Environmental Engineering Reference
In-Depth Information
mostly earns daily wages, and any missed day from work due to waterborne illness affects
their income. The other intangible effects of loss in quality of life as a result of having to
fetch water from distant sources cannot be easily quantiied. The fetching is mainly done
by women in the third world, and it has been noted with amusement that this gives them
cherished time out of sight of their spouses, a cultural issue observed by those drilling
nearby wells that eliminate the long walk!
Up to now, the response to the water crisis has been focused solely on water accessibility,
not on the critical issues of quality or sustainability, much less palatability. Government
agencies and nongovernment organizations (NGOs) have been putting efforts in digging
bore wells in communities to provide access to water. Generally, water from deeper bore
wells do not contain pathogens and may contain higher levels of dissolved salts but are
safe to drink as moderately higher levels of salts may affect the taste but not the health.
Shallower wells, particularly the open ones, may contain pathogens. Over the course of
time, if the deeper bore wells are not constructed or maintained properly, the water in the
well can become contaminated. The contamination may occur from surface water seeping
into ill-designed or ill-maintained wells, bringing with it harmful microbiological organ-
isms from the fecal matter of human beings or livestocks or other surface contaminants
such as chemicals used in agriculture. Depending on the geographical location, an addi-
tional risk with deeper wells may be the presence of other impurities such as higher levels
of arsenic or luorides that may make the water unsafe to drink. Providing access to water
only solves part of the problem; it does not assure quality or sustainability. Bore wells
can become contaminated or dry up in the summer when water is most needed, while
trucking in water from nonreliable sources is neither safe nor economically sustainable.
Community hand pumps contain movable parts that wear and break down with usage.
They require ongoing service and maintenance to keep them running, and funds may not
be available at all times to pay for their repair and maintenance.
Every year millions of people, mainly in developing countries, most of them children, die
of diseases like cholera that are associated with inadequate water supply, sanitation,
and hygiene. For example, in 1993, a mutant strain of cholera broke out in parts of India,
Bangladesh, and Thailand, and thousands perished in this epidemic. One of the research-
ers at the Lawrence Berkeley National Laboratory (LBNL) witnessed the suffering caused
by this epidemic and was determined to develop a water disinfection system suitable for
this environment to address the problem. The result was a groundbreaking technology
that used UV light to inactivate harmful pathogens in contaminated water and did not
require much power to run it. WaterHealth licensed the ultraviolet (UV) technology from
LBNL in the late 1990s, and since then has advanced the technology and developed a
scalable and sustainable model for building WaterHealth Centers (WHCs) globally. The
company has centers in India, Africa, and Southeast Asia, with plans to continue building
facilities wherever there is a need.
To address the drinking water needs, WaterHealth believes that a safe, clean, sustain-
able, and affordable water supply using the locally available sources is the best solution.
Using off-the-shelf proven technologies, WaterHealth has immediately deployable designs
that can purify water from any available source to exceed drinking water guidelines set by
the WHO. WaterHealth's strategy is to combine the use of such decentralized puriication
centers in partnership with local communities to create a scalable and sustainable solution.
Communities with a WHC have seen a signiicant reduction in the number of common
illnesses like cholera, dysentery, diarrhea, and other waterborne diseases. These commu-
nities not only realize immediate beneits from improved health and well-being brought
by clean water, but they also beneit economically by sharing in a portion of a center's net
