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CLEARW_ _�'KATER C R 0 U P I N C Enrwonneental Services Proposed Methods Geo robe Drilling and Sa=ling Prior to drilling, Clearwater will prepare site specific Health and Safety Plan for drilling activities Prior to conducting drilling, the site will be marked by Underground Service Alert (USA) to identify utilities leading to the site Appropriate drilling and encroachment permits will be obtainedAO the start of fieldwork All fieldwork will be conducted in accordance with Clearwater's Field Protocols(attached) PC or Soil borings will be advanced using a truck-mounted Geoprobe® 5400 direct-push drill-rig Soil samples will be collected at 5-foot depth intervals using a sampler lined with acetate sleeves from all borings Portions of each soil sample will be retained for a visual sedimentologic description by a Clearwater geologist using the Unified Soil Classification System and screening for organic vapors using a photo-ionizing organic vapor meter(OVM) Soil samples retained for laboratory analysis will be covered with Teflon lined end caps, labeled, documented on a chain-of-custody form, and placed on ice in a cooler for transport to the project laboratory Soil samples will be selected for laboratory analysis based on elevated OVM reachngs, field observations, and proximity to the capillary fringe It is anticipated that at least onetwo samples will be subirutted for analysis from each borehole The bonngs will likely be advanced to a depth approximately five feet beyond the depth of the water table to facilitate . collection of a groundwater sample It is anticipated that boring depths will not exceed approximately 20 feet bgs A grab groundwater sample will be collected directly through drill-pipe at each boring with either a stainless steel or a disposable polyethylene bailer If needed, a temporary well will be placed in each borehole to facilitate collection of a groundwater sample Each temporary well will be constructed with clean schedule 40 PVC materials with machine slotted screen Samples will be transferred to laboratory supplied sample bottles, labeled, documented on a chain-of-custody form, and placed on ice in a cooler for transport to the project laboratory Upon completion of sampling and removal of temporary well casing, all boreholes will be backfilled to the surface with cement Dnll-pipe and sampling devices will be cleaned by steam cleaning or in an Alconox®wash followed by double rinse in clean tap water to prevent cross-contamination Rinseate will be stored in labeled 55-gallon drums on-site pending removal and disposal Groundwater and soil samples will be analyzed for concentrations of TPHg and BTEX by EPA Methods 8015 (modified) and 8020 Additionally, samples will also be analyzed for concentrations of MTBE by EPA Method 8260 Sample analysis will be performed by Entech Analytical Labs, Inc (Entech), a California DHS-certified laboratory, located in Sunnyvale,California Re-Installation,of Well MW-5.Development,and Survey As mentioned earlier, well MW-5 was damaged during recent resurfacing activities Field observations indicate that approximately several feet of the uppermost part of well casing and protective box were damaged, however, the well casing and borehole remain accessible Based on these conditions, Clearwater recommends overdnlling the original borehole to remove damaged casing so that a new well may be constructed Data from MW-5 provide valuable Ms Lon Duncan 3 September 30 1999