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I <br /> Additionally, soil samples were collected by driving a <br /> California-type split spoon drive sampler ahead of the hollow- <br /> stem augers Soil samples were collected, starting from the <br /> existing ground surface, at every 5 feet, at any li.thologic <br /> changes and areas of obvious contamination down to the water <br />' table The soil samples were also screened using a PID Six <br /> soil samples were collected from each boring for a total boring <br /> depth of approximately 30 feet <br />' The 20 feet of 4-inch-diameter, 0 010-inch slotted casing were <br /> located between the approximate depths of approximately 10 and 30 <br /> feet Approximately 10 feet of flush-threaded, 4-inch-diameter <br />' PVC solid casing were installed from the top of the slotted <br /> casing to existing grade The drill augers were then slowly <br /> retrieved from the borehole as the well annulus materials (sand, <br />' bentonite, and grout) were added The slotted interval was sand <br /> packed using Lonestar No 3 sand or equivalent to a minimum of 2 <br /> feet above the uppermost slot An annular seal was placed from <br /> the top of the sand pack to the surface The sealing material <br />' was placed in one continuous operation until the specified <br /> interval was filled The annular seal consisted of a neat cement <br /> grout composed of one sack of Portland Type I/II Cement (94 lbs ) <br /> to five gallons of clean water A bentonite "spacer" not <br /> exceeding 1 foot in length was installed between the sand pack <br /> and the cement seal The cover of the monitoring well was <br /> clearly marked "monitoring well" <br />' The total boring depth, as well as the depths of the sand pack <br /> and bentonite seal, was sounded with a weighted tape during <br />' installation of the wells <br /> After the wells were completed, the elevation of the top of <br /> casings were surveyed to the nearest 0 01 foot, and tied <br />' vertically to mean sea level (MSL) and horizontally to a <br /> permanent benchmark located an the vicinity of the Site <br />' 4 .2 .2 Well Development <br /> The monitoring wells were developed on December 14 , 1999 The <br />' monitoring wells were developed by hand-bailing to remove fine <br /> particles near the well screen to improve hydraulic communication <br /> with the surrounding formation Parameters such as water <br /> clarity, pH, temperature, specific conductance and volume <br />' extracted were measured during the development process to gauge <br /> its progress Observations regarding odor and possible oily <br /> sheens were also noted When the parameters stabilized, the <br />' wells were considered developed <br /> 4 <br />