ARCHIVED REPORTS XR0000115 - Laserfiche WebLink

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very saline or conductive water After the water level had been determined, the bailer was lowered to a point just below the liquid level, retrieved, and inspected for PSH If PSH was encountered, its thickness was measured with an oil/water interface probe This ' instrument's dual-sensing probe utilizes an optical liquid sensor and electrical conductivity probe The instrument emits a solid tone when immersed in oil, and an oscillating tone when immersed in water If PSH greater than 1/32-inch in thickness was detected, a sample was ' not collected from that well All liquid measurements were recorded to the nearest 0 01 foot in the field logbook The ' groundwater elevation at each monitoring well was calculated by subtracting the measured depth to water from the surveyed well-casing elevation Total well depth was measured by lowering the sensor to the bottom of the well Total well depth, used to calculate purge ' volumes and to determine whether the well screen is partially obstructed by silt, was recorded to the nearest 0 5 foot in the field logbook ' Well Purgeng ' Before sampling was performed, standing water in the casing were purged from the monitoring well using a bailer, pneumatic displacement pump, or a piston pump Samples • were collected after three well volumes had been purged, and the pH, specific conductance, ' and temperature had stabilized, or after 5 well volumes had been evacuated Low-yield monitoring wells may be expected to be evacuated to dryness after the removal of less than ' three well volumes Such low-yield monitoring wells were allowed to recover for a minimum of two hours If the well had recovered to 80%of its original water level after two hours, a sample was collected Otherwise, the well was allowed to recover up to 24 hours ' prior to sampling If sufficient water had recharged after 24 hours, the monitoring well was sampled ' Field measurements were recorded in a waterproof field logbook Water sample field data sheets were prepared to record the field data These data sheets were reviewed by the sampling coordinator when the sampling event was completed The pH, specific conductance, and temperature meter were calibrated each day before ' beginning field activities The calibration was checked once each day to verify meter performance Field meter calibrations were recorded in the field logbook ' Groundwater generated from well-purging operations was contained for temporary storage in 55-gallon drums All drums were labeled and stored on site in a location designated by the client representative The sampler will record the following information on the drum label ' for each drum generated • Drum content (groundwater) 1