Laserfiche WebLink
' . <br /> Margaret Lagorio <br /> July 18,2008" <br /> CONESTOGA-ROVERS <br /> &ASSOCIATES <br /> Technical Rationale for Proposed Scope'of Work <br /> • Soil and groundwater beneath the sits have been impacted bygasoline constituents. <br /> • Shallow zone,,groundwater Bow direction beneafh the site is.variable,`but:is predominantly.towards" <br /> the northeast: <br /> • �The`horizontal extent_of'impacted.shat low,groundwater is unknown-downgradient and to the east of <br /> the site. <br /> • The vertical extent ofimpacted'groundwater neak shallow zone wel.LMW-5 is unknown. <br /> •, . Shell proposes,drilling two.; soil'borings to assess the horizontal extent 'of impacted shallow <br /> groundwater downgradient afid`.to the east of•thesite and one soil boring to assess the vertical extent <br />- . of impacted groundwater near impacted shallow-zone well MW-5. The borings will be converted to . <br /> groundwater monitoring-wells. <br /> WORK TASKS <br /> Permits. A permit for drilling will be obtained from the SJCEHD:.- <br /> Health and Safety Plan:A site-specific Health-and Safety Plan will be prepared for fieldwork. <br /> Utility Clearance: The proposed,drilling locations will be marked and the locations cleared.through' <br /> Underground Service Alertand&private underground utility locating company prior to drilling. <br /> Site Investigation:. Three .exploratory.. soil borings (MW-8 through° MW-10) wily be drilled at the <br /> locations Shown on Figure-2...-Soil boring MW-8:will be-;drilledzusing.dual:cased.air.rotary or rotosbnic . <br /> equipment or. hoilow-stem auger-with...conductor'.casing and will be'converted 'to a deeper :zone <br /> groundwater monitoring'well. Soil borings MW-9 and.MW-10-will."be drilled using:hollow-stem auger <br /> equipment and will be converted to shallow zone groundwater..monitoring wells. <br /> A CRA geologist will supervise the drilling and: describe encountered:soils using.the Unified Soil <br /> Classification, System. Soil,.-..samples:from: the.:borings will be collected at 5-foot intervals for soil°. <br /> description, possible:,chemical. analyses; arid,organic•vapor screening with a photo-ionization detector, <br /> (PID)., CRA will. prepare an". exploratory ib.oring_ log for each well'boring and will record PTD <br /> measurements'on'the boring logs. . _ <br /> CRA will retain soil-samples designated for chemical analyses in stainless steel or brass sample tubes. <br /> CRA will cover the tubes on both ends with Teflon sheets and plastic end caps, label the soil samples, <br /> 1359 - 2 <br /> - Worldwide Engineering,Environmental,Construction,and IT Services <br />