Climate change is having a growing impact on global access to sanitation and with it creating new risks for populations, businesses and government.
In the run up to World Toilet Day, on 19 November, UN-water has launched its campaign to highlight the threat that poor sanitation poses and raising awareness of the 4.2 billion people living without access to safely managed sanitation. It warns unless action is taken the world will fail to meet Sustainable Development Goal 6: water and sanitation for all by 2030.
“This year the World Toilet Day 2020 focuses on sustainable sanitation and climate change,” said the organisation. “Climate change is getting worse. Flood, drought and rising sea levels are threatening sanitation systems – from toilets to septic tanks to treatment plants. Everyone must have sustainable sanitation, alongside clean water and handwashing facilities, to help protect and maintain our health security and stop the spread of deadly infectious diseases such as COVID-19, cholera and typhoid. “Sustainable sanitation systems also reuse waste to safely boost agriculture and reduce and capture emissions for greener energy.”
UN Water added: “So, what does a sustainable sanitation system look like? Sustainable sanitation begins with a toilet that effectively captures human waste in a safe, accessible and dignified setting. The waste then gets stored in a tank, which can be emptied later by a collection service, or transported away by pipework.
“The next stage is treatment and safe disposal. Safe reuse of human waste helps save water, reduces and captures greenhouse gas emissions for energy production, and can provide agriculture with a reliable source of water and nutrients.”
However, in a report on the impact of climate change on world sanitation UN water warned that the issues will only worsen.
“Climate change exacerbates the risks that the current climate, including variability, poses for sanitation, and creates new risks, heightens uncertainties, and can increase inequality in sanitation access,” stated the report. “These three dimensions are informed by three key perspectives in the climate change literature, namely risk-hazard, resilience and vulnerability.
“Further, the potential consequences of climate change for the sustainability of water and sanitation services intersect with other causes of failures such as mechanical failure, poor siting or construction, and underlying institutional, financial and social factors.”
It added: “The effects of climate variability and change are often framed in terms of the physical risks that climate hazards pose. Many risks for sanitation come through extreme events and gradual changes to the hydrological cycle with corresponding changes to water resources.”
The study said there several ways in which climate hazards can create risks for sanitation service delivery:
- More intense or prolonged precipitation: Greater rainfall in an event potentially creates more frequent or more intense flooding that can disrupt faecal sludge management (FSM) services if roads and access to containment and/or treatment plants are blocked, result in sewage overflows, and exceed the intake capacity of wastewater treatment plants.
- More variable or declining rainfall or run-off: Longer dry periods can lead to a decline in water supply that impedes the functioning of water-reliant sanitation systems, for instance concerning flushing toilets or blockages due to low sewer flows. High variation in rainfall can cause ground movement in soils with high clay content, resulting in pipe damage for sewer conveyance. Drier conditions can also have a beneficial effect of attenuating the flow of pathogens into water sources.
- More frequent or more intense storms or cyclones: Storms can damage or destroy latrine superstructures, conveyance pipes, power supplies etc, potentially resulting in increased slippage to open defecation and disruptions to pumping and treatment facilities.
- Sea-level rise: Rising sea-levels and consequent salinization can expose coastal wastewater treatment plants and other sanitation infrastructure to inundation and corrosive saltwater.
- More variable and increasing temperatures: Higher water temperatures can be conducive to the proliferation of algal blooms and compound the effects of sanitation pollution in freshwater. Higher temperatures can also have a beneficial effect of increasing the efficiency of biological processes in wastewater treatment.