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F � • • 26 October 2000 AGE-NC Project No 95-0128 Page 2 of 10 Six USTs were removed from the site on 8 April 1994 In May 1994, two 12,000-gallon USTs and associated piping were re-installed at the site to replace the removed tanks Details of the UST removals and soil sampling were presented in reports to the PHS-EHD Hydrocarbons in soil were detected in the area of the former USTs The hydrocarbon-impacted soil was limited to the eastern portion of the UST-removal area and the dispenser islands Between 1991 and 2000, eleven soil borings, one vapor extraction well and twelve ground water monitoring wells were installed on and near the site The vertical and lateral extent of hydrocarbon- impacted soil has been delineated on the site(data collected from the site indicates that hydrocarbon- impacted soil is present in the vadose zone from depths of approximately 5 feet to 55 feet bsg ), however the lateral extent of hydrocarbon-impacted ground water has not been delineated to the satisfaction of the PHS-EHD Hydrocarbon-impacted and methyl tertiary butyl-ether (MTBE)- impacted ground water has been encountered north and east of the property in the down-gradient direction from the suspected former source area of the unauthorized hydrocarbon release, although the dissolved plumes do not total coincide with one anther The plume of MTBE-impacted ground water has not been fully delineated, necessitating the installation of the additional ground water monitoring wells and due to the off-site extent of the M fBE, immediate ground water remediation 30 SCOPE OF WORK The scope of the work includes the advancement of ten soil borings for the installation of ground water monitoring wells and a ground water extraction well Nine ground water wells will be installed at the north and northeast of the property, across Pacific Avenue One ground water extraction well should be installed at the northeastern corner of the property, down-gradient of the known hydrocarbon release and in the area of the highest concentration dissolved hydrocarbons Assessment and interim remediation activities will consist of the following tasks • Permitting and pre-field work activities, " It ] 11 +,I1 +,nn "11111ng anll " eu anst"aaiu�.v.., • Dedicated ground water pump installation, • Pumping, treatment and temporary storing produced ground water, • Properly disposing of produced ground water, • Preparation of monthly reports Advanced GeoEn-,ironmental,Inc