Crude oil was observed in shot rock and water (meltwater) exposed at a reported depth of approximately 12 feet below ground surface in the excavation dug to enable the reinsulation of the pipeline deadleg at PS-4. According to Alyeska, the suspected source of contamination was a May 5, 1984 spill of 210 gallons of crude oil due to the failure of a seal on the pig launcher in the manifold building.