BOSTON (AP) State transportation officials said the Big Dig tunnels will continue to have leaks and it may be largely up to the state to pay for fixing them in the future.

Secretary of Transportation Richard Davey said that the tunnels were not designed to be completely leak proof and not all leaks can be pinned on design flaws. But he said the state will seek to tap a Big Dig trust fund whenever it believes engineering or design problems were responsible.

The Boston Herald reported that the state is on pace to spend $2.5 million plugging leaks this year. The federal government has said the trust fund cannot be tapped for routine maintenance on the tunnels.

The trust fund was created in 2008 from a settlement with Big Dig contractors over allegations of shoddy construction.