re U.S. PUBLIC HEALTH SERVICE, DIVISION OF RADIOLOGICAL HEALTH PHOTO FIGURE 15.—Collection of water sample near the Nevada Test Site by U.S. Public Health Service personnel. lee Milk Sampling Milk samples were and are collected routinely one time per month within the 300 mile radius of the NTS, from approxi- mately 25 sources, including all dairies and some additional ranches having one milk cow. In the event that radioactivity was found in any area additional samples were collected often on a daily basis. Water Samples Water samples were and are in general collected monthly from approximately 30 sources (fig. 15). There were no known surface supplies for human use in the off-site area except for Lake Mead. tee Loess: cpm ae ete Research In support of the operational procedures described above to assure safety to-the public, there were and are extensive basic and applied research studies conducted in such fields as meterology, hydrology, and ground motion. These were and are accomplished by (a) cooperation with other Government agen- cies including the U.S. Weather Bureau, U.S. Public Health Service, U.S. Geological Survey, U.S. Bureau of Mines and U.S. 42