ARCHIVED REPORTS XR0010505 - Laserfiche WebLink

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• � to the west and the site plume in the area of the Pep Boys parking lot. Also this letter requested that work begin on remediation of the this site. We Propose to drill five hydropunch borings HP-1 to HP-5, one auger boring B-2 , and one additional monitoring well BM-12 . The locations of these borings are shown on Figure 1 . Also we propose to drill six vapor wells to further define the soil contamination and to prepare the site for remediation. HYDROPUNCH TESTING A total of five ( 5) hydropunch borings will be made around the site. The borings will be made with a Cone Penetration rig using a Hydropunch lI devise to collect water samples. Borings HP-1 and HP-2 are positioned in order to assess a suspected plume coming from the west of the site. Since monitoring wells BM--3 and BM-6 did not contain any contamination above the capillary fringe no soil samples will be collected nor will the stratigraphy be logged. Borings HP-3 , HP-4 and HP-5 are positioned in order to assess the position of the groundwater plume coming from the Darpetro site. No soil contamination is expected to exist in the area of these wells, therefore, no cores or stratigraphic information will be obtained. The water samples collected by the Hydropunch II will be decanted into a 40 ml glass vial and placed on ice in a cooler until delivered to the laboratory. BORINGS AND MONITORING WELLS Boring B-2 is positioned in order to assess the soil contamination north of well BM-5. The boring will be from the surface to the capillary fringe and drilled with a hollow stem auger. The well BM-12 will be augered to a depth of at least 60 feet, which is projected to be 10 feet below the water table. In previous wells the top of a clay zone was found about 60 feet below the surface. The well will be drilled to this clay zone which acts as a vertical barrier to the downward migration of the gasoline plume in the groundwater. The boring section below 60 feet will be backfilled with bentonite chips to a level of 60 feet below the surface, where 20 feet of slotted casing will be Placed between 60 and 40 feet. Number 3 sand will be placed opposite the slotted casing and up to a level of 35 feet. A bentonite seal made of hydrated bentonite chips will be placed from 35 to 32 feet to inhibit the cement slurry infiltration into • the sand pack. A well seal of neat cement with 5% bentonite will be placed in the annulus from 32 eet to the surface. The well 7 50 , UPage 2 k!�L M 4