Mount Everest is filled with trash left by the thousands who have taken on the world’s highest peak. The iconic mountain has been littered by tents, sleeping bags and oxygen cylinders discarded by climbers. Rookies have also been known to leave odd objects like coffee makers and gear to watch movies inside tents. To remove the trash, Nepalese tourism authorities said Monday that climbers must bring down 18 pounds of trash when they return. The waste is a serious problem: A mountaineering guide sampled water at locations on the mountain and found the bacterial levels were “100 times the EPA’s legal limit for E. coli in those areas.”