1
could potentially be used beneficially in such
settlements. Additional precautions therefore need
to be taken if use of greywater for irrigation or other
non-potable purposes in informal settlements is to be
considered. Aside from the precautions with respect
to greywater management, quality and quantity, as
outlined in the remainder of this report, the creation
of a sense of community and the engaging of such a
community with the concept of the potential dangers
of greywater use are critical prerequisites for any
greywater irrigation implementation.
Specifically, potential users should be informed that
greywater should be:
• Limited in terms of the number of uses within the
household prior to use, and must not be collected
for use after discharge into the environment.
• Isolated at source before reuse.
Recent research being undertaken as part of a
Western Cape Government project referred to as
‘Genius of Place’ (DEDT, 2016) is investigating the
potential for decentralised / off-site treatment of
polluted run-off from informal settlements — using
biomimicry and green infrastructure options. The
pilot project is aimed at separating out the greywater
from the combined run-off flows from the informal
settlement of Langrug, Franschhoek, to reduce
pollution levels in the Berg River, and help to improve
health issues within the settlement. Screens are used
to remove solid waste material and the greywater is
then directed into ‘bioremediation filter tanks’ and
tree pits, which act as treatment facilities. In this way,
it is hoped that the environmental and health risks
www.plumbingafrica.co.za
35
HEALTH AND SANITATION
2
There are various
challenges relating to
the technical aspects of
designing, managing,
and maintaining
greywater systems in
terms of treatment and
subsequent storage.
1.
2.
Greywater collection tanks.
A simple system for
cleaning greywater.
associated with the unmanaged disposal of
greywater can be reduced, whilst also resulting
in secondary benefits associated with greening of
informal settlements.
GENERAL RULES FOR HARVESTING GREYWATER
There are various challenges relating to the technical
aspects of designing, managing, and maintaining
greywater systems in terms of treatment and
subsequent storage. Some of these are highlighted
in existing guidance documents, such as have been
provided by Wood et al. (2001), City of Cape Town
(2005), and Murphy (2006). These include design
aspects — of both the treatment facility (including
reference to quantity and quality) and the greywater
system as a whole — as well as operation and
maintenance guidelines to ensure the sustainable
management of the system.
Continued on page 37 >>
January 2019 Volume 25 I Number 1