The Sanitation And Climate Nexus

In sanitation service provision, ensuring toilet availability, flushing of the sewer to safe storage and conveyance to the onsite or offsite treatment of generated sewage and management of faecal sludge properly is a pre-requisite to avoiding any water-borne disease. On site or non-sewered sanitation chains refer to the technologies, infrastructure and services required to safely operate and maintain toilets which hold waste on site for a certain period (containers, pits or septic tanks). Depending on the design of the containment structure and the number of users, faecal sludge is emptied on a scheduled or on-demand basis and transported by vehicles via road networks to centralised or decentralised treatment facilities. Offsite or sewered sanitation chains refer to technologies, infrastructure and services required to safely operate and maintain toilets connected to a piped sewer network.

Studies suggest that there are direct and indirect impacts of inadequate management or mismanagement of sanitation services on climate change. At the same time, inadequate sanitation services mean there is uncontrolled emission of greenhouse gases in terms of mainly methane and nitrous oxide. Methane is 25 times more potent than carbon dioxide, and nitrous oxide (N2O) is 300 times more potent in causing global warming. Greenhouse gases are emitted when the domestic waste water is not treated adequately or not treated at all. For example, around 80% of the global emissions of N2O from human waste are from uncollected waste management. Untreated wastewater released into the environment generates roughly three times greater greenhouse gas footprint than when the same sewage is treated in a traditional wastewater treatment plant. As only 20% of wastewater produced globally is treated, extending waste treatment capability represents a significant opportunity for greenhouse gas mitigation.

Similarly, organic waste disposal at unmanaged landfill sites results in uncontrolled landfill gas (LFG) emissions, around 45% methane. Another matter of concern is open waste burning, which results in the emission of black carbon (soot), which is also considered to contribute to global warming. Methane, nitrous oxide and black carbon are classified as short-term climate pollutants (SLCPs) as their residence time in the atmosphere is much less than carbon dioxide. Studies indicate that managing SLCPs alone can result in around 40% reduction in greenhouse gas emissions.

The Climate Effect

Climate change impacts can also impact sanitation services through flooding, extreme events and sea level rise. These changes affect sanitation systems and the infrastructure, water resources, water services, and other social and governance systems on which sanitation depends. Many direct and indirect effects on sanitation threaten human health and development.  Climate change-related health consequences from sanitation systems generally fit within two categories—increased risk of disease or illness from exposure to pathogens and environmental contaminants in water and soil and increased risk of infection or disease resulting from a lack of access to adequate sanitation when systems are destroyed or damaged due to climate impacts. Sanitation workers may experience additional risks depending on their work context and level of occupational health and safety. Poor and vulnerable groups face the most immediate and severe consequences of climate change, and health is no exception. People without access to good quality healthcare and essential services experience overlapping forms of disadvantage and are likely to face the worst effects.

Heavy precipitation and flood events can lead to physical damage to sanitation infrastructure and indirect damages from flooding, such as impacts to transportation and energy supply that may disrupt regular operation and maintenance of systems. In coastal areas, sea-level rise is also predicted to increase flooding. Pit latrines and septic systems become non-functional when filled with water. They may collapse or experience damage to the above-ground structures during flood or storm events, making them unusable, with users forced to practice open defecation. These events also impact collection and transportation systems for faecal sludge, particularly in densely populated urban areas and informal settlements, which are more vulnerable to flooding.

Reduced precipitation and limited water availability impact piped sewer systems, as these systems rely on adequate water availability to remove waste to be conveyed to treatment systems. Limited water availability due to drought can increase pollutant concentration, resulting in more contaminated wastewater, which can increase the load on sewage treatment plants or have more significant impacts when discharged untreated into the environment. In addition, high temperatures, heavy rainfall, flooding and drought events can modify the distribution of diarrhoeal diseases. These sanitation-related health effects contribute to undermining gains made in public health over the last several decades.

India has made tremendous progress in providing sanitation facilities to the unserved, including achieving open defecation-free (ODF) status for most parts of the country in the last decade or so. Similar achievements have been recorded in providing improved solid waste management services—segregated collection of waste, dry waste sorting in material recovery facilities, creating infrastructure for organic waste processing and improved recycling, ensuring that less and less waste is required to be sent to landfill site. The long-term aspirational goal is to create garbage-free cities with zero waste to the landfills. The focus of SBM 2 is on ensuring appropriate usage and maintenance of infrastructure built under the mission, which was a lacuna in previous attempts to create sanitation infrastructure.

Suneel Pandey is Director, Environment & Waste Management Division, TERI.