REMOVAL_2008 CLOSURE IN PLACE - Laserfiche WebLink

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` K L E I N F E L D E R L 2. Soils were noted to be primarily light brown silty sands and sandy silts from near surface to approximately 12 feet bgs underlain by olive brown silty clays from approximately 12 feet bgs to the total explored depth of approximately ` 15 feet bgs. 3. Two soil samples were collected at each of the four test pits at depths of Lapproximately 8 and 15 feet bgs. The 8 foot samples were collected near the estimated center of the five UST, Nos. 1 through 5, and the 15 foot samples were collected approximately 1 foot beneath the estimated base depth of the five asphalt oil USTs. The observed depths during the exposure of the ends of UST Nos. 4 and 5 appears to confirm the reported diameter (10 '/z feet) and total depth (approximately 14 feet bgs) of the USTs. L 4. Total extractable petroleum hydrocarbons and BTEX constituents were not detected at or above laboratory reporting limits. Reporting limits were not Ir found to be elevated and were consistent with typical reporting limits in the industry for the requested compounds. 6, 5. Based on observation of soils during test pit excavation and the soil sampling results, it does not appear that the requested petroleum constituents have impacted soil at the locations and depths sampled. Based on this data and L information and the exempt status of asphalt oil tanks, Kleinfelder does not recommend further soil sampling and analyses related to the five UST, Nos. 1 L through 5. 6. Kleinfelder recommends abandoning UST Nos. 1 through 5 in place using a L concrete and sand slurry after receiving approval from EHD. 7. Kleinfelder recommends informing EHD of Granite Construction's desire to receive a closure letter for these USTs from EHD. Granite Construction ` should forward this report and the proposed abandonment methodology for the five USTs to EHD for their review and comment. ` This report, and the conclusions and recommendations presented in this report are subject to the "Limitations" presented below. Any other party Granite Construction Company or regulatory agencies having enforcement jurisdiction for this site who would ` like to use this report shall notify Kleinfelder, Inc. in writing of such intended use. LIMITATIONS L Kleinfelder has prepared this report in accordance with the generally accepted standards of care which exist in San Joaquin County at the time of writing. It should be L recognized that definition and evaluation of geologic and chemical subsurface conditions is difficult. Judgments leading to conclusions and recommendations are L 90163.T03BT07R1061 January 3,2008 ©2007 Kleinfelder Page 5 of 7 L