ARCHIVED REPORTS XR0012752 - Laserfiche WebLink

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�. . ATTACHMENT A SAMPLING PROCEDURES AND LABORATORY ANALYSIS Sampling Procedures The sampling procedure consisted of first measuring the water level in each well with an electronic water level indicator, and checking each well for the presence of i. separate-phase hydrocarbons using a clear Teflon bailer. If the wells did not contain separate-phase hydrocarbons, they were then purged of approximately four casing volumes of water(or to dryness)using a centifugal pump. During purging, temperature, PH, and electrical conductivity were monitored in order to document that these parameters were stable prior to collecting samples. After purging the water Levels were x allowed to partially stabilize. Groundwater samples were collected using a. Teflon bailer, placed into appropriate EPA-approved containers, labelled, logged onto chain- of-custody documents, and transported on ice to a State-certified laboratory. Chain-of- custody documentation is attached. t Laboratory Analysis Groundwater samples were analyzed in the laboratory for the presence of total r Petroleum hydrocarbons calculated as gasoline (TPH gasoline), and benzene, toluene, ethylbenzene, and xylenes (BTEX compounds). Samples were also analyzed for total petroleum hydrocarbons calculated as diesel (TPH-diesel). Analysis for BTEX compounds is by EPA Methods 5030/8020, and analysis for T'PH-gasoline was ' performed according to the DHS LUFT method. Extraction was performed by the purge-and-trap technique with.final detection by gas chromatography using a tlame- ionization detector and a photo-ionization detector. The analysis for TPH-diesel was performed according to the DHS LUFT method. This method involves extracting the samples with solvent and examining the extract by gas chromatography using a flame- ionization detector. All analyses were performed by a State-certified laboratory. 3100102/1Q91 April . 1!>'.�t