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above the filter pack material to act as a sanitary seal and prevent liquids from leaking into the screened interval through the well annulus. The remainder of the annulus will be filled with a bentonite and cement grout slurry seal to approximately three feet bgs. The groundwater monitoring well will be completed to the surface with concrete. For wellhead protection, a traffic rated monument box will be installed in the surface concrete and a locking well cap will seal the top of the PVC casing. The surface concrete will be finished so that the top of the monument box is elevated approximately 2 inches above the ground surface to prevent liquid infiltration. Figure 4 is a Monitoring Well Construction Diagram. The groundwater monitoring well will be developed by surging and bailing to remove fine grained sediments from the filter pack material and remove groundwater from the area of the filter pack which may have been affected by the installation of the well. 2.2.3 Drilling Waste Handling Soil cuttings, development water, decontamination rinse water, and purge water will be contained in Department of Transportation (DOT) certified 55-gallon drums and stored in a secure area on-site pending laboratory analysis. Upon completion of chemical analysis the waste will be transported, under manifest, to a licensed disposal site. 2.3 SAMPLING METHODS All soil samples will be screened by ambient temperature headspace methods for indications of hydrocarbon contamination. Results of the headspace readings will be recorded on the boring logs. The headspace method involves placing approximately 5 cubic inches of soil into a sealed polyethylene bag and allowing the soil temperature to equilibrate for approximately 15 minutes. At that time, the probe of a portable PID, calibrated with isobutylene, will be inserted into the bag headspace and the volatile hydrocarbon concentration in units specific to the PID will be recorded on the boring log. Soil samples will be selected for analysis based on staining, odor, PID headspace readings and location within the soil boring. All soil samples will be sealed with Teflon sheets, capped, labeled, and transferred under chain-of-custody to a state-certified laboratory. Following monitoring well installation and development, the well will be allowed to equilibrate overnight then gauged with an electronic water sounding meter. Prior to sampling, the monitoring well will be purged of at least 3 well volumes with an electrical purge pump. Purging will be continued until water pH, conductivity and temperature readings have stabilized. A dedicated polyethylene bailer will then be used to collect water samples from the well. Water samples will be transferred directly from the dedicated polyethylene bailers to appropriate laboratory-supplied sample containers. A label indicating the date and time of sample collections, sampler's initials, sample designating, and analysis requested, will be affixed to each sample container. All groundwater sample containers will be immediately placed in a pre-cooled ice chest and maintained at a 2403c.20\stockton.pin 4