An Oak Grove man who was part of a plot to steal half a ton of pseudoephedrine waste material has been sentenced to 15 years in prison. The federal prosecutor had accused Garland Hankins had worked for a contractor that disposed of the waste at the Sanofi Aventis Pharmaceuticals plant. The case against Hankins broke open three years ago with the investigation of the theft of a 110-pound drum of pseudoephedrine powder that had been used to make the medication Allegra-D.