WRI has worked to reframe sludge and wastewater as inputs rather than outputs, reducing water stress and greenhouse gas emissions while creating cleaner water and renewable energy. Analyses of this potential informed a wastewater reuse policy in Gujarat, India, and a push in China’s 13th Five-Year Plan to recover energy and resources from sludge and wastewater.
Rapid urbanization in China and India stresses energy grids and water resources in regions that are already water-stressed. China’s water resources per capita, for example, are only 35 percent of the global average, and India’s are just 19 percent. At the same time, rapidly growing economies in China and India are accelerating demand for energy. Waste and wastewater are usually regarded only as wastes and pollutants. Conventional organic waste and sewage treatment methods for removing pollutants are energy-intensive and release potent greenhouse gases like methane and nitrous oxide.
Since 2013, WRI China has worked in six cities to introduce circular economy approaches to capture previously wasted resources. WRI’s work with large Chinese cities shows that such approaches can help cities achieve multiple Sustainable Development Goals, including cleaner water, less waste, renewable energy production and reduced greenhouse gas emissions. WRI developed an analysis to determine the national, city and project-level potential to avoid greenhouse gas emissions and capture energy. WRI worked with local and national stakeholders to advance circular economy approaches for waste and wastewater once their potential was realized.
WRI India supported the government of the water-poor state of Gujarat in developing its Waste Water Recycle and Reuse Policy, providing research support and technology evaluation for wastewater and sharing WRI’s international experience.
For the first time, China’s 13th Five-Year Plan requires the recovery of energy and resources from sludge and wastewater in cities across China to the extent possible. Three new sludge-to-energy projects in Beijing were initiated in the last year, serving 4.5 million people and producing 136 million kilowatt hours of renewable energy per year, equivalent to avoiding the use of 41,000 metric tonnes (more than 45,000 U.S. tons) of standard coal. By 2020, these approaches could cut China’s methane emissions – currently the world’s largest – by up to 4 percent. Besides meeting the energy demand of the projects’ operation, the captured methane could be used to replace 1.9 billion liters (500 million gallons) of gasoline, equivalent to the annual greenhouse gas emissions of 1.3 million cars.
Gujarat became the first Indian state to adopt a wastewater reuse policy, mandating that urban local bodies recover 20 percent of wastewater. The states of Karnataka, Madhya Pradesh and Rajasthan have since adopted similar policies.