Analysis of background distributions of metals in the soil at Lawrence Berkeley National Laboratory

Diamond, David ; Baskin, David ; Brown, Dennis ; Lund, Loren ; Najita, Julie ; Javandel, Iraj

Lawrence Berkeley National Laboratory

关键词: Modifications;    58;    Monitoring;    Us Epa;    54;   

DOI  :  10.2172/951960
RP-ID  :  LBNL-1782E
RP-ID  :  DE-AC02-05CH11231
RP-ID  :  951960

美国|英语

来源: UNT Digital Library

【 摘 要 】

As part of its Resource Conservation and Recovery Act (RCRA) Corrective Action Program (CAP), the Lawrence Berkeley National Laboratory (LBNL) Environmental Restoration Program conducted an evaluation of naturally occurring metals in soils at the facility. The purpose of the evaluation was to provide a basis for determining if soils at specific locations contained elevated concentrations of metals relative to ambient conditions. Ambient conditions (sometimes referred to as 'local background') are defined as concentrations of metals in the vicinity of a site, but which are unaffected by site-related activities (Cal-EPA 1997). Local background concentrations of 17 metals were initially estimated by LBNL using data from 498 soil samples collected from borings made during the construction of 71 groundwater monitoring wells (LBNL 1995). These concentration values were estimated using the United States Environmental Protection Agency's (USEPA's) guidance that was available at that time (USEPA 1989). Since that time, many more soil samples were collected and analyzed for metals by the Environmental Restoration Program. In addition, the California Environmental Protection Agency (Cal-EPA) subsequently published a recommended approach for calculating background concentrations of metals at hazardous waste sites and permitted facilities (Cal-EPA 1997). This more recent approach differs from that recommended by the USEPA and used initially by LBNL (LBNL 2002). The purpose of the 2002 report was to apply the recommended Cal-EPA procedure to the expanded data set for metals that was available at LBNL. This revision to the 2002 report has been updated to include more rigorous tests of normality, revisions to the statistical methods used for some metals based on the results of the normality tests, and consideration of the depth-dependence of some sample results. As a result of these modifications, estimated background concentrations for some metals have been slightly revised from those presented in the original 2002 report. In cases where estimated background concentrations were reduced, site data were reviewed to assess whether significant changes to results of the RCRA CAP findings would result. This assessment indicated that no significant changes in RCRA CAP findings would result from the revisions.