The scourge of untreated wastewater: The economic, environmental and human costs of inaction is a report written by Economist Impact for Back to Blue, an initiative of Economist Impact and The Nippon Foundation. The report is additionally supported by the Ocean Sewage Alliance. This is a pilot study intended to establish a foundation to more widely explore this issue in the future. Its broader purpose is to highlight the need for countries to reduce the discharge of inadequately treated domestic wastewater.

The analysis in the report is based on a model that estimates the economic loss that selected countries suffer from domestic wastewater pollution. The model’s scope in this exploratory effort was confined to five countries—Brazil, India, Kenya, the Philippines and the UK—and selected contaminants and impacts. (See the Appendix for a detailed description of the model methodology.) We intend to widen the model’s scope in future research.

The model was devised and constructed by Bilge Arslan, Ritu Bhandari, Shivangi Jain and Shreyansh Jain. The report was written by Denis McCauley and edited by Naka Kondo. The initiative lead for Economist Impact is Charles Goddard.

This project has benefitted from counsel provided at various stages by a panel of experts consisting of prominent authorities on water resources and wastewater pollution. These include the following (listed alphabetically by institution):

• Jitendra Kumar Singh, water supply and sanitation specialist, Water and Urban Development Sector Office, Asian Development Bank
• Harry Liiv, special envoy for transboundary waters, Ministry of Climate, Estonia; vice-chair, Bureau of the Convention on the Protection and Use of Transboundary Watercourses and International Lakes
• Ricardo Cepeda-Márquez, head of waste strategy and technical programmes, C40 Cities
• Michelle Devlin, science theme lead—chief science officer, Centre for Environment, Fisheries and Aquaculture Science (Cefas)
• Leon Barron, reader in analytical and environmental sciences, Imperial College London
• Jasmine Fournier, executive director, Ocean Sewage Alliance
• Stephanie Johnson, senior program officer, The National Academies of Sciences, Engineering, and Medicine
• Richard Damania, chief economist, Sustainable Development Practice Group, The World Bank
• Esha Zaveri, senior economist, The World Bank
• Martha Rogers, senior economist, The Nature Conservancy
• Martin Gambrill, former lead water and sanitation specialist, The World Bank; consultant, The World Bank; visiting professor, University of Newcastle and University of Leeds
• Juliet Willetts, professor, Institute for Sustainable Futures, University of Technology Sydney
• Amelia Wenger, conservation scientist and water pollution program lead, Wildlife Conservation Society
• Stewart Sarkozy-Banoczy, managing director and CEO, World Ocean Council, and steering committee chair, Ocean Sewage Alliance

To inform our analysis, we also conducted a series of in-depth interviews with experts in this field:

• Will Le Quesne, director, Centre for Environment, Fisheries and Aquaculture Science (Cefas), UK Department for Environment, Food and Rural Affairs
• Nitin Bassi, senior programme lead, Sustainable Water Team, Council on Energy, Environment and Water (CEEW)
• Grace Wambui, water and sanitation consultant, Dev-Afrique Development Advisors
• Cristiano von Steinkirch de Oliveira, environmental engineer, SEMAE Mogi das Cruzes

Untreated domestic wastewater (sewage) is a killer, deeply affecting the health of humans and the environment. The harmful effects on human health, fisheries and agriculture result in economic value disappearing across sectors, leading to reduced economic growth and loss of job opportunities.There are also indirect impacts such as deterring tourists around polluted beaches and rivers. For countries that fail to act in treating their sewage, cascading impacts will further grow over time as some impacts of today (eg, poor health of school children from contaminated water) will translate into lost economic value in the future.

This pilot study estimates the economic loss from inaction towards treating domestic wastewater. The losses represent the disastrous consequences of wastewater pollution on the ground. When wastewater reaches the sea and rivers, the changes it induces in fragile water bodies result in untold losses of fish and other marine life. The bacteria and other pathogens from these water bodies also contaminate drinking water which in turn gives rise to diseases that impact millions of lives each year, especially in the developing world. It also imposes economic costs on countries through these and other human and environmental impacts.

Untreated wastewater is an age-old problem that plagues developing and developed countries alike, yet its full impacts are not widely understood. It is also an insidious problem. Poor water quality can often go unnoticed, making it hard to track the environmental and health threats. This report seeks to help change that, by tracing and quantifying its major economic impacts. It models the economic value lost to countries from poorer health outcomes and environmental damages to the agriculture and fisheries industries. Five countries are included in our analysis: Brazil, India, Kenya, the Philippines and the UK, selected to highlight diverse experiences across the globe. This is a pilot study that is drawn from a carefully chosen set of data and parameters (see the research methodology note in the Appendix for more details). Having established the feasibility of quantifying the impacts of wastewater pollution, we intend to widen the scope of the research to many more countries in the future.

Our analysis in this initial undertaking finds that the economic losses linked to untreated wastewater are sizeable, particularly for the four lower- and middle-income countries in the model. It also finds that all five countries, the UK included, face distinct challenges relating to their wastewater management.

As indicated in the table above, the losses in each pathway are almost certainly higher than our estimates as, due to the limited data availability, the latter do not capture all the possible contaminants in untreated wastewater or their impacts.

Wastewater pollution is also rife with social inequities. Its burdens fall disproportionately on the poorest layers of society, who often live in areas that lack access to sewerage and safely treated wastewater. In Africa and elsewhere, women often bear the brunt through exposure to contaminated water in domestic chores and childbirth.

The clearest path to safer wastewater is to improve water and sanitation systems, in particular through the expansion of water as well as wastewater treatment facilities. To their credit, governments in the most afflicted countries in our study are laying the policy and institutional groundwork for this, and treatment capacity is expanding. Stakeholders in the sanitation sector are also applying creative solutions, such as decentralised water treatment in Kenya and water pricing reform in India.

Wastewater pollution of course afflicts many more countries, and in more ways, than our pilot research captures. We aim for the study to spur further modelling and analysis so that all water stakeholders—policymakers, regulators, administrators, utility executives, investors and others—have the information they need to shape informed decisions about wastewater management.