ARCHIVED REPORTS XR0001587 - Laserfiche WebLink

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. BID SPECIFICATIONS 1) Permitting and Pre-Field Activities The bidder must prepare a workplan, a boring permit application, a proposed boring location map, and health and safety plan for submittal to SJCEHD. The permit must be approved prior to drilling the borings. Following obtaining approval from the SJCEHD, Bidder will commence the actual field assessment. 2) Drilling of Soil Borings and Monitoring well Installation Four (4) soil borings will be advanced to depths of approximately 40 to 55 feet below surface grade (bsg) at the Hydropunch and monitoring well locations respectively, to further define the hydrocarbon-affected groundwater. Based on previous soil samplings and the site-specific depth to groundwater, during the advancement of the proposed borings, soil samples will be collected at 5-foot intervals for lithologic classification and qualitative field screening beginning at a depth of 25 feet below grade. The 12 samples will be submitted to a qualified lab for the following analyses: TPH Purgeable by EPA Method 8015M/5030 (gasoline range) BTEX by EPA Method 8020 . The samples will be analyzed on a normal laboratory schedule requiring approximately two weeks (ten working days) for completion. In an attempt to fully define the extent of hydrocarbon-affected groundwater with a limited number of wells, the use of a Hydropunch II was recommended. The Hydropunch II is advantageous because it allows further plume definition of hydrocarbons within an aquifer (with defined groundwater flow direction and gradient) so that a limited number of wells can be utilized. By limiting the number of wells used, long-term monitoring costs are significantly reduced. The Hydropunch II would be used in 2 of the 4 borings proposed for this site. Once the plume has been further defined, using the Hydropunch II data, the Two (2) 55-foot deep borings would be advanced at a location based on the data obtained and 2 monitoring wells would be installed. The borings will be drilled approximately 20 feet into groundwater (approximately 55 feet bsg) . All soil borings will be advanced using a truck-mounted drill rig equipped with 8-inch hollow stem augers. The borings will be drilled, logged, and sampled by a qualified engineer or geologist. Following completion of the drilling, a 2-inch diameter Schedule 40 PVC well will be installed in each of the monitoring well borings. All of the wells will be surveyed for well location and elevation above mean sea level (msl) by an independent subcontractor so that subsequent water-level-sounding data can be utilized in determining groundwater flow directions and gradient. i' 3) Monitoring well Development and Sampling At least Forty-eight hours after installation, the new monitoring wells will be developed to remove sediment-laden water and to increase the hydraulic radius of the wells.