Luis Ramirez leapt onto the roof of his bright blue water truck to fill the plastic tank that by day's end would empty into an assortment of buckets, barrels and cisterns in 100 homes.
It was barely 11 a.m. and Ramirez had many more stops to make on the hilly, grey fringes of Tijuana, a sprawling, industrial border city in northwestern Mexico where trucks or “pipas” like Ramirez's provide the only drinking water for many people.
