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1 <br /> 12 July 1992 <br /> (GeoAudit CV 42F5-1.26) <br /> Page 4 of 6 <br /> 1 <br /> Because of a laboratory accident, the sample from MW-2 (sample MW- <br /> 2-6/9/92) could not be analyzed for TPH as diesel . Sample MW-2- <br /> 7/1/92 was collected to replace the original sample for the diesel <br /> analysis. <br />' Neither TPH as gasoline nor BTE&X was detected in any of the water <br /> samples. TPH as diesel was detected in samples from all three <br /> monitoring wells (MW #1 (Union Ice well) at 240 µg/L, MW #2 at 76 <br />' µg/L, and MW #3 at 100 µg/L) . The water sample analyses are <br /> summarized in Table 3 . The laboratory results and chain of custody <br /> are attached in Appendix C. <br /> BOIL STRATIGRAPHY <br />' The site is underlain by unconsolidated Quaternary sediment, mostly <br /> silt and clay but including some sand. Directly beneath the surface <br /> asphalt is a layer of black, highly organic sand and gravel of <br /> uncertain origin and composition. This material may be asphaltic in <br /> composition or may be more similar to coal or charcoal . This layer <br /> is generally 1. 5 to 2 .5 feet thick in the excavation area. <br /> From 2 . 0 to 4 . 0 feet, the soil is light yellow-gray in color and <br /> consists of moderately sorted fine-grained sand. This material <br /> exuded a slight petroleum odor during soil removal. <br /> From 4 . 0 feet to the bottom of the excavation at about 13 feet, the <br /> material consisted of brown to yellow-brown, clayey to sandy silt. <br /> This material emitted strong hydrocarbon odors during excavation, <br /> but no odors were detected during drilling of monitoring wells <br /> around the margins of the excavation. The silt is saturated at a <br /> depth of approximately 13 feet. <br /> In the monitoring wells, the yellow-brown silt extends to a depth <br /> of between 15 and 20 feet. It is underlain by the first important <br /> aquifer, which consists of orange to gray moderately well sorted <br /> medium-grained sand. <br />' DEPTH TO GROUNDWATER <br /> The three monitoring wells were surveyed prior to sampling on 9 <br /> June 1992 . Casing elevations were surveyed to the nearest 0. 01 <br /> foot, relative to a temporary bench mark with an assumed elevation <br /> of 100 feet. A Solinist water meter was used to measure the depth <br /> to water, and the relative groundwater elevation in the three wells <br /> was calculated: <br />