Laserfiche WebLink
i <br /> Mr Bob Fratto <br /> November 16, 1995 <br /> Page 2 <br /> increase in aquifer recharge after very wet winter and spring Water-level data are shown in <br /> Table 1 Historical groundwater flow directions and gradients are shown in Table 2 <br /> Analytical results of the groundwater samples for this and previous quarters are summarized in <br /> Table 3 The August 31, 1995 analytical results are shown on Figure 1 Laboratory reports are <br /> included as Exhibit A Analytical results did not identify any BTEX, TPH-G, or TPH-D <br /> compounds in any of the groundwater samples TPH-MO was detected in the groundwater <br /> sample collected from MW-1 at a concentration of 340 micrograms per liter (pg/L) The <br /> laboratory report indicates that the motor oil range pattern is typical of plasticizers or polymeric <br /> resins A laboratory representative was contacted and he explamed the chromatograph <br /> illustrates discrete peaks of polymers, rubbers or plastics, not motor oil The sample could have <br /> been contaminated by minute pieces of PVC that the well is constructed The sample volume <br /> did not contain enough water to reanalyze <br /> Discussion <br /> Concentrations of BTEX and TPH-G are below detectable levels this quarter Detectable <br /> concentrations of TPH-MO have been identified in the groundwater sample collected from well <br /> MW-1 This is the second time since sampling was initiated in May, 1994 that constituents in <br /> the motor oil range have been detected in groundwater at this site The analytical laboratory <br /> report qualifies the motor oil range pattern is typical of plasticizers or polymeric resins and may <br /> be a false positive A database file search indicated that several sites exist up-gradient that may <br /> potentially be off-site sources of petroleum hydrocarbons constituents Additional investigation <br /> of these potential off-site sources is continuing into the fourth quarter 1995 <br /> If you have any questions regarding this report, please contact me at (916)444-0123 <br /> Sincerely, <br /> BROWN AND CALDWELL <br /> at G Cul en, R G #4932 <br /> Project Manager <br /> TMB ksc <br /> Enclosures <br /> cc Mr Steve Sasson, San Joaquin County Environmental Health Department <br /> Use or disclosure of data continued on this sheet is subject to the restriction specified at the beginning of this <br /> document <br /> 1422,REPORTSU5QTR RMRD95QTR DOC <br />