The last of a series of Ketchikan International Airport improvement projects will involve renovating the main terminal, including the old, leaky roof.

An approximately $3.9 million contract with Wasilla-based Wolverine Supply, Inc., to do that work is in front of the Ketchikan Gateway Borough Assembly on Monday.

A borough memo describing the project states that airport employees have been patching the terminal roof for years, but can’t keep up with leaks. The roof portion of the project will involve replacement of about 18,000 square feet of roof over the main part of the building.

The project also will update the terminal’s HVAC system, electrical and mechanical systems, ceilings, lighting, carpets and tile.

The memo states that the airport will remain fully operational throughout the project. Work will be phased so that interior work will start after the busy summer season.

Most of the contract cost will be paid for through a $9.9 million grant the borough received in 2013 for the series of airport improvement projects. There is about $3.67 million left from that grant. Borough staff has recommended making up the difference through the borough’s land trust fund and airport enterprise fund.

Monday’s assembly meeting starts at 5:30 p.m. in borough assembly chambers at the White Cliff building. Public comment will be heard at the start of the meeting.