Africa Water, Sanitation & Hygiene Africa water, Sanitation May-June2015 Vol. 10 No.3 | Page 18

Water Supply

Facts and Figures on Water Quality and Health
The global health challenge: preventing water quality-related
disease

The partners involved in the project include the
International Center for Tropical Agriculture (CIAT),
Nairobi City Water and Sewerage Company (NCWSC),
Kenya’s electricity generating company KenGen, Water
Resources Management Agency, Kenya, Coca Cola Africa
Foundation and smallholder farmers who have adopted
agricultural practices to conserve the environment and
improve dry season water flow.
Fred Kizito, a senior scientist with CIAT, Kenya, says
scientific guidance and research will play a major role in
making sure that the programme succeeds.
He tells SciDev.Net: “Research helped build the ‘business
case’ to show that investing at least US$10 million in onthe-ground environmental management efforts for the
Upper Tana River will have a tangible impact on water
quality and quantity, and farm productivity.
“We can only know if the [Nairobi] Water Fund is delivering
on its promises by monitoring ongoing impact on soil
erosion and water quality. CIAT is using various monitoring
and assessment tools such as real-time water quality sensors,
runoff and erosion detectors, soil moisture probes and
rapid infiltration tests, among others, to quantify impact of
interventions.”
Philip Gichuki, the NCWSC managing director, who
also chairs the fund, notes that Nairobi has witnessed
tremendous growth in water demand.
“We plan to invest in expanding our water supply, since at
least 30 per cent more water is needed,” Gichuki says.
Meeting this demand depends on the conservation efforts in
the catchment area and on farmers championing the cause
such as Jane Kabugi, whose home on a steep slope overlooks
Kiama River, a source of the nearby Ndakaini Dam that
supplies 85 per cent of Nairobi’s water.
“Alongside other farmers, we have dug trenches, planted
grasses and bamboo to prevent soil erosion and sedimentation
in the river as part of conservation measures to ensure that
the dam has adequate water supply throughout the year,”
Kabugi says.
This article has been produced by SciDev.Net’s Sub-Saharan
Africa desk.

• No safe drinking-water: almost 1 billion people lack
access to an improved supply
• Diarrhoeal disease: 2 million annual deaths
attributable to unsafe water, sanitation and hygiene
• Cholera: more than 50 countries still report cholera
to WHO
• Cancer and tooth/skeletal damage: millions exposed
to unsafe levels of naturally-occurring arsenic and
fluoride
• Schistosomiasis: an estimated 260 million infected
• Emerging challenges: increasing use of wastewater
in agriculture is important for livelihood opportunities,
but also associated with serious public health risks
The Health Opportunities: Implementing good practice

• 4% of the global disease burden could be prevented
by improving water supply, sanitation, and hygiene
• A growing evidence base on how to target water
quality improvements to maximize health benefits
• Better tools and procedures to improve and protect
drinking-water quality at the community and urban
level, for example through Water Safety Plans
• Availability of simple and inexpensive approaches
to treat and safely store water at the household-level

Wastewater use
Safe use of wastewater, excreta and greywater

• A growing world population, unrelenting
urbanization, increasing scarcity of good quality
water resources and rising fertilizer prices are the
driving forces behind the accelerating upward
trend in the use of wastewater, excreta and greywater
for agriculture and aquaculture.
• The health risks associated with this practice have
been long recognized, but regulatory measures were,
until recently, based on rigid guideline values whose
application often was incompatible with the socioeconomic settings where most wastewater use takes
place.
• In 2006, WHO published a third edition of its
Guidelines for the safe use of wastewater, excreta
and greywater in agriculture and aquaculture. In four
volumes, these Guidelines propose a flexible
approach of risk assessment and risk management
linked to health-based targets that can be established
at a level that is realistic under local conditions.
The approach is to be backed-up by strict monitoring
measures.

Africa Water, Sanitation & Hygiene • May - June 2015

17