Five contractors have submitted proposals to build the $523-million National Bio- and Agro-Defense Facility in Manhattan, Kan., project sources confirm. Construction of the megalab, to be the center of U.S. infectious disease research, is being managed by the U.S. Dept. of Homeland Security. It will replace an aging facility in New York state. DHS would not disclose details of the ongoing procurement, but according to company executives, those proposing to build the facility include: a joint venture of Gilbane Building Co. and Turner Construction Co.; a JV of Mortenson Construction and McCarthy Holdings Inc.; a JV of Bovis Lend Lease and Hunt Construction Group Inc.; a JV of PCL Construction Enterprises Inc. and Vaughn Construction; and The Whiting-Turner Contracting Co., proposing without a partner. However, a DHS spokesman confirms a lawsuit by a Texas con- sortium challenging selection of the Kansas site that seeks to block the procurement. The suit will be heard on June 8 in U.S. Federal Claims Court, but the procurement is proceeding, he says.