ARCHIVED REPORTS_XR0002632 - Laserfiche WebLink

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1 risks and the appropriate precautions required to reduce such risks All field personnel present signed the Attendance List in the Health and Safety Plan acknowledging that a Health and Safety meeting was held V&W Drilling Company, drilled and constructed the monitoring wells V&W used a truck-mounted drill rig, equipped with 8 25-inch outside diameter (OD) hollow-stem auger Down-hole equipment was decontaminated by steam cleaning after each borehole was completed The cuttings generated by the auger were stored in 55-gallon drums pending analytical results to determine their appropriate final disposition R During drilling activities a lithologic description of soils encountered were made by a State of California Registered Geologist Descriptions recorded during sample logging were in accordance with the Unified Soil Classification System (USCS) as outlined in ASTM Standard Method D2487 Boring logs are included in this report as Appendix IV After the borings were completed, they were converted to 2-Inch groundwater monitoring wells 4.4 Monitoring Well Installation Following the drilling of the borings, six single-cased groundwater monitoring wells were constructed (per the attached workplan dated October 19, 1999, Appendix II) on February 11, 2000 The wells were constructed of 2-inch inside diameter (I D ), flush threaded, schedule 40 PVC casing All wells were constructed in accordance with standards for exploratory wells contained in the California Code of Regulations, Title 12, Chapter 15, Article 8 (Well Construction and Licensing of Well Drillers) and its associated revisions The 2-inch solid casing was connected at the bottom with fifteen feet of machine-slotted, schedule 40 PVC screen Therefore, there was five feet of solid casing with 15 feet of screen The top of the screened interval was set i approximately 2 feet above the water level inside the borehole to account for potential water level fluctuations The screen slot size for all monitoring wells is 0 010 inches A filter pack consisting of clean, washed, Monterey sand was placed from the bottom of the screen to about one foot above the screened interval Above the filter pack, the annular space was filled with a bentonite pellet seal measuring two feet in thickness The remainder of the annular space was backfilled with a cement grout mixture containing less than 5% bentonite powder Finally, a cement pad and traffic rated, water-tight, bolt-down surface flush mount vault i box with locks, were set around the top of the PVC well casing Avalon Environmental Consultants 9627-001-2 Joes Truck Plaza 15600 South Harlan Road March 20, 2000 S Lathrop, Caltfornia I