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21 September 2005 <br /> AGE-NC Project No. 05-1282 <br /> Page 6 of 7 <br /> • Assessment near the northwest corner of the facility revealed high concentrations of toluene <br /> in the soil and ground water samples from boring B-1 (13,000 mg/kg in soil at 15 feet bsg <br /> and 6,800,000 µg/1 in the water); lower levels of toluene were detected in the ground water <br /> samples from borings B-2, B-3 and B-5. The toluene concentrations in soil exceeded the <br /> EPA Region 9 Preliminary Remediation Goal of 520 mg/kg; the ground water toluene <br /> concentration in boring B-1 exceeded the DHS-established maximum contaminant level <br /> (MCL)of 150 µg/1 for toluene in drinking water;the water samples from B-3 and B-5 were <br /> below this limit. The oxygenated compound MIBK, detected in the ground water sample <br /> from B-1, is a common product of glue or paint thinner. No MCL can be found for this <br /> analyte. <br /> • Soil and ground water samples taken from the southwest corner of the site,near the former <br /> location of the two 4,000 gallon diesel USTs detected TPH-d concentrations up to <br /> 2,900,000 mg/kg and 5,300,000µg/l,respectively.No contamination was detected in the soil <br /> sample from B-6. TPH-d was detected in both soil and ground water samples from borings <br /> B-7 and B-8. Maximum concentrations were detected in the samples from B-7, indicating <br /> close proximity to the original point of release. <br /> • Soil and ground water samples collected in the southwest corner of the site, around the <br /> former 210,000 gallon#6 Fuel Oil UST location, showed no ground water contamination, <br /> but some soil contamination. The maximum concentration detected was 25,000 mg/kg <br /> TPH-d at 15 feet from boring B-15. <br /> RECOMMENDATIONS <br /> In both the northwest and southwest areas of concern,AGE recommends excavating contaminated <br /> soil and treating contaminated ground water by way of ground water extraction(pump and treat).The <br /> remaining soil contamination in the southeast corner, in the location of the former 210,000 gallon <br /> #6 Fuel Oil UST would be best treated by excavation as well. <br /> LIMITATIONS <br /> Our professional services were performed using that degree of care and skill ordinarily exercised by <br /> environmental consultants practicing in this or similar localities. The findings were based mainly <br /> upon analytical results provided by an independent laboratory.Evaluation of the geologic conditions <br /> at the site for the purpose of this investigation was made from a limited number of available data <br /> points(i.e.soil and ground water samples)and subsurface conditions may vary away from these data <br /> points. No other warranty, expressed or implied, is made as to the professional interpretations, <br /> opinions and recommendations contained in this report. <br /> Advanced GeoEnvironmental,Inc <br />