ARCHIVED REPORTS_XR0004448 - Laserfiche WebLink

Home Browse Search

' Groundwater Investigation,Monitor Well Destruction and Installation,and Interim Remediation Pump Report Test A ort Boyett Petroleum,419 S.Main 5L,Manteca,CA January 30,2004 Page 5 were collected from HP-2 through HP-5. The depth of each sample interval is noted in Table 1, Section ' 3.5.2. Groundwater samples were collected at discrete depth intervals using a Hydropunch® type groundwater sampling system. A retrievable tip was advanced using 1.75-inch diameter hollow rods. A stainless steel filter screen was attached to the tip. At the desired sampling depth, the rods were retracted exposing the filter screen. Groundwater flowed hydrostatically from the formation into the filter screen. A small diameter bailer was then utilized to collect the groundwater sample through the hollow.rod. The groundwater sample was discharged directly from the bailer into laboratory supplied sample containers. All groundwater sample containers were sealed, labeled, placed in a cooler chilled with ice, and delivered under chain-of-custody procedures to Argon Laboratories, Inc. (Argon) of Ceres, California for analyses. ' The samples were analyzed using U.S. EPA Methods and California-approved methods. The stainless steel bailer, groundwater sampler, and associated push rods were thoroughly steam-cleaned ' prior to each depth advancement and sample collection. Upon completion of the sampling, each boring was grouted from the bottom to the surface with neat cement introduced to the bottom of the boring through the push rods. 1 3.3.2 Soil Sampling Soil samples were collected from borings CPT-3, CPT-4, and CPT-5 from immediately above a continuous clay horizon identified in each boring's geologic log. Soil samples were collected for Iaboratory analyses from CPT-3, CPT-4, and CPT-5 at depths of 24.5, 22.5, and 23.5 feet, respectively. Soil samples were collected using a piston type soil sampler. The soil samples were collected in 1.123- ' inch diameter stainless steel tubes. During soil sampling, the sampler was driven in one-foot intervals. Soil samples were retained undisturbed in the liners. Each sample end was covered with Teflon® sheeting, sealed with plastic end caps, and labeled. All soil samples retained for laboratory analyses were ' stored in a cooler chilled with ice and delivered within 24 hours of collection, under chain-of-custody procedures, to Argon. The soil sampler and associated push rods were thoroughly steam-cleaned prior to the collection of each sample. ' 3.4 LABORATORY ANALYSES Groundwater and soil samples collected from the borings were analyzed for TPH-G by EPA Method ' 8015B, and for BTEX and gasoline oxygenates/additives by EPA Method 8260B. The gasoline oxygenates/additives include MTBE, ethanol (EtOH), TBA, di-isopropyl ether (DIPE), ethyl tertiary- butyl ether (ETRE), TAME, 1,2-Dichloroethane (1,2-DCA), and 1,2-Dibromoethane (EDB). Results of laboratory analyses of groundwater and soil samples collected during the October 2003 investigation are ' presented in Table 1, Section 3.5.2. 3.5 INVESTIGATION RESULTS ' The results of the groundwater investigation include field observations (CPT boring observations, visual inspection of groundwater samples, and detection of sample odors), and laboratory analytical results. 3.5.1 Field Observations No floating product or sheen was observed and no petroleum hydrocarbon odors were noted in the groundwater samples collected during the October 2003 investigation. Borinuc CPT-1 CTT-4 and (-PT-A I • were advanced to depths of approximately 125 feet bgs; CPT-5 encountered refusal and was terminated at a depth of approximately 66 feet bgs. The CPT boring logs indicate an upper soil horizon (surface to approximately 22 feet bgs) dominated by relatively continuous, fine-grained soil types with sandy 1 �� CONDOR