In the bone-dry hills overlooking Lima, the luxury of running water is just a dream for thousands of Peruvians who get theirs delivered by tanker truck. More than 635,000 people in Lima lack running water, says the National Institute of Statistics and Computer Science, and many of them live in informal settlements high above the city, in spots not reached by the water and sewer lines. "[We get] stomach cramps and headaches... There are worms in the bottom of the tank," says Catalina Naupa, a 59-year-old resident of San Juan de Miraflores. Peru's capital, home to more than 10 million people, is also the world's second largest city located in a desert, after Cairo. IMAGES AND SOUNDBITES