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Ms. Dot Lofstrom Page 3 of 5 samples are summarized in Table 3 and Table 4, respectively. The locations of the borings are shown in Figure 2. 2.3 Recent Groundwater Sampling Monitoring well MW 1 was most recently sampled on May 31, 2000. At the request of PHS/EHD the analytical suit included TPHg, BTEX and a full VOC scan by EPA method 8260. The wellhead elevation of MW 1 was also tied to the elevations of the monitoring wells installed as part of the investigation of the adjacent 601 E. Miner site. No analytes except for MTBE were detected in the groundwater sample (Table 2). Groundwater flowed in an easterly direction. Groundwater elevation data are presented in Table 5. 3.0 WORKPLAN To further evaluate the nature and extent of groundwater impact on the property the following workscope is proposed. 3.1 Monitoring Well Drilling and Construction One additional groundwater monitoring well will be constructed at the site. The well will be located downgradient of existing well MW 1 and north of previous hydropunch boring HP4. The proposed location of the well is shown on Figure 2. The following drilling procedures and construction specifications will be used: All work will be performed by a C-57 licensed drilling contractor under the supervision of an experienced geologist. The contractor will advance one soil boring using a rig equipped with 8" diameter hollow stem augers and complete the boring as a groundwater monitoring well. The well will be completed at a depth of approximately 50 feet below ground surface (bgs), and will be constructed with 2-inch diameter, Schedule 40 PVC casing and 0.020" slotted screen. The screened interval will be from approximately 25 feet to 50 feet bgs to accommodate water level fluctuations. Filter pack will consist of No. 3 Monterey sand from the bottom of the well to approximately 2 feet above the top of the screen. The remaining annulus will be completed with 2 feet of hydrated bentonite overlain by neat cement grout tremied to the surface. At the surface the well will be fitted with a locking cap and water tight,traffic rated well box. Soil samples will be collected at 5-foot intervals during drilling for stratigraphic and field screening concerns. All soil samples will be classified in accordance with ASTM Designation D2488-90, which is equivalent to the Unified Soil Classification System. Selected soil samples will be submitted for laboratory analysis. At a minimum these will include the sample collected from the capillary fringe and the deepest sample collected. Samples selected for analysis will be immediately capped, labeled and placed in an ice chest at a temperature of 4 degrees Centigrade for shipment to the laboratory under chain of custody protocol. The samples will be analyzed for TPHg using EPA Method 8015, and BTEX using EPA method 8020. Gasoline oxygenate additives, 1,2 • dichloroethane(DCA)and ethylenedibromide(EDB)will be analyzed using EPA Method 8260. vaIIc"VvpotU\wkpinmw2.doc