WORK PLANS - Laserfiche WebLink

Home Browse Search

TO E RO E K SOP No.026,REV.1 ASSOCIATES,INC INDOOR AIR AND SUB-SLAB SOIL GAS SAMPLING METHODS I PAGE 6 • Drill rig-driven (hollow-stem auger) probe, typically good for deep, permanent applications including nested, multi-depth probe constructions. The probes may be assembled in series to reach the desired sampling depth. The probes will be driven to or emplaced at the desired sample collection depth, and then fitted with the Teflon® or equivalent sampling tube. During probe emplacement, subsurface conditions are disturbed. To allow for subsurface conditions to equilibrate, the following equilibration times are recommended: • 30 minutes for probes installed by hand emplacement; • 20 minutes for probes installed by direct-push method where the drive rod remains in the ground; • 30 minutes for probes installed by direct-push method where the drive rod does not remain in the ground; and • 48 hours for probes installed by hollow-stem auger drilling method. 2.3 SAMPLE COLLECTION USING SUMMA® CANISTERS Canisters, such as SUMMA® canisters, are typically used for indoor air and soil gas sampling and are certified clean by Gas Chromatography/Mass Spectrometry(GC/MS) analysis before being utilized in the field. After sampling is completed, the samples can be analyzed in the field laboratory, or are stored and shipped in travel cases for off-site laboratory analysis. Most VOCs can be recovered from canisters with minimal loss up to 30 days. Prior to sample collection, a pre-sampling building survey should be completed (Figure 1) and a field data sheet (Figure 2) should be referenced to ensure that all required information is recorded in the field logbooks. Pre-sampling building survey forms and field data sheets may be used provided the forms and data sheets contain the required fields and information to sufficiently document and re-create the sampling event (see Section 2.4). The proximity of the indoor air sample location to the sub-slab sample location should be detailed and any problems or deviations encountered during installation and sampling activities should be described in field logbook and on the field data sheet.