COMPLIANCE INFO - Laserfiche WebLink

Home Browse Search

PEt__.EPORT(June 20,2003) LOCKEFORD ELEMENTARY SCHOOL EXPANSION concentrations were made up of aromatic carbon compounds, rather than less toxic aromatic carbon compounds. The hypothetical TPH concentration that would result in a HQ value of no greater than one is about 1,200 mg/kg. As shown in Table 11, the total HQ value for exposure to COPCs in indoor and outdoor air (0.12) was well below a value of 1, indicating little likelihood of adverse health effects due to those exposure routes. Based on the maximum detected soil lead concentration of 49.2 mg/kg, the DTSC blood lead model (Lead Risk Assessment Spreadsheet) predicted 99th percentile blood lead concentrations of 6.3 pg/dl for the child resident and 3.8 µg/dl for the adult resident. These values are well below the 10 pg/dl blood level of concern. The 99th percentile is the point of departure for risk management, and indicates that there is only a 0.01 (M) risk of exceeding the estimated blood lead levels. Regarding the potential for elevated lead concentrations in soil due to migration from lead-based paint that may have been used on the building, four surface soil samples (within the upper foot of soil) were collected exterior to, and within about ten feet of, the building, and five surface soil samples were collected interior to the building. The lead concentrations in these nine surface soil samples were relatively low, ranging from 3.6 to 27.2 mg/kg. 13.2 RECOMENDATIONS Based on the data collected during this PEA, the following recommendations are made: • no further action regarding chemical compounds considered to be carcinogenic, • before the Site is used as a school facility, all soil containing greater than 1,200 mg/kg of petroleum hydrocarbons should be removed from the Site and disposed of in accordance with all applicable waste-disposal regulations, • to provide a greater margin of safety against possible negative human health/aesthetic or ecological impacts, the school district may prefer to remove all soil containing any detectable concentration of petroleum hydrocarbons from the Site and dispose of it in accordance with all applicable waste-disposal regulations, and • if the existing building is removed, proper handling of possible hazardous materials (e.g., potential asbestos-containing materials, lead-based paint, and bricks with elevated metals content) to assure that they do not remain on the Site. 13-3 URS CORPORATION PAPEA Locke ford\Report\Loc keford Report Rev.doc