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19.Deceniber 2001 ;f AGE-NU Project No, 95-0128 Page.3 of 12 W 4 -40.feet bsg -TPH-g was not;detected h•a_ny of the grab water.samples collected; but TPH 'd was S F ._ detected in`seVen of.the eight:grab watei samples-at concentrations as high:as-1,200- g/1..'Various' BTEX cornpounds were detected tri the grab water.samples frorri-borings B13,.B14 afid'B17 at _ concentrations.as high as 1'4.micrograms_per.liter(µg/1),benzene was detected onlyin the-sample . y : -collected•from boring B1.3 a:t.a depth of:60"feet bsg; at,a-•concelitration of 0:61-•µg/1 In addition, a } _ MTBE-was-detected in seven-of the,eight-grab,ground water samples collect ed.at:a-.maximum J. concentration of 1,400 µg/ly in sample 1316-H2O TBA was detected in'sampl-eB13 HzOB'at a 14 concentration of46 µg/1 `-r rt On 20 March 2001, groundwater extraction well-EW 1.Was installed at the site for performance of- _ a ground water pumping test.At the.regulatory directive of the EHD a twelve-hour aquifer pump test-' - _wasperformed on 27 March-2001 to assess the general-'grou_rid water aquifer characteristics and to I = assess aqu fer_response to ground water extraction,at a',co_nsOnt pumping-rate utilizing:well EW-1 for ground water extraction and wells°1VIW=1,_MW-2,IMIW 4,MW-5 and-MW-6.andvaporwell:VW- 1 as observation wells::Three groundwater samples were collected from'the extracted ground water, and purged ground water was.containerized in anon-site 6;500 gallon poly tank..The Implications z_ 1 from the March 2001 aquifer-ground water,pumping_test are Ground'water draw=down-of at:least 11.45 feet was oliserved;in'extraction well EW=1" r� -' followin 700 minutes of continuous um in 5'.GP'-Ml • ound water draw=down was- 71 f observed in well-MW,-55 (located 15 feet to the east)'at 1.1 feet,.well MW=4.(lacated 60 feet'"' f , ,. toward fhe sou#heast) at Q l fee A,_well MW-6 (lac'ated 50 feet toward.the north=northwest) t. at'-0 121eet and in welt vapor well,-VW-1 (located 60 feet toward the west} at_0.06 feet - - Utilizing a semi=logarithrnlc plot of.ground water draw down vs observation well distance . 3, _ to pumping.'well, a_bek, re can-.be utilized tot.project a :radius of influence of ; approximately 65 feet at S,GPM Utilizing the I]istance-Drawdown Method,a transmis'sivity s .•. - _ _ -was calculated at 205 ftZ/day.(equivalent to 1,536 gallons-per day/ft) and a storativity value- was-calculated of 0:054 _ - Based on a transmissivity_value of 205.ft2/day and the e extraction well screen thiclaies`s equal . - to 25 ft (screen-interval at; EW.=1},_, a hydraulic: conductivity value was :calculated 61.44.ft/day, or 0.022 cm/s; a hydraulic conductzvxty-of;0.022 -cm/s.is consistent with a { screened interval located within a-well,sorted.sand to'clean`sand ` ` �� Laboratory analysis t,of'extracted dater during the purriping-jest'"detected .elevated.Y- • ` �" tions of TPH BTEX grid MTBE Concentra 4 g, r On 05 and 06 June 2001, four ground water monitoring wells-were-installed off-site as part of the,. •-invesiigafion. Borings MW13 through MW 16 were completed.as ground water monitoring wells-. - £ ' - r Y Adva)fced GeoEnvironmental,Inc S` - f_ '•- _ - _ -'� - A r'-. �1 f'` 1, ''] S. k'• '.-r� -.