6.6 PILOT SOIL REMOVAL PROJECT (by Bert Friesen, H&N) During an inspection visit to Enewetak Atoll in January 1978, the Director, DNA, decided that a Pilot Soil Removal Project should be conducted to obtain parameters required to make reasonable estimates of the time and effort consumed in soil removal and transport, and to develop and test alternative excision and transport methods. Several islands were considered as candidate sites for the pilot project, with Sally being selected (the selection being in part influenced by proximity to the Ursula base camp). The Kickapoo GZ area was picked as the site of the first experiments. This area, located on the northern tip of Sally, encompassed less than one hectare requiring soil removal. Experience gained in the Kickapoo area formed the basis for all soil removal activities conducted during the cleanup, although some steps were later modified to increase efficiency. (The actions described below were initiated in the Kickapoo area and continued into the Yuma and Hustead areas. The Pilot Soil Removal Project was officially concluded prior to the final efforts to complete soil removal from Sally. The exact sequence of events is not critical to this report. Work described was all done by military elements directed by the JTG, with DOE in an advisory role.) Before soil removal could start, the vegetative cover had to be removed and several methods for accomplishing this were tested and evaluated. The most rapid technique was pushing vegetation into windrows with a bulldozer, as done on Janet, but this method mixed and spread the surface soil so that high levels of surface contamination could be spread over a larger area than initially existed. Also, the windrow would contain a substantial volume of contaminated soil which could not easily be separated from the vegetation. The second method utilized a front loader with what is called a four-in-one bucket.* This machine wasinitially tried and determined to be unsuccessful because it did not remove many roots and bush stumps. After realizing the drawbacks of windrowing by bulldozer, the bucket loader was reevaluated and several successful techniques were developed. Small bushes or brush could be effectively removed with minimal soil disturbance by lowering the bucket to six inches above ground and making a forward pass up to 50 feet long. For larger bushes, the oucket was clamped over the bush and the whole bush plucked from the soil and carried to the brush pile. The latter technique created the least disturbance of surface soil. A road grader with scarifier teeth was determined to be least satisfactory as a means of removing stumps and roots. several different combinations of machines were tested and evaluated for effectiveness at soil removal. It was quickly determined that the road grader was not effective. The bucket loader, with the bucket down and closed, could remove about 50 to 60 cubic yards of soil per hour, taking a six-inch "lift" or cut, The bulldozer, when operated in its lowest gear, made acceptable six-inch cuts when the length of push was no more than 50 feet. percent of the blade width in new soil Each successive lateral pass had only 10 to 20 The rest of the blade was used to accumulate pushed up material. (Soil began to spill off the open end at about 50 feet.) The bulldozer could windrow about 180 to 200 cubic yards of soil per hour. The bucket loader would then be used to load the windrowed material into a dump truck. The hauling eapability of different-sized dump trucks and water craft was also evaluated. The them. Common parameters used to evaluate water craft for soil hauling are summarized in Table 6-5. This evaluation contributed substantially to the decision to configure additional LCM-8s and LCUs for bulk haul of soil. (Loading procedures were modified during the following year to obtain better results than shown in the table.) One side benefit of utilizing bulk hau] was that trucks did not have to ride back and forth. This became of critical importance as more and more trucks were put out of commission by mechanicalfailure. *Four separate hydraulic controls governed all possible motions of the bucket, including the ability to clamp items between longitudinal halves of the split bucket. 170 LL smaller trucks were found acceptable for the sandy conditions while the largest trueks were prone to getting stuck, which was not only a nuisance but required diversion of other equipment to extricate