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A9111, 0 C: .IATES. INC , Equal Elevation of Groundwater in:the Flood Control+& Water Vonservadon District Fall 197 G otindwater;Ro&t was inconclusive for the location. Proposed.well locations are shown.on Figure 2. andwate r'MMonitoring Wells Construction Details. The two soil borings will,be completed as groundwater monitoring wells,.: The mronitoft wells will lie const +of 2-inch inside diameter schedule 40 PVC well screen and caging. A.0.020- inch well screen"and#V12:mesh s W pack will be used. Neat cement will.be used to sed-the wells in accordance with California Well Standards(December 1981). To protect the integrity:of the wdls,loch wafter-tight,welt plugs will be installed on each well and a water-tight.wellhead; labeled *monitoring wall" will be concreted over each well. Proposed well construction details. are shown on Figure 3. !*.top of casing of the existing and new wellheads will be wed to assess groundwater gradient and flow direction. All drill cuttings will be stared:on site in 55 gallon drums pending laboratory results. SaMgj&AnAh2k Selected nail samples will he immediately planed on ice and delivered under chain-of-amodyy documentation to a State- tified laboratory for analysis. Samples will be analyzed for total petroleum hydrocarbons as gasoline (TPHg, EPA Method 8015), benzene„ toluene,ethylbenzene, and xylenes(BTEX EPA Method-8020), and oxygenate fuel additives(EPA Method 8260). WeR Deve122ment and fiMg2df►at nnl ng Measurement of depth to water in all wells 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 waiter is relatively sediment free. Prior to the collection of groundwater samples, a minimum of three well volumes(casing and sand pack-)will be purged. Temperature, pH, and electric conductivity will be measured and allowed to stabilize. Water samples will be collected using disposable bailers, one dedicated to each well. Groundwater ;samples collected from all monitoring wells will be submitted usmg chaiin-of- caastody record to,State-c�kified laboratory. Groundwater samples., three total, will be analyzed: for TPHg,:BTEX, and oxygenate fuel additives. Purge water will be stared `in 5 -gallon drums: approved for hazardous liquid storage pending laboratory analysis: llleg%g; ` rMrst on Upon completion of'th+e well installation and development activities,.a.summiq ieport will he prepared for submittal to PHS/EW.. The report will include a description of`a.l field activities, laboratory auialytical tilts,and well/boring logs.