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ENVIRONMENT AND ENERGY
When the water flows in Alex
Rivers of untreated greywater flow through dusty township
streets across South Africa, and a programme to construct
artificial wetlands to clean this greywater is underway in
Alexandra township, Johannesburg.
By Professor Craig Sheridan
"Over 12
million
people in
South Africa
who live in
an urban
environment,
live in
informal
settlements."
Greywater refers to water that does not go down a
toilet. It is usually used for hand and body washing,
cooking, and cleaning. When greywater mixes with
toilet water, it is known as black water (or sewage).
Black water contains faecal matter and carries
disease-causing bacteria.
The greywater of an informal settlement is not the same as
the greywater of a wealthy suburb. Those who have to carry
their tap water home may use it to wash fruit and vegetables,
then bath children, then wash textiles, and then clean the
floor. Only then is the water discarded. If shack-dwellers feel
unsafe to go outside at night, they amass night soil [human
excrement collected at night from buckets or outhouses),
which they may then add to greywater in the morning.
Disposal of this wastewater amid inadequate or non-existent
drainage systems poses health and environmental risks.
Hazards such as home car repairs and home slaughtering of
livestock in informal settlements aggravate the risks. Under
these conditions, waterborne diseases such as cholera thrive
and undermine health. Absenteeism from school and work
can be expected under these conditions.
A feasible option to improve hygiene in these communities
is the installation of constructed wetlands and a network of
greywater disposal points. A constructed wetland (CW) is an
artificial swamp made of plants and gravel and is designed
to treat [purify] greywater. CWs can act as a drainage system
and can treat wastewater in an eco-friendly, sustainable way.
Accessible greywater solutions for urban informal
townships in SA
The Centre in Water Research and Development (CIWaRD)
at Wits University will lead an international team on a project
to provide Accessible Greywater Solutions for Urban Informal
Townships in South Africa (URBWAT).
The URBWAT project aims to install constructed wetlands in
Alexandra township, Gauteng, and incorporates an existing
CW project in Langrug township in Stellenbosch, Western
Cape, where CWs have been installed but not fully evaluated.
Professor Craig Sheridan is an
associate professor from the
University of the Witwatersrand
at the School of Chemical and
Metallurgical Engineering and
is also the director of CIWaRD
and the URBWAT project lead.
www.plumbingafrica.co.za
There is probably a lot of black water in greywater in South
Africa, which has implications for people’s health. Greywater
is under-studied in South Africa and this project provides a
research opportunity. International project partners include
the Helmholtz UFZ in Leipzig, Germany, and Linköping
University in Sweden.
The URBWAT project is one of eight awarded by the Council
of the European Union through the Water Joint Programme
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Initiative (JPI) grant. The Water Research Commission in South
Africa will administer the funds here through CIWaRD at Wits,
which will host the project. The grant is valued at EUR840 000.
Planning for the project kicked off in February 2019 in
Paris, at the International Cooperation for Water (IC4WATER)
meeting of Funded Research, Development and Innovation
(RDI) Projects for the Water JPI.
Integrated research across engineering, psychology,
and biology
A unique multidisciplinary project, URBWAT will operate in
the fields of engineering, the social sciences (psychology
and geography), and the natural sciences (systems ecology
and microbiology). While engineering and natural science
objectives include evaluating the success of CWs in Langrug
while designing and installing CWs in Alex to analyse and
treat greywater there, social science objectives include
assessing the attitudes and experiences of community
members and other stakeholders to CWs, through
workshops, focus groups, and surveys.
Through URBWAT, we’ll engage and train community
members on the use of the CW system and educate them
about the risks and dangers of poor sanitation. Andrew
Thatcher, professor and chair of Industrial/Organisational
Psychology at Wits, and Geneviève Metson, assistant
professor at Linköping University, will lead the social
sciences components of this research.
Water challenges for a changing world
Over 12 million people in South Africa who live in an urban
environment live in informal settlements. In fact, 55.9% of
urban dwellers in sub-Saharan Africa live in urban slums.
The sheer number of people (and the effect of wastewater
treatment on health and thus on livelihood and prosperity)
make the need for ‘adequate and equitable sanitation and
hygiene’, and ‘improved water quality’, both by 2030, a priority.
Indeed, these are the second and third targets after the
United Nations’ Sustainable Development Goal 6 (UNSDG6) of
‘access to safe and affordable drinking water for all by 2030’.
The URBWAT project meets the dire need in South Africa for
a low-cost, sustainable solution for informal settlements that
lack adequate sanitary infrastructure. Additionally, new data
will enable further analysis of greywater and the removal of
pathogens. Ultimately, constructed wetlands have potential
when temporary settlements have to be constructed to
deal with an emergency — such as when people are
displaced by fires or floods — or for use in refugee camps,
where tent-dwellers have poor access to sewerage and/or
greywater treatment. PA
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August 2019 Volume 25 I Number 6