Effective water treatment through solar disinfection

Clean and safe water is a cornerstone of sustainable development. The Sustainable Development Goals (SDGs) address this issue in SDG 6, which aims to “Ensure availability and sustainable management of water and sanitation for all”. Target 6.1, “by 2030, achieve universal and equitable access to safe and affordable drinking water for all”, aims at substantially increasing the recycling of water globally.

Solar disinfection (SODIS) is a household water treatment system which has the potential to make a powerful contribution in achieving SDG 6 in Bangladesh. SODIS is known for its positive effects on public health, more particularly in reducing viruses, bacteria, and protozoa in water as well as diarrhoeal disease incidence. The technique is affordable, sustainable, and socially well accepted.

SODIS is one of the household water treatment systems (HWTS) officially recognised and recommended by the World Health Organization (WHO). To date, 33 countries in Africa, Latin America and Asia have been using this specific technique for water purification.

SODIS in Bangladesh – a focus on women

Bangladesh has made significant progress in tackling the water crisis and in improving health and sanitation. Yet there are about 20 million people without access to safe drinking water. The challenge is particularly salient in arsenic hot-spots and prone coastal salinity areas, where an estimated 43,000 Bangladeshis die of waterborne diseases each year, particularly in the rural areas.

With regard to gender roles, women have the strenuous task of fetching water every day. Besides, water scarcity is often a cause of domestic violence. Increased salinity has further exacerbated the vulnerability of marginalised and disaster-prone coastal communities. In the remote villages of Bagerhat, water scarcity has had serious impacts on marriage. Parents are not interested to have their children relocate in villages where water is scarce. Neither do they want their daughters to marry men from such communities only to end up walking long distances to fetch water.

SODIS efficiency is dependent on the amount of sunlight available, and the most favourable regions for SODIS are the semi-arid regions. Given its location, Bangladesh can rely on solar energy for the effective treatment of water. Furthermore, SODIS guarantees a number of social, environmental and economic benefits, which together underline the sustainability of this technique.

Social benefits such as the solar energy used to destroy pathogenic microorganisms causing waterborne diseases, therefore improving the quality of drinking water and family health. SODIS serves as an entry point for health and hygiene promotion and education. Further, it provides local communities with a simple method that can be applied at home. This technique does not require literacy and is therefore suitable for contexts with very low levels of education. Particularly, SODIS entails women to engage in other productive activities, improving family wellbeing and strengthening their position in the family and their self-esteem. Safe drinking water also positively impact the health of children and increases their studying capacity.

Environmental benefits include being able to rely on renewable and natural sources of energy. SODIS reduces the need for traditional and high-intensity energy sources such as firewood, kerosene and gas. Consequently, the use of SODIS reduces deforestation, which is a major environmental challenge. SODIS also decreases air pollution caused by the burning of conventional energy sources.

Economic benefits include individuals being less dependent on the government’s water supply. SODIS does not require costly infrastructure and is easily replicable. Among its financial advantages are families spending less on health services, as well as fewer expenses for traditional energy sources.

By providing easy access to safe drinking water and ensuring year-round safe water access for the communities, SODIS has the potential to considerably improve the wellbeing of the poorest communities living in arsenic hot-spots and salinity- prone coastal areas of Bangladesh. Still, awareness raising remains to be done. Policy-makers at national and local levels as well as other NGOs can work together to actively promote SODIS benefits, achieving the SDG 6 target and improving the wellbeing of millions of Bangladesh’s people.

Md Abu Hena Mostofa Kamal, Field Coordinator, HELVETAS Swiss Intercooperation
mostafa.kamal@helvetas.org