ARCHIVED REPORTS XR0007672 - Laserfiche WebLink

Home Browse Search

RECEIVED 0 e T 2 6 1992 ENVIRONMENTAL HEALTH PERM I7/SF-RvicEs analyses performed for the chemicals of concern. Review of the results of the soil borings , confirmed that no significant lateral migration beyond the immediate confines of the tank #5 excavation had occurred. Cverexcavation of the tank #5 excavation was required to remove the impacted material from the ground, and to achieve the Public Health Services ' RAL ' s . The proposed overexcavation of the tank #5 area was carried out on November 12, 1991 , and was effective in removing most of the above action level soils . Analyses performed on samples collected from the excavation after the removal of the impacted soils indicated that additional contamination still existed in the soil beneath the level which was excavated. This material could not be removed due to the physical limitations imposed by the excavation equipment and the threat to the integrity of the surrounding structures. The excavation was backfilled and surface paving restored so as to prevent its being a liability to the public pending the implementation of an alternative clean up method. All excavated material was legally transported and disposed of at Laidlaw Environmental Service ' s Lokern facility in Buttonwillow, California, as per Federal , State, and Local guidelines . Due to the inability of the overexcavation proceedings to remove all of the hydrocarbon impacted soil in the tank #5 area , It is being proposed to drill six (6) borings in this area, one boring of which will pass through the center of the previously existing excavation. These borings will be converted to vapor recovery wells , and will be used to alternately extract organic vapors from the subsurface soils , as well as force ambient air to be induced into the subsurface environment . The extracted vapor stream will be processed through a trailer mounted, electrically powered thermal oxidizer unit , permitted through the Air Pollution Control District, to perform destruction of the hydrocarbon vapors . Once the vapor concentrations being extracted from the subsurface have decreased to a sufficient extent , and upon review of the vapor stream concentration data by the San Joaquin County Public Health Services Department, the treatment unit will be shut down. At that time additional soil borings will be advanced to collect soil samples to confirm that subsurface soils have undergone sufficient treatment to below Regulatory Action levels. The Remediation Workplan for the installation of the Vapor Extraction System is on file with the San Joaquin County Department of Public Health Services . For more information concerning this project , contact either Neal Holdridge at Ryan-Murphy, Inc . at (714) 279-6210 , Dennis Miller at Miller Engineering at (510) 831-3255 , or Vern Willrich at Bridgestone/Firestone Tire and Rubber Co. , at (310) 927-7010.