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Corrective Action Plan Page 4 DISTRIBUTION AND CONCENTRATIONS OF HYDROCARBONS Data Compilation Investigation of the distribution and concentrations of components of gasoline in the subsurface beneath the 152 East I lth Street site has progressed in stages, with the results from each stage being used to plan subsequent stages of investigation and establish a groundwater-quality monitoring program Where applicable, the results of the ' investigations performed for the subject property (i a 152 East I Ith Street) have been supplemented by available data from investigations performed for the Beacon station at 153 East 11th Street (Refs 7, 10, 11, 13, 16 and 17) For convenience of reference, measurements of depths to the water table and the results of L analyses of all soil and groundwater samples that have been recovered from borings and wells installed for both the 152 and 153 East Street sites have been compiled in Tables 1, 2 and 3 respectively The available well logs are presented in Appendix A Interpretation of Area of Subsurface Affected by Release of Gasoline The geotechrucal and geocherrucal data from the investigations performed for the 152 and 153 East 11th Street properties have been synthesized and used as the basis for an interpretation of the extent to which the subsurface has been affected by hydrocarbons released at the 152 East Street site (Ref 10) This interpretation is presented in the form of the plan view on Figure 2 and the longitudinal- and cross-sections shown on Figures 3, 4and S It is important to understand that, while the interpretations shown on Figures 2, 3, 4 and 5 provide information needed to design a corrective action plan for the 152 East 11 th Street property, they are not intended to precisely define the exact boundaries of hydrocarbon fuel components affecting the subsurface Specifically, they should not be used for reaching a conclusion as to whether groundwater affected by hydrocarbons that may have been released into the subsurface on the 152 E I lth Street site has, or has not, coalesced with hydrocarbon fuel components released into the subsurface at the Beacon Station site However, when taken together, the geotechnical, geochemical and hydrogeologrcal data that have been gathered support an interpretation that gasoline that leaked from underground tanks, or the associated piping, that were on the 152 East IIth Street property has moved down gradient from the point where those tanks and piping were formerly located toward the East 11th Street frontage of the site and has migrated some distance northward under the street