HEALTH AND SANITATION
23
Development of resource guidelines for rainwater harvesting
recreational, agricultural, and industrial) classes of water
use (DWAF, 1996).
However, these
guidelines are unable
address other
CHAPTER 3 RAINWATER
QUALITY
& to TREATMENT
components of the rainwater harvesting process that
also have an effect on the ultimate quality of the water.
It is critical that rainwater that will be used for
potable use within the public water distribution
3.1 INTRODUCTION
system meets the same criteria as that of other
sources
water used
in the water
distribution
Guidelines for Human Settlement, Planning
and of Design
(CSIR,
2000)
placed a highly restrictive
system.
Once
source
water
(in
this
case
rainwater)
guideline on the use of rainwater. They suggested that rainwater “should
be considered as a
has been shown to be of a potable standard for use
supplementary supply for non-potable use since it could pose a health risk”. However, numerous
in a public distribution system, there are other inbuilt
studies have shown the potable use of rainwater as long as contamination during collection is
mechanisms within a distribution system that then
minimised and efficient treatment of water post harvesting occurs. The ambiguity with regard to the
ensure that the quality of water that comes out of
use of rainwater would be avoided if there was in existence established rainwater harvesting
the tap is not compromised.
guidelines which ensured harvested rainwater quality for various uses.
One such system is the Blue Drop Certification
Programme, which is a nationwide programme
with a list of regulatory criteria, which when
3.2 APPLICABLE STANDARDS AND designed
GUIDELINES
implemented in conjunction with South African Drinking
Water
Guidelines
(DWAF, guidelines
1996), ensures
The quality of rainwater is assessed against
drinking
water
as that
an excellent
interim solution to the
water is of produced
by a given
distribution
lack of clear guidelines that govern the use drinking
and quality
rainwater.
The water
South
African Water Quality
system.
The
Blue
Drop
Certification
Programme
is states exactly the
Guidelines developed by the Department of Water and Sanitation (DWAF, 1996)
a
means
to
regulation,
which
was
designed
and
water quality requirements required by the four (domestic, recreational, agricultural and industrial)
implemented with the core objective of safeguarding
classes of water use (DWAF, 1996).
tap-water quality management.
Table 3.1
Definition of water quality terms
Table 1: Definition of water quality terms
TERM
DEFINITION
SOURCE
Water quality The physical, chemical, biological and aesthetic properties of
water which determine its fitness for a variety of uses and for
protecting the health and integrity of aquatic ecosystems. Many
of these properties are controlled or influenced by constituents
which are either dissolved or suspended in water. South African Water
Quality Guidelines for
Domestic Water use,
1996
Water quality
guideline A water quality guideline is essentially a user needs specification
of the quality of water required for a particular use. Guidelines
are developed as an important information resource primarily for
water quality managers but can be used by me mbers of the
public who are interested in various aspects of water quality and
its management. Guidelines are reviewed periodically and if
need be updated to include relevant new information that has
been obtained locally or internationally. South African Water
Quality Guidelines for
Domestic Water use,
1996
Water quality
criteria Are scientific and technical information provided for a particular
water quality constituent in the form of numerical data and or
narrative descriptions of its effects on the fitness of water for a
particular use or on the health of aquatic ecosystems. South African Water
Quality Guidelines for
Domestic Water use,
1996
Constituent Any of the properties of water and/or the substances suspended
or dissolved in it. South African Water
Quality Guidelines for
Domestic Water use,
1996
Continued on page 25 >>
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