ARCHIVED REPORTS_XR0011563 - Laserfiche WebLink

Home Browse Search

r On September 26, 1990, Alton Geoscience personnel supervised the installation of Ground Water Monitoring Wells AW-1 through AW-4. The monitoring well locations are shown in Figure 2. The findings and conclusions from this and past site investigative work, and from the results of laboratory analyses and field observations of the preliminary ground water investigation are presented in the Alton Geoscience report dated December 14, 1990. On April 30, 1991, and May 1, 1991, Alton Geoscience conducted a supplemental site investigation by drilling additional soil borings (B-1 through B-9) . Soil Borings B-2, B-3 , B-4, and B-9 were subsequently converted to ground water Monitoring Wells AW-5, AW-7, AW-6, and AW-8, respectively. The monitoring well locations are shown in Figure 2. On May 6, 1991, Alton Geoscience developed wells AW-5 through AW-8. On May 7, 1991, Alton Geoscience performed monitoring and sampling of ground water Monitoring Wells AW-1 through AW-8. Ground water samples were analyzed for TPH-G, TPH-D, and BTEX, except AW-1 and AW-3, which were also analyzed for fecal coliform. Petroleum hydrocarbon constituents were not detected above method detection limits in the samples, except AW-3, which had detectable concentrations of TPH-G (210 ppb) , ethylbenzene (0.3 ppb) , and total xylenes (0.8 ppb) . The findings from the supplemental investigation are presented in the Alton Geoscience report dated July 9, 1991. On August 21, 1991, Alton Geoscience monitored and sampled Monitoring Wells AW-1 through AW-8 . Results of this sampling event were reported in a quarterly report dated January 21, 1992. The former Mobil Oil Bulk Terminal is presently a fenced, vacant lot, located on the south side of East Grantline Road at an elevation of approximately 33 feet above mean sea level (NGVD-1929) . Adjacent properties are either vacant or commercial and industrial developments.