WORK PLANS - Laserfiche WebLink

Home Browse Search

U A LE04 Ms.Margaret Lagorio Page 2 San Joaquin County Environmental Health Department January 13,2004 SUBSURFACE CONDITIONS The site subsurface is dominated by interbedded silt, silty sand,and sand. The total depth explored at the site is approximately 75 feet bgs. General geologic cross-sections generated from drilling logs of previous boring activities at the site are included as Attachment B. Based on inspection of the drilling logs, groundwater ranges from approximately 56 to 65 feet bgs and occurs in fine- to coarse-grained sand. Based on inspection of quarterly evaluations of groundwater flow, the inferred direction of groundwater flow in the site vicinity is to the southeast at a gradient of 0.013 feet per foot. SCOPE OF WORK Phase I—Soil and Groundwater Grab Sampling URS proposes to drill four soil borings for the purpose of collecting soil and grab groundwater samples. The grab groundwater samples are being collected to assess the lateral extent of 1,2-dichloroethane(1,2- DCA)in the groundwater beneath the site. Phase II —Groundwater Monitoring Well Installation Following receipt of the data from the soil and groundwater grab sampling,URS will evaluate the data to properly place one deep groundwater monitoring well to assess the vertical extent of 1,2-DCA and pow install four additional shallow monitoring wells to monitor the lateral extent. Prior to monitoring well installation,URS will submit a figure to your office showing analytical data results from the soil and groundwater grab sampling with proposed well locations along with the appropriate permits and fees. The sections below include discussion of permitting,underground utility location,drilling, soil and groundwater sample collection,monitoring well installation,equipment decontamination and waste disposal, sensitive receptor survey, and report preparation for both phases of proposed work. A site- specific health and safety plan(HASP)will be prepared and be available on site during field activities. PERMITTING The City of Lodi and SJCEHD require that permits be obtained prior to drilling. URS will submit the appropriate permit application(s)with fees to the City of Lodi and SJCEHD prior to conducting any field activities. KAWprocessV5 BP ARCO\00760\2004 Assessment\760 GW Workplan 04.doc