Removing asbestos-laced materials discovered during expansion of Charleston International Airport will cost $670,000 and delay the project's expected completion by 32 days to September 2015.

Matt McCoy with Michael Baker Inc., the firm overseeing construction at the 29-year-old terminal building, told an airport committee Monday the cost will chew into the $11.2 million set aside for unexpected expenses during the two-and-a-half-year project. To date, about $1.85 million of the contingency fund has been used.

"The (cost of) asbestos is a little more than I would have liked for it to have been, but it is significantly less than what it could have been," Airports Director Paul Campbell said. "I don't think it will be significant as far as the delay."

The discovery of asbestos in January was originally estimated to extend construction by 77 days, he said.

Exposure to asbestos has been linked to cancer. It was found in the front wall of the terminal building and behind the outside walls of Concourse A. The front wall is being ripped away to be replaced with glass to allow more light into the building. The other walls where asbestos was found will be part of an expanded two-story area to house consolidated security checkpoints and upper-level administrative offices.

The terminal is in the throes of a $189 million makeover. Construction was originally set to be completed in August 2015.

When the asbestos was first found, crews contained areas housing the substance, and airport officials said air travelers and visitors were never affected because the contaminated walls were already barricaded with temporary walls and not in public areas.

"We are very confident that none of this material caused any harm," McCoy said.

The asbestos was discovered in a black tar-like substance used to install vapor barriers or waterproofing material. It was concealed behind the bricked-up walls.

A good portion of removal is completed, but more work remains as demolition and renovation starts behind the airline ticket counters to make an entrance to the new eight-lane security checkpoint area under construction.

Also, part of the one-month construction delay is the recent discovery that a waterline and existing fire hydrant and valve have to be repaired. That will cost $252,000 extra and will also come from the contingency fund.

Reach Warren L. Wise at 937-5524 or twitter.com/warrenlancewise.