ARCHIVED REPORTS_XR0007356 - Laserfiche WebLink

Home Browse Search

02 October 2001 . AGE-NC Project No 98-0452 Page 2 of 3 I 2 2 COLLECTION AND LABORATORY ANALYSIS OF GROUND WATER SAMPLES IFollowing purging and allowing a minunum of 80% recovery of initial water volume In the wells, water samples were collected from each purged well using new disposable plastic bailers Additionally, a water sample was collected from domestic well DW-1 Each water sample was transferred into laboratory-supplied 40-rill VOA vials containing 0 5 ml 18% hydrochloric acid as a sample preservative After collection, the samples were properly labeled, placed in a chilled I container and transported under chain-of-custody to McCambell Analytical Laboratories, Inc and were analyzed for Total petroleum hydrocarbons quantified as diesel (TPH-d) in accordance with EPA Method 8015 Modified, and • Oxygenated fuel additives-methyl tertiary butyl ether(MTBE),tertiary butyl alcohol(TBA), di-isopropyl ether (DIPE), ethyl tertiary butyl ether (ETBE), and tertiary amyl methyl ether (TAME) in accordance with EPA Method 8260 Modified 3.0. FINDINGS Ground water elevation and flow direction were calculated from field data, hydrocarbon--impact to ground water was assessed by laboratory analysis of the ground water samples 3 1 GROUND WATER GRADIENT AND FLOW DIRECTION The elevation of ground water in each well was calculated by subtracting the depth to ground water ' from the surveyed well head elevations (Table 1) Depths to ground water ranged from 3 59 feet to 4 75 feet below the tops of the well casings Ground water elevations at the site ranged from-0 21 feet in MW-3 to -0 54 feet in MW-1 relative to mean sea level The ground water gradient was Icalculated to be 0 004 ft/ft with a flow direction toward the southwest (Figure 3) 3 2 ANALYTICAL RESULTS OF WATER SAMPLES TPH-d was not detected above laboratory reporting limits in the four groundwater samples analyzed MTBE was detected by EPA Method 8260 in the ground water samples collected from MW-2 and MW-3 at concentrations of 35 micrograrns per liter (µgd) and 180 µg/l, respectively No analytes of concern were detected in the sample collected from the domestic well • Analytical results of ground water samples are summarized on Table 2 The laboratory report (MAI Laboratory ID 77230 through 77233) and chain-of-custody forms are included in Appendix B Advanced GeoEnvironmentai,Inc