Northern Virginia’s Washington DC metropolitan area and surrounding suburbs include clay sewer pipe some of the nation’s oldest neighborhoods, with some of the nation’s oldest sewer pipes. On any given day, Virginia plumbers servicing sewer lines know they can expect to encounter pipes made from materials ranging from cast iron, to ceramic, tar paper, even aspects. These older materials haven’t been used since the early 1970′s. Those that remain in use today are failing at ever increasing rates.