ARCHIVED REPORTS XR0003464 - Laserfiche WebLink

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A-3 specific conductance, and temperature stabilized or until the well went dry No water or chemicals were introduced into the monitoring wells during well development 1.8 Ground Water and Liquid Phase Petroleum Measurements ' Prior to purging the monitoring well, a water/petroleum product interface probe was used to determine the presence and thickness of liquid-phase hydrocarbons and to measure the ground water depth in each ' well If a liquid-phase hydrocarbon layer was not detected by the interface probe, the tip of the probe was subjectively analyzed for hydrocarbon sheen Depth to ground water was measured to the nearest 0 01 foot 1.9 Subjective Analysis of Ground Water Prior to purging the monitoring well, the depth to ground water was recorded and a water sample was ' collected for subjective analysis for liquid-phase petroleum A clear, disposable plastic bailer was gently lowered down the monitoring well until approximately one-half the bailer length was past the air/liquid interface The bailer was then retrieved and the sample contained within the bailer was examined for liquid-phase hydrocarbon layer or the appearance of a hydrocarbon sheen ' 1.10 Ground-Water Sam lin Following well development, a water sample was collected from each well with the same plastic batter ' used to develop the well Each sample was appropriately labeled and stored on ice at approximately 4°C from the time of collection through the time of delivery to the laboratory 1.11 Surveying The top of each monitoring well casing was surveyed using automatic-leveling survey equipment The survey point on each well riser was notched to ensure all water level measurements would be taken from ' the same location The top of casing elevations were surveyed with reference to a California Department of Transportation benchmark (No 1618L) with an elevation of 0 728 feet above mean sea level All ' elevations were surveyed to the nearest 0 01 foot RPT 112 JDM