Water of poor quality can cause disease outbreaks.
How safe is our drinking water?
While water is the very source of life, contaminated water can be
hazardous, as it may harbour waterborne diseases. The question is,
therefore, what constitutes safe drinking water and how is it measured?
By Helgard Muller, Pr Eng
What is safe water?
The quality of water, whether used
for drinking, domestic purposes, food
production, or recreational activities, has
an important impact on health. Water of
poor quality can cause disease outbreaks
and it can contribute to background rates
of diseases manifesting themselves
on different timescales. Initiatives to
manage the safety of water do not only
support public health, but also often
promote socio-economic development
and well-being (WHO, 2013). A group
of researchers reviewed the microbial
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quality of drinking-water and estimated
that 1.8 billion people globally use a
source of drinking-water that is faecally
contaminated (Bain et al, 2015).
The World Health Organisation
(WHO) provided drinking-water quality
guidelines for global use, and the 2011
guideline states the definition for safe
water as water that “does not represent
any significant risk to health over a
lifetime of consumption, including
different sensitivities that may occur
between life stages” (WHO, 2011). The
guidelines further advise that “safe
Water Sewage & Effluent September/October 2017
drinking water is required for all usual
domestic purposes, including drinking,
food preparation, and personal hygiene”
(WHO, 2011).
At a meeting of the WHO Task Team,
where global indicators for safe drinking
water were discussed, a simple but very
practical phrase was given to describe
safe water: “Safe water is … a glass
of water you would give to a child …”
(Muller, 2013).
There is no global standard for safe
water and most countries have their
own specific national standards. Here in