The division uses the EPA Regional Screening Levels (RSLs) to determine whether levels of contamination found at a site may warrant further investigation or cleanup, or whether no further investigation or action may be required.
The division uses the direct exposure levels for residential and industrial exposure scenarios listed in the EPA Regional Screening Levels (RSLs). This table, which EPA updates on a regular basis, can be found at:
Please use one of the links to the Summary Table in the top row of links.
A benefit of adopting the national approach to calculating screening levels is that EPA also has a Calculator that can be used to adjust the input parameters for the purpose of coming up with site-specific screening levels. A link to this feature is provided on the web page referenced above. A useful background document and User's Guide identifying the toxicity values, equations and exposure assumptions used to calculate Regional Screening Levels is also provided on this web page.
Screening values presented in the Regional Screening Levels table are based on human health risk from the combined exposure of direct soil ingestion, dermal contact with soil, and inhalation of vapors or particulates associated with soil. Other pathways, such as indoor air or food chain effects, may need to be consdered on a site-specific basis. Users should also be aware that some sites in sensitive ecological settings may need to be evaluated for potential ecological risk. In addition, please continue to take into consideration the following:
The division uses the Groundwater Protection Level and Leachate Reference Concentration columns in the Groundwater Protection Values (GPV) soil cleanup table, which has replaced the Colorado Soil Evaluation Values (CSEV) table. The last column in this table identifies the water standard used in the calculations which are based on standards and methods established and employed by the Water Quality Control Commission.
Groundwater Protection Values Soil Cleanup Table March 2014 NEW
These two columns should be consulted when reviewing site data because in some cases, decisions on whether or not further evaluation or remediation are needed may be based on the mobility of constituents and their potential to reach and degrade groundwater quality.
Although the method by which the division calculates air exposure screening numbers is identical to the method used by EPA, there are a few differences between our Air Screening Concentration Table and air columns listed in the Regional Screening Levels. You are therefore advised to continue using the division's air table.
Target indoor air concentrations for those chemicals not included on the division's list may be found in the EPA Regional Screening Levels table.
If you have questions about the derivation or application of these table values, please email email@example.com , putting "Avramenko" in the subject line.