Pocket gophers and redistribution of plutonium in soil

The effect of pocket gopher mound building activities on plutonium distribution in soil at the Rockwell International Rocky Flats Plant were studied on a 2.6 ha plot during 1975 and 1976. Pocket gophers generally confined activities to the upper 30 cm of soil. During seven months, the rodents cast about 3000 kg of subterranean soil to the surface containing about 1.1 x 108 dis/min of plutonium. Mound soil concentrations averaged 39 dis/min g-1. Mean undisturbed soil profile concentrations decreased from 167 dis/min g-1 at 0-10 cm depth to 10 dis/min g-1 at 20-30 cm depth. The data show that pocket gophers effect vertical redistribution of plutonium in soil, with a small degree of horizontal dispersion as an implied consequence. (author)