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� E .11 levels required several hours after purging to ' ne:ar their initial levels. All soil and water samples were transported and submitted to the laboratory with appropriate chain--of-custody forms. Also submit- ted to the laboratory was one blind duplicate identified as fictitious MW4 to check analytical repeatability. 4 � (! Site: Ceol.o€ r a.Tld Hydr ogeology Cinar.a.cte.rizat.:ir)n of the soil lithologies was based on cuttings re:t_urned by th,.e auqe�rs and those brought to the surface by a hand �- auger. The lithology .found was quite consistent across the site, c t :dace soils rJL:iid 1-4 feet. below ground surface are primarily .::lays with different- admixtures of sand and silt. These sandy, ,_ -I -.y clays and clayey silts are unsaturated but. generally : :IAghtlV moist, Soils below approximately 4 . 5 feet. consist ;Y almost entirely of sandy clays (borehole BE contained silty clay) , and are generally moist. Saturated soils occur generally at 5-6 feet below around surface. No sand or gravel lenses were observed at any depths and no perched water was observed at any simple location,=. An examination of the water levels in the three monitoring wells at this site for June 1.989, indicates a localized groundwater g--adient of 0 . 0052 feet per :foot toward the northeast (Figure 3) . J.P.:is gradient d:irectinnn agrees well with regional gradient information pi)bli.shed by the San Joaquin County Flood Control and Water Conservation District (Unconfined and semi-confined water .� table elevations, spring 1989) , although the regional gradient is lass steep (0. 0022 feet per foot) . The steep local gradient may be a result of local topography and drainage conditions. It not kncwn whether or, not the shallow groundwater beneath the' site is ;art of the- primary unconfined aquifer or if it is a ;;hallow perched :�,.c,ne, Deeper borings at the site would be required to deinine the nature of the aquifer. The poor yield of the wells observed during the sampling program reflects low t.ransmi.ssivity which can be expected for soils containing extremely high amounts of clay as found on-site. This poor transmissivit:.y suggests that movement of water both verti- cally and laterally .is extremely slow, 5 _ 0 A.nalyt.ica,l. Results .. A total of 1s soil samples and 4 water samples were collected from the site. All samples collected at the site were submitted to the WESTON Analytics ' Stockton, California laboratory. Portions of .samples requiring carbamate analysis were subsequent- subcontracted to Appl, Inc. Laboratory in Fresno, California. Bot€:i laboratori.e_�s are certified by the State of California for the analyses .requested .