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CVATCo A S S O C I A T E S I N C . foot intervals and at least two soil samples from each boring will be submitted for laboratory analysis. The soil borings will then be completed as groundwater monitoring wells. All drill cuttings will be stored on site in 55-gallon steel drums pending laboratory results. Well Construction Procedures Two-inch diameter, schedule 40 PVC casing and screen will be used to complete the groundwater monitoring wells. The proper lengths of clean screen will be threaded above ground prior to lowering inside the hollow stem augers. The bottom of the screen interval will be fitted with an end plug and the top of the casing will be fitted with an expandable, water-tight, locking cap. It is anticipated the well screen length will extend from a depth of 8 to 28 feet bgs. No glue will be used in the assembly of the two groundwater monitoring wells. The annular space between the well screen and the sidewall of the borehole will be filled with clean No. 2116 sand or equivalent to provide filtration capacity and impede movement of fine particles into the well. The sandpack will extend 2 feet above the top of the well screen. A 3- foot thick interval of hydrated bentonite will be placed above the sandpack and the remaining annular space will be backfilled with a neat cement grout containing 5% powdered bentonite. The monitoring wells will be finished with water tight security traffic boxes to protect from vandalism or entry of surface fluids. Soil Sample Analysis The selected soil samples will be immediately placed in a cooler with ice and delivered under chain-of-custody documentation to a State-certified analytical laboratory. Samples will be analyzed for total petroleum hydrocarbons as gasoline (TPHg) and TPHd by EPA Method 8015 modified, benzene, toluene, ethylbenzene, and xylenes (BTEX) by EPA Method 8020, and methyl tertiary butyl ether (MTBE)by EPA Method 8020. If MTBE is detected by EPA Method 8020,the sample will be analyzed for oxygenate fuel additives by EPA Method 8260. Monitoring Well Sampling and Analytical Procedures Measurement of depth to water in all wells, MW1 through MW5, will be completed to evaluate the direction and magnitude of the groundwater gradient beneath the site. The new wells will be developed using surge and bail techniques until the produced water is relatively sediment free. The development of these wells will be performed at least 24 hours after the wells have been installed. After well development, the relative elevations of the new monitoring wells (i.e. top of casings) will be surveyed and tied into the existing monitoring wells. All survey elevations will be performed to an accuracy of 0.01 feet. All monitoring wells, MW 1 through MW5, will be slowly purged a minimum of three well volumes. Temperature, pH, water elevation, and electric conductivity will be measured and allowed to stabilize prior to sampling the wells. If the well evacuated prior to the removal of w:1625001repam\wkpiiiadd.doc 3