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t 5.1 )Exploratory Soil Bari Installatio�r Twelve exploratory soil borings will be drilled (refer to section 5.3) using hollow stem auger techniques. Each boring will FQ advanced to first ground water, with one boring continued to 40 below ground surface (BGS) to the subsurface geology the additional information on g gy at the site. The ground surface at this site, due to prior excavation, will be measured from the adjacent roadway surface and not from the excavated surface. All drill { ' cuttings will be containerized in 55 gallonheld the site until results of the soil samplechemi aln a alys st are obtained. The method of disposal for the cuttings will be r1 determined based on the results of the soil sample analytical results. After the samples are obtained each boring will be f=� sealed to within 1 foot below grade with a 51 bentonite-cement ij grout' The uppermost foot will be capped with concrete to provide structural support. 5.2 Monitor well Installation As the anticipated depth to water is approximately 20 feet BGS, !" the wells will be installed techniques. All drill using hollow stem auger drilling ;.� cuttings will be containerized in 55 gallon drums and held at the site until results of the soil sample chemical analyses are obtained. The method of disposal for the cuttings will be determined based on the results of the i soil sample analytical results. For soil sampling interval and for the determination if analysis is required, refer to section 5.3. The well casing and screen will be constructed from nominal 411 diameter flush threaded P.V.c. pipe, with a 15 foot screened interval placed lo feet into the uppermost extending 5 feet above the saturatedzone saasedaturat on zone and previous experiences in the area, a 0.010 inch slot screen size will be �+ used. rhis may require modification if the saturated formation is substantially differentfromain the s the -• slot size. screen The gravel pack for the wells will utilize a washed, kilned and bagged Monterey 2-15 silica sand placed well screen to a height of 2 feet above thetop of the well screen. The sandsin the event a ize may require modification different screen size is required. A one foot thick bentonite seal will be placed above the sand pack and the well annulus will then be sealed to the surface with a 5% bentonite cement grout. As the wells are in a construction area cx volume of equipment. traffic, all of the wells will be gr..ompleted z at the surface in a reinforced, pavement level vault, once installation is complete, the relative elevation of each well, as measured to the top of the 4 inch well casin by hand leveling. g, will be determined 9 - ia.