Chapter 4—Monitoring Accidental Radiation Releases ¢ 73 Figure 4-8—StandbyAlr Surveillance Network Stations : 3 e ae eM < Washin oe * gton eee Mon ; e tana e e Minnesota e @ | daho ; . e 3 “3 - North Dakota ° Oregon CalitOrni ° “a Nevaaa e ° e e e outh Dakota Wyomi ° oming ° e Nebraska =e lowa e e e Utah e e e Colorado Kansas e e ° e Missourr @ Oklahoma e e e Arkansas e New Mexico e e Louisiana Texas e fe 86 standbyair surveillance stations are availabie and samples are collected and analyzed every 3 months to maintain a data base SOURCE: Modified from Environmental Protection Agency. level for drinking water) of krypton-85, chlorine-36, therefore the most mobile of the radioactive maten- Radioactive material from nuclear testing moves through the groundwater at various rates and is tritium (12.3 years) and slow movement of the “ : groundwaterpreventsit from reaching the Test Site ruthenium-106, technetium-99 and iodine-129. filtered by rock and sediment particles. Tritium, however, is an isotope of hydrogen and becomes incorporated in water molecules. Asa result, tritium movesat the same rate as groundwater. Tritium is als. Althoughtritium migrates, the short half-life of boundary. No analysis of groundwater has ever found tritium at a distance greater than a few hundred meters from someoftheoldtest sites. None of the water samples collected outside the bounda-