The Army Corps of Engineers has awarded four construction firms separate indefinite delivery, indefinite quantity contracts worth a potential $488 million combined for Department of Homeland Security (DHS) tactical infrastructure projects in the Rio Grande Valley Sector of the Southwest U.S. border. The four firms are Environmental Chemical Corp., Kiewit Texas Construction, Weston Solutions, and Kellogg Brown & Root [KBR].The award has a base year and four one-year options. Each firm will compete for task orders. The Corps of Engineers is also expected to award a $78 million small business set aside for three contractors to build tactical infrastructure in the Southwest border region for DHS.