Laserfiche WebLink
l <br /> CH2M HILL . <br /> 1111 Broadway <br /> 1 1; P.O.Box 12681 <br /> f <br /> Oakland,CA <br /> CH2MHILL J 1 r 94604-2681 <br /> rIl Qf <br /> Tel 510.251.2426 <br /> Fax 510.893.8205 <br /> March 1,2000 <br /> 131420.A1.08 <br /> Ronald Rowe <br /> San Joaquin County Public Health Services <br /> LOP/Site Mitigation Unit <br /> Environmental Health Division <br /> 304 E. Weber Ave.,Third Floor <br /> Stockton,CA 95202 <br /> Subject: Disco Site-Additional Investigation <br /> 110 Filbert Street,Stockton California <br /> Dear Mr. Rowe: <br /> As per your phone message of March 1,2000, this letter serves as a final proposal for <br /> {. borehole locations for the additional CPT investigation at the Disco site,located at 110 <br /> Filbert Street,Stockton,California. <br /> In concurrence with your recommendation,we are proposing to install 6 additional CPT <br /> borings at locations shown on the attached figure. The purpose of the borings is to assess the <br /> extent of petroleum hydrocarbons downgradient, and cross-gradient from the site. Four <br /> borings shall be installed on the shoulder of the south side of Highway 4,downgradient and <br /> across the freeway from previous borings CPT-6,-7,and—8. One additional boring shall be <br /> installed east of CPT-8,on the north shoulder of Highway 4. Each of these borings will be a <br /> maximum of 130 feet deep,and two groundwater samples will be collected from each <br /> boring. One groundwater sample will be collected from the zone around 75 ft bgs and one <br /> sample will be collected from a deeper zone(exact depth will depend upon the lithologic <br /> logs). One additional boring shall be installed onsite,between boring CPT-5 and monitoring <br /> well MW-DIS-9.Groundwater samples will be collected from the zone around 100 ft bgs <br /> and one sample will be collected from a deeper zone (exact depth will depend upon the <br /> lithologic logs).We will follow the same sampling methodology outlined in the October 8, <br /> 1999 "Work Plan for Additional Investigation at the Disco Property", (CH2M HILL,October <br /> 1999). <br /> All groundwater samples will be analyzed for the following: <br /> • TPH-gas/BTEX,by EPA Method 8015M <br /> 0 Oxygenates, 1,2-DCA,and EDB by EPA Method 8260 <br />