Not One Drop of Water Wasted
Cities and their respective water utilities are beginning to promote the reduction of water consumption, reuse of water, and recovery of materials from wastewater.
Since the Industrial Revolution, the total amount of waste has increased exponentially as economic growth has been based on a ‘take-make-consume-dispose’ model. This linear model assumes that resources are abundant, available, and cheap to dispose of.
However, the linear model faces significant challenges from a variety of mega-trends including rapid population and economic growth, rapid urbanization, and climate change impacting the availability and quality of resources for sustainable development. Regarding water, by 2050 global demand for water will outstrip supply under a business-as-usual scenario, while water quality will deteriorate further: already 80% of the world’s wastewater is released into the environment with no treatment.
Around the world, there is a transition towards the ‘circular economy’ that focuses on the 3Rs of reducing material consumption, reusing materials, and recovering materials from waste.
In the context of water resources management, cities and their respective water utilities are beginning to promote the reduction of water consumption, reuse of water, and recovery of materials from wastewater.
Reducing water consumption
Water utilities are using a variety of demand management tools to reduce water consumption including pricing of water, reducing leakages in the system, metering all customers, using subsidies and rebates to encourage the installation of water-efficient technologies and appliances in businesses and homes, and education and awareness initiatives that educate the public on the need to use water wisely. The overall aim of demand management is to modify the attitudes and behavior of customers towards water during both normal and atypical times.
Anglian Water’s Bits and Bobs program
Anglian Water services the fastest growing region of the UK and will face variable weather in the future. As part of Anglian Water’s drive to reduce water consumption by 20 liters per day, the utility has initiated its Bits and Bobs program that involves free water-saving home visits that include the distribution of free water-saving devices. During the visit, a member of the utility will provide homeowners with water saving advice as well as fit water-saving products where possible. Some of the free items include a dual flush converter that helps reduce the volume of water used with each flush by up to 50%, tap inserts for around the house, and an Eco Pulse shower head that achieves the temperature and powerful flow of traditional shower heads with only 40–60% of the water supply by creating tiny gaps between droplets.
Toronto Water’s MyWaterToronto
Toronto Water’s MyWaterToronto water meter program lets customers view their water use information online anytime, anywhere, and on any device (laptop, mobile). Customers can view their total and average water use by day, month, or year in an easy-to-read graph or chart format. Extra details including temperature and precipitation can be added to help water users connect water usage with climatic conditions.
Recycling water
Water reuse involves collecting, treating, and reusing wastewater (recycling). It can also involve the re-use of greywater or rainwater in houses or buildings. Recycled water can be used for non-potable uses e.g. industrial, agriculture etc. If treated appropriately recycled water can be blended with surface or groundwater to increase supplies. This reduces the economic and environmental costs related to establishing new water supplies.
Singapore’s NEWater
NEWater is a process involving the treating of used water into ultra-clean, high-grade reclaimed water. It provides up to 40% of Singapore’s current water needs. The reclaimed water is mainly used for industrial and air-con cooling purposes and is delivered via a dedicated pipe network. During dry periods, NEWater is added to the Public Utilities Board’s reservoirs to blend with raw water. The blended water is then treated at the waterworks before becoming potable water. By 2060, NEWater is expected to meet up to 55% of the country’s future water demand.
City of Guelph’s Residential Greywater Reuse Rebate
The City of Guelph, Canada, offers a $1,000 incentive for homeowners to install city- approved greywater systems. The incentive is available on a first-come, first-served basis. It is available for new homes or retrofits. The system collects greywater from household showers and baths and treats the greywater with chlorine. The treated greywater is then used to flush toilets within the home. The installed systems must meet national water quality standards for reclaimed water.
Recovering resources from wastewater
Traditionally, wastewater is seen as a burden that needs treating and disposing of. However, wastewater is a source of valuable resources including energy and nutrients. The positive impact of recovering resources from wastewater is additional revenue streams for utilities and mitigation of emissions.
Hamburg Wasser’s urban biogas
Hamburg Wasser’s 10 digester towers produce, under anaerobic conditions, 95,000 cubic meters of digester gas per day. The gas is either converted into electricity for use on-site or is fed as biomethane into the urban gas network. Urban customers can choose the wastewater treatment plant-associated biogas content in their gas supply with two different pricing options available: Alster Shore (the cheap entry-level tariff has at least 1% urban biogas content) or Alster Pearl (the premium gas tariff has at least 5% urban biogas content).
DC Water’s Bloom Initiative
Bloom is the District of Columbia Water and Sewer Authority’s (DC Water) brand name for its EPA-certified Exceptional Quality biosolids product. At DC Water’s Blue Plains Advanced Wastewater Treatment Plant, solid materials are separated from liquid and sent to DC Water’s new state-of-the-art thermal hydrolysis process and anaerobic digesters. From there heat, pressure, and helpful bacteria remove harmful pathogens and reduce odor. The output is Bloom, a biosolid product that can be used in any area, from large farms to backyard gardens and lawns. Currently, Bloom is on sale for $3.50 per cubic meter, providing additional revenue for DC Water to mitigate the impacts of rising tariffs on its customers.
The take-out
Cities and their respective water utilities can transition towards the circular economy by using demand management strategies to reduce water consumption, ensuring every drop of water is utilized by reusing water where appropriate, and recovering valuable resources from wastewater.
LinkedIn Groups
Our Future Water | Urban Water Security
Mitidaption | Our Future Water| YoungH20Leader | Urban Water Security | Robert Brears
Books
