420-friendly may not be that environmentally friendly. A new study that is sure to kill the buzz of pot proponents reveals that the forests of Northern California may be seriously suffering due to medical marijuana farming. While the state allows for medical marijuana growth, much of the crop is not only being sold for personal use in other states, but the farms are drying out and polluting coastal forests. Biologist Scott Bauer studied how water was being diverted for marijuana growth when he noticed more of the rivers running dry. He found that 30,000 plants were being grown in each river system and each using about six gallons of water per day during the marijuana growing season. Marijuana growers argue that they are being unfairly vilified because of the stigma surrounding pot, but northern California officials say there are real environmental concerns. "People are coming in, denuding the hillsides, damming the creeks and mixing in fertilizers that are not allowed in the U.S. into our watersheds," said Denise Rushing, a supervisor for Lake County in California.