Onsite treatment as an integral part of a smart public toilet



According to Centre for Science and Environment (CSE) and National Environmental Engineering Research Institute (NEERI), a large quantity of water in India is used for carrying human excreta. This clearly is not the best use of water. Indian government has launched a lot of environment conservation campaigns and schemes over the years such as Prime Minister Narendra Modi’s Swachh Bharat (Clean India) Mission, Namami Gange, Ganga Action Plan, National Mission for Clean Ganga, Atal Mission for Rejuvenation and Urban Transformation (AMRUT), and Smart Cities Mission. Under all these schemes, the government has highlighted the need for development of low cost and self-sustainable toilets, these being the major contributors of domestic wastewater.

So, the question is: What do we realistically need to achieve a Swachh and Healthy Bharat? It’s obvious that merely building conventional toilets is not the solution. Pushing the problem under the surface, literally and figuratively, will in fact just compound the crisis instead of eliminating it. The sooner the government accepts this, the better it is for all the stakeholders involved in the sanitation scenario in India.

CSE and NEERI also emphasized that for the success of future toilet models in the country, it is crucial to focus on sustainable and affordable on-site wastewater treatment systems with local reuse or safe disposal of the treated water into the environment. At present, a number of solutions exist all over the world, such as turning the waste into products like hydrogen, fertilizer, biological charcoal, biofuels, minerals, and clean water, or to go for composting and anaerobic digestion. However, these systems are either costly for developing countries or they are unable to comply with the national discharge guidelines. In India, toilets mainly employ the conventional septic tanks and often rely on discharge of partially treated effluents into the sewer. However, considering the stringent environmental legislations and water scarcity, these systems are not capable of delivering the effluents of desired quality. Recently, some Indian companies have started “TOILET to TAP” projects. These toilet models reduce their environmental footprint by treating and reusing the waste streams or by turning waste into value-added products.

With this understanding, it is necessary to develop onsite treatment of toilet waste which could treat the wastewater to a level sufficient for onsite reuse like flushing, gardening etc. There is an urgent need for low cost and easy-to-install solutions. SUKRITI is developing a prefabricated onsite blackwater treatment system that not only treats the black water but also allows for reuse of this treated water.