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' Mr Ronald Rowe November'), 1998 Page 3 ' Department of Health Services for the analysis of hazardous materials Certification Number 1346) Samples were analyzed for total petroleum hydrocarbons as gasoline (TPH-G) and benzene, toluene, ethylbenzene, and xylenes (BTEX) using EPA Method 5030/8015 and 8015 Modified, and oxygenates using EPA Method 8260B The analytical reports for the tHydroPunchTM groundwater sampling are included in Attachment C Groundwater Monitoring Well Constructions. All boreholes were constructed with 2-inch ' diameter Schedule 40 polyvinyl chlonde (PVC) blank casing and 0 020-inch slotted casing Table I summarizes the well construction details ' Groundwater Monitoring Well Development, Sampling, and Surveying The newly constructed wells were developed on August 14, 1998 by Wayne Drilling, Inc (California C-57 License Number 718139) of Lincoln, California and supervised by a BC field technician After ' development, each well was sampled by the BC field technician and the samples were submitted to Acculabs, Inc The development and decontamination water was transported to an on site evaporation pond The analytical reports for the well sampling are included in Attachment C Development and sampling notes are included as Attachment D Top-of-Casing and groundwater surface elevations, and horizontal locations of each groundwater monitoring well (MW-1 through MW-4) were surveyed by Tom Morrow, Incorporated of West Sacramento, California A copy of the survey site map by Tom Morrow, Incorporated is included as Attachment E ' Results The following summarizes the results of the investigation ' Local Geology and Hydrogeology. Results from previous site investigations conducted by Leeward Consultants, are consistent with this investigation The subsurface stratigraphy is ' interbedded silts, sandy silts, silty sands, and sand Bedding contacts are commonly gradational However, there are a few sharp contacts that usually separate an overlying sand from a finer ' gramed soil Grain size analyses of three samples collected in MW-2 correspond with the lithological descriptions given for the same interval Cross section A-A' is shown on Figure 2 and Figure 3 shows the lithogic cross section of A-A' ' Groundwater was encountered during drilling at 69 to 73 feet bgs Depth to water measured in the wells on September 16, 1998 ranged from 68 51 to 68 87 feet bgs (Table 2) Measured static ' water levels in the wells were higher than the depth of groundwater during drilling which may indicate semi-confined or confined groundwater conditions Groundwater flow direction beneath the facility vanes due to a very flat gradient ' Use or disclastrre of data continued on this sheet is subject to the restriction specified at the beginning of this document BCSACO111600011627 11WELLMTXOC