The pipes that ferry drinking water from public wells to home taps may let in viruses that cause more than a million cases of stomach illness every year, two new studies show. ¡°This is a really big deal,¡± says Jeffrey Griffiths, MD, MPH&TM, a professor at Tufts University and chair of the drinking water committee of the U.S. EPA's science advisory board. ¡°This research is very important.¡±