Four union steamfitters rebuilding the World Trade Center lost their clearance to work on the site yesterday after Port Authority detectives found them drinking heavily during lunch, The Post has learned.

“Obviously, it’s my own fault; I should have known better,” said 48-year-old Michael Galvani, of Wantagh, LI. “I had two beers with my burger. I think there’s a lot worse going on on that job, but I’m going to pay for it.”