The contractor shall remove navigation obstructions on the Missouri River to include the remaining foundation of old bridge piers, tributary debris, and rock outcropping. The obstruction areas are between RM 397 to RM 365. The general scope of the work includes, but is not limited to: dismantling, demolition, removal, and disposal of navigation obstructions. Work consists of mobilization to the obstruction areas with appropriate removal equipment and the lowered of obstructions to the elevations specified or as directed by the Contracting Officer. All work to be performed will be completed by floating plant as no land access will be available unless authorized by the Contracting Officer. Mechanical methods will be used for removal of the obstructions. Contractor shall be required to be in full compliance with state and federal Clean Water Act Guidelines (Sections 404(b)(1) and 401 water quality permits).