moving in this closed loop also mix with those of the open ocean, resylting in a flushing action. At Bikini, ocean water flows in over the northern and eastern reefs and flows out of changes over the western portion of the Eneu Channel. the western reefs with the tides, The water ex- the ocean water flowing and mixing with the flood and lagoon water flowing out with the lows. in The net rate of flushing of Bikini waters is such that half of the lagoon waters are replaced by ocean water in 22 days and the original volume will account for only 10 percent of the lagoon volume after 24% months. At Enewetak, the flushing is more rapid and has two major routes. first is directly through the eastern reefs to the western reefs; The the sec- ond is through the Deep Passage between Japtan and Parry and out the Wide Passage west of Enewetak. These two routes also function to keep the wa- ters of the northern part of the lagoon separate from the southern waters. The land areas of Enewetak and Bikini atolls, their lagoons, and the waters within 3 miles (4.8 km)of their seaward sides constituted the PpPG.* These islands are part of thé Trust Territory, a strategic area trusteeship of the United Nations, administered by the United States. The U.S. agency in charge of the PPG itself was the AEC. The Test Division of the AEC Division of Military Applications, Santa Fe Operations Office, administered the test site through its Enewetak Branch Office, which supervised engineering, construction, maintenance, operation, and management activities performed by its contractor, Holmes & Narver, Inc. (H&N), of Los Angeles. Physical Conditions in 1954 Enewetak had been the site of nuclear testing since 1948: the islands in the southeast quadrant served as the base for the task forces, and the * After 1956, the PPG was designated the Eniwetok Proving Ground, or EPG. 42