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Cvv:ATC <br /> • <br /> A S S O C I A T E S I N C <br /> Groundwater Monitoring Wells Construction Details <br /> The borings will be completed as groundwater monitoring wells The monitoring wells will be <br /> constructed of 2-mch inside diameter schedule 40 PVC well screen and casing A 0 020-inch <br /> well screen slot and #2112 mesh sand pack will be used Neat cement will be used to seal the <br /> wells in accordance with California Well Standards (December 1981) To protect the integrity of <br /> the wells, locking, water-tight well plugs will be installed on each well and a water-tight <br /> wellhead labeled "monitoring well" will be concreted over each well Proposed well <br /> construction details are shown on Figure 3 The top of casing of the new wellheads will be <br /> surveyed and tied into the existing groundwater monitoring well to assess groundwater gradient <br /> and flow direction All drill cuttings will be stored on site in 55-gallon drums pending laboratory <br /> results <br /> Sam le Analysis. <br /> Selected soil samples, at least two from each boring, will be immediately placed on ice and <br /> delivered under chain-of-custody documentation to a State-certified laboratory for analysis <br /> Samples will be analyzed for total petroleum hydrocarbons as gasoline (TPHg, EPA Method <br /> 8015), total petroleum hydrocarbons as diesel (TPHd, EPA Method 8015), total petroleum <br /> hydrocarbons as kerosene (TPHk, EPA Method 8015), and total petroleum hydrocarbons as <br /> • motor oil (TPHmo, EPA Method 8015) benzene, toluene, ethylbenzene, and xylenes (BTEX, <br /> EPA Method 8020), and oxygenate fuel additives (EPA Method 8260) <br /> Well Development and GroundwaterSamplin>II <br /> Measurement of depth to water in all wells will be completed to evaluate the direction and <br /> magnitude of the groundwater gradient beneath the site The new wells, MW2, MW3, and <br /> MW4, will be developed using surge and bail techniques until the produced water is relatively <br /> sediment free Prior to the collection of groundwater samples, a minimum of three well volumes <br /> (casing and sand pack) will be purged from wells MW1 through MW4 Temperature, pH, water <br /> elevation, and electric conductivity will be measured and allowed to stabilize Water samples <br /> will be collected using disposable bailers, one dedicated to each well <br /> Groundwater samples collected from all four monitoring wells will be submitted using chain-of- <br /> custody record to a State-certified laboratory Groundwater samples, four total, will be analyzed <br /> for TPHg, TPHd, TPHk, TPHmo, BTEX, and oxygenate fuel additives Purge water will be <br /> stored on site in 55-gallon drums approved for hazardous liquid storage pending laboratory <br /> analysis <br /> w 1625771repodslwkpwels doc 3 <br />