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ENVIRONMENTAL 1+,E-jALT1I DEPARTMENT
<br /> � QUI/y
<br /> QP.... SAN JOAQUIN COUNTY
<br /> Unit Supervisors
<br /> Donna K.Heran,R.E.H.S. g Carl Bor man,R.E.H.S.
<br /> 304 East Weber Avenue;, Third Floor
<br /> Director
<br /> Mike Huggins,R.E.H.S.,R.D.I.
<br /> Al Olsen,R.E.H.S. Stockton, California 95202-2708 Douglas W.Wilson,R.E.H.S.
<br /> FOR�'�P Program Manager Telephone: (209) 468-3420 Margaret Lagorio,R.E.H.S.
<br /> Laurie A.Cotulla,R.E.H.S. , Robert McClellon,R.E.H.S.
<br /> Program Manager Fax: (209) 464-0 38
<br /> Mark Barcellos,R.E.H.S.
<br /> DALE BOYETT MAY 2 9 2093
<br /> BOYETT PETROLEUM
<br /> P O BOX 576277
<br /> MODESTO CA 95357-6277
<br /> Re: BOYETT PETROLEUM Site Code: 1433
<br /> 419 S. MAIN ST.
<br /> MANTECA CA 95336
<br /> San Joaquin County Environmental Health Department(EHD) office met with your consultant
<br /> Condor Earth Technologies,Inc. (Condor) in a meeting on May 15,2003,at the EHD conference
<br /> room. Present at the meeting were Lee Morse,representing Condor;,and Nuel C.Henderson,Jr.
<br /> and Jeffrey Wong representing EHD. EHD and Condor discussed recommendations proposed in
<br /> First Quarter Groundwater Monitoring Report March 2003 (the report),dated Al:ril 3,'2003,prepared by
<br /> Condor,and other concerns EHD has, such as the need for an interim remediation system, survey of
<br /> potential receptors,and delineation of the vertical and horizontal extent of methyl tert butyl ether
<br /> (MTBE) contamination in groundwater. The following is a summary of the meeting.
<br /> 1) Priority should be given to installing an interim remediation system such as a groundwater
<br /> extraction system. Concentrations of MTBE in groundwater has fallen in the two highest
<br /> impacted monitoring wells,MW-7 and MW-1. MW-7 is located approximately 40 feet west
<br /> of MW-1. Based on the MTBE concentration trends in MW-7 and MW-1 since December
<br /> 2000 (see Table 1 below), the consistent groundwater flow direction to the west,and the
<br /> generally sandy geology of the area,the center of the MTBE plume appears to be migrating
<br /> toward the west,potentially off site. The site is considered to be a high priority site for
<br /> MTBE cleanup since the MTBE concentration levels have repeatedly exceeded 10,000 parts
<br /> per billion. Submit a work plan to EHD to install,test and operate an interim remediation
<br /> system to reduce the dissolved MTBE mass and to establish hydraulic control over the
<br /> groundwater contaminant plume by July 1,2003.
<br /> Table 1. MTBE Concentrations in MW-1 and MW-7
<br /> 12/00 01/Ol 03/01 06/01 09/01 12/01 09/02 /000 ;18.33
<br /> MW-1 8,800 NS 15,000 27,000 23,000 13,000 1,700 23,
<br /> 13-33'bs
<br /> DTW NNI 16.15 15.74 17.62 20.46 19.06 21.81 19.33
<br /> MW-7 1,000 NS 2.2 8,300 20,000 26,500 12,000 3,500
<br /> 1 o-25'bs
<br /> DTW �NN�11�6.42 15.98 17.94 19.72 �19-3�221.61 19.98
<br /> All results are in micrograms per liter(µg/1)
<br /> DTW:Depth to Water NM: Not Measured. NS: Not sampled
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