ARCHIVED REPORTS XR0003044 - Laserfiche WebLink

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Chevron Products Company 3 Former Chevron Station #9-5775,.301 Wet Kettleman Lane, Lodi California October 9 2000 SKettleman Lane. This is preliminary data and further evaluation will be performed to verify this data. C&A Orders No. 4 and 5 require you to submit a complete PAR and FRP, respectively. The reports submitted show monitoring wells were screened inappropriately, aquifer parameters have not been tested, and an assessment of petroleum hydrocarbons in soil and groundwater has not been completed. A PAR and an FRP were submitted on July 24, 2000 and August 25, 2000, respectively, in accordance with the C&A Order compliance dates. The Review Problem Assessment Report and Final Remediation Plan attached to the NOV refers to one well (MW -8B) as inappropriately screened. As part of the recent assessment activities, ten groundwater monitoring wells (MW -513, MW -8B, MW- 1OA and B, MW -1 IA and B, MW -12A and B, MW -13, and MW -14) were drilled and installed at the site. Monitoring wells MW- IOA, MW -I IA, MW -12A, MW -13, and MW -14 were drilled and completed to approximately 65 feet bgs. Monitoring wells MW -5B, MW -8B, MW- IOB, MW -11B, and MW- I2B were drilled and completed to approximately 90 feet bgs. Monitoring well MW -8B was screened in a saturated sandy silty clay layer at depths of approximately 85 to 90 feet bgs (SJCEHD was onsite during the installation of MW -8B and approved the completion of the well at this depth). It should be noted that wells MW -5B, MW- 1OB, MW -I IB, and MW- I2B were screened at the same depths as well • MW -8B and that the screens were all placed within a saturated clayey silt to silty clay. In addition, the water levels reported in the deep zone wells were consistent during the three monitoring events in July, with the exception of the most recent data collected on July 24, 2000. After further review of the July 24, 2000 water level data, it appears that the water levels from MW -8A and -8B may have been switched by the sampling technician. This will be confirmed through continued monitoring; the next well monitoring event is scheduled for later this month. An attempt to evaluate aquifer parameters was performed by pumping from well EX -1 on August 7, 2000; however, as stated in the FRP, construction activities at the site made nearby monitoring wells inaccessible, and thus measurement of water levels in nearby wells not possible. Additionally, SECOR in June 2000, requested approval from the RWQCB to pump from other extraction wells onsite to evaluate aquifer parameters; however, the RWQCB did not approve pumping of additional wells at this time thereby limiting capture zone analysis to well EX -1. Upon receipt of RWQCB approval to pump from other extraction wells onsite (August 23, 2000), and when access was available, wells EX -1 and MW-14/EX-2 were re -developed. Capture zone evaluation on wells MW-141EX-2 and EX -1 (after re -development) was performed in early October 2000. Analysis of the capture zone data is currently ongoing. As stated in the FRP, an addendum to the FRP will be prepared once this evaluation is complete (expected to be during the 1 st week of November). Preliminary water level data • collected on October 5, 2000 suggests that extraction from wells EX -1 and MW-14/EX- 077,41991.043/October 9, 2000.doc