ARCHIVED REPORTS XR0000927 - Laserfiche WebLink

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' Contamination detected in MW-1 maybe moving differently than that detected in MW--2 and MW-3 due to different sand bodies contributing to the wells. ' Silty sand was encountered at 10 feet bsg in MW5 and MW6 and at 20 feet bsg in MW6 and B7. Silty clay was encountered at 5 feet and 15 feet through 30 feet bsg in MW5 and at 5 feet, 15 feet, ' 25 feet, and 30 feet in MW6. Silty clay was also encountered at 5 feet through 15 feet, 25 feet, and 30 feet in boring B7. The sand at 10 feet bsg appears to have a north-northeast to south-southwest orientation;the sand at 20 feet bsg appears to have a east-northeast to west-southwest orientation and ' limited lateral extent. Damp to saturated,"gray to brown, silty sand was encountered at 10 feet and 20 feet bsg in borings ' MW7 and MW8. Dry to saturated, brown, silty clay and clay were encountered at all other depths- in borings MW7 through MW10. ' Saturated soil was encountered in each boring at depths of approximately 10 feet bsg. ' GROUND WATER GRADIENT AND FLOW DIRECTION - WELL NETWORK ' Depths to ground water averaged 12 feet below the well casing tops. The depth to ground water has ranged from 9.78 to 14.01 feet below the well casing tops. Ground water elevations at the site ranged from 26.45 to 30.68 feet above mean sea level (MSL) in well MW-1, over the monitoring ' period. Ground water levels have steadily decreased over the past four to five years. The water elevations were within the screened intervals of all the monitoring wells on-site. The ground water flow direction was inferred using ground water elevation data. The ground water at the site has ' inferred to be flowing to the north under an average gradient of 0.005 feet/feet across the area monitored. I I I Advanced GeoEnvironmental,Inc.