ARCHIVED REPORTS XR0000762 - Laserfiche WebLink

Home Browse Search

Weld Background Information Weldon Church Site Page 4 of 4 additive MTBE was detected in the four soil samples analyzed from borings B 17 and B 18, at a maximum concentration of 0.29 mg/kg (B17-5), and was detected in soil samples collected from total depth in both borings,at a concentration of 0.012 mg/kg.No other target analytes were detected in the samples analyzed. ' Seventeen ground water samples were analyzed; TPH-g and BTEX compounds were detected only in the grab ground water samples collected at water-table depth(approximately 10 feet bsg) and at total depth of borings B 17 and B 18. The highest concentrations of contaminants were detected in the water table samples at 160,000 µg11 TPH-g in sample B17-1, and 5,600 µg11 benzene, ' 14,000 pg/l toluene, 3,200 µg11 ethylbenzene, and 12,000 µg/1 xylenes in sample B18-1. At total depth,maximum TPH-g concentration was 3,900 ltgll(B18-2);however,the BTEX concentrations were considerably lower; benzene was not detected, maximum toluene concentration was 3.8 �Lg/l (B18-2), maximum ethylbenzene concentration was 2.2 µg/1 (B17-2), and maximum xylene concentration was 16.8µg/l(B1 8-2).No other target analytes were detected in the samples analyzed. ' A total of 24 soil borings have been advanced on and off the site, seven of which have been completed as ground water monitoring wells,providing data concerning hydrocarbon impact on soil and ground water, soil composition, and ground water flow direction. Laboratory analysis of soil samples collected from monitoring wells and soil probe borings constrain the plume of impacted soil to the immediate vicinity of the former UST excavation.The lateral extent of impacted ground water appears to be delineated in all directions from the former UST excavation. Laboratory analysis of ' ground water samples collected from well MW-4, north of the former UST excavation, has consistently detected TPH-g and BTEX. Sample analytes have also generally been detected in samples from well MW-1.These detections,however,were not confirmed north of well MW-4 with ' additional soil borings toward the north, east, and west of MW-4. r r • Advanced GeoEnvironmental,Inc.