LITTLETON, Colo. (AP) — A Colorado unit of Tetra Tech EC Inc. has been awarded a $15.7 million military contract for construction in Afghanistan.

The Defense Department said Tuesday the project is an expansion of the Afghan Air Force Shindand Air Wing Squadron.

Work is expected to be finished in March 2014.

Tetra Tech Construction Services is based in Littleton, Colo. Its parent company, Tetra Tech Inc., has headquarters in Morris Plains, N.J.