COMPLIANCE INFO - Laserfiche WebLink

Home Browse Search

Project No. 014-13157 Page No. 3 soil/debris mounds. Mr. Scott Kurteff, a representative of the owner of the subject site familiar with the subject site for 14 years, stated that the southern-most soil mound may be associated with the installation of new septic tanks/leach fields several years ago. However, Mr. Kurteff indicated that he did not have definitive knowledge of the origin of the southern-most soil/debris mound, nor did he have knowledge of the origin of the other on-site soil/debris mounds. Additionally, neither Mr. Brandon Scott, the subject site property manager, nor the subject site occupants knew the origin of the on-site soil/debris mounds. Krazan's experience indicates that imported soil can be contaminated with agricultural chemicals or other hazardous materials, dependent upon the specific location from which the soil is derived. Given the absence of any definitive information concerning the origin of the on-site soil mounds, the presence or absence of hazardous materials in these soils is unknown. According to records on file with the SJCEHD, potential areas of concern identified during a Phase I ESA of the Stockton 99 Speedway, located adjacent to the northeast of the subject site, were investigated via a 2005 Phase II Limited Soil Assessment (LSA) of the property. Areas of the speedway investigated in the Phase II LSA included an area west of the race track noted as containing debris and fill material, a fuel AST located on site, dry wells located on site, and the area in the interior of the oval race track. A total of 33 soil samples were collected from these four areas and analyzed for a variety of potential contaminants, including heavy metals, petroleum hydrocarbons, volatile organic compounds (VOCs), and semi-volatile organic compounds (SVOCs). Analysis of soil samples collected from the AST, dry well, and race track interior areas did not reveal an impact from any of the above-referenced COCs. Analysis of soil samples collected from the debris/fill area did not reveal evidence of a soil impact except for elevated concentrations of several heavy metals, particularly lead, ranging from 273 to 1,610 mg/kg. The debris/fill area was defined by the consultant as a narrow band of fill material located along the western side of the Stockton 99 Speedway; a portion of which is located proximate to the cell tower in the northwestern portion of the subject site. Analysis of a soil sample collected approximately 100 feet to the north of the northwestern portion of the subject site revealed a lead concentration of 300 mg/kg and higher lead concentrations were detected in the fill material located farther to the northeast (350 to 700 feet to the northeast of the subject site). All of the heavy metal impact identified was associated with fill material located in this portion of the speedway property and the debris contained within the fill was reported to be primarily building demolition materials. No evidence of a groundwater impact was reported. Groundwater was estimated to be first encountered at a depth of 55 to 65 feet bgs. Additional investigation of the speedway property was conducted by The Source Group, Inc. (SGI) in November 2005, and SGI also developed a Preliminary Endangerment Assessment Workplan dated April 12, 2007. The SGI workplan indicates that the fill material at the Stockton 99 Speedway is believed to have been originally imported in the 1960s from a railroad overpass reconstruction project in the downtown area of Stockton. Soil samples collected from twelve test pits advanced during the November 2005 SGI investigation were analyzed for heavy metals and selected samples were analyzed for petroleum hydrocarbons, organochlorine pesticides, VOCs, and lead using the wet extraction test. Maps contained in the SG1 report depict the southwestern extent of the speedway fill area as being the property boundary with the northwestern portion of the subject site near the subject site cell tower. Results obtained from heavy metals analysis are generally similar to those obtained earlier in 2005. SGI also collected soil samples (SG-11) from the fill material at a location approximately 75 to 100 feet to the north-northeast of the subject site. Analysis of one of the soil samples collected from SG-11 revealed a total lead concentration of 440 mg/kg (10 feet bgs), a lead (wet extraction test) of 20 mg/1, and trace concentrations of the organochlorine pesticides DDD (0.024 mg/kg) and DDT (0.046 mg/kg). The SJCEHD file did not contain any reports related to the additional work proposed in the above-referenced SGI workplan, and according to a representative of the California Department of Toxic Substances Control (DTSC) no records related to this site are on file with the DTSC. Consequently, it is KRAZAN & ASSOCIATES, INC. With Offices Serving the Western United States 014-13157-Wilson Property Workplan FINAL