing everything from human waste to highly toxic industrial discharges”.
Countries in the developing world –let’s not forget, 152 out of the 193 member states of the United Nations– are often too poor to provide proper sanitation systems, and suffer from many internal conflicts which makes water treatment even less of a priority. This results in communities that get sick easily from their unsafe drinking water, crops that have more difficulty growing (and when they do, they’re filled with toxins), and overall decimates living conditions even more. Untreated water systems can lead to thousands of deaths, increase in undereducation, and strong micro and macro economic impacts, making it even more strenuous to break out from the developing world.
Despite (or maybe due to) the dire situations, not all hope is lost. In stress-ridden Dar es Salaam in Tanzania, new low-cost, innovative and effective water treatment systems are underway. We’re talking about the Decentralised Wastewater System (DEWATS), a bio-based wastewater treatment system. According to the Engineering for Change website, DEWATS is a “technical approach to decentralized wastewater treatment in developing communities. The passive design uses physical and biological treatment mechanisms such as sedimentation, floatation, aerobic and anaerobic treatment to treat both domestic and industrial wastewater sources”.
The benefits of this system are truly incredible, and its applications even more. Because it uses local materials, a community-based approach, is electricity-free, low-cost and low-maintenance, it proves to be a strong ally for countries in the developing nations. More than 3,000 systems have been implemented worldwide in countries such as Afghanistan, Bangladesh, Bhutan, Cambodia, Cuba, Ecuador, Haiti, India, Indonesia, Iraq, Lao People’s Democratic Republic, Lesotho, Mali, Mexico, Myanmar, Nepal, Nicaragua, Philippines, South Africa, Tanzania, Viet Nam, and Zambia by Bremen Overseas Research & Development Association (BORDA). DEWATS can be used in a myriad of places; not only homes, but hospitals, schools, small and medium-sized enterprises (SEM), the agriculture industry, hospitals, and more. One million people have gained access to sanitation services thanks to DEWATS.
The case of DEWATS in Tanzania is remarkable. The BORDA-Africa operations states that: “Currently less than 10% of the city is connected to a public sewer network, and more than 50% of wastewater from these sewer networks is being discharged into the ocean untreated. The remaining 90% of the population use on-site sanitation options, with more than 90% of this wastewater being discharged via soak-aways into the ground, or into stormwater drainage and rivers. This lack of wastewater treatment leads to groundwater contamination, public health risks and environmental degradation.” With these conditions, Dar es Salaam proved to be the perfect site for the implementation of DEWATS.
However, BORDA is not acting alone in Tanzania. They’re working alongside UNEP, who have dedicated an entire project to the city. The goal of the joint-project, which also includes local stakeholders, is to promulgate the December 2018 Guidelines on Decentralized Wastewater Treatment Systems, a sort of handbook for policymakers to support the scaling up of wastewater treatment solutions. The guidelines were developed by UNEP, BORDA, UN-Habitat and the Ministry of Water of Tanzania and have been translated into Swahili in order to make it easy-to-access to the general public. According to the document, “In Tanzania there are currently no guidelines or standards explicitly for small-scale wastewater treatment systems and the reuse or disposal of the by-products from the treatment process. This document provides guidance on the holistic approach needed to implement and scale up small-scale wastewater treatment systems and should serve as the basis for the development of Tanzanian standards for Decentralised Wastewater Treatment Systems (DEWATS)”
Riccardo Zennaro, a wastewater expert with UNEP, gave more insights on the innovative systems and the challenges of managing wastewater in an interview with UNEP. During the interview, Zennaro confirmed that the system gives access to basic sanitation services whilst simultaneously reducing contamination, both in-water and in-air, and converts wastewater into reusable by-products from agriculture and energy purposes. “Typically, they treat up to 1,000 cubic metres of wastewater per day, operate with zero or minimal power, require minimal maintenance, reuse resources wherever possible, and recover energy and nutrients. Investment and operating costs are much lower than centralized systems,” he said.
Zennaro also added that, although it is a small-scale solution with optimal results, not everything can be easy. The main challenges to implement systems like DEWATS across the rest of Tanzania, and the developing world, are the “limited resources, the low willingness of stakeholders to commit to change, wrong priorities, misconceptions about alternatives for wastewater treatment, lack of capacity and lack of enforcement of existing laws”, reaffirming the low position that water waste occupies in the list of priorities.
While these innovative systems exist, and new research is dedicated solely to wastewater treatment, it’s up to companies, private stakeholders and local communities to take that first step into demanding policymakers for the right changes to improve their life.