5 minute read
Developing the Circular Water Economy
MARK AND FOCUS MAGAZINE
VOL 02/01 MARCH 2018
Intelligent urban design
Resilient cities
D e v e l o p i n g t h e circular water economy
By Robert C. Brears
Water utilities are beginning to promote the circular water
economy to not only mitigate greenhouse gas emissions but
also enhance resilience to climate change.
In our current economic model, manufactured capital, human
capital, and natural capital all contribute to human welfare by
supporting the production of goods and services in the eco
nomic process, where natural capital — the world’s stock of
natural resources (provided by nature before their extraction
or processing by humans) — is typically used for material and
energy inputs into production and acts as a ‘sink’ for waste
from the economic process. This economic model can be best
described as ‘linear’ which typically involves economic actors
(people or organisations) harvesting and extracting natural
resources, using them to manufacture a product, and selling
a product to other economic actors, who then discard it when
it no longer serves its purpose.
In the linear economy, following this ‘Take-Make-Dispose’
model, the water sector typically employs the ‘Take-Use-Dis
charge’ 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 In this strategy, water is ‘withdrawn’ from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 con
sumptive and non-consumptive uses. Non-consumptive used
water is ‘returned’ to the river basin directly or via a munici
pal treatment facility. Depending on the location within the
basin this returned water could then be used downstream or
lost to the basin.
While the current linear economic model has generated an
unprecedented level of growth, the model has led to con
straints on the availability of natural resources in addition to
the generation of waste and environmental degradation. In
response to climate change, increasing resource scarcity, and
environmental degradation, governments around the world
are implementing a variety of policies to encourage the tran
sition towards the ‘circular economy’ that focuses on reduc
ing material consumption, reusing materials, and recovering
materials from waste.
The Circular Water Economy
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 with Smart Meters in Singapore
To meet future demand for water with today’s technologies, Singapore’s Public Utilities Board’s (PUB) energy footprint will
need to quadruple from the current 1,000GWh/year to 4,000GWh/year. To reduce this demand, PUB is trialling a smart water
network that will collect detailed data on household water consumption to build customer consumption profiles and identify
consumption patterns and trends. The data will then be analysed and provided to customers enabling them to monitor their
water usage patterns and better manage water consumption. PUB will also enable customers to set water-saving goals and
track their performance. This is part of an experiment to see if game playing is more effective at engaging and motivating cus
tomers to conserve water rather than increasing water prices.
Reusing Water in New York City
New York City’s Department of Environmental Protection has launched its On-Site Water Reuse Grant Pilot Program to provide
commercial, mixed-use, and multi-family residential property owners with incentives to install water reuse systems. Grants are
available for water reuse systems at the individual building and district level, with district-scale projects involving two or more
parcels of land such as a housing development, where the project reduces demand in the shared distribution system. Individual
building-scale projects can receive up to $250,000 in reimbursement for a system designed to save at least 32,000 gallons per
day (gpd), and district-scale projects are eligible to receive up to $500,000 in reimbursement for a system designed to save at
least 94,000 gpd. The NYC Construction Code regulates two types of on-site water reuse systems that can be installed: waste
water reuse systems (black water, greywater, rainwater) for non-potable uses including flushing of toilets and urinals, laundry,
and subsurface drip irrigation systems and rainwater reuse systems for non-potable uses including subsurface drip irrigation.
Recovering Biogas in Stockholm
In Stockholm, the two sewage treatment plants, Henriksdal and Bromma, serve more than one million people and industries in
the city plus surrounding municipalities. Rather than viewing the city’s wastewater as waste, it is being turned into a resource.
During the sewage treatment process, the organic material is separated in the form of sludge from the water. In total, the
two plants produce around a million tons of sludge per year. When the sludge is digested biogas is formed, providing a steady
stream of vehicle fuel: currently, around 17 million cubic meters of crude gas is produced which is sold to Scandinavian Biogas,
who then transform the raw gas into vehicle gas. The gas that is not converted to vehicle gas is used for heating and electricity
generation. Most of the gas produced at Henriksdal is used by SL’s inner-city buses. Meanwhile, vehicle gas from Bromma is
sold, partly from a tank outside the plant and partly at other filling stations in the city, to taxis, private cars, buses, and waste
trucks. Overall, the biogas mitigates more than 22,000 tons of carbon dioxide emissions annually.
Concluding thought
In conclusion, a range of innovative technologies is available to close the loop and create a circular water economy.
SERIES EDITOR Robert C. Brears is the founder of Our Future Water, Mitidaption, Mark and Focus, and is a Director on the International Board of the Indo Global Chamber of Commerce, Industries and Agriculture.
ABOUT THE SERIES The Palgrave Studies in Climate Resilient Societies series provides readers with an understanding of what the terms resilience and climate resilient societies mean; the best practices and lessons learnt from various governments, in both nonOECD and OECD countries, implementing climate resilience policies (in other words what is ‘desirable’ or ‘undesirable’ when building climate resilient societies); an understanding of what a resilient society potentially looks like; knowledge of when resilience building requires slow transitions or rapid transformations; and knowledge on how governments can create coherent, forwardlooking and flexible policy innovations to build climate resilient societies that: support the conservation of ecosystems; promote the sustainable use of natural resources; encourage sustainable practices and management systems; develop resilient and inclusive communities; ensure economic growth; and protect health and livelihoods from climatic extremes.
CONTACT FOR PROPOSALS We welcome proposals from both academics and practitioners working in this highlyinterdisciplinary field. For further information about the series or if you would like to discuss a proposal please contact: Rachael Ballard, Publisher | Geography, Environment and Sustainability | rachael.ballard@palgrave.com
