ARCHIVED REPORTS_XR0005321 - Laserfiche WebLink

Home Browse Search

i ' was not detected in soil samples collected at a depth of 30 feet or 35 feet bsg TPH-d was detected in soil samples collected from a depths of 15, 20 and 25 feet bsg at concentrations ' of 5,100 mg/kg, 13,000 mg/kg and 490 mg/kg,respectively TPH-d was not detected in soil collected at a depth of 30 feet bsg or below (Tables 1 and 2) On 26 October 2001,a total of four soil probe borings(P 12A/B and P 13A/B)were advanced at the site south of the and near the former UST location Probe borings were advanced in the area of the former UST's to collected depth discrete water samples TPH-d was detected in all four of the grab ground water samples analyzed at concentrations from 130 micrograms per liter(µg/1) to 550 µg/1 (Table 2) ' On 28 and 29 October 2002, monitoring well MW-5 and six ozone sparge wells (OPS IA through OPS3B) were installed A total of three soil samples were collected from MW-5 and analyzed for ' TPH-g, TPH-d, BTEX and fuel additives None of the target compounds were detected in the soil samples analyzed ' Between June 1996 and February 2003, 20 ground water monitoring and sampling events were performed at the site to monitor dissolved petroleum hydrocarbon concentrations in ground water and to characterize ground water flow direction and gradient on the site (Table 3) • During the most recent sampling event TPH-d was detected in ground water samples collected from ground water samples MW-1 and MW-4 at concentrations of 20,000µg/1 and I0 93,000 µg/l, respectively TPH-g was detected in samples MW-1 and MW-4 at concentrations of 1,400µg/1 and 6,700µgd,respectively In addition,the BTEX compounds ethylbenzene,toluene and total xylenes were detected in sample MW-4 at concentrations of ' 1 8 µg/l, 2 1 µg/1 and 8 4 4g/l, respectively • Ground elevations have increased approximately 0 8 feet during the monitoring period • The lateral extent of the dissolved petroleum hydrocarbon plume is delineated by the current area bound by wells MW-1 through MW-5 and soil borings GROUND WATER DEPTH AND FLOW DIRECTION In February 2003, ground water depth was measured at approximately 24 feet below surface grade (bsg) Review of historical AGE depth to ground water measurements indicates that ground water depth near the site has fluctuated between approximately 15 and 20 feet bsg Ground water flow direction at the site can vary seasonally However, the overall regional flow direction is southwest ' Advanced GeoEnvironmcntal,Inc