McMahon Meeting The Honorable Robert H. McMahon, assistant secretary of defense for sustainment, presides over the first meeting of the PFAS task force in Washington, Aug. 9, 2019. SHARE: Download: Full Size (0.36 MB) Tags: marines, senior enlisted advisor, air force, coast guard, joint chiefs of staff, army, navy, national guard bereau Credit: Air Force Staff Sgt. Andrew L. Carroll, DOD VIRIN: 190809-D-UO644-0012.JPG Photo Gallery