ARCHIVED REPORTS XR0000196 - Laserfiche WebLink

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' California Department of Transportation Revised September 23, 1994 Project No 102818-01 Business Enterprise (MBE) participation, Ninyo & Moore used Quality Assurance ' Laboratories as specified in the Caltrans contract agreement. The purge water stored in 55-gallon drums was collected by Ramos Environmental Services on August 15, 1994, and transported under non-hazardous manifest No 93465317 to the Ramos Environmental Services facility located in West Sacramento, California for disposal. A copy of the manifest for the purge water transfer is also presented in Appendix B GROUNDWATER MONITORING WELL ABANDONMENT As part of our field activities, rune groundwater monitoring wells were abandoned at the facility The monitoring wells were abandoned because they are either currently dry or are located within the footprint of proposed new buildings The required monitoring well abandonment permit was obtained from the San Joaquin County Public Health Services Environmental Health Division (PHSEHD) prior to commencement of abandonment and is presented as Appendix C Groundwater monitoring wells MW-1, MW-2, MW-3, MW-4, MW-5,MW-6,MW-7,and MW-8 were abandoned by drilling out the well (including the well casing,well screen,filter pack and annular seal) The excavations resulting from the removal of monitoring wells MW-1 through MW-5 were filled to ground surface with a mixture of neat cement and approximately 5 percent bentonite grout Monitoring wells MW-6,MW-7, and MW-8 were initially backfilled with bentonite chips to approximately 5 feet above the groundwater level and then hydrated with potable water The excavations were subsequently filled to ground surface with a mixture of neat cement and approximately 5 percent bentonite grout Groundwater monitoring well MW-10 was located in the center of a former tank excavation that was backfilled with gravel The gravel backfill extended to a depth of 20 feet below ground surface (bgs) Attempts to drill out the monitonng well were not successful due to the surrounding gravel Accordingly, with the approval of San Joaquin County PHSEHD, groundwater monitoring well MW-10 was abandoned by pressure grouting the well from the bottom to the top with a mixture of neat cement and approximately 5 percent bentonite grout 5