A sewer line in Morse Hall backed up on Monday night, flooding the west end of the building with up to four inches of water and finally draining after a six-hour plumbing and pumping operation. The toilets in the Morse basement did not function for much of the day, but OPP employees and outside plumbers quickly cleared the pipe and pumped the water off of the floor. No significant damage occurred, and the smell dissipated over the next few days. Lawrence Rivera, a plumber for John’s Sewer and Pipe and a resident of North Andover, arrived at 4:30 p.m. In the basement of Morse, he started a “snake,” a plumbing tool used to clean blockages. He finally discovered a blockage of wipes and personal items 400 feet away in the pipes by Commons. “It was just a pain in the butt,” Rivera said. But after Rivera cleared out the pipe, water still stood on the floor of the electrical room. Rafael Luciano, an OPP employee for eight years and a resident of Lawrence, came down to pump out the water. He pumped the water into a large container and wheeled it down the long basement corridor to the east drain. The smell of sewage began to dift down the corridor, but Luciano concentrated on the job. He made more than five trips up and down the basement hallway to move the floodwater to the larger east drain, where it could run out more quickly. Luciano said, “This is the first in a couple of years we’ve had a problem with this.” Summer Session this year also had a problem with a sewage line.