ARCHIVED REPORTS XR0011751 - Laserfiche WebLink

Home Browse Search

+-- Work Alan for Refined Plume Definition and Management of Floating Product-7500 W 11 th St., Tracy, CR. Page 22 7.0 ADDITIONAL MONITORING WELLS TO REFINE PLUME DEFINITION SJC's proposal for extension of the existing array of groundwater quality wells to improve .r definition of the limits of the plume of hydrocarbon-affected groundwater emanating from the 7500 West Eleventh Street property is presented below. Well locations have been selected to enhance definition of the western and northern limits of the plume and investigate �- changes in the concentrations of analytes of concern with distance down-gradient from the source of the release of fuel hydrocarbons. A discussion of the procedures that will be used to install the wells, to sample and analyze soil recovered from their borings and an outline of the extended groundwater-quality monitoring program that they will support is also included below. ►- 7.1 Proposed Wells Seven new groundwater-quality monitoring wells are proposed to meet the objectives stated above. Their locations are shown in plan on Figure 4 and, to the extent that they are on the section lines or close by, they are also shown on Cross Section A-A', B-B' and C-C' on Figures 5, 6 and 7. The proposed new wells are listed below, together with notes on their individual function in the context of the global array of wells that are used to monitor groundwater quality at the 7500 West Eleventh Street site. Proposed Casing Total Purpose Well No Diameter Depth MW-13 6 in. 25 ft. To investigate groundwater quality and check for the presence of floating product along the plume axis up- gradient from Monitoring Well MW-7. If necessary, this well may also be used to recover floating product. J` a Groundwater-quality data from this location will also k .ra be useful at later stages of site characterization to evaluate intrinsic bioremediation and natural attenuation of chemicals of concern in groundwater. MW-14 6 in 25 ft. To investigate groundwater quality and check for the presence of floating product along the plume axis down-gradient from Monitoring Well MW-7. If necessary, this well may also be used to recover o� floating product. Groundwater-quality data from this location will also be useful at later stages of site characterization to evaluate intrinsic bioremediation and natural attenuation of chemicals of concern in groundwater. MW-15 2 in. 25 ft. To investigate groundwater quality along the western fringe of the plume of affected groundwater. It is currently assumed that groundwater at that location will SJC