Evaluation of Contaminated Properties
Use of California Human Health Screening Levels in Evaluation of Contaminated Properties is a recent publication of California Environmental Protection Agency (CalEPA).
The California Human Health Screening Levels (CHHSLs or "Chisels") are concentrations of 54 hazardous chemicals in soil or soil gas that the CalEPA considers to be below thresholds of concern for risks to human health.
The CHHSLs can be used to screen sites for potential human health concerns where releases of hazardous chemicals to soils have occurred.
Under most circumstances, the presence of a chemical in soil, soil gas or indoor air at concentrations below the corresponding CHHSLs can be assumed to not pose a significant health risk to people who may live (residential CHHSLs) or work (commercial/industrial CHHSLs) at the site.
The presence of a chemical at concentrations in excess of a CHHSL does not indicate that adverse impacts to human health are occurring or will occur but suggests that further evaluation of potential human health concerns is warranted.
The CHHSLs are NOT regulatory "cleanup standards". Use of the CHHSLs is voluntary on the part of those who choose to use them.
At sites where cleanup of contaminated soils to levels at or below the CHHSLs would be costly, the time and effort to develop more site-specific cleanup may be desired.
At sites where the extent of contaminated soil is limited or the timeframe available to carry out cleanup actions is very short, use of the CHHSLs as final soil cleanup standards may be cost-beneficial.
Regulatory agencies cannot be compelled to use the CHHSLs as final cleanup standards for a contaminated property.
The table below presents CHSSLs for indoor air and soil gas.
Example: The indoor air CHSSL for Tetrachloroethylene (dry cleaning solvent, also known as PCE or Perc) inside residential space is 0.412 micrograms per cubic meter of air. For this chemical as vapor in the soil under a residential space, the CHSSL is 180 micrograms per cubic meter of air.
Go to http://www.calepa.ca.gov/Brownfields/documents/2005/CHHSLsGuide.pdf to download the complete publication. |
