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1 IReport of Findings Frontier Transportation - ' March 12, 2004 Page 3 ' sands from 30' to 40' bg during well advancement of MW-15 through MW-18 (See Appendix A for boring logs) Cross sectional diagrams are included as Figures 3 and 4 .31 First subsurface water was encountered at depths from W to d�bg during tank removal ' and monitoring well installation at this site in 1995 and 1996 Since then, shallow subsurface water has been encountered beneath the site between 6' and 10'bg The three newly installedo ' deep wells MW-15, MW-16 and MW-18 encountered groundwater at approximately.315 bg during boring advancement ' The most recent data collected in December of 2003 identified the flow of groundwater in a generally western direction beneath the site ' 4.0) SITE ASSESSMENT RESULTS On January 27, 2004 through January 29, 2004, BEII supervised the installation ' groundwater monitoring wells MW-15, MW-16, MW-17 and MW-18 to help define the extent of dissolved MTBE beneath the site (See Figure 2 for well locations) Deep monitoring wells MW- 15, MW-16 and MW-18 were advanced to 40' bg Shallow monitoring well MW-17 was ' advanced to 20' bg ' An 8-inch outside and 4 25-inch inside diameter hollow stem auger was used to install the monitoring wells The new groundwater monitoring wells were constructed of schedule 40 FVC casing The screen slots were sized at 0 02-inch with a size #2/12 sand annular pack The deep ' wells were screened from 30' to 40' bg and the sand annular pack extended from 28'bg to 40'bg The annular seal was five feet thick and consisted of bentonite pellets The remaining annular space was grouted to surface with a Portland cement and potable water mixture The shallow ' well was screened from 5' to 20' bg and the sand annular pack extended from 4 5'bg to 20'bg The annular seal was one foot thick and consisted of bentonite pellets The remaining annular space was grouted to surface (See Appendix A for well construction) 1 Soil samples were collected at 5-foot intervals from a split spoon sampler that contained three brass liners, which were 2 inches in diameter and 6 inches long Soil samples were ' screened for petroleum hydros ns in the field using an H-Nu DL 101 photoionization detector (PID) A total of twenty-eight ( soil samples werw�ollected from newly installed monitoring w0s MW-15, MW-16, MW-17 and MW-18 Eighl"samples were taken for each deep well and , �[r samples were taken for the shallow well All samples were analyzed for TPH-g, BTEX, and��e ��Y`r MTBE, TBA, DIPE, ETBE, TAME, 1,2-DCA and TBA using EPA methods 8015M and 8260B Z(,4 as requested by the PHS/EHD 1� 5 'k.��j L'� ' FAV)i2