A woman, living in a squatter camp, collects water for her family from a nearby source in Lahore March 21, 2010. The Earth is literally covered in water, but more than a billion people lack access to clean water for drinking or sanitation as most water is salty or dirty. March 22 is World Water Day.Women, living in a squatter camps, carry water to their families from a nearby source in Karachi March 21, 2010. The Earth is literally covered in water, but more than a billion people lack access to clean water for drinking or sanitation as most water is salty or dirty. March 22 is World Water Day.