When 12-year-old Mason went to lunch each day last year, he could choose between orange juice and milk, but he couldn't get a cup of water.  
 
Like many public schools, his doesn't provide cups. To have free water with his lunch, Mason would have to wait in line at a water fountain shared by hundreds of other middle-school students and take a few sips of water before returning to eat.  
 
Not surprisingly, he usually didn't bother.  
 
His mother...like other parents across the country, assumed her child had enough water, but nutrition advocates believe schoolchildren's access to water is a national problem the federal government has only begun to address.  
 
Fifteen percent of kids in Mason's age group consume adequate amounts of water, according to the CDC's National Health and Nutrition Examination Survey...