Laserfiche WebLink
04 October 2000 <br /> . AGE-NC Project No 97-0290 <br />' Page 8 of 9 <br /> • The most intensely impacted soil appears to be in a silt and clay layer at depths between <br /> approximately 40 to 47 feet bsg <br /> • High concentrations of TPH-g detected during this phase of work were at the depth Interval <br /> representing the most Intense hydrocarbon impact, 25 to 45 feet bsg The vertical extent of <br /> BTEX and overall TPH-g are not fully defined within the former UST areas,however greatly <br /> reduced concentrations were detected in soil samples collected from the terminal depth of <br />' the air-sparge well soil borings (SW's) <br /> • The vertical extent of TPH-d may be constrained in two former UST areas to depths less than <br />' 60 feet bsg <br /> • Hydrocarbons were detected in soil-vapor samples collected at the SVE unit at <br />' concentrations considered to be acceptable for a successful on-going SVE remediation <br /> However, the duration of total operation of the SVE unit was less than optimal Corrective <br /> measures are being implemented and will continue over the next quarter to increase the <br />' overall SVE operational time An estimated 717 gallons of gasoline were removed over the <br /> first two months of operation <br /> • Elevated dissolved oxygen concentrations In ground water were detected along the southern <br />' portion of the site and at the southern edge of Elm Street, suggesting that the IAS operation <br /> is effective and has potential to volatilize dissolved hydrocarbons <br /> I <br /> 5.0. RECOMMENDATIONS <br />' Based on the findings of the environmental activities recounted in this report, AGE recommends <br />' 0 Operation and monitoring of the soil vapor extraction unit along with in-situ air-sparging <br /> • Continued quarterly ground water monitoring of the existing well network <br /> 1 <br /> I <br />' Advanced GeoFnwronmental,Inc <br />