WORK PLANS - Laserfiche WebLink

Home Browse Search

♦' NOOO 1%W0' Site Background Information- Ripon Farm Service Page 5 of 10 analyzed,the remaining five soil samples did not contain detectable concentrations of either range of petroleum hydrocarbons. On 13 May 1998, five soil borings were drilled on-site (B18 and B19) and off-site (B20 through B22)with three off-site borings completed as ground water monitoring wells (MW-6, MW-7, and MW-8); the two on-site borings were dual-completed as remediation pilot-test wells VW-1 and VW-2. Saturated soil conditions were.encountered in all borings at a depth of approximately 17 feet bsg. • TPH-g was detected in two out of eleven analyzed soil samples collected from borings B18 through B21, BTEX was detected in five of the samples. The greatest concentrations of TPH-g and TPH-d detected were 440 mg/kg and 1,400 mg/kg,respectively, encountered in sample B19-20. Toluene, ethylbenzene, and total xylenes were detected in the soil samples at concentrations as great as 8.6 mg/kg(xylenes).Oxygenated compounds were not detected in the soil samples analyzed. Volatile organic compounds (VOCs) were detected in soil samples collected at variable concentrations. • Soil samples collected from the Jimco Truck Stop at depths of 20 feet bsg were impacted with TPH-d at concentrations as high as 490 mg/kg, and xylenes at concentrations as high as 0.017 mg/kg. • Naphthalene was detected at a concentration of 2,600 micrograms per kilogram(mg/kg).The VOC encountered at the greatest concentration in the soil samples was 1,3,5- trimethylbenzene, which was detected at a concentration of 12,000 µg/kg. Quarterly monitoring events have been conducted at the site since the first ground water monitoring wells were installed in Apri11994.The general results of the ground water monitoring events are as follows: • TPH-g has been detected in ground water samples collected from wells MW-1 though MW-10 at concentrations as high as 420,000 mg/l.TPH-d has been detected at concentrations as high as 210,000 µg/1. TPH-g and TPH-d have been detected in ground water samples collected from soil vapor wells (VW-1 and VW-2)at concentrations as high as 76,004 µg/1 and 290,000 µg/l, respectively. TPH-d concentrations typically exceeded TPH-g concentrations in the samples containing both analytes. • Benzene has been detected in the samples from wells MW-1 through MW-6, VW-1, and VW-2 at concentrations as high as 2,000 µg/1 (VW-IA). Toluene has been detected in the samples from wells MW-1 through MW-7, VW-1, and VW-2 at concentrations as high as 130µg/1(MW-2).Ethylbenzene has been detected in the samples from wells MW-1 through MW-6,VW-1,and VW-2 at concentrations as high as 870µg/1(VW-1A).Xylenes have been detected in the samples from wells MW-1 through MW-8, VW-1, and VW-2 at Advanced GeoEnvironmental,Inc.