vs perations Soil Cleanup O ty nics into plants and their availabili for .a| for uptake of transura n. (NOTE: The degree to which this ai y into the food ch eequertkeentr pobs su might occur was not plant upta known. Firm estimates on the anic uptake hazard were not available at this time, so the Director, decisions rransul eferred to assume it could be significant and made DNAingly) Additionally, he believed that plowing could possibly transuranics ease the potential for plants uptake by redistributing the et the root zones of plants. eliminate "Second VADM Monroe was concerned that plowing would forever any possibility of removal of transuranics. As it was now, these dangerous radionuclides originally had been deposited ina thin layer on the surface, and even after many years of storms, leaching, weathering, and some man-made disturbance, they werestill generally ina thin surface taver. This fortuitous history made removal possible; however, once plowing was carried out, the Opportunity for a moreeffective solution would be fost. Regardless of the drawbacks and despite the fact that plowing had proven effective in reducing surface contamination, all goals in soil excision and removal operations eventually were met without plowing. AIR SAMPLING FOR BERYLLIUM AT ENJEBI Rocket motors using a propellant containing beryllium had been tested Nw on Enjebi in 1968 and 1970 as described in Chapter 2. The exhausts were directed toward the lagoon in both instances, and decontamination procedures were implemented following both tests. However, subsequent soil analysis by McClellan AFB Central Laboratory indicated that not all the beryllium contamination was removed. The remaining concentrations were as high as 30 micrograms of beryllium per gram of soil. The concentrations would be removed during soil cleanup but were high enough to represent a potential resuspension problem and additional hazard during soil removal operations. Field Command determined that a reasonable MPCof beryllium in air was 0.01 microgram per cubic meter of air averaged over a 30-day period. The actual concentration may be determined by calculating the resuspension of beryllium given its concentration, the type of soil, the prevailing winds, and other factors, or by direct air sampling. The latter method is more effective, and it was used on Enjebi. The location of the rocket engine tests and the JTG-installed air samplers appear on the partial map of Enjebi in Figure 7-10. The air samplers were downwindof the points where soil sample results indicated the beryllium concentration in soil to be the highest. The air samplers were