ARCHIVED REPORTS_XR0010189 - Laserfiche WebLink

Home Browse Search

' 20 January 2005 AGE-NC Project No 97-0343 ' Page 4 of 21 ' and 125 feet bsg, respectively • Based on CPT-denved physical and hydrological properties of the subsurface soil, AGE Identified three hydrogeologic units (HUs) between the vadose zone and total depth, HU1 (60 to 80 feet bsg), HU2 (80 to 96 feet bsg) and HU3 (96 to total depth of 134 feet bsg) ' • Ground water samples CPT2-76-80 and CPT3-74-78 were collected from HU1 TPH-d was detected in sample CPT3-74-78 at a concentration of 64 micrograms per liter (µg/1) Total xylenes were detected In sample CPT2-76-80 at a concentration of 0 97 11g/1 No other target ' analytes were detected In samples CPT2-76-80 and CPT3-74-78 • Ground water samples CPT1-92-96 and CPT2-92-96 were collected from HU2, sample CPT 3-92-96 was collected at the boundary between HU2 and HU3 TPH-g and TPH-d were ' detected in sample CPT1-92-96 at concentrations of 530 µg/l and 98 µg/l, respectively Toluene, ethyl-benzene and total xylenes were detected in sample CPT1-92-96 at concentrations of 9 9 µg/1, 20 µg/1 and 140 µg/l, respectively No other target analytes were ' detected In the samples from HU2 • Benzene and fuel additives were not detected at or above laboratory reporting limits in any of the ground water samples • The general count of heterotrophic organisms In soil sample CPT1-31 was 12 2 X 105 ' (colony-forming units/gram) cfu/g and the selective count was 2 1 X 105 cfu/g, which indicate a moderate population of organisms capable of gasoline metabolism In add>tion,the nutrient concentrations are at moderate to high levels to sustain ongoing bioremediation, nitrates (NO3), phosphate (PO4) and ammonium (NH4) were detected In the sample at concentrations of 57 2 parts per million (ppm), 22 ppm and 28 38 ppm, respectively, indicating The moisture content (MC) of the soil sample was 23% (Table 3) On 14 Jams 2002 an 8-hour SVE pilot test was conducted at the site using vapor well VW-2 �'Y p g p I screened from 15 feet below surface grade (bsg)to 35 feet bsg as the extraction well The pilot test was performed to provide SVE data prior to installation of a full scale remediation system Additional data is provided In Tables 4 and 5 • TPH-g was detected in the soil gas/vapor samples(vapor samples)at concentrations ranging from 1,300 µg/1 to 2,700 µg/1 Toluene, ethylbenzene and total xylenes were detected In the gas/vapor samples at concentrations as high as 47µg/1 toluene,30µg/1 ethylbenzene and 220 µg/1 total xylenes Benzene and MTBE were not detected at or above laboratory reporting limits in the gas/vapor samples IThe SVE unit was operated at approximately 2.300 RPMs for the eight-hour test The flow rate was measured between 25 cfm (standard cubic feet per minute) and 30 scfln for the IAdvanced GeoEnvironmental,Inc