New research finds nearly two-thirds of sewage and human waste in 15 major cities is unsafely managed, worsening urban sanitation crisis
WASHINGTON (December 18, 2019)—The number of urban residents who lack safely managed sanitation services has increased from 1.9 billion in 2000 to 2.3 billion in 2015, costing $223 billion a year globally in health costs and lost productivity and wages. According to new research from WRI Ross Center for Sustainable Cities, the problem is even more dire than most realize, particularly for low-income households in dense urban areas whose needs have often been overlooked.
New research from WRI Ross Center, Untreated and Unsafe: Solving the Urban Sanitation Crisis in the Global South, finds that, on average, 62% of sewage and human waste is unsafely managed at various points along the sanitation service chain across 15 cities in the global south. Access to sanitation is generally lowest in South Asia and sub-Saharan Africa. In three cities - Colombo, Sri Lanka; Caracas, Venezuela; and Karachi, Pakistan - researchers found that 0% of human waste was safely managed. For human waste sludge specifically, 5 out of the 15 cities did not have any management regulations in place.
Waste that is not properly contained, transported, treated, reused or disposed of affects the entire city, as contamination can spread via polluted water, food and flies. In the 15 cities studied, households that could not afford to connect to a sewer system or where no sewer system was available constructed on-site sanitation solutions (septic tanks and pit latrines), or relied on unsafe methods. Many used self-provisioned drains to dump untreated or partially treated human waste in storm drains and waterways, or residents resorted to open defecation. The cities include Bengaluru, India; Caracas, Venezuela; Cochabamba, Bolivia; Colombo, Sri Lanka; Dhaka, Bangladesh; Kampala, Uganda; Karachi, Pakistan; Lagos, Nigeria; Maputo, Mozambique; Mumbai, India; Mzuzu, Malawi; Nairobi, Kenya; Rio de Janeiro, Brazil; Santiago de Cali, Colombia; and São Paulo, Brazil.
“No city can be healthy, or in the long term successful, without providing its residents with universal access to safe, affordable sanitation services,” said David Satterthwaite, lead author and senior fellow at the International Institute for Environment and Development. “But the issue has received very little attention from most governments and aid agencies, especially for the urban under-served.”
WRI’s analysis also found that, contrary to popular perception, on-site alternatives to sewer access – septic tanks and pit latrines – are not necessarily less expensive for households than sewer connections, especially when considering the entire service chain. For example, latrines require regular emptying, an unaffordable service for low-income households. To avoid this, residents let pits “flood out,” contaminating drinking water, or hire cheaper manual laborers who dump untreated human waste in nearby waterways, on agricultural lands, or other places. Sometimes, the upfront installation cost of on-site facilities is out of reach for low-income residents. For one informal settlement in Lagos, researchers found that building a ventilated latrine cost over 600% of a household’s average monthly income.
As with water access, commonly used global indicators have underestimated the lack of sanitation access in dense urban areas, particularly the affordability aspect for households. Methods considered to be “improved sanitation,” such as private pit latrines, are not only less cost-effective for households than originally thought, but not appropriate for densely populated settlements. In Dhaka, Bangladesh, the most densely populated city in WRI’s sample, 75% of households rely on septic tanks, many of which leak and are not constructed according to safety standards.
Though the indicators were not specifically designed for urban areas, there aren’t many better alternatives. This has resulted in an overemphasis on sanitation solutions that don’t always fit cities in the global south – including the high-tech, market-based solutions that many investors have pinned their hopes on. WRI’s research finds that for dense urban areas, public sector investment and regulation are required to solve the sanitation crisis.
“For too long, urban policymakers and governments have turned a blind eye to the problem of untreated human waste in cities, and pretended, because it was handled by households and out of sight, that the problem was taken care of,” said Victoria A. Beard, co-author, fellow at WRI Ross Center for Sustainable Cities, and professor of city and regional planning at Cornell University. “But the fact is that this presents a huge public health risk as well as a drag on the economy.”
What can cities do? Evidence suggests four specific actions that can be taken in struggling and emerging cities in Latin America, Asia and sub-Saharan Africa to improve safe sanitation access for the urban under-served:
Extend the sewer network to household, communal and public toilets. Sewer systems require large capital investments and daily supplies of water to work properly, but they reduce the responsibility for and cost of sanitation services from the perspectives of individuals and households.
In the absence of sewer systems, support and regulate on-site sanitation options such as septic tanks and pit latrines. Cities should view these options as short- and medium-term approaches to providing sanitation while they lay the foundation for off-site solutions like sewer connections.
Support citywide, participatory upgrading of informal settlements that address the need for sanitation services. The Mumbai government, for example, supported work by Mahila Milan (the federation of women slum dwellers’ savings groups) to establish community management of public toilets, providing improved facilities to half a million residents.
Make a variety of sanitation services more affordable for low-income households. This includes subsidizing the cost of a sewer connection to household, communal and public toilets, and subsidizing the costs of safe on-site sanitation management.
To make these actions a reality, cities and sanitation authorities need disaggregated, accessible sanitation data to galvanize and inform action. They also need to enhance regulatory and financial capacity and set incentives to encourage and enforce safe containment, transport, treatment, and reuse or disposal of human waste.
“Widespread lack of access to safe urban sanitation is a risk to public health, the environment and the global economy, costing us $223 billion annually and growing. Comprehensive solutions are estimated at less than $300 billion. This is a solvable problem, but we need to act now,” said Ani Dasgupta, global director of WRI Ross Center for Sustainable Cities.
The working paper is part of the World Resources Report: Towards a More Equal City, a series of research papers and case studies examining whether providing equitable access to core urban services and infrastructure, like housing, water, energy and transportation, leads to more economically productive and environmentally sustainable cities.