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Former Dolly Madison Workplan Page 2 January 28, 2000 Project No. 2002-1426-02 zone (0 to 21.5 feet below ground surface) in soil borings B-2 and B-3, but were detected in the saturated zone. Analytical results of groundwater indicated dissolved hydrocarbons were detected in monitoring wells MW-1 and MW-2 (EMCON, August 4, 1997). TPHG was detected in monitoring wells MW-1 and MW-2 at concentrations of 18,000 parts per billion (ppb) and 220 ppb, respectively. Benzene was detected in monitoring wells MW-1 and MW-2 at concentrations of 4,400 and 33 ppb, respectively. In the vicinity of the site is a former ARCO Service Station, a Chevron Service Station, a Texaco Service Station, The Transmission Shop, and a former Colombo Bakery facility, all of which have or previously had USTs. Based on data collected from subsurface investigations performed at the former ARCO Service Station, the Chevron Station, The Transmission Shop, and the Texaco Service Station, residual and dissolved hydrocarbons have been detected beneath these facilities, and a commingled plume exists beneath Charter Way and Lincoln Street. Reportedly, data gathered from the former Colombo Bakery facility and the Texaco Station suggest that hydrocarbons extend greater than 100 feet bgs (80 feet below groundwater). It is our understanding that the groundwater flow direction near the intersection has generally been toward the east and northeast. The groundwater plume has not been delineated vertically or laterally. SCOPE OF WORK Stratus has prepared the following scope of work to define the extent of hydrocarbons beneath to the site. The proposed scope of work consists of assessing the vertical extent of hydrocarbons at 2 locations onsite using an electronic Cone Penetrometer Test (CPT) followed by depth discreet soil and groundwater sampling using direct push technology (Geoprobe, Hydropunch, or similar). All geologic work will be under the direct supervision of a State of California Registered Geologist and will be conducted in accordance with standards established by the Tri- Regional Board Guidelines for Hydrocarbon Site Assessment and Remediation (RWQCB 1991). Task 1 - Prefield Activities Following approval of this workplan by PHS/EHD, Stratus will initiate the following activities: • Obtain the necessary drilling permits from the PHS/EHD, • Contact Underground Service Alert to locate underground utilities at and adjacent to the site, • Retain and schedule a drilling contractor to advance CPT and direct-push borings. CAMy Documents\STRATUS\Ibc\Stockton\workplan.doc ST?Q'A7 _5