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Ms. Mary-'Meays Page 2 May 24, 1994 Sampling_Locations At-the 1515 West Weber Avenue..property=(Site #1), three boring locations are proposed as discussed during the April 13,1994,meeting and .presented on Figure 1. One boring will be drilled within. the former tank.-excavation area, approximately 3 feet south and 14 feet west of the corner rof-the warehouse previously used as.-a--reference point-for the confirmation sampling: In addition, two borings will be..installed._-within the.building footprint at approximately'18 feet_north;3 feet east and 10-feet north, 10 feet east of the reference corner. This!building-is currently vacant, .thus there are no expected impedances_ to borings at-these locations;:;however,subsurface obstructions may cause the boring`locati6hs to be shifted.slightly from those proposed in this workplan. = - Three borings are also-proposed for the 1325 West Weber Avenue property (Site #2) as presented on Figure 2. Two borings will be drilled within .the former-tank excavation area at-approximately 11 feet north, 6 feet west and 18 feet.north, 16 feet west of the'corner previously'used as a reference point for the confirmation sampling:_ In addition, one boring is proposed for within the building footprint at approximately 18.feet south and 31 feet east of:the reference corner: This boring location is tentatively proposed due to numerous surface obstructions in-the active warehouse area, and may,,,be shifted-to accommodate tenant activities or subsurface obstructions. In the_April 13, 1994; meeting, three additional sampling locations were identified within: the warehouse footprint, however, a site walk-.performed on May 11, 1994_ , confirmed_ that the_internal building configuratiori precludes installation of additional: borings. within the building. ERM-West believes that the one boring proposedfor the building footprint-will be sufficient to confirm that the extent of TPH-affected soils beneath the building -is not significant. SamplingProtocol. As agreed in the April113, 1994,,meeting.- the six borings will be drilled to-a total depth of 15 feet below ground surface(bgs): The three borings-located within--the excavation-footprintswill be drilled using a hydraulic drive point system.equipped'with_a 2-inch split spoon sampler. Samples will be collected immediately;below the base of-the clean backfill,-and .at five foot-increments until the 15-foot total depth is encountered, In most cases,the-depth.of the former excavation is such -that this plan will result in a total of three samples being collected at each-location. For example, at a given location,.samples migHt be collected at°7.5 to 8 feet:bgs, 9.5 to.10 feet'bgs, and 14.5 -to.15 feet bgs. At areas where the former excavation`depth exceeded 9 feet.bgs, the number of samples will be reduced to two; that is, one sample will be - -collected-'(the excavation base;and .the.second sample will.be collected at.14.5. to 15 feet bgs.