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, <br /> I <br /> I <br /> !E' C ® R <br /> i <br /> iMr Michael Infurna <br /> July 23, 2003 <br /> Page 3 <br /> I <br /> screen will be placed in the bottom of the boring threaded to blank pipe to extend above the ground <br /> surface A diagram of a temporary well constructed to a soil boring is presented as Figure 3 �{'+ <br /> Locations maybe modified based on field conditions observed during fieldwork Following collection <br /> of a representative sample, the temporary well casing will be removed and the soil boring will be {, <br /> backfilled in compliance with SJC-EHD requirements <br /> Groundwater Sampling ; <br /> Dedicated polyethylene tubing and a peristaltic pump or a disposable bailer will be used to sample <br /> each the temporary well Groundwater will be placed in laboratory supplied glassware Sample ; <br /> handling techniques are described in Attachment 2 Select samples will be submitted under chain- ;a <br /> of-custody manifest to a California State-certified laboratory and analyzed for the presence of <br /> petroleum hydrocarbons as described above <br /> Monitoring Well Installation <br /> Up to four hollow stem auger soil borings will be advanced to depths to be determined using <br /> analytical data from the temporary wells Following drilling, the boreholes may be backfilled to is <br /> approximately 25 feet bgs depending on the depth of drilling, and a two-inch diameter groundwater ; <br /> monitoring well will be installed at each location and screened across the bottom ten feet of the <br /> boring Field and laboratory procedures are presented as Attachment 2 A well construction <br /> diagram is presented as Figure 4 <br /> To ensure adequate yield, a slot opening of 0 020 inches has been selected corresponding to a <br /> medium to coarse sand in conjunction with graded number 2-filter pack Sod samples will be <br /> collected and logged continuously from each boring beginning from five feet bgs Field and <br /> laboratory procedures are included as Attachment 2 l`< <br /> , s <br /> Soil Sampling <br /> t <br /> Soil samples will be screened, through each 5-foot interval for the presence of petroleum <br /> hydrocarbons during hand auguring Screening with a photo-ionization detector will allow for <br /> selection of discrete interval samples to be analyzed <br /> 4 <br /> Positive screening results, suggesting hydrocarbons are present, will be used as a criteria for <br /> selecting sod samples for laboratory analyses Up to two intervals will be selected for analyses using <br /> screening criteria If screening suggests that no petroleum is present, then one sample will be <br /> collected at the capillary fringe At each selected sample interval, soil from cuttings or an impact <br /> sampler will be placed in sealable glass jars, or in brass liners and capped with Teflon squares and <br /> plastic end caps, and sealed in clean zip-lock bags Sample handling techniques are described in <br /> Attachment 2 Select samples will be submitted with a chain-of-custody record to a California State- <br /> certified laboratory and analyzed for the presence of petroleum hydrocarbons described above <br /> Monitoring Well Development and Sampling <br /> Following installation, the monitoring well cement seals will be allowed to cure for 48-hours, then <br /> ieach well will be developed by rigorously surging the well over the length of the screen interval and <br /> I 1Chevron11001621\REPORTS\200312003 Site Assessment MPRevO doc SECOR International incorporated <br />