Table 2. Land area fixation and/or decontamination efficiencies.* Method Mean initial (dpm/m*) Mean final (dpm/m?) Efficiency (percent) Plowing 2630 55 97.9 Oiling and scraping 1240 55 95.6 205 15 92.7 1405 118 91.6 Disking 500 54 89.2 1.0-inch water leaching 515 65 87.4 79 il 86.0 121 37 69.4 8133 3660 55.0 380 309 18.7 0.3-inch water leaching and scraping 0.3-inch water FeCl> Scraping Oiling (RC-0O road oil) 0.3-inch water leaching 0.3-inch water-Alconox leaching *From Dick and Baker (1967) 71