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Urban
water woes
IRIN News
January 02, 2013
http://www.irinnews.org/Report/97161/SANITATION-Urban-water-woes
In Zimbabwe's capital,
Harare (population 3,000,000), a man relieves himself in the dirt
next to his tin shack, holding his nose to ward off the stench of
a nearby overflowing latrine. In Ramallah (population 300,000) in
the occupied Palestinian territory a 14-year-old girl wakes with
menstrual cramps - and skips class because her school lacks a washroom
where she can clean herself in private. In Bangladesh's mega-capital
(population 12 million), a monsoon-season flash flood leaves thousands
with cholera.
Different continents,
same problem: City populations continue to grow above ground while
water resources shrink underfoot, leaving emptying aquifers to sate
growing needs, and compounding existing problems with wastewater
collection.
With water use
growing at more than twice the rate of overall population increase
(according to the Food and Agriculture Organization), how can authorities
ensure that every urban dweller gets 20-50 litres of clean water
daily for drinking, cooking and cleaning? How can governments create
sanitation systems that do not sicken city dwellers?
Background
Some 3.3 billion people
(more than half of the world's population) live in urban areas,
a figure which is expected to rise to five billion by 2030. Ninety-five
percent of this growth is taking place in countries least able to
afford the cost of expansion.
In East Asia alone -
in one of the most disaster-stricken areas worldwide - the UN Office
for Disaster Risk Reduction (UNISDR) estimates the number of people
living in urban flood plains may reach 67 million by 2060.
A Megacity Task Force
of the Germany-based International Geographic Union has called the
world's 40 or so megacities (concentrations of at least 10
million people) "major global risk areas" prone to natural
disaster and supply crises.
"The dimensions
of these urban disaster problems are huge," said Robert Piper,
UN resident coordinator in Nepal, whose capital, Kathmandu, is consistently
ranked as one of the world's most earthquake-prone cities.
"And doing something about it on the scale necessary is expensive."
Cities of less than one
million residents, such as Ramallah, are now growing at a faster
rate than larger urban areas, noted Graham Alabaster, manager of
the UN Human Settlements Programme (UN-HABITAT), in Geneva. Like
megacities, he said, smaller cities share the same pressing problems:
infrastructure too weak to handle ever-more densely packed populations,
and understaffing so severe it can put water, sanitation and hygiene
(WASH, in aid industry lingo) under the management of less than
half as many administrators as is necessary.
Weather
extremes
Climate change has not
made things any easier. World temperatures will rise by 4 degrees
Celsius by the end of the century, predict a joint team of researchers
from Germany's Potsdam Institute for Climate Impact and the
NGO, also in Germany, Climate Analytics.
"In developing
countries, the already-stressed, existing systems were built without
climatic change in mind," said Robert Bos, the WASH coordinator
for the World Health Organization (WHO) in Geneva.
Water may be delivered
in decades-old leaking iron pipes instead of flexible PVC ones that
expand and contract in response to temperature fluctuations. Sewage
systems may be too small to remove waste, which can ferment and
release toxic methane gas created when temperatures reach record
highs.
To brace against increasingly
volatile weather, cities in arid regions (such as Johannesburg and
Dakar) must stockpile water for annual droughts, while those in
flood-prone areas (such as Shanghai and Calcutta) must stockpile
medicines and recruit additional health staff to prevent and treat
water-borne diseases.
The countries at the
highest risk of weather-related disasters worldwide, identified
in a November 2012 report, are Thailand followed by Cambodia, Pakistan,
El Salvador and the Philippines.
As of March 2012, three
years ahead of schedule, the world achieved one of its Millennium
Development Goals: providing safe drinking water to half of the
2.6 million people who struggled without it in 2000.
Even so, 2.5 billion
people in the developing world lack adequate sanitation and 780
million of them lack clean water.
In addition to large-scale
efforts organized by national governments, here are five experiments
WASH experts are testing to manage water sources in an urbanizing
- and increasingly warmer - world.
1) DE-SLUDGING
TECHNOLOGY
Latrine pits into which
sewage systems drain are the most common way to collect waste in
slums in the developing world. But cleaning these pits, which are
often uncovered, can pose persistent challenges. Shacks may be so
densely packed that vacuum tankers cannot be deployed.
Individual workers may
have to clamber into pits and manually clean them, putting themselves
- and their families - at risk of disease. Absentee landlords may
have little interest in dealing with sewage pits, leaving them neglected
to the point where they overflow.
With a US$100,000
grant from the US-based Bill & Melinda Gates Foundation, researchers
in Belo Horizonte (the third-largest city in Brazil) are creating
biodegradable building blocks that replace conventional cement or
brick and allow latrine pits to decompose naturally once they are
filled. Another Gates grant of $4.8 million to the London School
of Hygiene and Tropical Medicine is funding the design of latrine
pits that have an active "bio-filter" of tiger worms
and other organisms to break down waste. This technology creates
environmentally-friendly sewage that poses few human health risks.
2) UPGRADING
SCHOOL SANITATION
Where school toilets
and latrines do exist (they are available in only an estimated 37
percent of countries where the UN Children's Fund, UNICEF,
is active), long queues snake around school buildings during breaks
and after class. "We need to upgrade sanitary facilities for
all children, but especially for menstruating girls so they can
continue to attend school and meet their needs for privacy, dignity
and cleanliness," said Ania Grobicki, executive secretary
of the Stockholm-based Global Water Partnership.
In China, UNICEF and
its partners built school hand-washing stations. In Malawi and Kenya,
they introduced a new design of urinals for girls. And in Bangladesh
and India, they have launched "menstrual hygiene projects"
so girls can continue their studies without interruption.
3) PRE-IDENTIFIED
WASTE DISPOSAL SITES
When natural disasters
strike, they can generate millions of tons of solid and liquid waste
that threaten public health and hinder reconstruction. The earthquake
that hit Haiti's capital of Port-au-Prince in January 2010
- killing more than 220,000 people, leaving more than 350,000 displaced
almost three years later and causing the capital's already-shaky
municipal waste collection system to collapse - highlighted the
need to select waste-disposal sites pre-disaster.
Garbage towered
along remaining roadsides; construction materials were piled up
in ravines, drains and other open spaces. Before aid agencies and
the government focused on hazardous waste disposal, surgeons tossed
body parts into fetid, decaying piles. After the disaster, the Haitian
government assigned one municipal landfill to dispose of medical
waste. In 2011, the UN released disaster-waste guidelines that outlined
dangers of different waste types.
4) TURNING
WASTE INTO WATER
In some urban areas in
the developing world, more water is lost through leakage and other
infrastructure problems than is delivered. "But wastewater
collection, recycling, and retreatment can multiply supplies,"
said Grobicki from Global Water Partnership.
Cities that are already
making wastewater potable include Singapore (where 3 percent of
drinking water is recycled) and Perth, Australia (where officials
hope 10 percent will soon be so). This microfiltration and chemical
treatment technology has also been used in Windhoek, Namibia, (population
300,000) which has been recycling wastewater since 1968, and is
holding a meeting in 2013 to evaluate its experience.
5) LOW-COST,
HIGH-IMPACT SOLUTIONS
WASH systems do not have
to be pricey to be effective, as proven by the shallow, gravity-driven
sewers that have long served the `favela' slums of Rio de
Janeiro, Brazil's second largest city of some six million
people.
"Increasingly,
municipal authorities are establishing `low-income customer service
units' or LICSUs," said Timeyin Uwejamomere with the
London-based NGO WaterAid. "One such programme recently brought
sanitation to 150,000 people and clean water to 400,000 in Lilongwe,
Malawi."
At King's College
London, researchers are examining how to deliver water with segmented
flexible rubber hoses. In India, Bangladesh, Kenya, and Uganda,
WaterCredit, a programme of the US-based Water.Org, helps households
buy drinking water and toilets through micro-financing.
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