SITE INFORMATION AND CORRESPONDENCE

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Libbey-Owens-Ford -2- 24 March 1986 the pit) and #9 (approximately 100 feet to the west of #10). I believe that the secret to removing the maximum amount of oil from the soil matrix is to raise the ground water level as high as possible in the contaminated area without floating oil up into uncontaminated soil . Libbey-Owens-Ford ( LOF) has placed an air-driven suction lift pump at the pit and one each in wells #9 and #10. During my inspection, the pit was pumped nearly dry, even though the ground water level on the sides of the pit looked to be at the 6 to 8 foot depth (the pit is approximately 12 feet deep) . Free oil was on the surface of the water in the pit bottom and a couple of small oil seeps were evident 1/3 and 1/2 of the way up the pit side. At my request, they shut off the pump in the pit at about 12: 30. I returned at 2:30 to inspect the pit. One of LOF' s lab employees had turned the pump back on at 1: 30 (he was unaware of our experiment) so the full effect of raised ground water was lost. However, about 1/2 of the water surface in the pit was covered by rafts of oil . The pump intake in well #10 was placed about two feet below the ground water surface. The well #9 intake was approximately four feet below ground water surface. I estimate the pumping rate was approximately 6-10 gpm at each well . We used a clear bailer and found oil at the ground water surface in each well . The bailer showed emulsified (or dissolved) oil at least 18 inches thick in each well . Two inches of dark free oil was in well #9. LOF was pumping the pit dry and pumping well below the surface in the wells to create a depression and discourage migration of oil from the leak site. While this should work for this purpose, I believe it actually inhibits j removal of oil from the soil . The fact that very little oil was evident until the ground water came way up in February indicates that the oil was trapped in the soil pore spaces. High ground water displaces at least some of the oil . Free oil and emulsified oil are at and near the top of the ground water. A skimming pump should be used to draw the oil and emulsion only from the water surface or just below it. I believe that a combination skimmer pump and drawdown pump below would have to be operated precisely to avoid excessive drawdown. Excessive drawdown would probably leave the oil in the soil pore spaces. I asked Mr. Quick to set the pump intakes close to the ground water surface in wells #9 and #10. I suggested that they monitor what those pumps produce at different levels to see what they pick up and to determine optimum oil recovery depth. I recommended that LOF consider selectively flooding or injecting water in specific areas around the oil plume in order to raise the ground water level under the plume without encouraging horizontal oil migration outward. I believe that oil could be concentrated on the ground water surface where it could be removed. The major problem is that the building is in the way on the north side of the plume and more oil could be forced under the building. In addition, care must be taken to avoid raising the ground