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APPENDIX D: <br /> FIELD, SAMPLING,AND ANALYTICAL METHODS <br /> D.1 DRILLING <br /> From March 17 through April 1,2008,29 soil borings (SB-1 through SB-29)were advanced to total <br /> depths ranging from 12 to 40 feet bgs. The borings were advanced using direct-push equipment equipped <br /> with 4-foot acetate liners to collect soil samples. <br /> The completion of soil borings generally conformed to SAIC Field Technical Procedure(FTP)No. 525, <br /> "Soil Sampling Using an Auger." In accordance with the approach prescribed in the Second Draft <br /> Revised Technical Approach to Site Evaluation and Decision Making, Old Valley Pipeline Sites <br /> (Geomatrix, 2005), and to the extent practicable, SAIC attempted to collect soil samples from the target <br /> depth. <br /> The samples were screened using photoionization detection equipment,using procedures consistent with <br /> SAIC FTP No. 750, "Field Measurement Procedures--Organic Vapor Detection,"to detect the presence <br /> of residual petroleum in soil. The soil was logged in general accordance to the Unified Soil Classification <br /> System as presented in American Society for Testing and Materials (ASTM)2488-90 under the <br /> supervision of a California Professional Geologist. Other information was entered into field logbooks to <br /> document where,when,how, and from whom any vital project information was obtained,using <br /> procedures described in SAIC FTP No. 1215,"Use of Field Logbooks." <br /> Each open borehole was plugged and abandoned following completion of the soil borings according to <br /> San Joaquin County Health Services Department requirements. <br /> D.2 SOIL SAMPLING <br /> Soil samples were collected into U.S. Environmental Protection Agency(EPA)-approved containers and <br /> submitted to a California-certified laboratory,Lancaster Laboratories(Lancaster)under SAIC chain-of- <br /> custody protocol and analyzed for the constituents of concern(COCs). <br /> SAIC also collected soil samples from less than 10 feet below ground surface for use in a human health <br /> risk assessment. Soil samples collected for the risk assessment were analyzed for the COCl. Refer to <br /> Appendix E,Data Usability Summary and Laboratory Reports for more information. <br /> D.3 GROUNDWATER SAMPLING <br /> Pre-packed well screens were installed in the borehole after drilling to total depth. The pre-packed well <br /> screens,manufactured by Geoprobe Systems,were installed in general conformance with ASTM <br /> Method D6725-04. The pre-packed well screens were constructed of 1 inch-diameter, 0.010-inch, <br /> machine-slotted polyvinyl chloride well casing packed with 20/40 mesh sand and encapsulated with a <br /> stainless steel screen. The external diameter was 2.5 inches. SAIC collected grab groundwater samples <br /> into EPA-approved containers using a ball-check valve and disposable tubing. Groundwater parameters <br /> such as temperature,pH, electrical conductivity, and turbidity were measured during purging. After <br /> purging the well casing,groundwater samples were decanted into laboratory-provided bottles, labeled, <br /> and placed in an ice-cooled chest pending analysis by Lancaster. <br /> DA SAMPLING LOCATIONS/SURVEY METHODS <br /> Soil borings were geo-spatially located using a global positioning system(GPS)unit. The GPS survey <br /> methods were consistent with SAIC FTP No. 175, "Field Measurement of Physical and Topographical <br /> Features." <br /> D-1 <br /> _.:::: <br /> M=FJ'21`® <br /> from serence to solutions <br />