The Linear 'Take-Make-Dispose' Model and its Impact
In our current 'linear' economic model, manufactured, human, and natural capital contribute to human welfare by supporting the production of goods and services. Natural capital, the world's stock of natural resources, is used for material and energy inputs into production and acts as a waste 'sink'. Economic actors harvest and extract natural resources, use them to manufacture a product and sell it to other actors, who then discard it when it no longer serves its purpose.
The water sector uses a 'Take-Use-Discharge' strategy in the linear' Take-Make-Dispose' model. Water is withdrawn from various sources, used by municipalities, industries, agriculture, and the environment, and then returned to the river basin. This returned water can be used downstream or lost to the basin.
Need for a Transition to a Circular Economy
Despite fostering growth, the current linear economic model has led to resource constraints and environmental degradation. Governments worldwide are promoting a 'circular economy' to reduce material consumption, reuse materials, and recover materials from waste.
In the context of water resources management, water utilities are beginning to promote the circular water economy that reduces water consumption, reuses and recycles water and wastewater, and recovers materials, including heat and minerals, from water and wastewater to not only mitigate greenhouse gas emissions but also enhance resilience to climate change.
Reducing Water Usage: Case Study of Singapore
Singapore's Public Utilities Board (PUB) is implementing a smart water network, installing 300,000 smart water meters across seven districts. These meters collect detailed data on water consumption, aiding customers in managing their water use effectively. PUB is also exploring solutions to reduce its dependency on fossil fuels and greenhouse gas emissions, currently harvesting around 70 MWp of solar power. The Water Efficiency Fund has been enhanced to support sustainable water management among businesses. New recycling requirements will be mandated from 2024 for specific water-intensive industries. Water prices are set to increase by S$0.50 per cubic meter in two phases starting from April 1, 2024.
Reusing Water: Case Study of New York City
The New York City Department of Environmental Protection's (DEP) Water Conservation and Reuse Grant Pilot Program incentivizes commercial, industrial, and multi-family residential property owners to install water efficiency technologies, including on-site water reuse systems. The program reimburses projects over $50,000 on a single private property. It includes conventional fixture retrofits and innovative water-saving technologies. Approximately $1 million is currently available for the program. Eligibility requires the participant to be an institutional, multi-family residential, or commercial customer who receives a water bill directly from DEP for their water use.
Recovering Biogas: Case Study of Stockholm
Stockholm's two sewage treatment plants, Henriksdal and Bromma, serve over a million people and industries. They convert the city's wastewater into a resource by separating organic material from water during treatment. This process produces around a million tons of sludge annually, digested to form biogas. This biogas provides about 17 million cubic meters of crude gas sold to Scandinavian Biogas for conversion into vehicle fuel. The remaining gas is used for heating and electricity. Most of the gas produced at Henriksdal powers the city's buses, while Bromma's gas is sold to various vehicles in the city. This process reduces carbon dioxide emissions by over 22,000 tons annually.
Conclusion: The Importance of Transitioning to a Circular Economy
In conclusion, transitioning from a linear to a circular economy is crucial for sustainable water management. This approach, as demonstrated by Singapore, New York City, and Stockholm, involves reducing water consumption, reusing water, and recovering valuable resources from waste. These efforts mitigate environmental impacts and enhance resilience to climate change.
