Environmental Engineering Reference
In-Depth Information
carried out in recent decades, with the objective of furnishing everybody in the
DCs, including the poor, with clean water safe for drinking together with basic
provisions for management of excreta. Although this program has achieved only
partial success, it has done much good and the effort continues. An evaluation
of the program's achievements made in 2004 by the
Economist
magazine
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showed there have been many problems that have hampered progress in the UN
program. One problem is that governments have persisted in delivering water
at much too low charge rates, so those with taps in their homes (typically the
better-off) have no incentive to conserve it. Because the UWSS has not been
self-funding, it has not been extended to the poorest areas, so the poorest have
ended up paying inflated prices to black-market water sellers.
In towns, private firms can work wonders if they are allowed to charge reason-
able prices. In rural areas, where the poorest of the poor live, the most progress
has been made by concentrating on small (and usually publicly funded) projects,
such as boreholes, rather than trying to follow urban water supply practice. The
locals should be trained to maintain their own boreholes. Pumps can be designed
to double as children's round-abouts, so that children pump water as they play.
Tanks to catch rain are simple and efficient. In one African village, for example,
the poorest residents pay a few cents each week for water and a communal
shower block. Better-off families pay extra for taps in their homes. The sums
raised pay for an engineer to live in the village and fix its pipes.
U.S. Agency for International Development (USAID)
Legislation was
enacted (“Water for Poor Act”) by the U.S. Congress in 2006 for authorizing
USAID to establish a program for assisting DC populations to have access to
clean water and basic sanitation, which is an example of efforts by bilateral coun-
tries to supplement the UN project
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. But it remains to be seen whether the U.S.
Congress will actually furnish funds to support this program.
Other Considerations
Desalinization
Desalinization technology and costs have steadily decreased in
the past several decades resulting in increasing use in the United States and other
affluent countries like the oil-rich Middle East countries. But little use has been
made of desalinization in the DCs because the costs are still beyond their means.
There are only special exceptions, such as in Baja California, in Mexico, where
use of “shelf” desalinization units has made it feasible to operate beach resorts
catering to affluent visitors.
Dual Water Supply Distribution Systems
Advocates of the use of dual
urban water supply systems in the ICs, including Dan Okun
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, argue that (1)
the established UWSS practice is to design the systems so then can accommo-
date the flows required for firefighting (which are very large compared to the
needs for domestic and other municipal purposes), which results in large resi-
dent time in the distribution system piping leading to growth of biofilms on the
