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HomeMy WebLinkAboutMITIGATIONTriHydro Corporation 920 Sheridan Street (307) 745-7474 Laramie, Wyoming 82070 FAX: (307) 745-7729 March 31, 2004 Mr. Anthony Medrano California Regional Water Quality Control Board Central Valley Region 3614 E. Ashland Avenue Fresno, CA 93726-3533 RE: Workplan to Conduct Subsurface Investigation and Remediation, Storage Tank 80008, Shell Oil Products US Bakersfield Refinery & Terminal, Bakersfield, California Dear Mr. Medrano, Shell Oil Products US (SOPUS) is the current owner and operator of a petroleum refinery and terminal located at 6451 Rosedale Highway, Bakersfield, California (Figure 1). As reported to you in March 2004, a release of an undetermined quantity of unleaded regular gasoline was discovered as part of tests performed on Tank 80008 (Figure 2). This workplan describes the proposed installation of three soil borings, to be completed as vapor extraction wells, and proposed vapor extraction remediation activities in the vicinity of Tank 80008. This workplan shall follow guidelines established in TriHydro Corporation's (TriHydro's) Master Workplan for Environmental Site Assessment, Shell Bakersfield Refinery, dated February 26, 2004. Further assessment and remediation of the vicinity of Tank 80008 will be performed in conjunction with work outlined in Study Section 4 - Mohawk Tank Farm, of the Master Workplan. Proposed Scope of Work This workplan was prepared to describe soil assessment, well installation, and vapor extraction system C/ES) hookup procedures in the vicinity of the Tank 80008. Because the release point appears to be atthe bottom of the tank, and due to the presence of large piping manifolds near the tank, it is difficult to assess the extent of the release without removal of the tank and its above ground appurtenances. TriHydro is proposing to combine the initial soil assessment with the installation of three vapor extraction wells adjacent to Tank 80008. The wells will be connected by above- and below-grade PVC and steel manifold piping to the Refinery's vapor extraction system located in Area 2. The wells will be opened to the YES in an effort to inhibit lateral and vertical migration of petroleum hydrocarbons, and to begin remediation of' petroleum hydrocarbon-affected soils in the vicinity of Tank 80008. Well Locations and Installation Figure 2 illustrates the proposed locations of the vapor extraction wells. Note that the actual locations of the wells may be altered if obstacles, are encountered during field activities (utilities, above ground impediments, etc.). The proposed wells are to be located along the southeast to southwest edge of Tank 80008. Wells VES-1 and ¥ES-2 will be completed at a depth of 35 feet H:\Projects\SHELL\Bakersfield\Final\O77-O53\WorkplanTank80008.doc Mr. Anthony Medrano March 31,2004 Page 2 below ground surface (bgs) and screened from 5 to 35 feet bgs. Well VES-3 will be completed at a depth of 65 feet bgs and screened from 35 to 65 feet bgs. The wells will be located as close as possible to the 1 '1 O-foot diameter tank to take advantage of the 50 to 70 foot vapor extraction radii of influence typically seen at the Facility. Procedures for permitting, drilling, sampling, logging, field screening, soil sample laboratory analysis, and surveying will be as described in the Master Workplan. The vapor extraction wells will be drilled and installed using a limited access hollow-stem auger drill rig. The vapor extraction well borings will be sampled at depths of 2 feet bgs, 5 feet bgs and at 5-foot intervals thereafter to the base of each boring. Vapor extraction wells will be constructed using 4- inch inside diameter (I.D.) flush-threaded, Schedule 40 PVC blank and slotted casing. A threaded end cap will be placed at the bottom of the PVC slotted casing, which will then be set through the. auger. The screened portion of each well will utilize 30 feet of 0.02-inch machine-cut slotted casing. Number 3 sand will be poured down the auger while removing approximately 3 feet of auger at a time. The filter pack will be placed to a height of 1 to 2 feet above the screened interval, 2 feet of bentonite pellets will be poured through the auger to form an annular seal, and bentonite grout will be tremmied through the auger to a depth of 1-foot bgs. The wells will be tied to the described vapor system by above-grade steel and below-grade PVC piping. Since the wells will be located within the confines of a tank farm, well casings will be extended to approximately 5 feet above ground surface (ags). In addition, a raised protective casing will be installed to prevent entry of surface runoff waters and provide access for future sampling. When a well is added to the extraction well network, a raised platform will be installed adjacent to the well to accommodate required valving and sample ports. Soil Sample Analyses Soil samples will be collected and submitted to Calscience Environmental Laboratories (Garden Grove, California). Selected soil samples will be analyzed for benzene, toluene, ethylbenzene, and xylenes (BTEX) and methyl tert-butyl ether (MTBE) by EPA Method 8260, and total petroleum hydrocarbons as gasoline (TPH-G) by Modified EPA Method 8015. As specified in the Master Workplan, the holding time for these analyses is 14 days from the date of collection. Project Schedule Because of the recent nature of the release, it is advantageous to begin vapor extraction in the near future to reduce potential impacts and overall remediation requirements. As such, SOPUS has already initiated work associated with the implementation of this work plan (procurement of equipment and materials, scheduling drilling activities, etc.) The drilling is expected to commence the week of April 26, 2004. CRWQCB personnel will be kept informed as field work progresses, and notified of possible delays in completing the field activities. H:~Projects\SHELL\Bakersfield~Final\077-053~WorkplanTank80008.doc Mr. Anthony Medrano March 31,2004 Page 3 ReportinR Within 60 days of the receipt of the analytical data associated with sampling during installation of the wells, SOPUS will prepare a brief summary report for the activities for submittal to CRWQCB. The report will include a description of field procedures, well completion information (including borehole logs), copies of well permits, and analytical results. Subsequent vapor extraction operational data will be reported in the quartedy groundwater monitoring report for the entire facility. If you have any questions or need any additional information, please call me at (714) 238-3477. Mark J Passar~CP.,E. ..: cc: Gene Freed, SOPUS Attachments 077-053-004 C:~Documents and Settings~mpassadni\Local Settings\Temporary Intemet Files\OLK1\WorkplanTank800081 .doc 'Oi~ Sump ; ".L.i AREA 1 'SHELL BAKERSFIELD REFINERY AREA 3 0 I i SCALE :Jig J~ 2000 ft. from U.$.G.S. 7.5 MIN. QUADRANGLE GOSFORD, CA 1949. PHOTOREVISED 1969 AND OILDALE. CA 1954. PHOTOREVISED 1968  FIGURE 1 .,.. SITE VICINITY MAP, SHELL BAKERSFIELD, TriHydro REFINERY AND SALES TERMINAL, Corporation BAKERSFIELD, CAL.IFOi~II~ 920 S herman Saeet Laramie, Wyoming 820~0 i Drawn By: BW I Checked By: NB I Scale: AS SHOWN I Date: 03/0B/03 I Ref: 077USGSSITES  FIGURE 2 PROPOSED VAPOR EXTRACTION WELL ~ LOCATIONS, TrtHydro SHELL BAKERSFIELD REFINERY, Corporation BAKERSFIELD, CALIFORNIA 920 Sheridan Street Laramie, Wyoming 82070 EXP/.,4fl,4 T/ON VES-2 PROPOSED VAPOR · EXTRACTION WELL LOCATION 0 80 ft. I I I SCALE e ua y 24, 200 ,..~~, nt Subject: Shell Oil Products US Shell Bakersfield Refinery 6451 Rosedale Highway Bakersfield, CA 93308 Tel +1 661 326 4200 Shell Bakersfield Refinery - Groundwater Remediation Projects; Transmittal of Quarterly Monitoring Reports Dear Mr. Huey: Please find enclosed a copy of the following reports for the groundwater monitoring and remediation projects at the Shell Bakersfield Refinery at located at 6451 Rosedale Highway and 3663 Gibson Street: · 4th Quarter and Annual 2003 Groundwater Monitoring Report; and · 4th Quarter and Annual 2003 NPDES Monitoring Report. The groundwater monitoring reports provide groundwater elevation and groundwater quality data for all areas of the refinery. The NPDES monitoring reports provide additional monitoring and analytical data for two groundwater recovery and treatment systems installed to contain and remediate dissolved hydrocarbons and MTBE in shallow groundwater within the Shell refinery and terminal and the vicinity of Fruitvale and Charity Avenues. If you shoUld have any questions, please call me at 661-326-4351 or Mr. Gene Freed at 661-326-4412. Sincerely, · Steven D. Overman Environmental Department SDO/ C: Gene Freed