http://www.almotamar.net صحيفة إلكترونية يومية تصدر عن حزب المؤتمر الشعبي العام (اليمن) http://www.almotamar.net/4934.htm 2008-06-17 CHAPEL HILL, NC – Despite recent progress, more than one billion people still lack decent water supplies, and more than two billion go without sanitation services. But, while we often assume that the benefits of improving water and sanitation systems always outweigh the costs, this is not always true.