In the linear economy, following the Take-Make-Dispose model, the water sector typically employs the Take-Use-Discharge strategy. In this strategy, water is ‘withdrawn’ from streams, rivers, lakes, reservoirs, oceans, and groundwater reservoirs as well as harvested directly as rainwater. Water is then ‘used’ by municipalities, industries, agriculture, the environment, etc. within the water cycle, including for consumptive and non-consumptive uses. Non-consumptive used water is ‘returned’ to the river basin directly or via a municipal treatment facility. Depending on the location within the river basin this returned water could then be used downstream or lost to the basin.
Circular Water Economy
This Take-Use-Discharge model is becoming fast obsolete with climatic and non-climatic trends including rapid population and economic growth as well as urbanization impacting the availability of water resources for both humans and nature. In response, water utilities are beginning to implement the circular water economy that aims to reduce water usage and reuse and recycle water to lower demand for scarce water resources while mitigating greenhouse gas emissions. A key aspect of the circular water economy is maximizing the use of water in industrial processes. The OECD Environmental Outlook to 2050 estimates that global water demand for manufacturing will increase by 400% from 2000 to 2050, which is larger than any other sector.
Exploring Industrialized Water Solutions in Singapore
In Singapore, water demand is currently about 430 million gallons a day, with the domestic sector consuming 45% and the non-domestic sector taking up the rest. By 2060, Singapore’s total water demand could almost double, with the non-domestic sector accounting for about 70%. This upwards trend in water demand combined with economic growth has led to Singapore’s Public Utilities Board (PUB) facilitating the private sector’s uptake of industrial water solutions. PUB’s Industrial Water Solutions Demonstration Fund has been launched to support high-impact and innovative projects to treat and reclaim freshwater from industrial used water for process reuse. Companies that consume more than 10,000 m3 are invited by the utility to submit proposals that make at least a 5% reduction in water consumption through reuse.
Enhancing Industrial Water Efficiency in Toronto
The City of Toronto is experiencing rapid population growth that is using the capacity of Toronto Water infrastructure faster than projected. At the same time, aging water infrastructure is placing unanticipated stress on the water system. Toronto Water operates the Water Efficiency for Business initiative that encourages businesses to use water more efficiently as it lowers operating costs, enhances the organization’s public image by demonstrating their commitment to the environment, and increases competitiveness by saving money and attracting new loyal customers. To enhance industrial water efficiency, Toronto Water operates the Industrial Water Rate Program which offers a discounted water rate to manufacturers in Toronto to help support economic growth while encouraging water conservation (the city has a 2 block rate structure, with a second block rate providing a 30% discount for eligible industrial customers). The Program is open to manufacturers that use more than 5,000 m3 of water annually, fall within the industrial property class, and have submitted a comprehensive water conservation plan to the satisfaction of Toronto Water.
A key aspect of the circular water economy is maximizing the use of water in industrial processes.