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Each of the groundwater-grab samples will be analyzed on a standard turn-around time of 5 to 7 working days for TPH-as-diesel, TPH-as-gasoline, BTEX and MTBE by Modified EPA Methods 8015 and 8020. 2.2.3 Borehole Abandonment and Site Restoration The 3 soil borings not to be converted to monitoring wells will be sealed with a bentonite/cement mixture. The seal will be placed using the tremie method. Following borehole abandonment, asphalt or concrete patches will be used to restore the surface pavement. 2.3 Monitorina Well Installation, Development, Sampling and Analysis In 3 of the B soil borings, groundwater monitoring wells will be installed. One of the proposed monitoring wells will be located as close as possible to the former UST excavation. The second monitoring well will be positioned approximately 90 feet southwest of the former UST excavation to evaluate the lateral extent of any impacted groundwater on the west side of the site. The third monitoring well will be located approximately 250 feet south of the former UST excavation to evaluate the potential migration of the plume of impacted groundwater toward the nearest municipal water well, approxirnately 600 feet southeast of the site. 2.3.1 Monitoring Well Construction Groundwater is anticipated at approximately 18 feet bgs. The well will consist of approximately 15 C Pp Y feet of two-inch diameter, Schedule 40, flush-threaded and machine-slotted (0:020-inch) polyvinyl chloride (PVC) well screen. The well screen interval will extend from approximately 13 to 28 feet bgs. Blank PVC casing will thread into the top of the well screen and extend to the surface. A filter pack of Monterey#3 graded and washed sand will be placed through the hollow stem augers as they are slowly retrieved and until the sand pack reaches approximately 2 feet above the toga of the screened interval. Overlying the sand pack, 2 feet of hydrated bentonite chips will be placed within the annular space, between the borehole and the well casing. Over the hydrated bentonite, a surface seal of 22:1 cement/bentonite grout mixture will be installed. The tops of the wells will be secured with a i ter-tight locking caps and traffic-rated, flush-mount street boxes. �( � 8 "� ��