The leak problem in Boston’s Big Dig – which includes portions of Interstates 93 and 90 – is even worse than first thought, media outlets reported Nov. 17.

The Big Dig was the largest construction project of its kind in U.S. history. It was created to take the elevated interstates that once ran into the center of Boston and replace them with wider, higher-capacity underground highways, including new tunnels and bridges to carry traffic over and under the city’s waterways. The Big Dig carries portions of several highways, including I-93 and I-90.

The Boston Globe reported in early November that the tunnel system was leaking water to the tune of 26 million gallons a year. Engineers quoted by the newspaper say the repairs could take 10 years and involve lane closures. The tunnel system was designed to handle 500,000 gallons of water removal a year – about 2 percent of the actual amount removed since last December. Local media outlets reported in January that one of the tunnels had experienced icing problems that closed lanes in some areas. The Globe report linked those troubles to the leaks.

Engineers also found documents that the firms in charge of construction may have known about the leaks as early as the late 1990s, The Globe reported.

The latest blow to the project came when The Globe reported Nov. 17 that rather than the 400 leaks previously reported, that one section of the tunnel, running roughly 1,000 feet, had as many as 700 leaks.

Now, Gov. Mitt Romney has reportedly called for the head of The Big Dig, Matthew Amorello, to resign from his post, the Statehouse News Service reported. Amorello is chairman of the Massachusetts Turnpike Authority, as well as a former state highway commissioner and senator. Amorello did not resign at that time.