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is f was detected in only one sample: 1 .6 mg/kg at a. depth of 30.5 feet in SB7. No benzene or ethylbenzene above the 0.005 mg/kg detection limit was found in the borings near the old product tank pits. Soil samples collected from the boring near the waste oil pit contained no detectable fuel constituents, oil and grease, or lead. Cadmium, chromium; and zinc values were within the range of concentrations- normally .found in clay-rich sediments (USGS 1976). Copies of the an results are included as Appendix F. 3.3 INSTALLA'T'ION OF MONITORING WELLS Monitoringwells MW1 ; MW2, and MW3 were completed with nominal 2 inch PVC casing: wells Mw4 and Mw5 with 4-inch casing. . Screened casing '.was installed from 30 to 70 feet below the-ground surface. The screened intervals were packed: with sand, and the. filter pack 3, was sealed with a layer pf: bentonite` pellets.- A neat cement ; fs -. . grout seal was pumped into the .remaining annular space from the i ( bentonite seal to. the surface. The well tops were completed' with traffic boxes set. in concrete and secured with locking well caps and padlocks. The completion details of each well are 'illus-- Crated in the boring logs (see Appendix D), 3.4 SAMPLING AND ANALYSIS OF GROUNDWATER wells MVdi MW2 a nd P1113 were first sampled on 13 November 1986. , . . 1 (Table 1 ) . well s 'MW4 and MW5 were first sampled on 26 June 1987, and 'wells MW1 , MW2, and MW3 were resampled then, These samples were, collected and submi*ted for..:analysis. by GTI. The monitoring > � r r welds were developed with hand bailing methods and then samples .. with 'a clean Teflon .bailer. All samples were handled and 'sub- mittedto analytical laboratories according to GTI's standard operating procedures (GTI : 1986b). e35/71050/2--90/tx 22 t a M _ r' FF