The former Big Tex Grain Site is located on a 7.5-acre lot in San Antonio, Bexar County, Texas, at 328 Blue Star Road. The geographic center of the site is located at Latitude 29.405° North Longitude -98.492° West.
The Big Tex Grain Site has historically been associated with industrial activity, including operating a vermiculite exfoliation plant, grain production, and sawdust warehousing. The EPA Region 6 office performed an assessment of the subject property to determine potential impact to human health and the environment based on the transporting of vermiculite from Libby, Montana, to the W. R. Grace vermiculite exfoliation plant in San Antonio, Texas. The property has been listed in the EPA CERCLIS database since 2000.
The site consists of approximately 32 structures including the Big Tex grain elevators and warehouses on the eastern portion of the property. To the north-northwest of the site, there are numerous grain silos that were converted into office spaces. The site is bounded to the south and west by Union Pacific railroad tracks and to the north and east by the San Antonio River. The site is secured by a chain link and barbwire fence extending around the entire perimeter of the facility. Within the facility exposed soil areas are heavily vegetated, but still accessible. The Big Tex Grain Site is scheduled to be developed into a “Mixed Use” facility.
Throughout this reporting period, USEPA, START, and ERRS contractors completed removal operations within the identified grids on the Big Tex property. Excavated soil has been loaded into roll-boxes or staged and covered daily on site. To date, all 47 grids have been successfully excavated.
Throughout this reporting period, ERRS conducted transportation and disposal of impacted soils. To date, approximately 1600 cubic yards of soil have been disposed of at the Allied Waste-Tessman Road Landfill located in San Antonio, Texas.
Throughout this reporting period, ERRS conducted restoration operations within excavated grids. To date, approximately 1240 cubic yards of clean soil been delivered and spread into excavation areas. Material is then tamped down to the original grade.
Throughout this reporting period, ERRS crews began the decontamination of the two site building identified to be impacted. ERRS completed the decontamination of one of the buildings, and continued the decontamination of the other.
START conducted AHERA indoor clearance sampling of the decontaminated building. START utilized the on site microscopist to ensure that the sample filter media was not overloaded and was in good shape to ship to LabCor, Portland for analysis.
The asbestos floor sheeting found in Building 23 has been successfully removed by Flagship PDG. The asbestos abatement contractor removed 10 bags of asbestos floor sheeting which will be disposed of along with the site generated PPE.
The EPA has been in contact with the City of San Antonio to coordinate the removal of the city’s stockpile located on the north central section of the site. This stockpile of soil is from the excavation of the city’s San Antonio river bridge project. The stockpile is approximately 600-700 cubic yards and is scheduled to be removed beginning 12/17/2008.
The City of San Antonio City Public Service (CPS) mobilized to the site to make the final repair and line closure of the of gas line broken during the last reporting period.
Throughout removal operations, soil samples have been collected from the four primary areas of concern. These samples were analyzed for the presence of asbestos and/or vermiculite by an on site microscopist. The finding of the initial removal sampling revealed that 21 additional grids showed the presence of asbestos and/or vermiculite; bring the amount of grids to be excavated to 47.
During all site operations, continuous on site and off site air monitoring has been conducted. Constant dust suppression operations have shown to be effective, and no site operations have generated dust levels that have exceeded site action levels. An air monitoring report is generated daily and sent to the major new paper for the San Antonio area.
Removal operations will continue throughout the month of December. Crews will complete excavations of grids and decontamination of impacted building. Throughout all removal activities, EPA will provide the local resident and the media with updated removal progress maps and air monitoring results.
City of San Antonio will utilize their contractors to begin the removal of the San Antonio river bridge project stockpile.
Removal and restoration operations will continue throughout the site. The remaining building to have AHERA indoor clearance sampling will be sealed up to insure that external removal operations will not further impact the structures in question. Site excavation areas will continue to be restored and site equipment/personnel will begin demobilization in preparation of the site closure.
The main issue regarding removal operations at the site is the suppression of all dust during removal activities. A power washers and a water truck will be constantly utilized to knock down dust. During the removal phase, START will continue particulate monitoring at the removal locations, as well as perimeter and off site particulate monitoring.
Due to the time of the year, winter cold fronts pose an issue as they generate high winds. During such conditions site operations are closed down until winds have subsided and site generated dust can be properly controlled.
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