ARCHIVED REPORTS XR0012588 - Laserfiche WebLink

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x !s A. Preliminary Hydrogeologic Assessment Prior to drilling monitor wells a preliminary hydrogeologic assessment must be initiated to define site conditions and determine the proper number and placement of wells. Site information can be obtained from the Soil Conservation Service, state and/or local governments, USGS, or previous work performed at the site. BP oil will make available to the contractor any relevant site history or completed hydrogeological studios in its .. possession. The contractor should develop from company drawings and site visits a suitable base map for use in summarizing project data. Additional maps such as topographic, utility, street, land ownership and use, ger-logic, soils, and aerial photographs should be obtained for use during the course of the investigation. If site and topography mapping is not available, the contractor will, develop a suitable base. map from surveys, site visits, ar,d aerial photography. i B. Soil Barings and Monitor Wells All drilling during Phase I investigations will be conducted on company property, unless written approval, or permits has been obtained from affected property owners and approved by BP of Figure l illustrates the monitor well ( specifications to be used during investigations in w water-table aqui:"ers. Well screen should be sized ' to accommodate seasonal water-table fluctuations a . and :allow entry of petroleum products. Note that all welly are four (4) inch diameter. Any variance from this standa'A diameter must be approved by BP oil. s k- C. Drilling Considerations contractor shall "hand dig" to a depth of four (4) `. feet at the start of each installation to check for the presence of any underground piping or structures. F A minimum of three wells is required to estimate groundwater velocity. Adequate well spacing should be addressed to obtain measurable variations in groundwater evaluations.