SITE INFORMATION AND CORRESPONDENCE FILE 1

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t ' October 1, 1997 Page ') As previously requested, the proposed onsite boring will be completed as a soil vapor extraction(SVE) well. The well will be constructed as follows: The boring will be converted into an SVE well by installing 3-inch diameter, flush- threaded, Schedule 40 PVC casing with 0.040-inch factory-slotted screen. The depth to groundwater is currently (as of May 1997) approximately 27 feet bgs. Approxi- mately 15 feet of screen will be placed across the most significantly impacted interval within the vadose zone, as determined in the field (anticipated to be approximately 12 to 27 feet bgs). An RMC Lonestar Medium Aquarium sand pack, or equivalent, will be placed in the annular space across the entire screened interval, and will extend approximately 2 feet above the top of the screen for the well. A bentonite and Portland cement seal will extend from the sand pack to the ground surface. A boring log will show well construction details. The SVE well may be tested at a later date for the feasibility of SVE at the site if it is determined that active remediation of the vadose zone is necessary. 2. On August 1, 1997, the field work was scheduled by Chevron's consultant Pacific Environmental forAugust 8, 1997. On August 8, 1997, after afield visit had been made and no drill rig observed, Pacific Environmental left a telephone message indicating that drilling had been postponed. There has been no further communication regarding the site or the scheduling of the proposed field work. Fieldwork must be scheduled to complete the investigation by October S, 1997, in order to avoid further enforcement action. Difficulties in scheduling a limited access drill rig and in gaining clearance by utility companies lead to several scheduling delays. The drilling is now scheduled with Spectrum Exploration, Inc. of Stockton, California, for Monday October 6, 1997. We understand from our conversation with you that the scheduled field date is agreeable to you and that no enforcement action will be taken. As requested, new drilling permit applications and a check for$178 for this work are enclosed. Analytical results should be available approximately 2 weeks from that date, on October 20, 1997. A report documenting the findings of the investigation is anticipated to be submitted approximately 4 to 8 weeks after the commencement of field work. 3. Also, a corrective action plan must be submitted by December 30, 1997 which includes the elements outlined in the California Code of Regulations, Underground Storage Tank Regulations. As requested, a corrective action plan will be submitted by December 30, 1997. 920-078.1 A/WPLANADD.DOC