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v Preliminary investigation and Evaluation Report
<br /> CSUS Multi-Campus Regional Center
<br /> February 7,2001
<br /> Page 2
<br /> 3.0 FIELD AND ANALYTICAL METHODS
<br /> L. This section includes a description of the site preparation, direct push boring installation procedures, soil
<br /> and groundwater sampling methods, and laboratory analytical methodology for the soil and groundwater
<br /> investigation.
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<br /> 3.1 SITE PREPARATION
<br /> A drilling permit application was prepared by Condor and submitted to the San Joaquin County
<br /> �- PHSIEHD for the five proposed soil borings. Condor received the drilling permit prior to initiating any
<br /> fieldwork. The proposed soil boring locations were marked with white paint and Underground Service
<br /> Alert(USA)was notified 72 hours in advance of the fieldwork to locate and identify underground utilities
<br /> 6.0 in and near the work area. However, because the proposed boring locations were on private property,
<br /> utilities contacted by USA did not mark their lines past property boundaries and on to the site. Therefore,
<br /> it was the responsibility of the property owner to locate and identify underground utilities in and near the
<br /> work area. The PHSLEHD was notified of the fieldwork schedule 72 hours in advance.
<br /> 3.2 GEOPROBE®PROCEDURES
<br /> i.. A Condor geologist was on site to supervise the work. Prior to commencement of fieldwork, a tailgate
<br /> safety meeting was held and a site-specific Health and Safety Plan was discussed with, and presented to,
<br /> all field personnel for their signatures.
<br /> The investigation included the advancement of five direct push soil borings (GP-1, GP-2, GP-3, GP-4,
<br /> and GP-5) using a Geoprobe® boring and sampling system. The boring locations are shown in Figure 2,
<br /> 4 N..W Appendix A. Borings GP-1 through GP-5 were advanced to depths of approximately 42 feet, 41 feet, 44
<br /> feet, 41 feet, and 41 feet below ground surface (bgs), respectively. The Geoprobe® borings were
<br /> hydraulically advanced using a 2-inch diameter conical bit. The bit and associated push rods were
<br /> thoroughly cleaned before each borehole was advanced using laboratory-grade, non-phosphate detergent
<br /> and de-ionized water and double-rinsed with de-ionized water. Upon completion of the drilling and
<br /> sampling, the boreholes were backfilled with neat cement. The cement was tremied into the boreholes to
<br /> avoid bridging.
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<br /> 3.2.1 Soil Sampling
<br /> The Geoprobeg borings were advanced to the depth at which groundwater was first encountered
<br /> (approximately 41 feet bgs during the field activities). Soil samples were collected in GP-I at
<br /> approximately 10.5, 18, and 36 feet bgs, in GP-2 at approximately 21., 31, and 41 feet bgs, in GP-3 at
<br /> approximately 16, 21, 26, 31, 36, and 44 feet bgs, in GP-4 at approximately 16, 21, 26, 31, 36, and 41 feet
<br /> *' bgs, and in GP-5 at approximately 16, 21, 26, 31, 36, and 41 feet bgs.
<br /> } Soil samples were collected from boring GP-I with a 1.75-inch O.D., 4-foot long, core barrel, fitted with
<br /> a clean, single use, polyethylene liner. Soil samples were collected from borings GP-2 through GP-5 with
<br /> a 1.75-inch O.D., 2-foot long, core barrel, fitted with a clean, single use, polyethylene liner. The soil
<br /> sampling equipment was cleaned prior to collecting each sample by washing the sampling spoon in a
<br /> rr solution of laboratory-grade, non-phosphate detergent and deionized water, and double-rinsing with de-
<br /> ionized water.
<br /> La During the sampling of GP-1 the core barrel was driven in 4-foot intervals. The sample liner was
<br /> extracted from the core barrel and used for geological logging and field observations. During the
<br /> sampling of GP-2 through GP-5 the core barrel was driven in 5-foot intervals. After the core barrel was
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<br /> L. J CONDOR
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