As directed by Section 2, Public Law 112-149, Insular Areas Act of 2011, this report provides information regarding the activities and results of the visual survey and groundwater radiochemical analysis of the Cactus Crater Containment Structure on Runit Island in the Republic of the Marshall Islands and a determination on whether the surveys and analyses indicate any significant change in the health risks to the people of Enewetak from the contaminants within the Cactus Crater Containment Structure.