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Mr.John Johnson October 18,1995 Site Geology Page 4 Site soils were continuously logged by a geologist from Artesian Environmental Consultants using the Unified Soil Classification System (USCS) and is their sole responsibility (Appendix C: Boring & Well Completion Logs). The soils encountered during drilling were found to be somewhat similar at the three well locations. f B-1, B-2 and B-4 had asphalt at the surface, while B-3 was advanced through the landscaped lawn. From beneath the surface down to about 11 feet depth the soil consisted of sand (SP), light brown, poorly sorted, very fine and moist: Below 11 feet, B-1 had clayey sand (SC) with low plasticity to termination at 15 feet. B-2 was sand to the total depth of 16 feet. B-3 had wet, medium sand (SM) to 17 feet, and sandy clay (CL) from 17 to 19 feet. B4 was moist silty medium sand (SM) from 11 feet to the total depth of 16 feet. No groundwater was encountered in the borings. Groundwater Monitoring Well Sampling MW-4 was sampled on May 19, 1992, using a teflon bailer. Prior to use, the bailer was washed in Alconox and rinsed twice in tap water. About 5 well volumes ( 8 gallons) were bailed from the well prior to sampling, and measurements of water pH, temperature and conductivity were obtained. Initial water level in MW-4 was 27 feet BGS, and unchanged after bailing. The water sample was placed in 2 40-milliliter vials from the bailer until no head space remained and a positive meniscus was apparent. The bottles were sealed, labeled, and placed into a cooler with ice for transport to the state certified,analytical lab. Chain of custody documentation was initiated. The groundwater and wash water was placed in DOT 17H/E drums and stored on site. At the lab, the samples were analyzed for TPH as gasoline by EPA methods 5030/8015, BTEX by EPA method 602. SAMPLE ANALYTICAL RESULTS Soil Sample Analytical Results Eight soil samples from the four borings were analyzed for TPH as gasoline and BTEX (Figure 3: Site Plan, Sample Results). Two samples from each boring were analyzed. All samples were non-detect for TPH-g and BTEX except for B-1-2. Sample B-1-2 had 2.5 parts per million (ppm) TPH-g, and less than 1 ppm each, of toluene, ethylbenzene and xylenes. Benzene was not detected in B-1-2. Groundwater Sample Analytical Results The MW4 sample was analyzed for TPH as gasoline (EPA method 5030/8015)with BTEX (method 602). All items tested for were not detected. The results of these analyses are summarized below. Parker Environmental Services, 190 East 7th Street, Pittsburg, CA 94565-2317 Phone (510) 439-1024 Fax (510) 439-2566