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ppm. . .Parts per million . Visual analysis was conducted of soils acquired from the borings with a 30x microscope. Dark particles were observed in all samples; with the (dark) particle sizes smaller in samples B1KVA and B4KVA than those contained within B2KVA and B3KVA. It is the opinion of the undersigned that the large, dark particles are asphalt and/or aged, well aerated hydrocarbon compounds originating from diesel, motor oil, or other petroleum products which were mixed with the sandy soil when the underground tanks were removed and the excavations subsequently backfilled. Asphalt is a residue of petroleum refining and consists primarily of heavy, saturated hydrocarbons, alkenes, PNAs (polynulear aromatic compounds ) , and alkylated PNAs. While asphalt is not typically considered a contaminant, it does influence analytical procedures, including those referenced above, by giving a positive hydrocarbon reading. The Hanby Test conducted on B3KVA yielded an orange coloration that is indicative of gasoline contamination; and the results of TLC analysis of B2KVA yielded results consistent with the presence of motor oil . While asphalt could obscure the presence of other hydrocarbons , the Hanby process is specific to aromatic compounds, and should be less susceptible to interferences from asphalt constituents . The samples of soil ( sands ) were considered to be too well graded to be native. Also, hard rock was encountered at 8 feet bgs in borings B2KVA and B3KVA-. . material which would not normally , be found at such a depth and is, therefore, probably ' representative of concrete or other backfill material . PHASE III. . .EXPANDED SUBSURFACE INVESTIGATION On March 20, 1991 , three ( 3) additional soil borings were placed at the locations illustrated within Figure #2, attached. Each of these borings were advanced with a truck-mounted, hydraulic drive drill rig (a CME-55 ) equipped with 8"-outside diameter, continuous-flight, hollow-stem augers operated by employees of HEW Drilling, Inc. of East Palo Alto, CA. This was accomplished under the direction of a Uriah staff hydro- geologist supervised by a registered geologist. Discrete soil samples were collected at five foot intervals (beginning at five ( 5 ] feet bgs ) within a California Modified Split-Spoon Sampler fitted with clean brass tubes 1 . 9 inches in diameter by 6. 0 inches in length. The sampler was driven 18" into undisturbed soil using a standard 30-inch drop of a 140-pound hammer. Samples were logged using the Unified Soil Classification System (USCS) . Upon being retrieved-from the sampler, the ends of each brass tube were covered with teflon t sheeting, fitted with plastic caps, and sealed with black 5.