Laserfiche WebLink
1 <br /> ti <br /> Mr Ronald Rowe <br /> August 17, 1999 <br /> CAMBRIA <br /> Soil samples were collected from the wells Figure s <br /> 1� TPHg Concentration in Sad vs Depth <br /> and borings as deep as 41 ft below grade As 960 I <br /> indicated in Figure B, the highest hydrocarbon E e00 _ • - E <br /> concentrations near the former tanks occurred 660 — - • - - <br /> e soo <br /> at about 26 5 ft depth This corresponds to dust b 400 <br /> 300 -- <br /> above the water table at the time of sampling o zoo - <br /> The highest hydrocarbon concentration U 700 • • <br /> pp mE 0 10 2oDepthiit)30 40 50 <br /> detected below the water table was 36 in <br /> well MW-2 at 41 ft depth Therefore, it - -- - - <br /> appears that the water table limited downward migration of hydrocarbons in sorbed phase <br /> SPH Distribution <br /> As indicated in Figure C, up to 4 48 ft of free Figure C <br /> product was initially detected in SPH Thickness(Well MW-2)well MW-2 s 00 __ _ _ _ _ eo <br /> Lesser product thickness was detected in wells 40070LtI <br /> 70 <br /> so <br /> MW-3, MW-4 and MW-7 The estimated3 00 50 E <br /> 40 <br /> distribution of free product is shown on a20oaofigure in Attachment B 06 200 <br /> There was no product thickness data In our a°°0OP-Pd&41 omg1IgP0 eC°' 9h�°I 0Fp4A<5P4b <br /> files between August 1990 and April 1992 and ©SPM -GW E -Top of Screen- <br /> groundwater elevation was not calculated in early reports for wells containing free product (see <br /> data tables in Attachment Q The data tables merely indicate that free product was detected in <br /> the wells We have assumed a product thickness of l ft for this time interval for well MW-2 as <br /> shown on Figure C <br /> I <br /> No free product has been detected since February 19, 1993, after the SVE and product skimming <br /> had been in effect As indicated in Figure C, the water table was well below the top of well <br /> screen elevation until May 21, 1998 Therefore, if free product were in the formation, we should <br /> have observed some measurable product in the well Since no product was observed after <br /> February 19, 1993, it is likely that the product has been removed by a combination of bailing, <br /> skimming, and SVE <br /> Hydrocarbon Distribution in Groundwater <br /> The highest hydrocarbon concentrations in groundwater are found in the same area where free <br /> product was detected The highest TPHg concentration detected was 490,000 ppb in well MW-4 <br /> 3 <br />