John Rothnie, Port of Seattle project manager for Seattle-Tacoma International Airport, made a record-breaking $200-million earthwork job coexist with stringent environmental standards. He led a team including contractor TTI Constructors in building North America's tallest mechanically stabilized earthwall. The 130-ft wall, the second largest in the world and easily the tallest ever used anywhere on an airport site, is directly adjacent to protected wetlands.

Mechanically stabilized earth walls reach to 130 feet high, among the largest in the Western Hemisphere.

The project extends the airfield plateau 2,000 ft to allow for a critically needed third runway while the MSE walls, supplied by The Reinforced Earth Co., Vienna, Va., separate the embankment from adjacent state-protected creeks and wetlands. Using a variety of techniques, Rothnie coordinated deliveries of as many as 200 daily trucks carrying 55,000 tons of fill while keeping the site and environs as pristine as possible.