Laserfiche WebLink
SECOR www.secor.corn <br /> S E C O R INTERNATIONAL <br /> PORAT <br /> INCORPORATED 3017 Kilgore Road,Suite 100 <br /> Rancho Cordova,CA 95870 <br /> 916-881.0400 TEL <br /> r.;,..� 916-861-0430 FAx <br /> April 5, 2004 <br /> Mr. Michael Infurna I`- f'�1_ ' 1V FD <br /> 1, <br /> San Joaquin County Public Health Services <br /> Environmental Health Division APR O 7 2004 <br /> 304 East Webber Avenue, Third Floor <br /> Stockton, CA 95202 <br /> �.i�ivl�;.til� + d1 HEALTH <br /> Re: Work Plan for the Reinstallation of Well MW-13 <br /> 76 Service Station (Former BP) 11195 <br /> 16500 South 1-5 <br /> Lathrop, California <br /> Dear Mr. Infurna: <br /> SECOR International Incorporated (SECOR) has prepared this letter on behalf of ConocoPhillips to <br /> present a work plan to reinstall well MW-13 at the site referenced above (Figures 1). During the first <br /> quarter 2004 quarterly monitoring and sampling event, ConocoPhillips sampling contractor (TRC) <br /> noted that the well had been damaged. During examination of the well by SECOR personnel, it <br /> appeared that the well, completed above-grade with a stove pipe finish, had been run over. The <br /> stove pipe was completely bent over and it appeared that several feet of well casing had come up the <br /> borehole compromising the well seal. The work plan includes a brief discussion of site background <br /> and previous investigations, proposed scope of work, and schedule. <br /> SITE BACKGROUND AND PREVIOUS INVESITGATIONS <br /> A retail gasoline outlet has been located at the subject site since at least 1983. BP Oil Company (BP) <br /> acquired the site from Mobil Oil Corporation in 1989, then sold the site to Tosco in 1994 (Alisto, <br /> Additional Site Investigation Report, dated January 25, 1999). <br /> Five onsite groundwater monitoring wells (MW-1 through MW-5)were installed in December 1992. Soil <br /> samples collected from the well borings were reported to contain petroleum hydrocarbons at <br /> concentrations of up to 120 parts per million (ppm) of Total Petroleum Hydrocarbons as gasoline <br /> (TPHg), and 16 ppm of benzene. The initial groundwater samples collected from wells MW-3 and <br /> MW-4 contained concentrations of up to 10,000 parts per billion (ppb) of TPHg (Alisto, 1999). <br /> Two additional wells (MW-6 onsite and MW-7 offsite) were installed in September 1993. Soil samples <br /> collected at a depth of 6 feet below ground surface (bgs) were non-detect for petroleum hydrocarbons <br /> (Alisto, 1999). <br /> One 550-gallon fiberglass waste oil UST and associated remote fill line were removed in 1997. One soil <br /> sample was collected from the bottom of the waste oil UST excavation at 10 feet bgs. A second soil <br /> sample was collected from beneath the remote fill line at 3 feet bgs. Both samples were non-detect for <br /> petroleum hydrocarbons (GeoStrategies, Waste Oil UST and Remote Fill Line Soil Sampling Report, <br /> dater)August 6, 1997). <br /> In July 1998, an abandoned water well, located north of the former UST pit adjacent to Louise Avenue, <br /> was properly destroyed. The well was destroyed by perforating the steel casing and grouting the well <br />