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Vicki McCartney [EH] <br /> From: Jim Barton Obarton@waterboards.ca.gov] <br /> Sent: Friday, February 17, 2006 6:32 AM <br /> To: Vicki McCartney[EH] <br /> Cc: Nuel Henderson [EH] <br /> Subject: Re: FW: Requested Jimco Truck Plaza Report <br /> Thanks Vicki, <br /> Re: your last paragraph/question: I received a similar question on vapor intrusion <br /> yesterday from Nuel re: where's the guidance? I will get back to you on the soil vapor <br /> guidance question ASAP and fwd it to both of you. FYI - I am attending a three day State <br /> all-staff cleanup roundtable the first week of April that will cover "all pathways" risk <br /> assessments and vapor intrusion. More to follow. Thanks. <br /> Jim <br /> James L.L. Barton, P.G. <br /> Engineering Geologist <br /> California Regional Water Quality Control Board <br /> Central Valley Region, <br /> 11020 Sun Center Drive, Suite 200, <br /> Rancho Cordova, CA 95670 <br /> office (916) 464-4615 <br /> fax (916) 464-4704 <br /> >>> "Vicki McCartney [EH] " <vmccartney@sjcehd.com> 2/16/2006 3 :31 PM >>> <br /> Jim, <br /> I am forwarding a chromatogram for a groundwater sample collected from monitoring well MW- <br /> 1 at the Jimco Truck Plaza site in Ripon, California, along with chromatograms I requested <br /> from McCampbell Analytical, Inc. for the instrument method blank, motor oil standard, <br /> overlay of the sample with the diesel standard, and an instrument blank. The first <br /> attachment is the chromatogram for the sample (file 11170513 .D) analyzed on November 17, <br /> 2005, at 5:16 pm. The second chromatogram is for the method blank associated with this <br /> sample (file 11150521.D) analyzed on November 16, 2005 at 12 :14 am. As you can see, this <br /> method blank was analyzed 41 hours prior to analyzing the sample. The third chromatogram <br /> is for motor oil. I believe this chromatogram is taken from running a curve on this <br /> instrument on April 26, 2005 (seven months prior to analyzing this sample) . The fourth <br /> attachment shows the sample chromatogram overlaid.by the diesel continuing calibration <br /> standard chromatogram (file 11170501.D) . It appears to, me that the sample fingerprint <br /> matches the diesel fingerprint quite well. The last attachment is an instrument blank <br /> (file 11170505.D analyzed eight positions prior to analyzing the sample. The consulting <br /> firm would like to stop analyzing groundwater samples collected from MW-1 for motor oil <br /> since the sample chromatogram appears to match the diesel standard. My concern is that I <br /> do not have a current motor oil standard chromatogram to compare with the sample <br /> chromatogram. The laboratory spokesperson stated in a different e-mail that the GC-FID <br /> instrument is very stable as verified by the diesel CCV and no major maintenance has been <br /> performed on the instrument since April 2005. This statement was in response to my <br /> concern about whether the column had been cut or any maintenance done on the instrument <br /> that would cause a retention time shift. Should I accept that there is no motor oil found <br /> in the groundwater sample without comparing the sample chromatogram to a current motor oil <br /> chromatogram? Please present this question to your chemist. <br /> Unrelated to the above I n uidance when requesting that a responsible party assess <br /> the threat of vapor inton�iia building. Exactly what must be done to evaluate this <br /> threat? Must air samples be collected? If so, how many and must the air samples be <br /> collected in a summa canister and sent to an air lab and analyzed by air methods as <br /> opposed to using water methods? <br /> Thank you, Jim. <br /> San Joaquin County <br /> 1 <br />