SITE INFORMATION AND CORRESPONDENCE

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L. MMIEXj-IfRNfR Ms. Linda Turkatte 6 May 1992 Page 2 petroleum hydrocarbons at a concentration of 140 mg/Kg (see Table 1). For safety considerations, the excavation was temporarily backfilled with gravel until a pian to excavate the contaminated soil could be approved by the Department. EXCAVATION OF TANK HOLE A corrective action work plan was submitted to the Department by Elder Engineering in L. their letter of 5 July 1991. The County issued a Public Notice for the proposed corrective action work plan and since no comments were received within the 30-day comment period the work plan was implemented as proposed with the stipulation that excavated soils with �.. concentrations above 50 ppm will be disposed of offsite. On 2 October 1991, the tank hole was excavated and approximately 80 cubic yards of soil LM was removed and stockpiled onsite. Samples EX-1 through EX-5 were collected from the sidewalls of excavation at the locations requested by the County's Inspector, Linda Turkatte. Subsequently, the County determined that additional samples would be required +- and samples EX-6, 7 and 8 were collected on 15 October 1991 at the requested locations. The results of this sampling indicated that petroleum hydrocarbons were still present in the sidewalk along the northern and western portions of the excavation. Although low concentrations of petroleum hydrocarbons were detected in samples collected from depths of 13 and 15 feet below the ground surface, it appeared that the most significant zone of contamination was in shallower soils. A revised work plan was then submitted by Elder Engineering on 31 October 1991 to excavate the areas around EX-2 and EX-6 where contamination appeared most significant. The plan provided for stockpiling excavated soil L" on plastic sheeting and covering the stockpiling with plastic sheeting until a permit to aerate the soil could be obtained from the local Air Pollution Control District. After receiving verbal approval from Ms. Turkatte, an additional 30 cubic yards (approximately) of soil were excavated from the areas around EX-2 and EX-6 on 4 November 1991. Samples EX--9 and 10 were collected from the sidewalls after the removal of soils containing petroleum hydrocarbons was deemed completed. DISPOSAL OF EXCAVATED SOIL After all of the contaminated soil was removed from the excavation, the stockpiled soil was also sampled to characterize the concentrations of petroleum hydrocarbons that were present in the stockpiled soil. Twelve individual samples (four from each of the east, west, LW and center portions of the pile) were collected and were then composited into 3 composite samples (Sample #11 east, #12 center, and #13 west) for analysis. The three samples were L. L.