ARCHIVED REPORTS_XR0007742 - Laserfiche WebLink

Home Browse Search

* SAMPLING PROCEDURES FOR GROUNDWATER MONITORING WELLS 1. The top of casing is surveyed from an on-site reference point for all wells if not already done. 2. New polyethylene sheeting is placed around the well to be sampled. Designate a "clean" area for decontaminated equipment and a "dirty" area for equipment already used. 3. The depth to water and depth to product if present, is measured using an ORS Interface Probe. The total depth of the well is also measured. If free product is present, collect sample with steel interface sampler, place in vial, label, and store. 4. Four to five casing volumes of water are bailed with a PVC bailer (.163 gallons per foot of depth of two inch wells, .653 gallons per foot with four inch wells) and discharged into DOT drums. When finished, the bailer is placed in the "dirty" area to await decontamination procedure. If water is turbid, continue bailing until clean. After bailing, the well is allowed sufficient time to return to the static groundwater elevation. A minimum of 30 minutes is allowed prior to sampling. 5 The teflon sampling bailer and cord are rinsed with distilled water. A groundwater sample is collected by carefully lowering the bailer into the well. The bailer is only allowed to intercept the upper groundwater surface and is then brought to the surface. 6 The water is discharged into a vial and filled until overflowing. The vial is sealed, labeled, and placed in a plastic container, sealed with security tape, and stored in small ice chest with ice. 7. The well and cover are replaced and secured. B. The field data sheet and chain-of-custody form are completed with all pertinent data. 9. All equipment including the interface probe and bailers or pumps are cleaned by the 3 ibucket wash prior to re-use.