Following the 1966 Palomares B-52 crash, the Savannah River Site received contaminated soil from the environmental clean up and remediation. Soil with radiation contamination levels above 1.2 MBq/m2 was placed in 250-litre (66 U.S. gallon) drums and shipped to the Savannah River Plant for burial. A total of 2.2 hectares (5.4 acres) was decontaminated by this technique, producing 6,000 barrels. 17 hectares (42 acres) of land with lower levels of contamination was mixed to a depth of 30 centimeters (12 in) by harrowing and plowing. On rocky slopes with contamination above 120 kBq/m2, the soil was removed with hand tools and shipped to the United States in barrels.