Soil Screening Guidance for Radionuclides
These calculations are based on the U.S. Environmental Protection Agency's (EPA) Soil Screening Guidance for Radionuclides. The guidance must be read before attempting to calculate values. The guidance is available through:
Soil Screening Guidance for Radionuclides: User's Guide
EPA Document Number: EPA/540-R-00-007
Soil Screening Guidance for Radionuclides: Technical Background Document
EPA Document Number: EPA/540-R-00-006, October 2000
Highlight 1: Key Attributes of the Soil Screening Guidance for Radionuclides
Usage and Limitations:SSLs are not national cleanup standards.
Radionuclide SSLs are based on a target risk of one-in-a-million (10-6), or, for the ground water migration pathway, a maximum contaminant level (MCL), where available.
Although the application of SSLs during site investigations is not mandatory at sites being addressed by CERCLA or RCRA, EPA recommends the use of SSLs as a tool to facilitate prompt identification of radionuclides and exposure areas of concern.
In addition, this guidance presents methodologies to address the leaching of radionuclides through soil to an underlying potable aquifer. This pathway should also be addressed in the development of PRGs.
The Soil Screening Guidance is a tool for screening at National Priorities List (NPL) sites.
Some NPL sites will not meet all the conditions necessary for use of this tool; consequently, EPA does not expect this tool to be applicable for all NPL sites.
The guidance is intended to be used to screen out areas of sites, exposure pathways, or chemicals of concern from further consideration, assuming certain conditions are present, or to determine that further study is warranted at a site.
Generally, areas of a site which fall below the screening levels may be eliminated from further assessment. Areas above the screening levels generally warrant further evaluation.
The levels should not be interpreted to represent cleanup standards for a site, and concentrations in soil above screening levels do NOT automatically designate a site as dirty.
SSLs do not supersede existing federal or state ARARs and use of the guidance is not legally binding.
An ecological assessment should also be performed as part of the RI/FS to evaluate potential risks to ecological receptors.
Although SSLs are "risk-based," they do not eliminate the need to conduct a site-specific risk assessment for those areas identified as needing further investigation.
Exposure Pathways are as follows:
- Direct ingestion of soil
- Inhalation of fugitive dusts
- External radiation exposure from photon-emitting radionuclides in soil
- Ingestion of homegrown produce that has been contaminated via plant uptake
- Ingestion of contaminated ground water caused by migration of radionuclides through soil to an underlying potable aquifer
The Soil Screening Guidance for Radionuclides should NOT be used for chemical contaminants. Please see Soil Screening Calculations for chemicals.
I accept the Usage and Limitations and am fully informed about using the Soil Screening Guidance.
Begin Calculations for Radionuclides
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