Reuters: When her children started missing school because of persistent diarrhea and vomiting, Pat Farnelli began to wonder if she and her family were suffering from more than just a classroom bug. After trying several remedies, she stopped using the water drawn from her well in this rural corner of northeastern Pennsylvania, the forefront of a drilling boom in what may be the biggest U.S. reserve of natural gas. “I was getting excruciating stomach cramps after drinking the water,” …