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' r • The minimum purge volume was calculated to be three tunes the total well volume Once the minimum purge volume has been calculated purging was started Purging was conducted using either a centrifugal pump connected to a dedicated Watters tube, a 2-inch diameter submersible pump, a bladder pump, or a disposable polyethylene bailer The type of equipment used to purge the well was selected based on depth to water, the anticipated purge rate, and the amount of sediment expected to be contained in the well, and was recorded on the Groundwater Sample Collection Record Temperature, pH, and specific conductance of the purge water was monitored dunng the purging process at regular intervals Purging was ceased when the monitored parameters stabilized (three consecutive readings not varying by more than 10-percent)and a minimum of three well volumes had been purged In the event a well dried out during purging, the well was allowed to recover to 80-percent of it's onguzal well volume, or for 24-hours, whichever was less, pnor to collecting a groundwater sample Groundwater Monitonag Well Sampling Once the well was successfully purged a groundwater sample was collected using a disposable polyethylene bailer connected to clean nylon or polyethylene cord The bailer was lowered slowly into the water to avoid agitation of the sample A portion of the sample was placed in a container and the monitoring parameters were recorded The remaining portion of the sample was . transferred from the bailer to the appropriate, laboratory supplied sampling bottles, using a bottom emptying device The sampling containers were Filed completely, leaving a positive meniscus, so no airspace remained in the veal after sealing The sample bottles were labeled with the well identification (n a MW-1, MW-2, etc), date and time of the sample collection, the field technicians initials,job number, analyses to be performed, J � Y P ed, and other relevant information Samples were immediatelylaced in an insulated cooler containing g crushed ice The samples were maintained at approximately 3 to 4°C until reaching the analytical laboratory I , Laboratory Analysis Samples were shipped, under appropriate chain-of-custody procedures, to Southern Petroleum Laboratory in Houston, Texas (SPL) SPL Laboratory is certified by the State of California Department of Toxic Substance Control for performing the requested analyses Samples were shipped via Federal Express to minimize the time the samples remained in the cooler Samples were analyzed for total petroleum hydrocarbons as gasoline (TPHg), and benzene, toluene, ethylbenzene, and xylene isomers (BTEX), following Environmental Protection Agency Methods 5030, 8015 modified,'and 8020 Samples were analyzed on a standard two week turn-around time I r ' ',II �r I ` I I q I,� ,i , IE it Ij ' I i Mil I ill It,! U I I!I`II I I I I ' I