Photo by Tony Illia for ENR
Flaking antimicrobial coating, which was possibly misapplied, has required project rework and a delay.

The nation's second-tallest federal air-traffic control tower, under construction at McCarran International Airport in Las Vegas, faces at least a one-year delay after an antimicrobial coating, which may have been improperly applied, flaked off from ductwork and became airborne. Project participants are staying mum about the problem and its origin, but legal observers speculate that corrective repairs could be expensive and trigger lawsuits.

The Professional Aviation Safety Specialists, a Washington, D.C., union that represents an estimated 11,000 U.S. Federal Aviation Administration (FAA) and Defense Dept. aviation inspection, support, equipment installation and related employees, detailed the alleged mishap after members inspected the site in July.

The union notes that a spray chemical was to be applied to dry building walls, ducts and subfloors to suppress a potentially toxic black mold, called stachybotrys chartarum, inside the 352-ft-tall tower and a four-story 52,800-sq-ft base building, which are set to house terminal radar machinery, training simulators and administrative offices. Instead, the coating was placed in already lubricated flexible ducts and did not adhere properly. Flakes of the substance subsequently became airborne and circulated in rooms, reports the union.

"During my visit, the sheetrock and ceilings were being ripped up in order to access, remove and replace the air handlers and ducts," says union President and CEO Mike Perrone. "It's an extensive but required remedy needed to ensure the safety of our employees. We're planning a return visit once the work is completed."

FAA officials would not confirm the union's details, stating only that it has "identified some construction issues" with McCarran's new tower and building, says agency spokesman Allen Kenitzer, in a written statement. He says the agency is "working with the contractor" and "any outstanding issues [will be] resolved before accepting the final project."

Repairs could consist of swapping out three air-cooled chillers, 10 air-handling units and tens of thousands of pounds of ductwork. Gallagher-Kaiser Corp., the project's Troy, Mich.-based HVAC and mechanical piping subcontractor, did not return requests seeking comment.

Dan Galvin, a spokesman for general contractor Archer Western Contractors, a unit of the Chicago-based Walsh Group, also declined comment. The firm was set to finish work this summer under a $43-million contract after breaking ground three years before. The project— the total price tag of which, including equipment costs, totals $99 million—also involves construction of a guard station and a 190-space parking garage. Originally scheduled for 2015, tower operations have been pushed back to late 2016 or early 2017.

Walsh has had previous issues with defective aviation work. Last year, after making $26 million in previous repairs, the contractor agreed to pay nearly half of a $21-million settlement for defective steel and welding cracks at O'Hare International Airport's Terminal 2 and Terminal 3 canopies, which extend over a roadway. The 22-level octagonal cast-in-place concrete tower and accompanying structures suffered previous construction setbacks when Congress failed to pass FAA funding legislation in 2011.

Designed by WHPacific Inc., the Las Vegas tower is topped by a two-level, 850-sq-ft controller work area, or cab, with 14-ft-tall angled windows for better visibility. By comparison, McCarran's existing 30-year-old tower is about half the height, with a 62% smaller cab. The airport, the ninth busiest in the U.S., is expected to serve about 700,000 flights annually by 2020.

One legal expert notes the potential fallout. "Nonconforming contract work may require repairs or forfeiture of a multimillion-dollar performance bond, and liquidated damages may be applicable for late completion or delays that can also run into the millions," says Las Vegas construction attorney Jori Spangler, who is not involved with the project. "Oftentimes, the argument over who assumes responsibility for cost overruns, delays and damages leads to litigation."