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' STANDARD OPERATING PROCEDURE . GROUNDWATER MONITOR WELL PURGING AND SAMPLING (Includes No-Purge Sampling) Prior to purging the well, the static water level was measured using an electronic interface probe to evaluate the presence of any phase-separated hydrocarbons The measurements were obtained from a reference point on the north side of the top of the well casing Fluid measurements were recorded to the nearest 0 01-foot Depth to groundwater was measured from all site wells on the 1 same day The total depth of the well was also recorded If phase separated hydrocarbons are noted, a measurement of the apparent thickness was be obtained and the well was not be sampled To prevent cross-contamination, all monitoring equipment that is in contact with groundwater was washed with Alconoxo detergent and rinsed with distilled water prior to use in each well If well purging was required before collecting a water sample, both the static groundwater level and total depth of the well were used to calculate the volume of water in the well Based on this data, if free floating hydrocarbons are not present, a minimum of three well volumes of water were purged from the well using a2-tech Grundfose submersible pump or a PVC bailer Periodic measurements (at approximate 5-gallon intervals) of temperature, pH, and specific electrical conductivity were collected during purging When three successive stabilized readings were obtained, the well was sampled If the well is low yielding and is pumped or bailed dry, the well was allowed to recover at least 80% of the static groundwater level If the well does not recover ' 80% within a 24-hour time frame, a sample was collected and recovery noted on the Groundwater Sampling Log To prevent cross-contamination, equipment was washed with Alconoxv detergent and rinsed with distilled water prior to use in the well Groundwater purged from the well was stored on-site in 55-gallon drums pending proper disposition If no purging before collecting the water samples was required,then the above purging steps were skipped Groundwater samples were collected from the well using a disposable polyethylene bailer Each sample was collected in laboratory-preserved I-liter glass bottles and in 40-milliliter volatile organic analysis (VOA) vials Each vial was filled completely with sample and preservatives to eliminate headspace and create a positive meniscus The vial was capped with convex Teflon' septa Each vial was observed to ensure that no air bubbles are present within the vial Samples were marked for identification, placed on ice, and transported to a State-certified laboratory for analysts Chain-of-custody records were maintained and accompany all samples to the analytical laboratory