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Additional Soil and Groundwater Investigation and _ Monitor Well Installation Report : CSUS Multi-Campus Regional Center January'11,2002 ` m Page 4 E a ' Soil samples were collected from borings GP-6 through GP-9.with a l.5-inch:O.D., 2-foot long, core . barrel, fitted with a clean., single use, polyethylene liner. The soil-sampling equipment was cleaned prior `-to collecting each sample by washing the sampling spoon in °a solution of laboratory-grade, non- phosphate detergent and dcionized water, and double-rinsing with de-ionized water.. During the sampling of GP-6 through GP-9 the core barrel was driven In 5-foot'interv'als. After the core barrel was driven three feet, the conical tip was withdrawn and the core barrel was driven an additional 2 :.feet, resulting in a 2-foot sample"at five-foot.intervals-ne sample liner was extracted from the core barrel and used for geologic logging and field observations. All soil samples were logged according to the :Unified Soil Classification System (USCS). Geologic logs were prepared containing field observations ;including soil type, estimated:moisture content, photoionization detector (PID) measurements, and the ..presence of staining or odor. The geologic logs are included in Appendix B. Each soil sample selected for potential laboratory analyses was-cut from the liner. The soil samples were retained, undisturbed, in the liners. The liners were scaled at the ends with Teflon® sheeting, capped, and 'labeled. The samples were stored in a cooler chilled with Blue Ice® and delivered under chain-of custody procedures to Excelchem Environmental Laboratories, Inc.' (Excelchem) of Roseville, California. The samples were analyzed using U.S.EPA Methods and California-approved methods. 3.3.2 Discrete Depth Groundwater Sampling During the soil and groundwater investigation conducted in December 2000, groundwater was.first encountered in soil,borings at depths ranging from.41 to 44 feet. Groundwater rose 'in the.borings to a 1 depth of approximately 35 feet. Based on the results of the previous investigation and the'CPT boring logs, discrete depth groundwater grab samples were collected from three depth intervals from direct push { Sample Point borings advanced adjacent to the CPT borings. The depth of each sample interval is noted in Table 3, section 5.2. . Groundwater samples were collected.using a push-type groundwater sampler. The sampler has a sealed, - retrievable stainless steel screen. The,sampler was pushed in •a closed`'position to the desired sampling interval. The sampler push rod was then_ retracted exposing approximately,-four feet .of inlet screen. Groundwater flowed hydrostatically from the formation into the,inle't screen. A groundwater sample was retrieved from within the screen with a length of clean, 318-inch diameter polytygon tubing with a check valve at the bottom. The tubing was pumped up and down by hand to draw groundwater up the tubing. The groundwater sample was discharged directly from the tubing. into laboratory supplied sample containers. All groundwater sample containers were:sealed,aabeled, and placed in a cooler chilledwith Blue Ice® and delivered under chain-of-custody procedures-to Excelchem. The samples were analyzed using U.S. EPA Methods and California-approved methods. 3.4 LABORATORY ANALYSES . The groundwater samples collected from the borings were analyzed for total petroleum hydrocarbons quantified as gasoline (TPH-G) and total petroleum hydrocarbons (TPH)"quantified as kerosene, diesel, and motor oil by EPA Method: 8015M; .for BTEX by EPA Method -8020; :and. for gasoline �.. oxygenates/additives by EPA Method 8260. The gasoline oxygenates/additives include methyl to""rtiary- Butyl Ether (MTBE), ethanol, tertiary-Butanol, Di-isopropyl ether (DIPS), Ethyl tertiary-Butyl Ether (ETB.E), tertiary-amyl Methyl.Ether (TAME), ethylene dibromide (EDB), and 1,2-dichloroethane (1,2- DCA). CONDOR { a